Authors: Jenny Volstorf, Caroline Marques Maia
Version: B | 1.1 (2022-01-22)
1.1 General remarksEscapees and consequences: negative or at most unpredictable for the local ecosystem
- Unpredictable influence: no data found yet.
- Observations WILD: food competitors to native species (axolotl) 1.
- Disease transmission: no data found yet.
- Interbreeding: no data found yet.
1.2 Other remarksNo data found yet.
In the farm or lab: on daily rhythm, reproduction, communication, social behaviour, cognitive abilities, stress reactions
- For daily rhythm ➝ 4 5.
- For nest building ➝ 6 7 8 9 10.
- For courtship ➝ 7 9.
- For breeding ➝ 11.
- For acoustic communication ➝ 12.
- For shoaling ➝ 13.
- For dominance and subordination ➝ 14 15 16 17 7 18 19 20 21 8 22 23.
- For aggression ➝ 16 19 21 24.
- For learning ➝ 4 25 26.
- For coping styles ➝ 20 27 26.
- For observable stress reactions ➝ 28 20 29.
Natural distribution: Africa
Introduced: Africa, North America
4 Natural co-existence
5 Substrate and/or shelter
5.1 SubstrateSubstrate range, substrate preference: lives over sand and mud
- Plants: no data found yet.
- Rocks and stones:
- For substrate and nest building ➝ F1.
- Sand and mud: lives over sand and mud:
- Other substrate: no data found yet.
- Environmental enrichment and aggression:
- LAB: pairs of size-matched male JUVENILES in 40 x 24 x 20 cm 20 L tank, environmentally enriched with 1 kg of river pebbles and plastic kelp models. Higher number of bites and lateral fights than in control condition; no difference in latency to fight, duration of fights, frequency of chases, and mouth wrestles. Corresponds to hypothesis that enriched environment increases resource value which in turn prompts more intense fights 24.
- FARM: FINGERLINGS in 75 m2 1.2 m deep earthen ponds at 20,000 IND/ha. After five months, higher weight gain (202 g versus 155 g) and better FOOD CONVERSION RATIO (1.4 versus 1.9) with added bamboo poles where periphyton grew than without substrate. Addition of substrate without effect on chlorophyll-a-concentration 40.
5.2 Shelter or coverShelter or cover preference: complex structures or artificial alternatives (further research needed)
- Plants: no data found yet.
- Rocks and stones: no data found yet.
- Sand and mud: no data found.
- Other cover:
- WILD: takes refuge from predatory Nile perch (Lates niloticus) in structurally complex wetlands of lake Nabugabo (introduced) 41-37 42-37 43-37 44-37.
- LAB, ADULTS: after two months under laboratory conditions, more females were sexually active (61-63.5% versus 51-53%) when the concrete tank had an artificial reef installed made of bricks than when the tank had a bare bottom. Percentages for a sandy bottom (10 cm layer) were in between (56.6-57.2%). Trend towards fewer but heavier oocytes in females in the reef tanks than in the bare bottom tanks, sandy tanks in between 45.
- LAB, ADULTS: males preferred aquaria with shelter over those without, and aquaria with gravel over those without. In aquaria with shelter and gravel and bare bottom compartment, males preferred the gravel compartment on the first day and were indifferent between shelter, gravel, and bare bottom compartments on the following days 46.
6 Food, foraging, hunting, feeding
6.1 Trophic level and general considerations on food needsTrophic level: 2.0
- Observations: 2.0±0.0 se 32.
- Omnivorous F2. The fishery that provides fish meal and fish oil has two major impacts:
- It contributes considerably to overfishing, as it accounts for 1/4 47 or even 1/3 48 of the world catch volume.
- It challenges animal welfare, because in the face of 450-1,000 MILLIARD wild fishes caught worldwide each year to be processed into fish meal or fish oil 49, the individual fish gets overlooked and, thus, suffering increases at rearing, live marketing, and slaughtering levels 50.
6.2 Food itemsFood items, food preference: opportunistic – either mainly herbivorous or mainly omnivorous
- Food items: either predominantly herbivorous, mainly Phytoplankton (algae, epiphytic diatoms) and bottom debris, or omnivorous, mainly (macro)invertebrates and detritus:
- Observations herbivorous WILD: 53-37 54-37 55-37; lake Nyamusingiri and lake Kyasanduka, Uganda (introduced) 36, Ero reservoir, Nigeria (introduced) 38, Xochimilco wetland, Mexico (introduced) 1, Limpopo river, South Africa (introduced) 39.
- Observations omnivorous WILD: 56-37 57-37; lake Nabugabo, Uganda (introduced) 37, Mississippi bayou, USA (introduced) 58.
- Food items and habitat:
- WILD: mainly detritus in open water and wetland ecotone, mainly insects (chironomid and ephemeropteran larvae) and plant material in forest edge. Greater diet richness in forest edge and wetland ecotone than open water. In wetland ecotone, highest percentage of Oligochaetes and Phytoplankton: blue green algae Microcystis and Anabaena: lake Nabugabo, Uganda (introduced) 37.
- Food items and life stages:
- WILD: JUVENILES mainly animals and plants, ADULTS mainly Phytoplankton: lake George, Uganda 55-37.
- WILD: JUVENILES mainly detritus and Phytoplankton, ADULTS mainly detritus, insects, and plants: lake Nabugabo, Uganda (introduced) 37.
- WILD: JUVENILES mainly phytoplankton, ADULTS from 21 cm on mainly detritus and unidentified green spheres: lake Nyamusingiri and lake Kyasanduka, Uganda (introduced) 36.
- Food preference: no data found yet.
- Food partitioning:
- WILD: food items differ given presence of Lates niloticus: mainly detritus and insects given introduced L. niloticus, mainly Phytoplankton (1. Chlorophyta, mainly Scenedesmus, and 2. Cyanophyta, mainly Microcystis) and detritus without L. niloticus 57-37 36 37.
- WILD: great overlap in diet of introduced O. niloticus and indigenous O. mossambicus but difference in isotopic composition indicates food partitioning 39.
- Prey density: no data found yet.
- Prey size selectivity: no data found yet.
- Particle size:
- LAB, JUVENILES: optimum particle size relative to mouth width for fastest growth: 28 to 25% mouth width from 3 to 20 g fish weight. Particle size for highest food intake smaller than that for fastest growth 59.
6.3 Feeding behaviourFeeding style, foraging mode: depending on diet either bottom grazing or active pursuit
- WILD: depending on diet either filter feeding (Phytoplankton) or active pursuit and pecking (animals) 55-37.
- High percentage of mud, detritus, debris, sand grains in stomach indicates that species is bottom grazer:
- LAB: when fed the same daily ration for 12 weeks, JUVENILES grew heavier at a low compared to high initial stocking density (0.2 kg/m3 versus 0.6 kg/m3) and at a high compared to low feeding frequency (3 or 4 times/d versus 2 times/d). Increasing stocking density increased the variation in body weight for groups of 2 feedings/d but decreased the body weight variation at 3 or 4 feedings/d 60.
- LAB: in groups of 15 ADULTS, increased plasma cortisol levels even 1 h after feeding (ca 60 ng/mL) indicate food competition. No plasma cortisol increase in single-held ADULTS after feeding and in unfed ADULTS in groups of 15 (ca 10-20 ng/mL) 25.
7.1 Daily rhythmDaily rhythm: large inter-individual differences (further research needed)
- Daily rhythm:
- LAB, FRY: mainly diurnal feeding pattern with peaks at dawn and dusk 4.
- LAB, ADULTS: large inter-individual differences in activity rhythms:
a) When held under a cycle of "12 h light and 12 h dark", four of 12 males were diurnal, displaying average locomotor activity of 70.3% during the photophase, five males were nocturnal, displaying average locomotor activity of 64.4% during the scotophase, three males were arrhythmic.
b) When held in complete darkness, six of 12 males developed locomotor activity free-running rhythms of 24.1 hours on average.
c) When held under pulses of 45 min light and 45 min dark, seven of 12 males developed locomotor activity free-running rhythms of 23.9 hours on average.
d) When shifted to a cycle of "12 h dark and 12 h light", three males changed their locomotor activity to match the new photoscope immediately, four did so gradually, others did not resynchronise at all.
e) When held under a cycle of "12 h light and 12 h dark", five of 11 females were diurnal, displaying average locomotor activity of 74.4% during the photophase, one female was nocturnal, displaying average locomotor activity of 68.0% during the scotophase, five females were arrhythmic. In nine of 10 females that spawned during the experiment, reproductive activity decreased the locomotor activity prior, during, and/or after spawning 5.
- Nocturnal activity: ➝ Daily rhythm.
- Phototaxis: no data found yet.
- LAB: JUVENILES under 12 h PHOTOPERIOD had lower mortality (20% versus 40% versus 76.7%) and lower growth than under 24 h PHOTOPERIOD and 24 h scotopheriod. Under 24 h scotoperiod, JUVENILES displayed injuries on their bodies as well as suppressed behaviour and swimming activity compared to the other conditions 61.
7.2 Light intensityLight intensity and stress: direct relation (further research needed)
- LAB: groups of three similar-sized male ADULTS in 60 x 60 x 40 cm 140 L aquaria. Tendency of fewer aggression under low light intensity of 280.8 lux than under high intensity of 1,394.1 lux. No effect of light intensity on social hierarchy 22.
7.3 Light colourLight colour and stress: no effect of white, blue, or yellow light (further research needed)
- LAB: single individuals in 12 x 20 x 30 cm aquaria under 12 hours white, blue, or yellow light (ca 50 lux each) per day (06:00-18:00 h) for seven days. No difference in ventilatory frequency (85.7-94.7 opercular or buccal movements/min) 29.
- LAB: individual ADULTS in 40 x 25 x 20 cm 15 L glass aquaria covered with gelatin filter of different colours: blue 434.5 nm, violet 430.0 nm, red 609.7 nm, green 525.2 nm, yellow 545.2 nm. After 30 days, no difference in weight 62.
- LAB: groups of four similar-sized ADULTS in 60 x 40 x 30 cm 50 L glass aquaria. After 30 days, weight differences within groups under each light colour except yellow light. Highest variation under red light, lowest under yellow light, other light colours in between. No difference between individuals of the same size category under the different light colours 62.
...nest building ➝ F4,
...mouthbreeding ➝ F5,
...confinement ➝ F6.
8 Water parameters
8.1 Water temperatureStandard temperature range, temperature preference: 16-29 °C
- Standard temperature range:
- Optimum range for survival: 22-34 °C:
- Temperature preference: no data found yet.
- For temperature and spawning ➝ F7.
- Lower and upper lethal limits:
- FARM: eggs died within 24 hours when exposed to water temperatures of ≤17 °C and 39.5 °C directly after fertilisation, best hatching rates at 25-30 °C with peak at 28 °C. Eggs reared at 28 °C for 48 hours after fertilisation hatched best at 23.5-32 °C with peak at 28 °C. The higher the temperature the faster morphological differentiation and hatching 11.
- Range of temperature tolerance: 8-42 °C 65.
- High temperatures: contradictory results on influence of elevated water temperatures for 21 days on survival of first-feeding FRY:
a) No influence on survival: LAB: 34 or 36 °C water compared to 27 °C rearing temperature 66.
b) Lower survival: LAB: putative all-female population: 62.7% at 36.5 °C versus 71.9% at 27.9 °C, putative all-male (XY and YY each) population of temperature-sensitive (Egypt-Swansea) strain: XY males: 70.3% at 37.1 °C versus 90.7% at 30.1 °C, YY males: 53.0% at 36.5 °C versus 90.7% at 29.7 °C 67; 28 days treatment: 75% at 36.5 °C versus 93.3% at 32 °C 64.
c) Higher survival: LAB: putative all-male (XY) population: 59.5% at 36.5 °C versus 35.1% at 27.9 °C, putative all-female population of temperature-sensitive (Egypt-Swansea) strain: 75.0% at 37.5 °C versus 58.3% in 29.6 °C 67.
- Temperature must exceed: no data found yet.
- Temperature must not go beyond: no data found yet.
- Optimal temperature for growth:
- LAB: 20 day old FRY grew better when reared in 30 °C water than in 26 °C, 34 °C, and 22 °C. Higher food intake in 30 °C water than in 26 °C, 34 °C, or 22 °C 64.
8.2 OxygenDissolved oxygen range: 0-12 mg/L
- Observations WILD: 7.6 mg/L at surface, 0 mg/L in 4 m depth: lake Nyamusingiri, Uganda (introduced) 36, 12.0 m/L at surface, 0.1 mg/L in 2 m depth: lake Kyasanduka, Uganda (introduced) 36, 6.5 mg/L: lake Nabugabo, Uganda (introduced) 37.
- Observations FARM, JUVENILES: dissolved oxygen preferably >4 mg/L to prevent furunculosis. Alternatively, decrease density in cages 63.
8.3 SalinitySalinity tolerance, standard salinity range: probably euryhaline (further research needed)
- Lower and upper lethal limits:
- LAB: no difference in survival of first-feeding FRY reared at salinities of 0-26.8‰ for 21 days, lower survival in one sample at 0‰ because of bacterial infection 67.
- LAB: some JUVENILES survived 35‰ salinity for up to six weeks when gradually exposed to increasing salinity beginning at 15 days old. Mortality in intermediate levels of up to 50‰ in first days after transfer 68.
- Salinity change and stress: no data found yet.
8.4 pHStandard pH range: 7.9-8.0 (further research needed)
- Standard pH range:
- Observations WILD: pH 7.9-8.0: lake Nyamusingiri and lake Kyasanduka, Uganda (introduced) 36.
- pH preference: no data found yet.
8.5 TurbidityStandard turbidity range: Secchi depth 0.2-0.8 m
- Standard turbidity range: no data found yet.
- Secchi depth (water transparency): 0.2-0.8 m:
8.6 Water hardnessNo data found yet.
8.7 NO4No data found yet.
8.8 OtherNo data found yet.
9.1 Swimming type, swimming modeSwimming type, swimming mode: carangiform
9.2 Swimming speedNo data found yet.
9.3 Home rangeNo data found yet.
9.4 DepthDepth range, depth preference: 2-6+ m, up to 20 m (further research needed)
- Depth range in the wild:
- Observations WILD: 2 m: lake Kyasanduka, Uganda (introduced) 36, 4.9 m: lake Nyamusingiri, Uganda (introduced) 36, 0.75-6.4 m, Opa reservoir, Nigeria 3, 20 m 71-32.
- WILD: JUVENILES and smaller ADULTS more abundant in the forest and wetland ecotone habitat than in the open-water habitat 55-37 57-37 72-37 37.
- Depth in cages or tanks: no data found yet.
- Depth preference: no data found yet.
- Depth and daily rhythm: no data found yet.
- Depth and low temperatures: no data found yet.
- Depth and high temperatures: no data found yet.
- Position in habitat and age: no data found yet.
- Depth and light intensity: no data found yet.
- Depth and noise: no data found yet.
- Depth and threat: no data found yet.
9.5 MigrationNo data found yet.
10.1 Ontogenetic developmentMature egg: 4-5 days from fertilisation until hatching, 1.5-2.5 mm diameter (further research needed)
- Fingerlings: FRY with fully developed scales and working fins, the size of a finger, 12.6 cm, 1.8-40.3 g:
- Juveniles: fully developed to beginning of maturity, 7.6-9.4 cm, 5.3-25.5 g:
- Sexual maturity: 3-7 months depending on temperature (although it has also been reported at 50-60 days), 7-37 cm, 16-90 g:
- Observations TOTAL LENGTH WILD: 17-37 cm 79-11, length at maturity for 50%: 12-15 cm: lake Nyamusingiri and lake Kyasanduka, Uganda (introduced) 36, females: 8-35 cm: Mississippi bayou, USA (introduced) 2, length at maturity for 50% females: 11.3 cm: Mississippi bayou, USA (introduced) 2.
- Observations age, TOTAL LENGTH, and weight LAB: 3-6 months, 30 g 33-32, 5-7 months, 50-60 days, 7-12 cm, ca 16-90 g 11, average: 18.6 cm, range: 10-28 cm 32.
- Observations age: ➝ F10.
- Observations TOTAL LENGTH and weight WILD: 28-56 cm, 360-2,940 g: Nyanza Gulf of lake Victoria, Kenya (introduced) 35, 4,300 g 80-32, 22-26 cm: lake Nyamusingiri, Uganda (introduced) 36, 22-29.5 cm: lake Kyasanduka, Uganda (introduced) 36, males: 43 cm, females: 15-35 cm, Mississippi bayou, USA (introduced) 2, 18-37.7 cm, 110-969 g: Opa reservoir, Nigeria 3.
- Observations TOTAL LENGTH and weight LAB: 7.3-11.1 cm 28, 14.4 cm 20, 663 g 81, 7.8 cm, 17.2 g, 12.8 cm, 62.9 g 62, male 12.9 cm, 67 g, female 12.3 cm, 55.8 g 10, 493.3 g 82.
10.2 Sexual conversionSex and manipulation: elevated water temperature, androgen treatment, breeding programme increases portion of male fry
- Sex and temperature manipulation: mixed effects of elevated temperatures:
a) increase in portion of males: transfer to elevated water temperature after first feeding increases portion of male FRY compared to control rearing temperature:
- Observations LAB: 81% males at 36 °C versus 53% at 27 °C 66, putative all-female population: 0-89.6% males at 36.5 °C versus 0-36.8% at 27.9 °C, trend among putative all-female population of temperature-sensitive (Egypt-Swansea) strain: 37.3% at 37.5 °C versus 20.2% at 29.6 °C 67, average 61.4-78.4% at 36 °C versus 49.9-53.1% at 28 °C, no further increase at 38 °C 83, 64.2-80.0% at 36.5-36.8 °C versus 43.6-56.7% at 19.2-34.4 °C 64.
- LAB, FRY: temperature manipulation less effective at later transfer (from 15 days post fertilisation on) 66. Duration of 10 days under elevated temperature sufficient 66 83. Other influencing factors: less effective with interbred than with purebred individuals 83, effectiveness heritable 83, effectiveness varies with breeding pairs, as both partners influence sex ratio 83.
- LAB, FRY: elevated water temperature decreased portion of males in all-male YY populations of temperature-sensitive (Egypt-Swansea) strain compared to control rearing temperature: 7.6% at 37.5 °C versus 100% at 29.7 °C, 33.3-90.8% at 36.5 °C versus 100% at 28.8 °C 67.
- Sex and hormone treatment: highest portion of male FRY and concurrently highest weight gain and survival at androgen treatment of 40 mg/kg 17-alpha-methyltestosterone and 2,000 IND/m3 stocking density:
a) FRY at either 2,000 IND/m3 in hapa net versus 5,000 IND/m3 in concrete tank. Treatment after first feeding with 40 mg/kg of the androgen 17-alpha-methyltestosterone increased portion of male FRY compared to control (average 95.4-98.4% versus 52.3-53.3%) independent of stocking density. Higher weight gain at low density (221.4 mg versus 74.4 mg).
b) FRY in hapa nets at either high densities of 6,000 or 10,000 IND/m3 or low density of 2,000 IND/m3. Treatment with 60 mg/kg 17-alpha-methyltestosterone increased portion of male FRY more at high stocking densities compared to control, lower at low stocking density (average 96.7-99.4% verus 91.2% at versus 55.2% control). Lower survival (68.9-76.1% versus 92.2%) and lower weight gain (33.5-56.2 mg versus 138.4 mg) than at low density 84.
- FARM: FRY in earthen ponds at either high densities of 200 or 260 IND/m2 or low density of 75 IND/m2. Treatment with 60 mg/kg 17-alpha-methyltestosterone increased portion of male FRY more at high stocking densities than at low stocking density (average 96.5-98.2% versus 87.0-94.0%) 85.
- LAB: treatment after first feeding with 40 mg/kg of the androgen 17-alpha-methyltestosterone increased portion of male FRY compared to control (average 93.3% versus 53.1%) 86.
- Sex and genetic manipulation: breeding programme for large-scale application in aquaculture:
- Crossing XY delta females (i.e., males sex reversed using 1,000 mg/kg of the estrogen diethylstilbestrol) with XY males and progeny testing the resulting males yields YY males,
- crossing XY delta females with YY males and progeny testing the resulting males yields a higher proportion of YY males,
- crossing XY delta females with YY males and progeny testing the resulting females yields YY delta females,
- crossing YY delta females with YY males and progeny testing the resulting males and females yields an average 98.9-100% males 87.
- Sex and other manipulation: salinity
- LAB: no influence of salinity (0-26.8‰) on sex of first-feeding FRY of putative all-female population 67.
10.3 Sex ratioNatural male:female ratio: 1:1-2:1
10.4 Effects on growthGrowth and sex: bimodal pattern, noticeable from 2-5 months on
- Observations bimodal pattern LAB, JUVENILES: males developed faster than females 73.
- Beginning of noticeable size difference: at 2-5 months:
- Observations FARM: 2-5 months 63.
- Observations LAB: at 2 months, YY males in monosex population heavier than XX females in monosex population, at 3 months, additionally in 50-50 mixed population 88.
- LAB: using a self-feeder, although food intake was similar, 4 month old male FRY gained more weight over 41 days than females in mixed populations (average 58.4 g versus 40.1-42.8 g), most in male monosex populations (average 70.1 g). Females gained more weight when in monosex (average 42.8 g versus 40.1 g) than in mixed populations 4.
- LAB: after ca 130 days ad libitum feeding, male first-feeding FRY gained more weight than females a) in XY monosex population (versus females in 17% males and 83% females population) and b) in mixed populations (75% XY and 25% XX, 50% YY and 50% XY). Males grew better in a XY monosex population than in a YY monosex population, XX delta monosex population (i.e., males sex reversed using 30 mg/kg of the androgen 17-alpha-methyltestosterone) in between. Females gained most weight when proportion of population was 25% than when higher (50, 75, 100%), even surmounting that of YY males in population 88.
- Growth and size-grading:
- LAB, JUVENILES: size-grading at 8 weeks (stocking density 0.2 kg/m3) did not reduce size variation but established it anew in small, medium, and large size groups. In contrast, size variation in mixed groups decreased. Higher specific growth rate (log weight difference given time) at week 10 in mixed groups than size-graded groups 60.
- Growth, size-grading, and density:
- LAB: JUVENILES in a low initial size variability (0 versus 58%) and low density group (2.5 versus 10 kg/m3) grew heavier after 16 days than at high size variability and high density. After 30 days, high initial size variability did not influence weight anymore: weight of JUVENILES in low density groups was higher than weight of JUVENILES in high density groups. Coefficients of variance in both low and both high density groups converged by day 30 with variance in low density groups being lower (ca 15 versus 45%) than in high density groups 18.
- Growth and age of female:
- LAB: eggs from 1+ and 2+ years females were larger than from 0+ females. LARVAE grew larger and survived longer the larger the egg (i.e., yolk sac) or the older the female respectively. A higher number of FRY were able to feed exogenously and survive longer the older the female (50% survival at 16 and 17.5 days versus 13.5 days). When adding exogenous feed, the initial difference in growth rates of FRY ceased by day 60 11.
- Growth in polyculture:
- FARM: five months of polyculture of genetically improved O. niloticus strain with freshwater prawn Macrobrachium rosenbergii at 20,000 IND/ha of FINGERLINGS or POST-LARVAE did not affect survival or weight gain 40.
- FARM: FINGERLINGS in 150 m2 (1.5 m deep) earthen ponds either stocked under monoculture or polyculture at 3:1 ratio with Clarias gariepinus at low (30,000 IND/ha), medium (60,000 IND/ha), or high density (90,000 IND/ha). C. gariepinus were deliberately stocked 30 days after O. niloticus (5 g mean weight) so that these were too big for C. gariepinus to prey on. After 240 days, higher growth of O. niloticus under poly- than monoculture (75,460 g weight gain versus 66,879 g), specifically under low stocking density (204.7 g versus 141.6 g under high, 132 g under medium stocking density). Also, higher survival (98.1% versus 86.6-89.3%) and higher specific growth rate (1.6% versus 1.4%) but higher FOOD CONVERSION RATIO (3.5 versus 2.6-3.1) under low density. In C. gariepinus, higher weight gain under low than medium and high stocking density (579.5 g versus 519.2 under medium, 341.3 under high density). Also, higher survival (97.9% versus 89.5-96.6%) and higher specific growth rate (2.2% versus 2% in high density) but FOOD CONVERSION RATIO (3.5 versus 2.6 under high density). Results indicate that polyculture with C. gariepinus is beneficial for O. niloticus probably because C. gariepinus preys on O. niloticus juveniles that would otherwise compete for food with adults 89.
...substrate ➝ F11,
...particle size ➝ F2,
...feeding frequency ➝ F12,
...PHOTOPERIOD ➝ F13,
...light colour ➝ F14,
...water temperature ➝ F15,
...stocking density ➝ F16.
10.5 Deformities and malformationsNo data found yet.
11.1 Nest buildingNest building: males and females build nests in sand (further research needed)
- Nest building and substrate:
- ADULTS spawn in firm sand in 0.6-2 m water depth 33-32.
- LAB, ADULTS: males and females built nests in aquaria with 3 cm gravel layer. Average 0.3-0.6 nests per individual of average 85-311 cm2 area 9.
- LAB, ADULTS: groups of one male, two females in 60 x 60 x 40 cm glass aquaria divided into four compartments with 3 cm substrate: sand, mixture of sand and bivalve shells, stones, glass plate (no substrate). Before nesting, females and males did not prefer either compartment but explored all substrata by nipping with mouth. Males nested within five days, preferred sand over sand-shell-mixture, did not nest in other compartments 10.
- Nest building and water velocity: no data found yet.
- Nest building and water depth: no data found yet.
- Nest building: no data found yet.
- Nest building and light colour:
- LAB, ADULTS: males moved larger mass for nest building (average 311 versus 131 g) and built wider nests (average 208 versus 98 cm2 area) under blue than under white light (100-120 lux) in aquaria with 2 cm gravel layer 6.
- Nest building and olfaction:
- LAB, ADULTS: anosmic males built fewer and smaller nests than males with intact sense of olfaction in aquaria with 2 cm gravel layer. Not being able to smell did not influence spermatogenesis and aggressive, foraging, and courtship behaviour like nudging, leading, and circling. Olfactory input seems to influence motivation – but not consummation – of male reproductive behaviour 7.
- Nest building and dominance:
- LAB, ADULTS: in groups of two males and three females, the dominant males built nests and defended them against male and female conspecifics. The higher the investment in nest building (weight of gravel displaced per body weight), the higher the spawning frequency and the more frequent female nest visits 8.
11.2 Attraction, courtship, matingAttraction: reddish-brown colour, swollen urogenital papilla
- Courtship sequence:
- LAB, ADULTS: male gently bit or nudged the female near the anal region, swam ostentatiously in front of her to lead her to the spawning site, quivered sideways and circled around the female 7.
- LAB, ADULTS: increased male and female undulation behaviour (component of courtship) when visual or visual and chemical communication between male and female possible than when chemical communication alone or isolation 9.
- Courtship duration:
11.3 Spawningr or K selection: flexible
- Rather K selection, but may convert to r selection under aquaculture conditions 90.
- Diverse mating systems:
- LAB, ADULTS: 25 females and 12 males in 8 x 2 x 1 m3 hapa nets mated. 21.05% of fry from mating between single male and single female (monogamy), in 46.05% up to four males fertilised single batch of eggs (polyandry), in 10-30% a single male fertilised eggs from multiple mothers (polygyny), in 25% of batches multiple males fertilised eggs from multiple females (polygamy) 92.
- Spawning substrate:
- LAB, ADULTS: spawning frequency and latency independent of substrate in glass aquaria 8.
- Spawning season: several yearly spawnings every 20-90 days:
- Spawning (day)time: no data found yet.
- Spawning temperature:
- Spawning salinity: no data found yet.
- Spawning and water velocity: no data found yet.
- Spawning depth: no data found yet.
- Spawning density: no data found yet.
Effects on spawning: only dominant males spawn, visual contact necessary (further research needed)
- Spawning and dominance:
- Spawning and communication:
- LAB, ADULTS: spawning only when visual or visual and chemical communication between male and female possible 9.
11.4 FecundityFemale fecundity: 20-6,000+ eggs per batch in several batches
- Number of batches:
- Fecundity per batch:
- Observations absolute fecundity WILD (disection studies), ADULTS: 864-6,316 eggs 35, 30-2,603 eggs 2, 73-1,810 eggs of all stages per female 3.
- Observations absolute fecundity FARM, ADULTS: depending on hatchery system, stocking density, and sex ratio, average 2.2-8.8 seeds (eggs or FRY) per spawner per day with peaks in February-April and July-September 93, 62-183 FRY per female per month 63.
- Female sheds eggs in batches of 20-50 eggs, male sheds sperms over the site 33-11.
- Observations LAB, ADULTS: 121-2,030 eggs 11.
- Observations relative fecundity WILD (disection study), ADULTS: 0.3-26.8 eggs/g body weight 3.
- Number of spawns:
- LAB, ADULTS: spawning in males 2-4 times a day. The higher the spawning frequency, the less fertilised eggs 11.
- Fecundity per spawn: no data found yet.
- Fecundity and aquaculture system:
- FARM, ADULTS: higher seed production (eggs or FRY) in concrete tanks than hapa nets, no difference between male:female ratios of 1:4, 1:7, 1:10, no difference between stocking densities of male:female 4:16, 7:28, 10:40 93.
- Fecundity and age:
- LAB, ADULTS: the higher the female's age, weight, and length the higher the total fecundity (number of eggs per spawn). The older the female the higher the relative fecundity (number of eggs per kg weight) 11.
11.5 Brood care, breedingBreeding type: mouthbreeder: female takes eggs into mouth directly after fertilisation and carries 39-241 eggs in her buccal cavity for 7-18 days through hatching and conversion into fry (further research needed)
- Breeding type: mouthbreeder:
- LAB, ADULTS: females' churning of the clutch in their mouth decreased from 95-105 times/min after spawning to 20-30 times/min on day 3 and occasional churning (3-8 times/min) on days 5-10 11.
- Artificial incubation versus natural rearing:
- Mouthbreeding and light colour:
- LAB, ADULTS: higher proportion of mouthbreeding under blue than under white light 6.
- Rearing container:
- Eggs hatched at a higher rate (91.6% versus 74.6%) and survived with higher probability (92.3% versus 80.7%) in round-bottom than conical hatching jars, suggesting mechanical stress through friction between eggs and between eggs and container as major influence 11.
12.1 VisionVisible spectrum: violet, blue, green, yellow, red (further research needed)
- LAB: ADULTS had sensitivity peaks at short (380-420 nm, 440-480 nm), middle (500-600 nm), and long wavelengths (600-680 nm) 94.
12.2 Olfaction (and taste, if present)Importance of olfaction: risk perception, nest building (further research needed)
- Olfaction and risk perception:
- LAB: cortisol levels of mixed-sex JUVENILES that were exposed to water from stressed conspecifics were higher than those of a control group for at least 2 h. Cortisol levels after 2 h were similar to the stressed conspecifics. After 8 h, the levels were back to normal 95.
- For olfaction and nest building ➝ F4.
12.3 HearingHearing type, hearing spectrum: hearing generalist, 100-800 Hz (further research needed)
- LAB, ADULTS: no hearing loss when exposed to noise at 100-800 Hz for seven days. When exposed to noise for 28 days, only at 800 Hz (not below) auditory threshold 10 dB higher than control, indicating slight hearing loss 96.
12.4 Touch, mechanical sensingNo data found yet.
12.5 Lateral lineNo data found yet.
12.6 Electrical sensingNo data found yet.
12.7 Nociception, pain sensingNociception spectrum: anomalous behaviour and decrease of mucus cells after tail clip (further research needed)
- LAB: female ADULTS in 140 L tanks half covered with black plastic had caudoventral corner of tailfin clipped. Higher activity, predominantly random swimming, compared to untreated individuals and individuals, which were just caught by net and applied pressure to the tailfin, for at least 6 h after clipping. Back to control levels at next observation 24 h after clipping. Higher cortisol levels compared to untreated individuals at 6 h after clipping (334.6 nM versus 24.6 nM), back at control levels at 24 h after clipping. No difference in glucose and lactate levels. Decrease of mucus cells at 1 h after clipping indicate excretion of mucus and discriminates between pain from tail clip and stress from handling without clipping 99.
12.8 OtherNo data found yet.
13.1 VisualFor visual communication...
...and courtship ➝ F17,
...spawning ➝ F18.
13.2 ChemicalNo data found yet.
13.3 AcousticSounds during nest defence: pulse trains of 2-4 pulses of 114 ms each and 57 Hz
- LAB, ADULTS: when another male entered the territory, nesting males released pulse trains of 2-4 pulses of 57.4 Hz, each pulse lasting 114 ms and comprising a high pitched part and broader peaks, by moving the scapular and pelvic girdles backward while simultaneously moving the second pterygiophore of the anal fin forward. This compresses the rib cage and the swim bladder. They achieve the movement by contracting sonic muscles close to the swim bladder which results in resonance. Deflating the swim bladder artificially weakened the sound pressure but maintained duration and frequency 12.
- LAB, ADULTS: sounds by the pharyngeal jaws of a frequency of 2,868.1 Hz lasted 22.9 ms 12.
13.4 MechanicalNo data found yet.
13.5 ElectricalNo data found yet.
13.6 OtherNo data found yet.
14 Social behaviour
14.1 Spatial organisationAggregation type: shoal (further research needed)
- FARM, FRY: survival >75% at density of 1,000-3,000 IND/m3 during two month growing period, decreasing survival at increasing density 63.
- LAB: FINGERLINGS in 100 L tanks with 30% daily water exchange at densities 1, 2, 5, 10 IND/tank. After 60 days, higher plasma cortisol level in 10 FINGERLINGS group compared to single FINGERLINGS or pair tanks (ca 45 ng/mL versus 10 ng/mL); 5 FINGERLINGS groups in between. Lower weight gain in 5 and 10 FINGERLINGS groups (ca 11 versus 14 g) compared to single FINGERLINGS and pair tanks indicating chronic stress by overcrowding 77.
- Inverse relation:
- FARM, FRY: higher weight gain (average 419.0 mg versus 278.3 mg versus 92.1 mg) in ponds with stocking density 500 IND/m3 than hapa nets with 2,000 IND/m3 and concrete tanks with 5,000 IND/m3 84.
- FARM: FINGERLINGS in 1 m deep 100 m2 stagnant earthen ponds at 1 IND/m2 (ca 0.02 kg/m2), 3 IND/m2 (ca 0.05 kg/m2), or 5 IND/m2 (ca 0.08 kg/m2). After 90 days, no difference in survival (74-78.9%), but higher final weight (108.3-115.1 g versus 89.5 g), higher daily weight gain (1-1.1 g versus 0.8 g), and lower FOOD CONVERSION RATIO (1.3 versus 1.6) in low and middle stocking densities compared to high density. Probably due to lower dissolved oxygen (3.2 versus 5.3 mg/L) in high compared to low density; middle density in between. Probably higher feeding pressure in high density condition indicated by higher Secchi disc (51.3 versus 35 cm), lower chlorophyll a (11.6 versus 17.4 µg/L), and lower Zooplankton (561 versus 906) in high than low stocking density; middle density in between 76.
- For stocking density, growth, and size-grading ➝ F19.
- No effect:
- FARM: all-male FINGERLINGS in 2.5 x 1.5 x 1.1 m 3.75 m3 concrete outdoor tanks with water flow rate of 1 L/min/kg at densities 16 IND/m3 (ca 0.6 kg/m3), 32 IND/m3 (ca 1.3 kg/m3), 42.5 IND/m3 (ca 1.7 kg/m3). After 164 days, no difference in survival (95.9-99.2%), final weight (322-336 g), daily weight gain (1.7-1.8 g), and FOOD CONVERSION RATIO (1.8-2) 75.
14.2 Social organisationSocial organisation type: usually linear hierarchy (when in small groups)
- Hierarchy and group size: in small groups, individuals establish linear hierarchy, although not always:
- Observations linear hierarchy LAB, JUVENILES: of four males, one became dominant, two were of secondary dominance, and the fourth became subordinate 18.
- Observations linear hierarchy LAB, ADULTS: between two similar-sized males 16, of three similar-sized females, one became dominant, the others beta and gamma subordinate 17, between two males 7, of two males and three females, one male became dominant 8, of three similar-sized males, one became dominant, one intermediate, one subordinate 22.
- Observations exception LAB: pairs of size-matched FINGERLINGS in 100 L tanks separated by biological filter. After 60 days, no dominance hierarchies probably due to huge space available and establishment of territories in opposite corners 77. ADULTS: in seven of 10 groups of two males, one male became dominant 15.
- Establishing hierarchy: after 25-150 min:
- LAB: in pairs of size-matched male JUVENILES in 40 x 24 x 20 cm 20 L tank, fighting began after 4 min on average for ca 25 min on average 24.
- LAB: among groups of two similar-sized male ADULTS, hierarchy was established via fightings in about 2.5 hours. In the initial 5 min of pairing, both males did not differ in their colour pattern and the number of attacks initiated. Fightings increased in aggressiveness. Dominance relationship at a second pairing, 14 days after the first pairing, was again fought out and remained the same 16.
- LAB: groups of three similar-sized male ADULTS in 60 x 60 x 40 cm 140 L aquaria. Hierarchy had established at first observation session at day 3. Tendency of decreasing frequency of aggression after seven days 22.
- Features of dominance:
a) Dominant individual has lighter body and eye colour than subordinate:
- Observations body colour LAB, JUVENILES: lighter body colour 21 24.
- Observations body colour LAB, ADULTS: silver colouration with black stripes 16, pinkish-red colour 7, lighter body colour 20 8.
- Observations eye colour LAB, ADULTS: decreased percentage iris and sclera darkening compared to basal condition 15, lighter eye colour 20.
- Observations LAB: ADULTS 7.
- Hierarchy and territoriality: the resident becomes dominant over the intruder:
- Hierarchy and sex:
- LAB: no difference in fighting latency, fighting duration, and frequency of aggressive interactions between pairs of immature male FRY, pairs of immature females, and mixed-sex pairs. No effect of sex on dominance: of 30 mixed-sex pairs, 17 males and 13 females became dominant 23.
- For dominance and...
...nest building ➝ F4,
...spawning ➝ F18.
- Features of subordination:
a) Subordinate individual has darker body colour than dominant:
- Observations LAB, JUVENILES: darker body colour 21 24.
- Observations LAB, ADULTS: dark grey colouration without stripes 16 17, dark “zebra-like” pigmentation 7.
- Observations LAB, ADULTS: increased percentage iris and sclera darkening compared to basal condition 15 17, darker eyes than dominant males (>80% versus 25%) 15.
- LAB, ADULTS: both eye colour effects (difference to basal condition, difference between dominant and subordinate male) occurred only in pairs with 1-111 attacks (first and second quartile), not in pairs with 112-168 attacks (third and fourth quartile), although they might have occurred in high-attack pairs after the end of the observation period. This indicates that the eye colour changes only after establishment of hierarchy which can take place sooner (low-attack pairs) or later (high-attack pairs) 15.
- Observations LAB, ADULTS: 17.
- Hierarchy and stress: in pair of dominant and subordinate, the subordinate is stressed:
- LAB, ADULTS: dominant and subordinate males did not differ in levels of plasma cortisol, glucose, triglycerides, and total protein, but these levels were higher when the individuals were paired than when they were isolated 16.
- LAB, ADULTS: after pairing subordinate with dominant males for 60 min, the cortisol level in subordinates was increased immediately after the end of the pairing for at least 30 min. Glucose level was increased only at 30 min after the end of the pairing. Increased levels of cortisol and glucose were as high as those from groups of conspecifics receiving mild electroshocks (AC shock with 20 V, 15 mA and 100 Hz) for 60 min – without the delay in glucose level 19.
- LAB: single male ADULTS in 60 x 28 x 31 cm 48 L glass aquaria were paired with larger male residents resulting in focal individuals becoming subordinate. After 60 min, increased ventilatory frequency (ca 72 versus 98 opercular or buccal movements/min) compared to pre-stress condition. Of nine ADULTS, eight increased and one decreased their individual ventilatory frequency 20.
14.3 ExploitationNo data found yet.
14.4 FacilitationNo data found yet.
14.5 AggressionAggression and size-grading: biting, chasing, fights regardless of size-grading via linear hierarchy (further research needed)
- Size-matched pairs:
- LAB, JUVENILES: in pairs of size-matched males, dominants displayed higher frequency of a) biting on anterior (head), tail fin, median or ventral area, b) chases, and c) lateral fights. Only seldomly mouth wrestling 24.
- LAB, ADULTS: fights to establish hierarchy between two similar-sized males (➝ F20) comprised (in descending order of frequency) approaching, tail beating, and fleeing, then mouth fighting and ramming, then chasing and biting the flanks 16.
- Non-matched pairs:
- LAB, JUVENILES: in mixed-sex groups, dominant individuals displayed biting, ramming, cornering, and chasing of subordinate individuals and biting, ramming, and mouth-fighting of other dominant individuals 21.
- LAB, ADULTS: non-mature males paired with larger residents for 60 min received mostly nipping of the median body (not anterior, seldomly caudal or ventral), seldomly mouth fights and chasing, no lateral fights 19.
- Aggression and sex:
- LAB: no difference in frequency of aggressive acts between (descending order) pairs of immature male FRY, pairs of females, and mixed-sex pairs: mainly threats and bites, then lateral and frontal display, then chases, lateral fights, and mouth wrestles 23.
...environmental enrichment ➝ F21,
...light intensity ➝ F22,
...predator recognition ➝ F23.
14.6 TerritorialityFor territoriality and...
...sounds during nest defence ➝ F24,
...hierarchy ➝ F25,
...predator recognition ➝ F23.
15 Cognitive abilities
15.1 LearningClassical conditioning: failed with food as unconditioned stimulus (further research needed)
- LAB: in a group of 15, ADULTS learned to associate a conditioned stimulus (aeration off for 30 s) – in place of the unconditioned stimulus air emersion – with a conditioned response (stress = increased plasma cortisol level). Conditioning failed when the unconditioned stimulus was food – because food-competition-induced stress is milder than air-emersion-induced stress (48.9 ng/mL versus 228.4 ng/mL plasma cortisol)? 25.
- Managing self-feeder:
- Initiating flight:
- LAB: of 24 male JUVENILES, 22 learned to associate a conditioned stimulus (water off for 20 s) – in place of the unconditioned stimulus confinement stress – to initiate flight response. Latency to escape decreased from 513 s on day 1 to <30 s on day 7. JUVENILES avoided the aquarium department where confinement took place or took longer to return there compared to conspecifics only experiencing “water off” respectively 26.
15.2 MemoryNo data found yet.
15.3 Problem solving, creativity, planning, intelligenceNo data found yet.
15.4 OtherPredator recognition: innate
- LAB: single naive JUVENILES in 28.0 x 11.4 x 19.6 cm glass aquaria increased ventilatory frequency when exposed to the predator Pseudoplatystoma corruscans in an adjacent aquarium; no change in ventilatory frequency with a harmless fish Leporinus macrocephalus or an empty aquarium. Increasing ventilatory frequency improves oxygen uptake for upcoming flight 14.
- LAB: isolated predator-naive JUVENILES in 40 x 20 x 25 cm 12 L glass aquaria. On 10th day, paired with either smaller South American predator catfish spotted sorubim, Pseudoplatystoma corruscans, or smaller harmless South American threespot leporinus, Leporinus friderici. JUVENILES kept larger distance (measured as distance of fish eyes) to predator than non-predator. Higher number of dorsal fin displays and time of dorsal fin display compared to basal condition. Increase in time of fin display higher when paired with non-predator probably to enlarge body size and intimidate territory intruder. Three of seven JUVENILES displayed nipping of predator. Higher frequency of nipping (24.9%) and chasing (11.0%) of and lateral fights (1.9%) with non-predator. Results indicate innate predator recognition 78.
16 Personality, coping styles
- Individual differences in response to stress:
- LAB: single male ADULTS in 60 x 28 x 31 cm 48 L glass aquaria were:
a) confined by opaque partition to 10% aquarium volume. After 60 min, increased ventilatory frequency (ca 86 versus ca 70 opercular or buccal movements/min), but of nine ADULTS, five increased and four decreased their individual ventilatory frequency.
b) AC shocked with 20 V, 15 mA and 100 Hz for 1 min each 4 min. After 60 min, ventilatory frequency within range of pre-stress level (ca 62-72 opercular or buccal movements/min). Of nine ADULTS, four increased and five decreased their individual ventilatory frequency 20.
- LAB: single male ADULTS in 60 x 28 x 31 cm 48 L glass aquaria were:
In the structure of menu item 16 and the definition of "SHYNESS-BOLDNESS", we follow 100.
- Feeding resumption:
- LAB: single JUVENILES placed in 40 x 24 x 20 cm glass aquaria for eight days differed in coping with novel environment and isolated state: the higher ventilatory frequency the later onset of feeding in novel environment (from ca 55 opercular beats/min and onset at day 1 to ca 180 opercular beats/min and onset at day 7). Tendency of higher food intake with higher ventilation rate and with later onset of feeding 27.
- Neophobia and boldness:
- LAB: male JUVENILES with fast food intake recovery in a novel aquarium also showed less neophobia when exposed to a novel object, indicating boldness. No correlation between behaviour in novel environment, reaction to novel object, and number of body displacements in an emerged net. Males with more number of returns to and more time spent in former confinement area also displayed lower cortisol levels after emerged netting, faster food intake recovery in a novel environment, less neophobia towards a novel object, and more body displacements in an emerged net, indicating boldness 26.
In the structure of menu item 16 and the definition of "EXPLORATION-AVOIDANCE", we follow 100.
17 Emotion-like states
17.1 JoyNo data found yet.
17.2 RelaxationNo data found yet.
17.3 SadnessNo data found yet.
17.4 FearFear: associated with confinement situation (further research needed)
18 Self-concept, self-recognition
19 Reactions to husbandry
19.1 Stereotypical and vacuum activitiesNo data found yet.
19.2 Acute stressHandling: chasing for 60 s, netting is stressful (further research needed)
- LAB: FINGERLINGS in 100 L tanks with 30% daily water exchange at densities 1, 2, 5, 10 IND/tank. On 61st day, chasing with net for 60 s increased plasma cortisol level compared to control groups indicating acute stress (ca 150-300 ng/mL versus 10-45 ng/mL). Higher cortisol level in 10 FINGERLINGS group compared to smaller groups (ca 300 ng/mL versus 150-175 ng/mL) 77.
- LAB: cortisol levels of mixed-sex JUVENILES that were chased with a net for 60 s were higher than those of a control group for at least 2 h (ca 75 versus ca 15 ng/g body tissue). After 8 h, the levels were back to normal 95.
- LAB: female ADULTS in 140 L tanks served as controls for tailclipped individuals (➝ F30) and were just netted and slightly applied pressure to the tailfin. Higher cortisol levels compared to untreated individuals until last observation time 24 h after handling (256.4 nM 6 h after handling, 111.5nM 24 h after handling versus 24.6 nM). Lower lactate levels compared to untreated individuals (0.7 versus 2.6 mM). Back to control levels at next observation time 24 h after handling 99.
- LAB: confinement stress increased plasma cortisol levels in ADULTS held under white (590 lux; 18.1 versus 35.8 ng/mL) and green light (250 lux; 38.0 versus 47.2 ng/mL) but not under blue light (250 lux; 34.0 versus 27.6 ng/mL) 101.
- LAB: single ADULTS in 28 cm x 11.4 cm x 19.6 cm aquaria were confined by opaque partition to 10% of water volume:
a) After 30 min confinement, higher ventilatory frequency until second measurement at 5 min after stress compared to non-confined ADULTS (ca 110 versus 100 beats/min); back to normal at third measurement 15 min after stress. Higher cortisol level until 35 min after stress (100-150 ng/mL versus 40-60 ng/mL), back to normal at next measurement 75 min after stress.
b) Second experiment with different periods of confinement: highest difference to basal ventilatory frequency directly after stress in ADULTS confined for 30 min and ADULTS from control group where partition was dipped in water without actually confining. Faster decrease in control group than 30 min confinement group, but no return to basal frequencies in either group at end of measurement period at 27 min. Lower difference to basal ventilatory frequency directly after stress in ADULTS confined for 30 s, 5 min, and 15 min. Return to basal frequencies at around 15-18 min in 30 s- and 5 min-groups, around 27 min in 15 min-group 28.
- LAB: single individuals in 12 x 20 x 30 cm aquaria under 12 hours white, blue, or yellow light (ca 50 lux each) per day (06:00-18:00 h) for seven days. 15 min confinement on the morning of day 8 increased ventilatory frequency by average 8 opercular or buccal movements/min until 4 minutes after stress, more under white compared to blue light; yellow light in between. Back to basal level from 6 min after stress on 29.
...food competition ➝ F31,
...light intensity ➝ F22,
...light colour ➝ F32,
...olfaction ➝ F33,
...pain ➝ F30,
...linear hierarchy in small groups ➝ F27,
...coping styles ➝ F34 F3,
...fear ➝ F35,
...stunning ➝ F36.
19.3 Chronic stressFor chronic stress and...
...environmental enrichment ➝ F21,
...water temperature ➝ F37,
...salinity ➝ F38,
...rearing container ➝ F5,
...noise ➝ F39,
...stocking density ➝ F40,
...hierarchy ➝ F27,
...personality ➝ F3.
19.4 Stunning reactionsStunning rules: fast, effective, safe
- Stunning rules: to minimise pain reactions and enhance welfare before slaughter:
- induce insensibility as fast as possible,
- prevent recovery from stunning,
- monitor effectiveness (observations, neurophysiological measurements) 102.
- Time to loss of vital signs (no response to needle scratches):
a) electrical stunning with 50 Hz for 180 s: LAB, ADULTS: 30 s 82,
b) 50:50 ice water mixture: LAB, ADULTS: 20 min 82,
c) CO2 narcosis: LAB, ADULTS: 30 min 82.
- Electrical stunning:
- LAB: for specifics on electrical current (depending on water conductivity) ➝ 81:
Experiment 1: ADULTS in 50 x 20 x 70 cm plexiglass box restrained with clamp in lower jaw and plastic tie-ribs around body. Top-to-bottom stunning of 50 Hz for 1 s in fresh water. 9 s tonic phase with tense muscles, 13 s clonic phase with uncontrollably contracting muscles, 11 s exhaustion with flaccid muscles. Two of 28 ADULTS did not display epileptiform insult probably due to heart failure. In 16 of 28 ADULTS, response to needle scratches 30 s after stunning.
Experiment 2: see Experiment 1 but 5 s stun. No response to needle scratches in 24 of 24 ADULTS until 49 s after stunning when ADULTS where placed in iced water. Another eight ADULTS showed isoelectric line at 56 s after stunning and did not recover.
Experiment 3: see Experiment 1 but applied head to tail. 9 s tonic phase with tense muscles, 13 s clonic phase with uncontrollably contracting muscles, 11 s exhaustion with flaccid muscles. In eight of eight ADULTS, response to needle scratches after the exhaustion phase.
Experiment 4: side-to-side stunning of 133 Hz pulsed square wave alternating current for 1 s in seawater. 28 s tonic/clonic phase, 18 s exhaustion with flaccid muscles. In six of 17 ADULTS, response to needle scratches 30 s after stunning.
Experiment 5: see Experiment 4. After 1 s stun in five ADULTS, 38-52 s muscle contractions, 68-95 s uprighting. After 5 s stun in another five ADULTS, 181-489 s muscle contractions, 438-1139 s uprighting.
Experiment 6: see Experiment 4 but 5 s stun, thereafter gill cut. Of ADULTS gill-cut on the table, one responded to needle scratches 1 and 5 min later. In two of four ADULTS gill-cut under water, response to needle scratches 10 min after stunning.
Experiment 1-6: no broken bones, bruises, blood spots 81.
- LAB: for specifics on electrical current (depending on water conductivity) ➝ 81:
- LAB: immediately after death, higher cortisol levels in ADULTS stunned in 50:50 ice water mixture (22.2 ng/mL versus 15.9-17.5 ng/mL) compared to electrical stunning or CO2 narcosis. Could be due to higher dissolved oxygen in ice water (19.9 mg/L versus 6.2-6.3 mg/L) than in the other conditions. Levels below 50 ng/mL are considered low stress 82.
ADULTS = mature individuals, for details ➝ Findings 10.1 Ontogenetic development
AGGRESSIVENESS = agonistic reactions towards conspecifics. Tests: mirror image, social interaction/diadic encounters 100.
EXPLORATION-AVOIDANCE = reaction to new situations, e.g. new habitat, new food, novel objects. Referred to as neophobia/neophilia elsewhere. Tests: open field, trappability for first time, novel environment, hole board (time spent with head in holes), novel object 100.
FARM = setting in farming environment or under conditions simulating farming environment in terms of size of facility or number of individuals
FINGERLINGS = early juveniles with fully developed scales and working fins, the size of a human finger; for details ➝ Findings 10.1 Ontogentic development
FOOD CONVERSION RATIO = (food offered / weight gained)
FRY = larvae from external feeding on, for details ➝ Findings 10.1 Ontogenetic development
GENERALIST = Generalists detect a narrow bandwidth of sound frequencies (<50-500 Hz, 1,500 Hz max.). High hearing threshold = cannot detect quieter sounds. Typically no swim bladder or no attachment of the swim bladder to the inner ear. Live in loud environments (rivers) 97 98.
IND = individuals
JUVENILES = fully developed but immature individuals, for details ➝ Findings 10.1 Ontogenetic development
LAB = setting in laboratory environment
LARVAE = hatching to mouth opening, for details ➝ Findings 10.1 Ontogenetic development
MILLIARD = 1,000,000,000 51 52
PHOTOPERIOD = duration of daylight
POST-LARVAE = fully developed individuals, beginning of external sex differentiation; for details ➝ Findings 10.1 Ontogenetic development
SHYNESS-BOLDNESS = reaction to risky (but not new!) situations, e.g. predators or humans. Referred to as docility, tameness, fearfulness elsewhere. Tests: predator presentation, predator stimulus, threat, trappability (latency to enter a trap for first time can be exploration), resistance to handlers (Trapezov stick test), tonic immobility (catatonic-like death-feigning anti predator response) 100.
TOTAL LENGTH = from snout to tip of caudal fin as compared to fork length (which measures from snout to fork of caudal fin) 74 or standard length (from head to base of tail fin) or body length (from the base of the eye notch to the posterior end of the telson)
WILD = setting in the wild
1 Zambrano, Luis, Elsa Valiente, and M. Jake Vander Zanden. 2010. Food web overlap among native axolotl (Ambystoma mexicanum) and two exotic fishes: carp (Cyprinus carpio) and tilapia (Oreochromis niloticus) in Xochimilco, Mexico City. Biological Invasions 12: 3061–3069. https://doi.org/10.1007/s10530-010-9697-8.
2 Peterson, Mark S., William T. Slack, Nancy J. Brown-Peterson, Jennifer L. McDonald, and C. M. Taylor. 2004. Reproduction in Nonnative Environments: Establishment of Nile Tilapia, Oreochromis niloticus, in Coastal Mississippi Watersheds. Copeia 2004: 842–849. https://doi.org/10.1643/CE-04-134R1.
3 Komolafe, O. O., and G. a. O. Arawomo. 2007. Reproductive strategy of Oreochromis niloticus (Pisces: Cichlidae) in Opa reservoir, Ile-Ife, Nigeria. Revista de Biología Tropical 55: 595–602.
4 Toguyeni, Aboubacar, Benoit Fauconneau, Thierry Boujard, Alexis Fostier, Eduard R Kuhn, Koen A Mol, and Jean-Francois Baroiller. 1997. Feeding Behaviour and Food Utilisation in Tilapia, Oreochromis Niloticus: Effect of Sex Ratio and Relationship With the Endocrine Status. Physiology & Behavior 62: 273–279. https://doi.org/10.1016/S0031-9384(97)00114-5.
5 Vera, Luisa María, Louise Cairns, Francisco Javier Sánchez-Vázquez, and Hervé Migaud. 2009. Circadian Rhythms of Locomotor Activity in the Nile Tilapia Oreochromis niloticus. Chronobiology International 26: 666–681. https://doi.org/10.1080/07420520902926017.
6 Volpato, G. L., C. R. A. Duarte, and A. C. Luchiari. 2004. Environmental color affects Nile tilapia reproduction. Brazilian Journal of Medical and Biological Research 37: 479–483. https://doi.org/10.1590/S0100-879X2004000400004.
7 Uchida, Hiroshi, Satoshi Ogawa, Mina Harada, Masato Matushita, Munehico Iwata, Yasuo Sakuma, and Ishwar S. Parhar. 2005. The olfactory organ modulates gonadotropin-releasing hormone types and nest-building behavior in the tilapia Oreochromis niloticus. Journal of Neurobiology 65: 1–11. https://doi.org/10.1002/neu.20156.
8 Mendonça, Francine Z., and Eliane Gonçalves-de-Freitas. 2008. Nest deprivation and mating success in Nile tilapia (Teleostei: Cichlidae). Revista Brasileira de Zoologia 25: 413–418. https://doi.org/10.1590/S0101-81752008000300005.
9 Castro, A. L. S., E. Gonçalves-de-Freitas, G. L. Volpato, and C. Oliveira. 2009. Visual communication stimulates reproduction in Nile tilapia, Oreochromis niloticus (L.). Brazilian Journal of Medical and Biological Research 42: 368–374. https://doi.org/10.1590/S0100-879X2009000400009.
10 Mendonça, F. Z., G. L. Volpato, R. S. Costa-Ferreira, and E. Gonçalves-de-Freitas. 2010. Substratum choice for nesting in male Nile tilapia Oreochromis niloticus. Journal of Fish Biology 77: 1439–1445. https://doi.org/10.1111/j.1095-8649.2010.02754.x.
11 Rana, Kausik J. 1986. Parental influences on egg quality, fry production and fry performance in Oreochromis niloticus (Linnaeus) and O. mossambicus (Peters). Doctoral dissertation, U.K.: University of Stirling.
12 Longrie, Nicolas, Sam Van Wassenbergh, Pierre Vandewalle, Quentin Mauguit, and Eric Parmentier. 2009. Potential mechanism of sound production in Oreochromis niloticus (Cichlidae). Journal of Experimental Biology 212: 3395–3402. https://doi.org/10.1242/jeb.032946.
13 Delcourt, Johann, Christophe Becco, Nicolas Vandewalle, and Pascal Poncin. 2009. A video multitracking system for quantification of individual behavior in a large fish shoal: Advantages and limits. Behavior Research Methods 41: 228–235. https://doi.org/10.3758/BRM.41.1.228.
14 Barreto, Rodrigo Egydio, Ana Carolina Luchiari, and Ana Lucia Marcondes. 2003. Ventilatory frequency indicates visual recognition of an allopatric predator in naı̈ve Nile tilapia. Behavioural Processes 60: 235–239. https://doi.org/10.1016/S0376-6357(02)00127-4.
15 Volpato, G. L., A. C. Luchiari, C. R. A. Duarte, R. E. Barreto, and G. C. Ramanzini. 2003. Eye color as an indicator of social rank in the fish Nile tilapia. Brazilian Journal of Medical and Biological Research 36: 1659–1663. https://doi.org/10.1590/S0100-879X2003001200007.
16 Corrêa, S. A., M. O. Fernandes, K. K. Iseki, and J. A. Negrão. 2003. Effect of the establishment of dominance relationships on cortisol and other metabolic parameters in Nile tilapia (Oreochromis niloticus). Brazilian Journal of Medical and Biological Research 36: 1725–1731. https://doi.org/10.1590/S0100-879X2003001200015.
17 Gonçalves-de-Freitas, Eliane, and Aline Chimello Ferreira. 2004. Female social dominance does not establish mating priority in Nile tilapia. Revista de Etologia 6: 33–37.
18 Barbosa, J. M., S. S. S. Brugiolo, J. Carolsfeld, and S. S. Leitão. 2006. Heterogeneous growth fingerlings of the Nile tilapia Oreochromis niloticus: effects of density and initial size variability. Brazilian Journal of Biology 66: 537–541. https://doi.org/10.1590/S1519-69842006000300020.
19 Barreto, Rodrigo Egydio, and Gilson Luiz Volpato. 2006. Stress responses of the fish Nile tilapia subjected to electroshock and social stressors. Brazilian Journal of Medical and Biological Research 39: 1605–1612. https://doi.org/10.1590/S0100-879X2006001200012.
20 Barreto, Rodrigo Egydio, and Gilson Luiz Volpato. 2006. Ventilatory frequency of Nile tilapia subjected to different stressors. Journal of Experimental Animal Science 43: 189–196. https://doi.org/10.1016/j.jeas.2006.05.001.
21 Evans, Joyce J., David J. Pasnik, Patrick Horley, Kimberly Kraeer, and Phillip H. Klesius. 2008. Aggression and Mortality among Nile Tilapia (Oreochromis niloticus) Maintained in the Laboratory at Different Densities. Research Journal of Animal Sciences 2: 57–64.
22 Carvalho, Thaís B., Francine Z. Mendonça, Roselene S. Costa-Ferreira, and Eliane Gonçalves-de-Freitas. 2013. The effect of increased light intensity on the aggressive behavior of the Nile tilapia, Oreochromis niloticus (Teleostei: Cichlidae). Zoologia (Curitiba) 30: 125–129. https://doi.org/10.1590/S1984-46702013000200001.
23 Pinho-Neto, Candido Ferreira, Caio Akira Miyai, Fabio Henrique Carretero Sanches, Percilia Cardoso Giaquinto, Helton Carlos Delicio, Leonardo José Gil Barcellos, Gilson Luiz Volpato, and Rodrigo Egydio Barreto. 2014. Does sex influence intraspecific aggression and dominance in Nile tilapia juveniles? Behavioural Processes 105: 15–18. https://doi.org/10.1016/j.beproc.2014.02.003.
24 Barreto, Rodrigo Egydio, Graziele G. Arantes Carvalho, and Gilson Luiz Volpato. 2011. The aggressive behavior of Nile tilapia introduced into novel environments with variation in enrichment. Zoology 114: 53–57. https://doi.org/10.1016/j.zool.2010.09.001.
25 Barreto, Rodrigo Egydio, and Gilson Luiz Volpato. 2007. Evaluating feeding as unconditioned stimulus for conditioning of an endocrine effect in Nile tilapia. Physiology & Behavior 92: 867–872. https://doi.org/10.1016/j.physbeh.2007.06.013.
26 Martins, Catarina I. M., Patricia I. M. Silva, Luis E. C. Conceição, Benjamin Costas, Erik Höglund, Øyvind Øverli, and Johan W. Schrama. 2011. Linking fearfulness and coping styles in fish. PLOS ONE 6: e28084. https://doi.org/10.1371/journal.pone.0028084.
27 Barreto, Rodrigo Egydio, and Gilson Luiz Volpato. 2011. Ventilation rates indicate stress-coping styles in Nile tilapia. Journal of Biosciences 36: 851–855. https://doi.org/10.1007/s12038-011-9111-4.
28 Barreto, Rodrigo Egydio, and Gilson Luiz Volpato. 2004. Caution for using ventilatory frequency as an indicator of stress in fish. Behavioural Processes 66: 43–51. https://doi.org/10.1016/j.beproc.2004.01.001.
29 Maia, Caroline Marques, and Gilson Luiz Volpato. 2013. Environmental light color affects the stress response of Nile tilapia. Zoology 116: 64–66. https://doi.org/10.1016/j.zool.2012.08.001.
30 Reviewed distribution maps for Nile tilapia (Oreochromis niloticus). 2016. Aquamaps.
31 Trewavas, Ethelwynn, and Guy G. Teugels. 1991. Sarotherodon. In Check-list of the Freshwater Fishes of Africa: Cloffa, ed. Jacques Daget, J. P. Gosse, Guy G. Teugels, and Dirk F. E. Thys van den Audenaerde, 4:425–437. Brussels: ISNB.
32 Froese, R., and D. Pauly. 2014. FishBase. World Wide Web electronic publication. www.fishbase.org.
33 Trewavas, Ethelwynn. 1983. Tilapiine Fishes of the Genera Sarotherodon, Oreochromis and Danakilia. [Published in cooperation with] British Museum (Natural History) [by] Comstock Pub. Associates, a division of Cornell University Press.
34 Teugels, Guy G., and Dirk F. E. Thys van den Audenaerde. 2003. Cychlidae. In Fresh and brackish water fishes of West Africa, ed. Didier Paugy, C. Lévêque, and Guy G. Teugels, 521–600. Institut de recherche pour le développement.
35 Lung’ayia, H. B. O. 1994. Some aspects of the reproductive biology of the Nile tilapia Oreochromis niloticus (L) in the Nyanza Gulf of Lake Victoria, Kenya. In Proceedings of the Second EEC Regional Seminar on Recent Trends of Research on Lake Victoria Fisheries, ed. E. Okemwa, E. O. Wakwabi, and A. Getabu, 121–127. Nairobi: ICIPE SCIENCE.
36 Bwanika, G. N., B. Makanga, Y. Kizito, L. J. Chapman, and J. Balirwa. 2004. Observations on the biology of Nile tilapia, Oreochromis niloticus L., in two Ugandan crater lakes. African Journal of Ecology 42: 93–101. https://doi.org/10.1111/j.1365-2028.2004.00468.x.
37 Bwanika, G. N., L. J. Chapman, Y. Kizito, and J. Balirwa. 2006. Cascading effects of introduced Nile perch (Lates niloticus) on the foraging ecology of Nile tilapia (Oreochromis niloticus). Ecology of Freshwater Fish 15: 470–481. https://doi.org/10.1111/j.1600-0633.2006.00185.x.
38 Oso, J. A., I. A. Ayodele, and O. Fagbuaro. 2006. Food and Feeding Habits of Oreochromis niloticus (L.) and Sarotherodon galilaeus (L.) in a Tropical Reservoir. World Journal of Zoology 1: 118–121.
39 Zengeya, Tsungai Alfred, Anthony J. Booth, Armanda D. S. Bastos, and Christian T. Chimimba. 2011. Trophic interrelationships between the exotic Nile tilapia, Oreochromis niloticus and indigenous tilapiine cichlids in a subtropical African river system (Limpopo River, South Africa). Environmental Biology of Fishes 92: 479–489. https://doi.org/10.1007/s10641-011-9865-4.
40 Uddin, M. S., A. Farzana, M. K. Fatema, M. E. Azim, M. A. Wahab, and M. C. J. Verdegem. 2007. Technical evaluation of tilapia (Oreochromis niloticus) monoculture and tilapia–prawn (Macrobrachium rosenbergii) polyculture in earthen ponds with or without substrates for periphyton development. Aquaculture 269: 232–240. https://doi.org/10.1016/j.aquaculture.2007.05.038.
41 Chapman, Lauren J., Colin A. Chapman, and Mark Chandler. 1996. Wetland ecotones as refugia for endangered fishes. Biological Conservation 78: 263–270. https://doi.org/10.1016/S0006-3207(96)00030-4.
42 Chapman, Lauren J., Colin A. Chapman, Richard Ogutu-Ohwayo, Mark Chandler, Les Kaufman, and Amanda E. Keiter. 1996. Refugia for Endangered Fishes from an Introduced Predator in Lake Nabugabo, Uganda. Conservation Biology 10: 554–561. https://doi.org/10.1046/j.1523-1739.1996.10020554.x.
43 Rosenberger, A. E., and L. J. Chapman. 1999. Hypoxic wetland tributaries as faunal refugia from an introduced predator. Ecology of Freshwater Fish 8: 22–34. https://doi.org/10.1111/j.1600-0633.1999.tb00049.x.
44 Schofield, Pamela J., and Lauren J. Chapman. 1999. Interactions Between Nile Perch, Lates niloticus, and Other Fishes in Lake Nabugabo, Uganda. Environmental Biology of Fishes 55: 343–358. https://doi.org/10.1023/A:1007544017989.
45 Duponchelle, Fabrice, and Marc Legendre. 2001. Rapid phenotypic changes of reproductive traits in response to experimental modifications of spatial structure in Nile tilapia, Oreochromis niloticus. Aquatic Living Resources 14: 145–152. https://doi.org/10.1016/S0990-7440(01)01109-3.
46 Delicio, Helton Carlos, Rodrigo Egydio Barreto, Edvaldo Bento Normandes, Ana Carolina Luchiari, and Ana Lúcia Marcondes. 2006. A place preference test in the fish Nile tilapia. Journal of Experimental Animal Science 43: 141–148. https://doi.org/10.1016/j.jeas.2006.01.001.
47 FAO. 2014. The State of World Fisheries and Aquaculture 2014. Rome: Food and Agriculture Organization of the United Nations.
48 Watson, R., Jackie Alder, and Daniel Pauly. 2006. Fisheries for forage fish, 1950 to the present. In On the Multiple Uses of Forage Fish: from Ecosystems to Markets, ed. Jackie Alder and Daniel Pauly, 14:1–20. Fisheries Centre Research Reports 3. Vancouver, Canada: Fisheries Centre, University of British Columbia.
49 Mood, A. 2012. Average annual fish capture for species mostly used for fishmeal (2005-2009). fishcount.org.uk.
50 Mood, A., and P. Brooke. 2012. Estimating the Number of Farmed Fish Killed in Global Aquaculture Each Year.
51 Kopf, Von Kristin. 2012. Milliarden vs. Billionen: Große Zahlen. Sprachlog.
52 Weisstein, Eric W. 2018. Milliard. Text. MathWorld - a Wolfram Web resource. http://mathworld.wolfram.com/Milliard.html. Accessed February 2.
53 Fish, G. R. 1955. The food of Tilapia in East Africa. The Uganda journal 19: 85–89.
54 Lowe-McConnell, R. H. 2000. The roles of tilapias in ecosystems. In Tilapias: Biology and Exploitation, ed. Malcolm C. M. Beveridge and Brendan J. McAndrew, 129–162. Fish and Fisheries Series 25. Springer Netherlands.
55 Moriarity, D. J. W., Johanna P. E. C. Darlington, I. G. Dunn, Christine M. Moriarty, and M. P. Tevlin. 1973. Feeding and Grazing in Lake George, Uganda. Proceedings of the Royal Society of London B: Biological Sciences 184: 299–319. https://doi.org/10.1098/rspb.1973.0050.
56 Gophen, M., P. B. O. Ochumba, U. Pollinger, and L. S. Kaufman. 1994. Nile perch (Lates niloticus) invasion in Lake Victoria (East Africa). Verhandlungen Internationale Vereinigung Limnologie 25: 856–859.
57 Balirwa, J. S. 1998. Lake Victoria wetlands and the ecology of the Nile tilapia, Oreochromis niloticus Linne. Ph.D. dissertation, Wageningen, The Netherlands: Wageningen Agricultural University.
58 Peterson, Mark S., William T. Slack, Gretchen L. Waggy, Jeremy Finley, Christa M. Woodley, and Melissa L. Partyka. 2006. Foraging in Non-Native Environments: Comparison of Nile Tilapia and Three Co-Occurring Native Centrarchids in Invaded Coastal Mississippi Watersheds. Environmental Biology of Fishes 76: 283–301. https://doi.org/10.1007/s10641-006-9033-4.
59 Azaza, M. S., M. N. Dhraief, M. M. Kraiem, and E. Baras. 2010. Influences of food particle size on growth, size heterogeneity, food intake and gastric evacuation in juvenile Nile tilapia, Oreochromis niloticus, L., 1758. Aquaculture 309: 193–202. https://doi.org/10.1016/j.aquaculture.2010.09.026.
60 Yousif, O. M. 2002. The effects of stocking density, water exchange rate, feeding frequency and grading on size hierarchy development in juvenile Nile tilapia, Oreochromis niloticus L. Emirates Journal of Food and Agriculture 14. https://doi.org/10.9755/ejfa.v14i1.4984.
61 Mustapha, Moshood Keke, Olatoyosi Taofeek Oladokun, Mubarak Mayowa Salman, Idris Adewale Adeniyi, and Dele Ojo. 2014. Does light duration (photoperiod) have an effect on the mortality and welfare of cultured Oreochromis niloticus and Clarias gariepinus? Turkish Journal of Zoology 38: 466–470.
62 Luchiari, A. C., and F. a. M. Freire. 2009. Effects of environmental colour on growth of Nile tilapia, Oreochromis niloticus (Linnaeus, 1758), maintained individually or in groups. Journal of Applied Ichthyology 25: 162–167. https://doi.org/10.1111/j.1439-0426.2008.01203.x.
63 Gilbert, P. 1996. Breeding and propagation of tilapia (Oreochromis niloticus) in a floating hatchery, Gabon. Naga, the ICLARM Quarterly 19: 26–33.
64 Azaza, M. S., M. N. Dhraief, and M. M. Kraiem. 2008. Effects of water temperature on growth and sex ratio of juvenile Nile tilapia Oreochromis niloticus (Linnaeus) reared in geothermal waters in southern Tunisia. Journal of Thermal Biology 33: 98–105. https://doi.org/10.1016/j.jtherbio.2007.05.007.
65 Philippart, J.-Cl., and J.-Cl. Ruwet. 1982. Ecology and Distribution of Tilapias. In The Biology and Culture of Tilapias: Proceedings of the International Conference on the Biology and Culture of Tilapias, 2-5 September 1980 at the Study and Conference Center of the Rockefeller Foundation, Bellagio, Italy, ed. Roger S. V. Pullin and R. H. Lowe-McConnell, 15–59. ICLARM Conference Proceedings 7. WorldFish.
66 Baroiller, Jean-Francois, Daniel Chourrout, Alexis Fostier, and Bernard Jalabert. 1995. Temperature and sex chromosomes govern sex ratios of the mouthbrooding Cichlid fish Oreochromis niloticus. Journal of Experimental Zoology 273: 216–223. https://doi.org/10.1002/jez.1402730306.
67 Abucay, Jose S, Graham C Mair, David O F Skibinski, and John A Beardmore. 1999. Environmental sex determination: the effect of temperature and salinity on sex ratio in Oreochromis niloticus L. Aquaculture 173: 219–234. https://doi.org/10.1016/S0044-8486(98)00489-X.
68 Cataldi, Emilia, Donatella Crosetti, Camilla Leoni, and Stefano Cataudella. 1988. Oesophagus structure during adaptation to salinity in oreochromis niloticus (Perciformes, pisces) juveniles. Bolletino di zoologia 55: 59–62. https://doi.org/10.1080/11250008809386600.
69 Videler, J. J. 1974. On the Interrelationships Between Morphology and Movement in the Tail of the Cichlid Fish Tilapia Nilotica (L.). Netherlands Journal of Zoology 25: 143–194. https://doi.org/10.1163/002829675X00209.
70 Lindsey, C. C. 1978. Form, function and locomotory habits in fish. In Fish Physiology VII, ed. William S. Hoar and D. J. Randall, 1–100. New York: Academic Press.
71 van Oijen, M. J. P. 1995. Appendix I. Key to Lake Victoria fishes other than haplochromine cichlids. In Fish Stocks and Fisheries of Lake Victoria: A Handbook for Field Observations, ed. Frans Witte and Wim L. T. van Densen, 209–300. Dyfed, Great Britain: Samara Publishing Limited.
72 Goudswaard, P. C., F. Witte, and E. F. B. Katunzi. 2002. The tilapiine fish stock of Lake Victoria before and after the Nile perch upsurge. Journal of Fish Biology 60: 838–856. https://doi.org/10.1111/j.1095-8649.2002.tb02413.x.
73 Fujimura, Koji, and Norihiro Okada. 2007. Development of the embryo, larva and early juvenile of Nile tilapia Oreochromis niloticus (Pisces: Cichlidae). Developmental staging system. Development, Growth & Differentiation 49: 301–324. https://doi.org/10.1111/j.1440-169X.2007.00926.x.
74 Pawson, M.G., and G.D. Pickett. 1996. The Annual Pattern of Condition and Maturity in Bass, Dicentrarchus Labrax, in Waters Around England and Wales. Journal of the Marine Biological Association of the United Kingdom 76: 107. https://doi.org/10.1017/S0025315400029040.
75 Siddiqui, A. Q., M. S. Howlader, and A. B. Adam. 1989. Culture of Nile tilapia, Oreochromis niloticus (L.), at three stocking densities in outdoor concrete tanks using drainage water. Aquaculture Research 20: 49–58. https://doi.org/10.1111/j.1365-2109.1989.tb00440.x.
76 Abou, Youssouf, Emile D Fiogbé, and Jean-Claude Micha. 2007. Effects of stocking density on growth, yield and profitability of farming Nile tilapia, Oreochromis niloticus L., fed Azolla diet, in earthen ponds. Aquaculture Research 38: 595–604. https://doi.org/10.1111/j.1365-2109.2007.01700.x.
77 Barcellos, Leonardo José Gil, S. Nicolaiewsky, S M G. De Souza, and F. Lulhier. 1999. The effects of stocking density and social interaction on acute stress response in Nile tilapia Oreochromis niloticus (L.) fingerlings. Aquaculture Research 30: 887–892. https://doi.org/10.1046/j.1365-2109.1999.00419.x.
78 Freitas, R. H. A., and G. L. Volpato. 2008. Behavioral response of Nile tilapia to an allopatric predator. Marine and Freshwater Behaviour and Physiology 41: 267–272. https://doi.org/10.1080/10236240802509767.
79 Fryer, Geoffrey, and T. D. Iles. 1972. The cichlid fishes of the great lakes of Africa: their biology and evolution. Oliver and Boyd.
80 International Game Fish Association. 2001. Database of IGFA angling records until 2001. Fort Lauderdale, USA: IGFA.
81 Lambooij, E., M. A. Gerritzen, H. Reimert, D. Burggraaf, and J. W. van de Vis. 2008. A humane protocol for electro-stunning and killing of Nile tilapia in fresh water. Aquaculture 275: 88–95. https://doi.org/10.1016/j.aquaculture.2008.01.026.
82 Oliveira Filho, Paulo Roberto Campagnoli de, Pamela Jenny Montes Girao, Mariza Pires de Melo, and Elisabete Maria Macedo Viegas. 2015. Indicators of stress in tilapia subjected to different stunning methods. Boletim do Instituto de Pesca, São Paulo 41: 335–343.
83 Tessema, Misikire, Andreas Müller-Belecke, and Gabriele Hörstgen-Schwark. 2006. Effect of rearing temperatures on the sex ratios of Oreochromis niloticus populations. Aquaculture 258: 270–277. https://doi.org/10.1016/j.aquaculture.2006.04.041.
84 Vera Cruz, E. M., and G. C. Mair. 1994. Conditions for effective androgen sex reversal in Oreochromis niloticus (L.). Aquaculture 122: 237–248. https://doi.org/10.1016/0044-8486(94)90513-4.
85 Phelps, R. P., G. Conterras Salazar, V. Abe, and B. J. Argue. 1995. Sex reversal and nursery growth of Nile tilapia, Oreochromis niloticus (L.), free-swimming in earthen ponds. Aquaculture Research 26: 293–295. https://doi.org/10.1111/j.1365-2109.1995.tb00915.x.
86 Mair, G. C., A. G. Scott, D. J. Penman, J. A. Beardmore, and D. O. F. Skibinski. 1991. Sex determination in the genus Oreochromis. Theoretical and Applied Genetics 82: 144–152. https://doi.org/10.1007/BF00226205.
87 Mair, G. C., J. S. Abucay, T. A. Abella, J. A. Beardmore, and D. O. F. Skibinski. 1997. Genetic manipulation of sex ratio for the large-scale production of all-male tilapia Oreochromis niloticus. Canadian Journal of Fisheries and Aquatic Sciences 54: 396–404. https://doi.org/10.1139/f96-282.
88 NOT FOUND
89 Shoko, Amon Paul, Samwel Mchele Limbu, Hillary Deogratias John Mrosso, Adolf Faustine Mkenda, and Yunus Daud Mgaya. 2016. Effect of stocking density on growth, production and economic benefits of mixed sex Nile tilapia (Oreochromis niloticus) and African sharptooth catfish (Clarias gariepinus) in polyculture and monoculture. Aquaculture Research 47: 36–50. https://doi.org/10.1111/are.12463.
90 Noakes, D. L. G., and E. K. Balon. 1982. Life Histories of Tilapias: An Evolutionary Perspective. In The Biology and Culture of Tilapias: Proceedings of the International Conference on the Biology and Culture of Tilapias, 2-5 September 1980 at the Study and Conference Center of the Rockefeller Foundation, Bellagio, Italy, ed. Roger S. V. Pullin and R. H. Lowe-McConnell, 61–82. ICLARM Conference Proceedings 7. WorldFish.
91 Worthington, E. B. 1932. A report on the fisheries of Uganda investigated by the Cambridge Expedition to the East African Lakes, 1930-31. Monograph or Serial Issue.
92 Fessehaye, Yonas, Zizy El-bialy, Mahmoud A. Rezk, Richard Crooijmans, Henk Bovenhuis, and Hans Komen. 2006. Mating systems and male reproductive success in Nile tilapia (Oreochromis niloticus) in breeding hapas: A microsatellite analysis. Aquaculture 256: 148–158. https://doi.org/10.1016/j.aquaculture.2006.02.024.
93 Bautista, A. M., M. H. Carlos, and A. I. San Antonio. 1988. Hatchery production of Oreochromis niloticus L. at different sex ratios and stocking densities. Aquaculture 73: 85–89. https://doi.org/10.1016/0044-8486(88)90043-9.
94 Lisney, T. J., E. Studd, and C. W. Hawryshyn. 2010. Electrophysiological assessment of spectral sensitivity in adult Nile tilapia Oreochromis niloticus: evidence for violet sensitivity. The Journal of Experimental Biology 213: 1453–1463. https://doi.org/10.1242/jeb.036897.
95 Barcellos, Leonardo José Gil, Gilson Luiz Volpato, Rodrigo Egydio Barreto, Ivanir Coldebella, and Daiane Ferreira. 2011. Chemical communication of handling stress in fish. Physiology & Behavior 103: 372–375. https://doi.org/10.1016/j.physbeh.2011.03.009.
96 Smith, Michael E., Andrew S. Kane, and Arthur N. Popper. 2004. Acoustical stress and hearing sensitivity in fishes: does the linear threshold shift hypothesis hold water? Journal of Experimental Biology 207: 3591–3602. https://doi.org/10.1242/jeb.01188.
97 Brown, Culum. 2015. Fish intelligence, sentience and ethics. Animal Cognition 18: 1–17. https://doi.org/10.1007/s10071-014-0761-0.
98 Amundsen, Lasse, and Martin Landro. 2011. Marine seismic sources part VIII: Fish hear a great deal. Recent Advances in Technology 8: 1–5.
99 Roques, Jonathan A. C., Wout Abbink, Femke Geurds, Hans van de Vis, and Gert Flik. 2010. Tailfin clipping, a painful procedure: Studies on Nile tilapia and common carp. Physiology & Behavior 101: 533–540. https://doi.org/10.1016/j.physbeh.2010.08.001.
100 Réale, Denis, Simon M. Reader, Daniel Sol, Peter T. McDougall, and Niels J. Dingemanse. 2007. Integrating animal temperament within ecology and evolution. Biological Reviews 82: 291–318. https://doi.org/10.1111/j.1469-185X.2007.00010.x.
101 Volpato, G. L., and R. E. Barreto. 2001. Environmental blue light prevents stress in the fish Nile tilapia. Brazilian Journal of Medical and Biological Research 34: 1041–1045. https://doi.org/10.1590/S0100-879X2001000800011.
102 Robb, D H F, and S C Kestin. 2002. Methods Used to Kill Fish: Field Observations and Literature Reviewed. Animal Welfare 11: 269–282.
1 / 3
2 / 3
3 / 3