Reviewer: Billo Heinzpeter Studer
Editor: Billo Heinzpeter Studer

• Initial release: 2015-11-15
• Appearance version: 2022-06-12
• Major version: 2018-10-20
• Minor version: 2022-01-22

Cite as: »Volstorf, Jenny, and Ana Roque. 2022. Penaeus vannamei (Dossier). In: fair-fish database, ed. fair-fish. World Wide Web electronic publication. Version B | 1.1. https://fair-fish-database.net.«

• Unpredictable influence: 1 2 3.
• Competition:
  • Observations WILD: competition for food and space 1 4 3.
• Disease transmission: 1 3, Taura Syndrome Virus: 2.
• Interbreeding: no data found yet.

• For migration → 12 13 14 3.

• For feeding → 15 4.
• For daily rhythm → 12 16.
• For swimming → 17 18 19.
• For courtship → 20 21.
• For spawning → 20 22.
• For observable stress reactions → 23 24 25.

• Observations: Mexico 12 17 27 13 28 14, Parita Gulf, Panama 1, Peru 29.

• Observations western Atlantic coast: Azucena mangrove and Sánchez Magallanes (Tabasco) at Gulf of Mexico, Atlantic, Mexico 3, Brownsville shipping channel/Laguna Madre (Texas) at Gulf of Mexico, Atlantic, USA 1.
• Observations Asia: Bangpakong river, Thailand 2.

• Plants: no data found yet.
• Rocks and stones: no data found yet.
• Sand and mud: lives over sand and mud:
  • Observations WILD, POST-LARVAE-SUB-ADULTS: muddy peat and muddy sand, rich in organic matter: Carretas-Pereyra coastal system on Gulf of Tehuantepec, Pacific, Mexico 14.
  • Observations WILD, JUVENILES: muddy substrate: Mar Muerto lagoon system at Gulf of Tehuantepec, Pacific, Mexico 13, Azucena mangrove (Tabasco) at Gulf of Mexico, Atlantic, Mexico (introduced) 3. Mud with oyster shells: Sánchez Magallanes (Tabasco) at Gulf of Mexico, Atlantic, Mexico (introduced) 3.
• Other substrate: no data found yet.

• Direct effect:
  • FARM, JUVENILES: in 1 m³ polyethylene tank (80 cm water), 10 cm sediment layer on artificial substrate from shrimp pond (aquamats, geotextile fabric, or mosquito nets) increased bacteria-microalgae communities called periphyton. After 28 days, higher nitrate (2.39-3.03 versus 1.74), lower total ammonia (0.61-0.71 versus 1.08), and lower unionised ammonia level (0.05-0.07 versus 0.12) in tanks with 10 cm sediment layer than without substrate, indicating periphyton reduced ammonia levels and improved water quality. Higher final weight (10.4-10.9 g versus 8.7 g) and lower FOOD CONVERSION RATIO (1.9-2.0 versus 2.4) indicate periphyton increased feed conversion and promoted growth 30.
  • LAB, JUVENILES: in 850 L circular fiberglass tanks with 70 cm water depth, eight polyethylene screens with mosquito net placed vertically in tank (amounting to 3.5 m²). After five weeks in BIOFLOC system without water exchange, similar negligent amount of periphyton (0.35-0.4 mg/cm²) and chlorophyll-a (0.009-0.012 µg/cm²) on substrate at 5-45 cm water depth, indicating microorganisms rather linked to suspended solids in water (BIOFLOC) than to substrate. Effect of periphyton not possible to observe! Higher final weight (8.9 g versus 5.6 g) with substrate versus without possibly due to the added useful surface of the polyethylene screens decreasing stocking density (202.0 to 44.9 IND/m² in "238 IND/m³" condition, 402.0 to 89.3 IND/m² in "473 IND/m³" condition) and reducing stress: JUVENILES did not settle on smooth tank walls but on rough net surface. Difference in survival in tanks without substrate (70.6% at 238 IND/m³ versus 14.4% at 473 IND/m³) disappeared in tanks including substrate (92.6-95.2%) 31.
• No effect:
  • LAB, JUVENILES: no difference in growth regardless of substrate: 1) 25% silt + 25% clay + 25% very fine sand + 25% fine sand, 2) 50% fine sand + 50% very fine sand, 3) no substrate 32.

• Plants: no data found yet.
• Rocks and stones: no data found yet.
• Sand and mud: no data found yet.
• Other cover: no data found yet.
• For burrowing and daily rhythm → D1.

• 2.0-3.0 (inferred by FishEthoBase → D2).

• Omnivorous D2. The fishery that provides fish meal and fish oil has two major impacts:
  1. It contributes considerably to overfishing, as it accounts for 1/4 33 or even 1/3 34 of the world catch volume.
  2. 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 35, the individual fish gets overlooked and, thus, suffering increases at rearing, live marketing, and slaughtering levels 36.

• Food items: omnivorous:
  • WILD, JUVENILES: in Bangpakong river, Thailand, omnivorous with average 19.1% Phytoplankton (e.g., diatom, centric diatom, triceratium) found in stomach, 13.33% appendages of crustaceans, 12.2% vegetal matter (macroalgae, seagrass, plant tissue), 55.27% unspecified digested matter. High overlap with diets of native species Metapenaeus brevicornis, Metapenaeus ensis, Penaeus merguiensis, Penaeus monodon 4.
  • FARM: in culturing pond, omnivorous 39.
  • For prevention of cannibalism by stark light contrasts → D3.
  • For cannibalism and salinity → D4.
• Food items and habitat: no data found yet.
• Food items and life stages:
  • FARM: Phytoplankton and Zooplankton decreasing in importance from 70 mm to 200 mm, supplementary feed increasing 39:
    70-80 mm mainly: Phytoplankton, Zooplankton, detritus, to a lesser extent: Amphipoda, mud, supplementary feed, Crustacea, Isopoda, Nematoda, Mollusca, only seldomly: Polychaeta
    90-100 mm mainly: Phytoplankton, Zooplankton, to a lesser extent: mud, supplementary feed, detritus, Isopoda, Amphipoda, Mollusca, Nematoda, Crustacea, only seldomly: Polychaeta
    110-120 mm mainly: Crustacea, Phytoplankton, to a lesser extent: supplementary feed, Amphipoda, mud, detritus, Zooplankton, Isopoda, Nematoda, Mollusca, only seldomly: Polychaeta
    130-140 mm mainly: supplementary feed, detritus, Phytoplankton, Crustacea, mud, Zooplankton, Isopoda, Amphipoda, Nematoda, Polychaeta, only seldomly: Mollusca
    150-160 mm mainly: supplementary feed, Crustacea, detritus, to a lesser extent: Amphipoda, mud, Isopoda, Nematoda, Phytoplankton, Zooplankton, Polychaeta, Mollusca
    170-180 mm mainly: supplementary feed, to a lesser extent: Crustacea, detritus, Nematoda, Polychaeta, Amphipoda, Isopoda, Mollusca, Phytoplankton, Zooplankton, mud
    190-200 mm mainly: supplementary feed, Crustacea, mud, to a lesser extent: Amphipoda, Isopoda, detritus, Nematoda, Mollusca, Polychaeta, Phytoplankton, only seldomly: Zooplankton.
• Food preference: no data found yet.
• Food partitioning: no data found yet.
• Prey density: no data found yet.
• Prey size selectivity: no data found yet.
• Particle size:
  • LAB: 12 JUVENILES each in 52 L glass aquaria were fed particles of different sizes (0.7 mm crumble to 3.0 mm pellet). Average 4-7 of 12 JUVENILES fed. Although fed to satiation, JUVENILES displayed food competition: the larger the particle size (3.0 mm pellets versus 0.7-1.2 mm crumbles), the more JUVENILES attacked to obstruct others from feeding. After eight weeks, no difference in final weight (5.3-5.9 g), FOOD CONVERSION RATIO (1.8-2.1), and survival (80.2-90.6%) but tendency of best growth and survival at 2.2-2.6 mm crumble size. Tendency of lowest survival at 3.0 mm pellet size, probably due to death of smaller JUVENILES 40.

• LAB: metabolic parameters of JUVENILES in outdoor tanks almost exclusively higher than of JUVENILES in indoor tanks probably due to natural food (bacteria, microalgae) available to JUVENILES in outdoor tanks through seawater filtered with 15 μm instead of 1 μm filter 41 (for details on the study → D5).
• LAB, JUVENILES: lower survival after repeated handling stress (for details of the study → D5) only in JUVENILES fed a diet low compared to high in highly unsaturated fatty acids (HUFA) (90.7 versus 95.0%). Lower consumption of high-HUFA diet (10.6 g versus 11.1 g of low-HUFA diet). No effect of diet on haemocyanin, total proteins, glucose.
  Higher total proteins after single handling stress (for details of the study → D6) only in JUVENILES fed the high-HUFA diet (128 mg/mL versus 113.4 mg/mL with low-HUFA diet). Also, lower osmotic pressure in JUVENILES fed the high-HUFA compared to low-HUFA diet (786.9 mOsm/kg versus 828.9 mOsm/kg with low-HUFA diet) 42.

• FARM: considerable amount of mud and detritus in stomach indicate individuals are bottom grazers 39.
• WILD/LAB, JUVENILES: one individual of wild-caught native shrimp species and one individual of hatchery-reared L. vannamei each were paired in glass aquaria with a 0.5 g-piece of fresh shrimp meat put in the middle. L. vannamei JUVENILES took 1-3 min to catch food. 100% of L. vannamei consumed food faster than Penaeus merguiensis, Metapenaeus ensis, and Metapenaeus brevicornis. Even if L. vannamei was not first to reach food, fought for it. 80% L. vannamei consumed food faster than (hatchery-reared) Penaeus monodon. In some cases, L. vannamei consumed native opponent afterwards 4.
• For feeding and vision → D7.

• FARM/LAB, JUVENILES-ADULTS: undeliberately hurt each other with rostrums during food competition under high density conditions causing wounds in the carapace 43.
• For food competition, survival, and particle size → D2.

• LAB, ADULTS: in black polyethylene tanks at density of 5.3 IND/m² and restricted amount of food, ADULTS were observed for three days. In all-female condition, large females with higher number of feeding events (12.3 versus 4.7) and higher total feeding time (79.6 min versus 46.8 min) than small females; no difference in length per feeding event. In all-male condition, large males with higher length per feeding event (18.8 versus 10.6 min) and higher total feeding time (74.9 versus 58.4 min) than small males; tendency of higher number of feeding events (6.7 versus 4.3). In condition with random selection of females and males, males with higher total feeding time (71.0 versus 53.4 min) than females; tendency of higher number of feeding events (7.0 versus 5.7) and higher length per feeding event (13.4 versus 10.2 min) for males than females. In condition with males and females of equal size, males with higher number of feeding events (10.7 versus 7.0) and higher total feeding time (96.4 versus 26.8 min) than females; tendency of higher length per feeding event (10.8 versus 9.2 min) for males than for females. Results indicate that difference in growth of males and females (→ D8) is not due to more aggressive female feeding but maybe higher swimming activity in males and/or better food conversion in females 15.

• Feeding and temperature:
  • LAB, JUVENILES: after 48 days, decreasing food intake with decreasing temperatures from 13.7-14.5%/d at 30 °C to 7.7-8.8%/d at 20 °C 44.
• Feeding and salinity fluctuation:
  • LAB, JUVENILES: after 48 days, at 20-30 °C, no influence of salinity fluctuation (±0 to ±15 ppt) around 20 ppt on food intake 44.
• Feeding and moulting cycle:
  • LAB, JUVENILESno or decreased feeding during initial 1.5-3 days and final 14-21 days of moulting cycle. No or weak activity during intitial 1.5-3 days 45.

• Daily rhythm: nocturnal:
  • WILD/LAB, POST-LARVAE-JUVENILES: in 144 L aquaria with 5-6 cm fine sand substrate, JUVENILES of 100-150 mm burrowed during the day (white fluorescent light), from ca 06:00 h on, and emerged at night (dim red light) at ca 18:00-19:00 h. JUVENILES of 80-89 mm regularly burrowed but not in the same clearly defined rhythm. Among POST-LARVAE of 50-59 mm, seldom burrowing, presumably to meet increased energy – and therefore foraging – needs. Little to no burrowing in any size group under continuous dim red light over five days 12.
  • LAB: in 30 L glass aquaria (50 x 30 x 40 cm), JUVENILES of average 7.6 g were held under 12 h light (57 lux), 12 h dark (1 lux red light) with light phase either at 07:00-19:00 or 19:00-07:00 and random feeding only during the light phase. During 10 days, no swimming activity in any hour of the light phase but only during hours of the dark phase. Also, tendency of more inactivity (total absence of locomotion) during light than dark phase. No difference in average exploration of substrate in light and dark phases, but more exploration during 5-9 hours after beginning of light phase than during other hours in light and dark phase. Constant cleaning activity during light and dark phase 16.
• Nocturnal activity: → Daily rhythm.
• Phototaxis: no data found yet.

• Direct effect:
  • LAB, JUVENILES: after 50 days in 35 L glass aquaria with either incandescent lamp, cool white fluorescent lamp, or metal halide lamp hung 60-80 cm above water and shining only day or day and night, no difference in final weights (4.5-6.2 g) and no difference to darkness in control condition. Tendency of best growth under metal halide lamp emitting 2,500 lux shining only day, probably due to large infrared composition in spectrum aiding growth 46.
  • LAB, JUVENILES: in 850 L circular fiberglass tanks (bottom 1 m²), BIOFLOC system with zero water exchange, light source emitting 10,000 lux at water surface. After 40 days, higher final weight in density 300 IND/m³ under 24 h light condition than 24 h dark condition (10.4 g versus 9.1 g); "12 h light and 12 h dark" in between (9.7 g). Probably due to higher chlorophyll-a level in 24 h light condition (0.17 mg/L versus "12 h light and 12 h dark": 0.07 mg/L, 24 h dark: 0.05 mg/L) serving as additional food source. Effect not observable before day 28, indicating the influence of other factors than light. Tendency of lower survival in "12 h light and 12 h dark" and 24 h dark conditions (86.8% versus 97.4%) compared to 24 h light condition 47.
  • LAB, JUVENILES: lights with different intensities hung 60-80 cm above 35 L glass aquaria, shining with strong intensity for six days, abruptly changing to low 60 lux intensity for two days and repeating the cycle. After 45 days, lowest moulting frequency under periodic abrupt changing light intensity from 6,000 to 60 lux (4.56%/d versus 6.22-7.40%/d) compared to change from 600, 1,500, or 3,000 to 60 lux or constant 60 lux intensity. Lowest wet gain under periodic abrupt changing light intensity from 6,000 to 60 lux and under constant 60 lux despite identical feed intake in all conditions. Highest wet gain under periodic abrupt changing light intensity from 1,500 to 60 lux (105.12% versus 88.16-99.75%) 48.
• No effect:
  • LAB: after three weeks at stocking density 6 IND/L, no difference in final weight of 1.0 cm total length POST-LARVAE under 24 h dark, 24 h light, "12 h light and 12 h dark" condition (average 1,368 lux) 49.

• Light intensity preference: no data found yet.
• Light intensity and body colour:
  • LAB, JUVENILES: after 50 days in 35 L glass aquaria with either incandescent lamp, cool white fluorescent lamp, or metal halide lamp hung 60-80 cm above water, highest free astaxanthin concentration (controlling body colour) comparable to JUVENILES in the wild under fluorescent light emitting 210 lux and shining day and night and metal halide lamp emitting 2,500 lux shining only day. Lowest free astaxanthin concentration under a) incandescent light emitting 18 lux regardless of shining length, b) complete darkness, and c) incandescent light emitting 450 lux shining only day, indicating that astaxanthin could accumulate as protection against damage from intense light to otherwise transparent bodies 46.

• LAB, POST-LARVAE-ADULTS: reaction to areas with stark light contrasts. In 10 cm water body, light source 10-60 lux from above, opaque filter plate of PVC-like material with 0.2-2 cm perforations placed 4-9 cm into water provided bright and dark areas. Individuals moved to predetermined place and hid beneath light filter. In 10 stacked culture layers, corresponding to 3.9-22 kg/m² stocking density as individuals grew, survival 97.5-100%, indicating little cannibalism of moulting individuals by non-moulting ones. For other methods to enable bright and dark contrast effect directly via light or indirectly through reflection via painted figures, protrusions, filtrations → 50.

• Standard temperature range:
  • Observations WILD, POST-LARVAE-SUB-ADULTS: 22.9-36.8 °C: Carretas-Pereyra coastal system on Gulf of Tehuantepec, Pacific, Mexico 14, 26-34.4 °C: Bangpakong river, Thailand (introduced) 2.
  • Observations WILD, JUVENILES: 21 °C: Azucena mangrove (Tabasco) at Gulf of Mexico, Atlantic, Mexico (introduced) 3, 25°C: Sánchez Magallanes (Tabasco) at Gulf of Mexico, Atlantic, Mexico (introduced) 3, 25-37 °C surface temperature: Mar Muerto lagoon system at Gulf of Tehuantepec, Pacific, Mexico 13.
  • Observations WILD, ADULTS: 30.5 °C: Gulf of California, Pacific 17.
• Temperature preference:
  • LAB, ADULTS: in a horizontally placed PVC pipe 400 cm long, 20 cm in diameter, hot water (40 °C) was introduced at one end, cold water (10 °C) at the other. At 35 ppt, ADULTS preferrably moved to segment with average 26.2 °C (day: 26.2 °C, night: 25.6 °C), regardless of previously acclimated-to temperature (20, 23, 26, 29 and 32 °C) 51.
• For temperature and swimming speed → D9.

• Lower lethal limit: ca 12 °C:
  • LAB, POST-LARVAE: in groups of 10 in 140 L plastic containers and at 40 ppt, critical thermal minima were determined when individual did not escape when touched with a glass rod and laid on its side. Critical thermal minima at cooling rate of 0.5 °C/min decreased with lower acclimation temperature: from 12.3 °C when previously acclimated to 30 °C to 8.9-9.3 °C when previously acclimated to 15 or 20 °C. Even more at lower cooling rate 1 °C/h: from 11 °C at acclimation temperature 30 °C to 7.8 °C at acclimation temperature 15 °C. POST-LARVAE started to fall to their sides at 9.5-9.8 °C, though. 95-100% recovery rate after removing individuals from test temperatures and returning to acclimation temperatures. To prevent mortalities, best not let temperature drop below 12 °C 52.
  • LAB, JUVENILES: in groups of 10 in 140 L plastic containers and at 40 ppt, critical thermal minima were determined when individual did not escape when touched with a glass rod and laid on its side. Critical thermal minima at cooling rate of 1 °C/h decreased with lower acclimation temperature: from 10.2-10.8 °C when acclimated to 25 or 30 °C to 7.5 °C when acclimated to 15 °C. JUVENILES started to fall to their sides at 9.5-9.8 °C, though. 95-100% recovery rate after removing individuals from test temperatures and returning to acclimation temperatures. To prevent mortalities, best not let temperature drop below 12 °C 52.
• Upper lethal limit: 34-42 °C:
  • LAB, POST-LARVAE-JUVENILES: in groups of 10 in 140 L plastic containers and at 40 ppt, critical thermal maxima were determined when individual did not escape when touched with a glass rod and laid on its side. Critical thermal maxima at heating rate of 0.5 °C/min increased with higher acclimation temperature: from 35.7-35.9 °C when acclimated to 15 °C to 42-42.2 °C when acclimated to 30 °C. Overall flexing began at 34 °C and 39°C, though. 60-90% and recovery rate after removing individuals from test temperatures and returning to acclimation temperatures 52.
  • LAB, ADULTS: in groups of two in 40 L aquaria at heating rate 1 °C/min and 35 ppt, critical thermal maxima were determined when individual could not flip from lying on back to upright posture or remained reclined at 90°. Critical thermal maxima increased with higher acclimation temperature: from around 36 °C when previously acclimated to 20 °C to around 42 °C when acclimated to 32 °C 51.

• Temperature must exceed: no data found yet.
• Temperature must not go beyond: no data found yet.
• Optimal temperature for growth: ca 28-30 °C:
  • LAB: POST-LARVAE gained more weight (0.9-1.1 g versus 0.3-0.6 g) in 30 than 16 °C water, irrespective of gradually acclimated salinities (2-16 ppt) 53.
  • LAB, JUVENILES: at 20 ppt, higher final weight after 48 days at 30 °C (3.4 g versus 1.8 g versus 1.3 g) than 25 °C or 20 °C 44.
  • LAB, JUVENILES: at 2 and 4 ppt salinity after 21 days, higher weight gain (114-147.6% versus 24.1-54.1%) and higher survival (85-92% versus 48-50%) at 24 °C than 20 °C water temperature. After 28 days, higher weight gain at 28 °C (766.6-1,117.5%) than at 24 °C (348.9-530.5%) than at 20 °C (12.6-25.9%) 54.
• Temperature and moulting frequency:
  • LAB, JUVENILES: at 20 ppt, higher moulting frequency at 25-30 °C than at 20 °C (9.8-11.5%/d versus 7.6%) 44.
• For temperature and feeding → D10.

• Dissolved oxygen range:
  • Observations WILD, POST-LARVAE-SUB-ADULTS: 0.7-13.3 mg/L: Bangpakong river, Thailand (introduced) 2.
• Oxygen consumption:
  • LAB, ADULTS: oxygen consumption increased from around 40 mg O2/kg/h at acclimation temperature 20 °C to 90.0 mg O2/kg/h at 32 °C 51.

• Salinity tolerance:
  • Observations EURYHALINE: 54 25.
  • Natural and introduced distribution in seawater D11 D12, but adjusts to brackish water as well D13.
• Standard salinity range:
  • Observations WILD: POST-LARVAE of 50-150 mm: 16-35 ppt: Caimanero-Huizache lagoon system, Pacific coast, Mexico 12.
  • Observations WILD, POST-LARVAE-SUB-ADULTS: 0-32.8 ppt, with averages 0-4 ppt in July-November, 5-17 ppt in June and December-February, 18-29 ppt in March-May: Carretas-Pereyra coastal system on Gulf of Tehuantepec, Pacific, Mexico 14, 1.6-30.2 ppt during dry season (December-May), ca 0 ppt during rainy season (June-November): Bangpakong river, Thailand (introduced) 2.
  • Observations WILD, JUVENILES: 5-85 ppt surface salinity (ca 30-85 ppt in dry season, January-May, ca 5-80 ppt in rainy season June-August): Mar Muerto lagoon system at Gulf of Tehuantepec, Pacific, Mexico 13, 11 ppt: Azucena mangrove (Tabasco) at Gulf of Mexico, Atlantic, Mexico (introduced) 3, 24 ppt: Sánchez Magallanes (Tabasco) at Gulf of Mexico, Atlantic, Mexico (introduced) 3.
  • Observations WILD, ADULTS: 31 ppt: Gulf of California, Pacific 17.
• For salinity and...
  ...swimming speed → D9,
  ...migration → D13.

• Lower and upper lethal limits:
  • LAB, POST-LARVAE: 8 day-old POST-LARVAE survival <20% after 120 hours when directly transferred from 32 ppt to ≤8 ppt in 16 °C water. Survival >80% after 120 hours at 16-32 ppt. 22 day-old POST-LARVAE survival <50% after 120 hours at 2 ppt, <60% at 4 ppt, >70% at 8-32 ppt. Gradually acclimating (2 ppt/d) 22 day-old POST-LARVAE with mixed result: no influence on survival at 4 and 8 ppt, higher survival at 2 ppt, lower at 16 ppt. Gradually acclimating in water with 28-30 °C did not influence survival compared to 16 °C 53.
  • LAB, POST-LARVAE: 10 day-old POST-LARVAE survival ≤50% after 48 hours when gradually (4 ppt/h) acclimated from 23-24 ppt to ≤2 ppt in 26 °C water. Survival 80-100% after 48 hours at salinities 4-12 ppt. 15 and 20 day-old POST-LARVAE survival <10% after 48 hours at 0 ppt, survival 82-100% at 1-12 ppt. Acclimation rate (19.4%, 24.6%, 46.7%) of salinity reduction did not influence survival 55.
  • LAB, POST-LARVAE: 15 day-old POST-LARVAE survival 16% after 48 hours when directly transferred from 30 to 1 ppt in 28 °C water, 53% at 5 ppt. Survival 63-80% when gradually transferred (25-29, 8-9, 4 ppt/d) to 1 ppt, 94-96% at 5 ppt. 20 day-old POST-LARVAE survival <50% after 10 days when directly transferred from 30 to <1 ppt. Survival >85% at 1.5, 2, and 5 ppt. JUVENILES survival 65% at 0 ppt, 77% at 0.5 ppt, >90% at 0.75-5 ppt. POST-LARVAE and JUVENILES survival highest (96% versus 86% versus 46% versus 45%) after 12 weeks when directly transferred from (acclimated to) 5 ppt to a combination of low salinity (5 ppt) and high hardness (4,000 ppm) compared to normal seawater (30 ppt, 6,000 ppm) or other low salinity water (2 ppt and 1,300 ppm, 1.5 ppt and 450 ppm) 56.
  • LAB, LARVAE-ADULTS: increasing tolerance with increasing age, then again decreasing in ADULTS 25:
    a) 5 hour survival: NAUPLII, PROTOZOEA, MYSIS survival <20% after 5 hours when directly transferred from 32 to ≤10 and 60 ppt in 25 °C water. Survival 50-100% at salinities 20, 32, and 45 ppt. 1-3 day-old POST-LARVAE survival 0% at 5 and 60 ppt, 0, 60, 90% at 10 ppt, ca 100% at 20-45 ppt. 4-7 day-old POST-LARVAE survival 0% at 60 ppt, >60% at 5 ppt, 80-100% at 20-45 ppt. 12-19 day-old POST-LARVAE <10% survival at 60 ppt, >95% at 5-45 ppt. 22-27 day-old POST-LARVAE <20% survival at 60 ppt, >95% at 5-45 ppt. JUVENILES <80% survival at 60 ppt, 100% at 5-45 ppt. ADULTS 100% survival at salinities from 5-60 ppt.
    b) 48 hour survival: PROTOZOEA survival >80% at 20-32 ppt, <50% at 45 ppt. MYSIS survival <50% at 10-20 ppt, >80% at 32-45 ppt. 2-3 day-old POST-LARVAE survival <50% at 10 and 45 ppt, >80% at 20 ppt, <80% at 32 ppt. 4-5 day-old POST-LARVAE survival <60% at 5 and 45 ppt, <80% at 10 and 32 ppt, ca 80% at 20 ppt. 7-27 day-old POST-LARVAE survival >80% at 5 and 45 ppt (except 7 day-old POST-LARVAE survival 50% at 5 ppt), >90% at 10-32 ppt, <20% at 60 ppt. JUVENILES survival >95% at 5-45 ppt, <50% at 60 ppt. ADULTS survival >80% at 10-45 ppt, 0% at 5 and 60 ppt.
• Salinity change and stress:
  • LAB, 1-7 day-old POST-LARVAE: increased hyperactivity and cannibalism after direct transfer from 32 to 45 ppt 25.

• Salinity and growth:
  • LAB, POST-LARVAE-JUVENILES: best growth after 12 weeks in 28 °C water when directly transferred from (acclimated to) 5 ppt to a combination of low salinity (5 ppt) and high hardness (4,000 ppm) compared to normal seawater (30 ppt, 6,000 ppm) or other low salinity water (2 ppt and 1,300 ppm, 1.5 ppt and 450 ppm) 56.
  • LAB, JUVENILES: at 20 and 24 °C water temperature, after 21 days, higher weight gain at 4 than 2 ppt (54.1-147.6% versus 24.1-114.0%). At 20 °C, after 28 days, higher weight gain at 2, 8, and 16 ppt than 32 ppt (16.0-25.9% versus 12.6%), lower survival at 2 ppt than 8, 16, and 32 ppt (50% versus 80-97%). At 24 °C, tendency of higher weight gain at 32 ppt than 2, 8, or 16 ppt after 28 days (530.5% versus 348.9-454.2%) and 56 days (1,880.5% versus 1,525.6-1,795.2%), no difference in survival (98-100%). At 28 °C, higher weight gain (1,117.5% versus 766.6-873.8%) at 48 ppt than <4 ppt after 28 days and than <16 ppt after 56 days (4,240.6% versus 2,738.1-3,471.6%). Lower survival after 28 days (77% versus 90-98%) only at 1 ppt than 2-48 ppt 54.
• Salinity fluctuation and growth:
  • LAB: JUVENILES in 35 L aquaria (45 cm x 25 cm x 30 cm) were subjected to salinity fluctuation of ±5, ±10, or ±15 ppt around 20 ppt. One cycle: four days at 20 ppt, decrease by 5/10/15 ppt within one day, four days at final lower salinity, increase by 5/10/15 ppt within one day, four days at 20 ppt, increase by 5/10/15 ppt within one day, four days at final upper salinity, decrease by 5/10/15 ppt within one day. After 48 days, no influence of salinity fluctuation on growth at 20 °C. At 25 °C, tendency of higher final weight at fluctuation ±5 and ±10 (2.1-2.3 g versus 1.6-1.8 g) than ±0 and ±15. At 30 °C, higher final weight at fluctuation ±5 and ±10 (3.8-4.1 g versus 3.4 versus 2.9 g) than at fluctuation ±0 and ±15 ppt. Also, lower survival at fluctuation ±15 ppt (62.5-93.75% versus 87.5-100%) than at other fluctuations, decreasing with increasing temperature 44.
• Salinity fluctuation and moulting frequency:
  • LAB, JUVENILES: after 48 days, no influence of salinity fluctuation on moulting frequency at 30 °C. At 25 °C, tendency of higher moulting frequency at fluctuation ±10 and ±15 ppt (11-12.5%/d versus 9.8-10.3%/d) than ±0 and ±5 ppt. At 20 °C, higher moulting frequency at ±10 and ±15 ppt (9.1-9.3%/d versus 7.6-7.9%/d) than at fluctuation ±0 and ±5 ppt 44.
• For salinity fluctuation and feeding → D10.

• Standard pH range:
  • Observations WILD, POST-LARVAE-SUB-ADULTS: pH 6.0-8.0: Bangpakong river, Thailand (introduced) 2.
• pH preference: no data found yet.

• Swimming type: no data found yet.
• Ontogenesis of swimming behaviour:
  • LAB: MYSIS kept body in vertical position with head down. POST-LARVAE kept body horizontally via five pairs of pleopods as swimming organs 17.

• Absolute swimming speed:
  • LAB: at 20 °C and 32 ppt, JUVENILES of 8.3-8.8 cm total length maintained position in swimming channel of 40 x 15 x 14 cm (length x width x height) at current velocities of 5.4-11.5 cm/s. Swimming endurance decreased from around 8,000 s at 5.4 cm/s to around 1,000 s at 11.5 cm/s before JUVENILES fell against downstream screen from fatigue 18.
• Relative swimming speed:
  • LAB, JUVENILES: at 24.7 °C and 31 ppt, increasing absolute and decreasing relative critical swimming speed with increasing body length (from the base of the eye notch to the posterior end of the telson): e.g., 28.4 cm/s or 5.2 body lengths/s at 5.5 cm body length versus 40.8 cm/s or 4.1 body lengths/s at 10.0 cm 19.
• Swimming speed and temperature:
  • LAB: JUVENILES in a 100 x 25 x 25 cm (length x width x height) swimming channel underwent critical swimming speed test: were trained for 10 min at a speed of 23.0 cm/s. Then water velocity was increased by 4 cm/s every 20 min until JUVENILES fell against downstream screen from fatigue. At 31 ppt, for JUVENILES of 9.7-10.0 cm body length (from the base of the eye notch to the posterior end of the telson), the higher the temperature the higher the absolute (e.g., 27.7 cm/s at 17 °C versus 46.9 cm/s at 29 °C) and relative critical swimming speed (e.g., 2.9 body lengths/s at 17 °C versus 4.7 body lengths/s at 29 °C) 19.
• Swimming speed and salinity:
  • LAB, JUVENILES: at 24.6 °C, lower absolute (38 cm/s versus 40.8-43.4 cm/s) and relative critical swimming speed (3.8 body lengths/s versus 4.1-4.4 body lengths/s) at 20 ppt than at 25, 30, 35, or 40 ppt 19.

• Depth range in the wild:
  • WILD, JUVENILES: highest abundance in protected areas (so called "tablón") <1 m within Mar Muerto lagoon system at Gulf of Tehuantepec, Pacific, Mexico 13.
  • Observations WILD, ADULTS: 10-14 m: Gulf of California, Pacific 17, average 20 m: off the mouths of Presidio and Baluarte rivers, Pacific, Mexico 28.
• Depth in cages or tanks:
  • LAB, ADULTS: females preferred sitting at the bottom of a tank with 1.5 m diameter and 0.45 m depth instead of swimming 24.
• 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.

• ADULTS live 28 14 and spawn in the open ocean 17.
• POST-LARVAE migrate inshore to spend JUVENILES and SUB-ADULTS stages in coastal estuaries, lagoons 12 13 14, or mangrove areas 3:
  • Observations lagoon abundance WILD, POST-LARVAE: main abundance in November-May (dry season with higher salinity water → D4), decreasing June-October: Carretas-Pereyra coastal system on Gulf of Tehuantepec, Pacific, Mexico 14.
  • Observations lagoon abundance WILD, JUVENILES-SUB-ADULTS: main abundance of JUVENILES in March-May (dry season with higher salinity water → D4 D14), before fishery set in in June: Mar Muerto lagoon system at Gulf of Tehuantepec, Pacific, Mexico 13, main abundance of JUVENILES-SUB-ADULTS in April-June: Carretas-Pereyra coastal system on Gulf of Tehuantepec, Pacific, Mexico 14.
• At 2.5-5 months, throughout the year, JUVENILES and SUB-ADULTS migrate offshore for subsequent maturation and reproduction 14:
  • Observations age of emigration WILD, JUVENILES: 2.5-4 months (71-121 days), not specific to a season: Mar Muerto lagoon system at Gulf of Tehuantepec, Pacific, Mexico 13, 5 months 14.

• Observations time from fertilisation until hatching LAB: ca 13 h 17.
• Observations size LAB: 0.26-0.29 mm 17.
• Observations weight: no data found yet.

• Nauplii: hatching to ca 38 h, 0.3 mm:
  • Observations age LAB: ca 38 h 17.
  • Observations size LAB: initial body length: 0.31-0.34 mm, body width: 0.19 mm, six nauplii stages with final body length: 0.42-0.46 mm, body width: 0.22 mm 17.
  • Observations weight: no data found yet.
• Protozoea: from ca 38 h on, 0.8-2.0 mm:
  • Observations age: → Nauplii.
  • LAB: start of exogenous feeding, development of stalked eyes 17.
  • Observations size LAB: initial body length: 0.78-0.94 mm, three protozoea stages with final body length: 1.88-2.06 mm 17.
  • Observations weight: no data found yet.
• Mysis: fully shaped, 2.7-3.8 mm:
  • LAB: body shape resembles that of ADULTS 17.
  • Observations size LAB: initial body length: 2.65-2.93 mm, three mysis stages with final body length: 3.68-3.80 mm 17.
  • Observations weight: no data found yet.

• Post-larvae: 5-80 days, 4-74 mm, 1.5-2,200 mg:
  • Observations size WILD: 36.8 mm 14.
  • Observations age, size, and weight FARM: 10-15 days: 10-15 mm, 0.1-0.3 g 4.
  • Observations age, size, and weight LAB: initial body length: 4.00-4.24 mm (for details → 17), 5-27 days 53, 10 days: 1.5-2.2 mg, 15 days: 3.6-5.3 mg, 20 days: 3.8-14.5 mg 55, 8 days: 2 mg 57, 15.5 g 58, 4-80 days 59, 14 mg 56, 11.1 g 42, 5.5 cm, 1.2 g 52, 3 mg 60.
  • LAB: 12-16 days: 15-18 mm, 80-130 mg, beginning of organogenesis of the gonad and a) oviduct in females, b) vas deferens in males, 32-44 days: 25-35 mm, 180-280 mg, beginning of external sex differentiation, 44-48 days: 45-50 mm, 500-600 mg, 48-52 days: beginning of organogenesis of the androgenic gland, 52-72 days: 70-74 mm, 1.8-2.2 g, differentiation into female and male gonad 59.
• Juveniles: 72-150 days, 4-17.2 cm, 0.06-20.6 g:
  • Observations age, size, and weight WILD: range 40-110 mm (average 59.4-66.3 mm) and 1.8-2.5 g at 72-84 days, 75.7-79.5 mm and 3.6-4.2 g at 100-106 days, 88.1 mm and 5.6 g at 121 days 13, 36.8-134.7 mm, the latter at 5 months 14, 5.5-17.2 cm 4.
  • Observations size and weight FARM: 1.12 g, 3 g 61, 5-7 cm, 1.0-2.0 g 4, 15 mg, 2.8 g 62.
  • Observations age, size, and weight LAB: 8-12 g 41, 0.9 g 40, 2 months, 7.6 g 16, 1 g 56, 20.6 g 63, 10.6 g, 11 cm 52, 0.4 g, <2 months 64, 0.8 g 44, 9.7-10.4 cm body length (from the base of the eye notch to the posterior end of the telson), 10.5-12.2 g 19, 5.6 g 30, 3.3 g 47, 2.7 g 48, 0.06-0.32 g 54, 2.5 g 31, 1.7 g 25.
  • Individuals considered juveniles when body weight >1 g 65↶25.
• Sub-adults: 4-6 months, >7.2 cm, 19.4 g:
  • Observations size WILD: >71.6 mm 14.
  • Observations age and weight LAB: 19.4 g, 4-6 months 64.
• Sexual maturity: males: 6.5 months, 18-22 g, females: 8.5 months, 20.7-28.1 g:
  • FARM: in 440 m² concrete growout ponds at 2-3 ppt and 28 °C 57:
    1) Maturation in males: translucent males with small whitish ampoule without spermatophore from ca 5.5 months after POST-LARVAE (0 days) on, most frequent until 6.5 months. Males with developing spermatophore visible as white line inside ampoule (average 1.8 million sperms) most frequent around 6.5-8 months after POST-LARVAE (0 days) and ca 18-22 g. Males with larger white spermatophore inside ampoule (average 10.1 million sperms) from ca 8.5 months and 25 g on. Males with melanised (brownish-black) spermatophore (average 9 million sperms) most frequent at 9-9.5 months after POST-LARVAE (0 days) and ca 25 g.
    2) Maturation in females: at 8.5 months from POST-LARVAE (0 days) and 20.7-28.1 g, vitellogenin gene expression in ovaries only (not in hepatopancreas). Colour of ovaries changed from transparent to opaque.
  • FARM: in hatcheries in Thailand, males sexually mature at 11 months after POST-LARVAE (15 days) at average 15.4 cm, average 34.3 g, females of similar weight and size with 50% oocytes in ovaries 2.

• Observations weight WILD: 28.2-45.6 g 28.
• Observations age and weight FARM: around 9.5 months after POST-LARVAE (0 days), 26.8-29.9 g 57, spawners in commercial hatcheries in Thailand: 50-65 g, >1 year old 2.
• Observations age, size, and weight LAB: 161-178 mm and 35.4-40.7 g 23, 40-60 g 20, 10-12 months, 37.3-40.9 g 27, female 46.8 g 57, 14 months, 40 g 24, 15.4-28.5 g 28, 190 mm 66, 18-20 g 51, mean 33.4-57.7 g 15, females: average 33.5-35.1 g 22, 31 g 25.

• Natural growth rate:
  • WILD, JUVENILES: growth rates estimated at 0.2-1.2 mm/d, average 0.4 mm/d in dry season (with higher salinity water → D14), 0.6 mm/d in rainy season (Mar Muerto lagoon system at Gulf of Tehuantepec, Pacific, Mexico 13).
  • WILD, POST-LARVAE-SUB-ADULTS: growth rates estimated at 0.3-1.3 mm/d (Carretas-Pereyra coastal system on Gulf of Tehuantepec, Pacific, Mexico 14).
• Moulting: moults throughout life, duration of moulting cycle depending on life stage:
  • LAB, NAUPLII: duration of moulting cycle: 4-5 h 17.
  • LAB, JUVENILES: duration of moulting cycle: 27-40 days. For different stages → 45.
  • LAB, JUVENILES: shorter moulting cycle in unilaterally (17 days) and even shorter in bilaterally (10 days) ablated JUVENILES compared to control (24 days) probably due to decreased levels of moult-inhibiting hormones following ablation 58.

• Observations bimodal pattern LAB, ADULTS: males: 161 mm and 35.4 g, females: 178 mm and 40.7 g 23; males 38.7 g, females 48.3 g 15.
• Beginning of noticeable size difference:
  • FARM, ADULTS: in 440 m² concrete growout ponds at 2-3 ppt and 28 °C, females grew heavier than males, the difference noticeable from 6.5 months and ca 20 g on. At around 9.5 months after POST-LARVAE (0 days), females 29.9 g versus males 26.8 g 57.
• For growth, sex, and food competition → D15.

• Growth and lunar cycle:
  • FARM, JUVENILES: tendency of greater weight increment per week at full and new moon than first or last quarters. Only in Ecuadorian ponds with JUVENILES caught as larvae from the wild, not in Colombian ponds with laboratory-reared JUVENILES, indicating an external zeitgeber 67.

• Nest building and substrate: no data found yet.
• Nest building and water velocity: no data found yet.
• Nest building and water depth: no data found yet.
• Nest building: no data found yet.
• For mating and female spawning → D21.

• Courtship sequence:
  • LAB, ADULTS:
    1) Male approached female from behind, walking on tank bottom 20 21.
    2) Male lowered head under female's tail 20 21.
    3) Female swam away (2-3 m in distance 20, lasting several seconds to 3 min 21), male followed parallely on lower horizontal plane 20 21.
    4) Male probed female's THELYCUM ventrally with antennules for 1-60 s 21.
    5) Male grasped her for 1-20 s (1-2 s 20, 1-20 s 21) by turning his ventral side up, probing female's THELYCUM with antennules for 1-60 s 21. Usually face-to-face but sometimes also inverted 20. Male body rotated against female's 20-90°. Spermatophore ejected through rapid abdominal contraction that propelled male away from female 21.
  • LAB, ADULTS: male repeated chasing, turning, and grasping 2-3 times if spermatophore transfer missed (in 80%). Continued with other females after successful mating 20.
• Courtship duration: several seconds to several minutes (→ Courtship sequence):
  • Observations LAB, ADULTS: 3-16 s 20.
• Courtship and moulting:
  • LAB, ADULTS: in a 15 m³ tank with 70 cm water level and 1:1 male:female ratio, courtship and mating took place when females were in between moulting 20.
• Courtship and daily rhythm:
  • LAB, ADULTS: in a 15 m³ tank with 70 cm water level and 1:1 male:female ratio, courtship and mating took place in both PHOTOPERIOD and scotoperiod 20.

• Promiscuity:
  • LAB, ADULTS: males continued with other females after successful reproduction 20. Indication of promiscuity?

• Male:female ratio resulting in spawning:
  • Observations FARM, ADULTS: 1:1 27.
  • Observations LAB, ADULTS: 5:4 23, 1:1 20 22, 20 males:3 females 21, 2:1 22.
• Composition of broodstock: no data found yet.

• Spawning sequence:
  • For male spawning sequence or mating respectively → D22.
  • LAB, ADULTS: after successful mating, female swam with spermatophore attached to THELYCUM, spawned within two hours following mating, after which spermatophore came off. Eggs not fertilised if spermatophore accidentally not attached to THELYCUM, indicating sperm-release strictly tied to spermatophore attachment to THELYCUM 20.
  • LAB, ADULTS: mating observed at 19:00-21:00 h, females spawned at midnight 22.
• Spawning duration: no data found yet.

• Spawning and origin:
  • WILD/FARM: ADULTS of two origins – a) 10-12 months old second generation of captive individuals produced from wild spawners and b) wild-caught individuals – were both stocked in 25 m² black fiberglass tanks each, at density of 6-8 IND/m² and 1:1 male:female ratio. After acclimation week, females had eyestalks cut. Wild-caught females mated more frequently at least once during production cycle (88% versus 74%) compared to pond-reared females, more frequently >1 time (74% versus 54%), and more frequently >10 times (11% versus 4%). Wild-caught females mated more frequently per month (1.8-2.1 versus 1.2-1.9 matings/month). Time between matings decreased with increasing frequency of matings from 1-97 d between ablation and first mating to 2-22 d after tenth mating, no difference between wild-caught and pond-reared females. No effect on percentage fertilisation (80.8-91.1%) from spawn 1 to >10 27.

• Number of spawns:
  • Observations WILD/FARM, ADULTS: 1.2-2.1 matings/months when ablated, time between matings decreasing with increasing time since ablation (from 1-97 d between ablation and first mating to 2-22 d after tenth mating) 27.
• Fecundity per spawn:
  • Observations absolute fecundity WILD/FARM, ADULTS: 62,000-100,700 when ablated 27.
  • LAB: ADULTS stocked in April-June (off-season) in 2 m diameter black fibreglass tanks at 9.6 IND/m² stocking density and 1:2 male:female ratio. Mean fecundity per female per spawn: 48,483 eggs (30,000-80,000), mean fertilisation rate: 86.3%, mean hatching rate: 31%. Mean fecundity per female per spawn when unilaterally ablated: 79,778 eggs, increasing to 125,015 eggs (max 219,000) with 1:1 ratio, 5.7 IND/m² 22.
  • Observations relative fecundity: no data found yet.

• Number of spawns:
  • Observations → D23.
• Fecundity per spawn:
  • Observations absolute fecundity WILD/FARM, ADULTS: sperm count per spermatophore 50,000-29,310,000 in wild-caught versus 850,000-11,540,000 in pond-reared males 28.,
  • Observations absolute fecundity WILD/LAB, ADULTS: sperm count 81,800,000 in unilaterally ablated males versus 39,400,000 in bilaterally ablated, 31,900,000 in non-ablated males 23.
  • Observations relative fecundity: no data found yet.
  • For sperm count at different maturation stages → D24.

• Fecundity and origin:
  • WILD/FARM: ADULTS of two origins – a) 10-12 months old second generation of captive individuals produced from wild spawners and b) wild-caught individuals – were both stocked in 25 m² black fiberglass tanks each, at density of 6-8 IND/m² and 1:1 male:female ratio. After acclimation week, females had eyestalks cut. Wild-caught females had more viable spawns (>40% survival; 0.7-1.6 versus 0.6-1.1) and higher number of NAUPLII per spawn (66,400-100,700 versus 62,000-73,900). Pond-reared females had higher fertilisation rate per viable spawn (82.5-88.2% versus 80.7-86.2%) 27.
  • WILD/FARM, ADULTS: larger wild-caught males (36.1 g) with higher spermatophore weight (9.7-80.3 mg versus 1.7-19.5 mg) than smaller pond-reared males (21.4 g). Higher "spermatophore weight:adults weight" ratio in wild-caught males (0.03-0.18% versus 0.01-0.07%). No difference in sperm count per spermatophore due to large variation: 50,000-29,310,000 in wild-caught versus 850,000-11,540,000 in pond-reared males. Higher percentage of normal sperm (spherical body and straight and elongate spike) in pond-reared than wild-caught males (79.8-95.2% versus 14.0-91.5%). Pond-reared males: 9.8% of spermatophores with 70-80% normal sperm, 75% with 80-90%, 15.2% with >90%; wild-caught males: 21.3% of spermatophores with 70-80% normal sperm, 30% with 80-90%, 2.5% with >90%. Abnormal sperm mostly with missing spike and irregular form, seldomly bent or with double spike 28.

• Fecundity and temperature manipulation:
  • LAB: ADULTS stocked in April-June (off-season) in 2 m diameter black fibreglass tanks at 9.6 IND/m² stocking density and 1:2 male:female ratio. One cycle consisted of: water temperature maintained at 28 °C for two days, decreased to 20°C at 2 °C/d, maintained at 20 °C for two days, increased to 28 °C at 2 °C/d. First female spawning on day 25 (control condition on day 26). Lower mean fecundity per female per spawn (28,500 versus 48,483 eggs) and mean hatching rate (10.1 versus 31%) than control females. No difference in mean fertilisation rate (86.3-86.5%) 22.
• Fecundity and hormone treatment:
  • LAB: ADULTS stocked in April-June (off-season) in 2 m diameter black fibreglass tanks at 9.6 IND/m² stocking density and 1:2 male:female ratio. Females injected with serotonin (5-hydroxytryptamine, 5-HT, and creatinine sulfate complex) at dose of 50 µg/g. First female spawning after third injection on day 28 (control condition on day 26). Lower mean fertilisation rate (63.1 versus 86.3%) and lower mean hatching rate (18.5 versus 31%) than control females. No difference in mean fecundity per female per spawn (48,483-60,278 eggs) 22.
• Fecundity and eyestalk ablation in females:
  • LAB: ADULTS stocked in April-June (off-season) in 2 m diameter black fibreglass tanks at 9.6 IND/m² stocking density and 1:2 male:female ratio. Faster ovarian maturation in unilaterally ablated females than hormonally injected, thermally manipulated, or control females but no difference in time of spawning between groups (day 25-28 after beginning of treatment). Higher mean fecundity per female per spawn (79,778 versus 48,483 eggs) but lower hatching rate (8.5 versus 31%) than control females; no difference in mean fertilisation rate (86.3-88.4%). Lowering density to 5.7 IND/m² (3 m diameter black fibreglass tank) and changing male:female ratio to 1:1 yielded no difference in mean fertilisation rate (79.1-86.3%) and mean hatching rate (28.6-31%) compared to control females but higher mean fecundity per female per spawn (125,015 versus 48,483 eggs). Highest fecundity by one female: 219,000 eggs 22.
• Fecundity and eyestalk ablation in males:
  • WILD/LAB: ADULTS, caught wild as JUVENILES four month prior to the experiment, were stocked with unilaterally ablated females in 5:4 male:female ratio. Bilateral ablation condition in males terminated after 56 days due to mortality rate of 85%. After 56-104 days, higher spermatophore weight in unilaterally and bilaterally ablated males (0.08-0.1 g versus 0.05 g) than non-ablated males. Higher gonad weight (0.48 g versus 0.4 g) and gonad index (gonad weight relative to 100% body weight; 1.39 versus 1.07) compared to non-ablated males. Even higher gonad weight (0.89 g) and gonad index (2.33) in bilaterally ablated males. No difference in colour or deterioration of spermatophores in all conditions. Higher sperm count in unilaterally ablated males (81.8 million versus 31.9-39.4 million) than bilaterally ablated or non-ablated males. No difference in viability (90-100%) and abnormality of sperm (<10%) in all conditions 23.
• For ablation and...
  ...pain → D25,
  ...pain treatment → D26,
  ...stress → D27.

• Breeding type: sea spawner:
  • Observations: → D13.
• Nursery grounds:
  • Lagoons are considered nursery grounds: the shallow brackish water excludes many predators, offers higher temperatures D10 D28 D18 and lower salinities D4 D14 than the open sea, as well as abundant prey.

• LAB, JUVENILES-SUB-ADULTS: maximum on relative spectral response magnitudes at 544 nm (green). At and below 400 nm (violet) and at and above 621 nm (orange), on relative spectral response magnitudes less than half of that at 544 nm. Shape of curves for JUVENILES and SUB-ADULTS differ: at 336-544 nm, JUVENILES with lower on relative spectral response magnitudes than SUB-ADULTS, at 568 nm, JUVENILES with higher magnitudes than SUB-ADULTS. Indication of adaptation to habitat in respective developmental stage: estuaries in JUVENILES and clear offshore waters in SUB-ADULTS. At 518-597 nm, JUVENILES with higher off relative spectral response magnitudes than SUB-ADULTS, indicating adaptation to shadows possibly to escape predators. Spectral response curve magnitudes ≤350 nm indicate possible sensitivity to ultraviolet light 64.

• LAB, POST-LARVAE-SUB-ADULTS: at 1 cm total length, complete eye structure with crystalline cone, clear zone (no pigments), rhabdom, fasciculated zone. Eyes adapted to light and dark condition 64 49 (for processes in compound eye during adaptation → 64).
• LAB, JUVENILES-SUB-ADULTS: time of adaptation from 300 lux to darkness: on response magnitude in electroretinogram (i.e., positive deflection) stabilised after 70 min, off response magnitude (i.e., negative deflection) after 80 min in SUB-ADULTS, 80 min and 70 min in JUVENILES. Time interval required for a given light stimulus not to influence the response of a subsequent stimulus: 50 s for on response, 30 s for off response in SUB-ADULTS 64.

• Vision and foraging:
  • LAB: after 30 min, higher ingestion rate (62.0% versus 39.3%) in 0.5 cm POST-LARVAE under light (1,400 lux) than dark condition; no difference in 1.0 and 1.5 cm POST-LARVAE. Results indicate importance of vision for feeding 49.

• LAB, JUVENILES: in 50 cm diameter plastic tanks divided into four compartments with 2 cm coloured sand and walls covered in plastic paper of the same colour, 1 IND/tank was free to move between compartments. No preference on first two days. On day 3, tendency of higher visiting frequency to compartments with yellow and red sand and walls, avoiding compartments with blue and green sand and walls 68.

• LAB, JUVENILES: in 15 L aquaria (40 x 20 x 25 cm) with 2 cm coloured sand and walls covered in plastic paper of the same colour, individually reared JUVENILES showed a tendency of better weight gain and higher food intake after 60 days with red and yellow sand than with blue or green sand, equivalently to natural sand. Probably because JUVENILES could not easily find dark brown food pellets on blue and green substrate 68.

• Olfaction and adaptation:
  • LAB, ADULTS: long living decapods (Sicyonia brevirostris, Panulirus argus, Homarus americanus, Cherax destructor, Pagurus bernhardus, Cancer pagurus) adapt to changing olfactory environments thanks to persistence of neurogenesis 69. Further research needed to determine whether this applies to L. vannamei as well.

• Antennal contacts:
  • LAB, ADULTS: in the snapping shrimp Alpheus angulosus and Alpheus heterochaelis, differences in antennal contacts between sexes, species, and contexts: females of A. angulosus had higher frequency of antenna-to-body contact with males than with females. No such difference in males and neither females nor males of snapping shrimp A. heterochaelis. More antenna-to-body and antenna-to-antenna contacts during competitive (opposite sex) interactions in A. heterochaelis than A. angulosus, probably due to longer antennae in A. heterochaelis. More antenna-to-body and antenna-to-antenna contacts by the intruder during pairings (same sex interactions) in A. heterochaelis. In A. angulosus residents, more contacts with conspecific than heterospecific intruders. Unclear whether acquire tactile and/or chemical information 70. Further research needed to determine whether this applies to L. vannamei as well.
• For antennal contact during courtship → D22.

• Eyestalk enucleation:
  • LAB, ADULTS: females recoiled when their eyestalk was enucleated without anaesthetic 24.

• LAB, ADULTS: females given anaesthetic (Xylocaine-containing 2.5% Lidocaine) before eyestalk enucleation did not recoil in contrast to non-anaesthetised females. Frequency of lateral, erratic, or "spiral" swimming until two hours after eyestalk enucleation decreased (10 versus 12 females), in contrast to untreated individuals, with rubbed-in coagulating agent (Fibrase-Pentosan polysulfate sodium) afterwards; decreased more with applied anaesthetic before ablation (one individual); was absent in females treated with anaesthetic beforehand and coagulating agent afterwards. Onset of feeding after eyestalk enucleation was earlier (10 versus 30 min) with applied coagulating agent afterwards and was immediate with applied anaesthetic beforehand 24.

• Observations FARM: in ponds, built schools personal communication George Chamberlain 2017.

• Observations WILD, JUVENILES: from ca 0.2 IND/m² in January to around 1.4 IND/m² at peak abundance in March-May: Mar Muerto lagoon system at Gulf of Tehuantepec, Pacific, Mexico 13.
• Observations WILD, POST-LARVAE-SUB-ADULTS: average 0.001-0.302 IND/m², higher in rainy season (May-October) than in dry season (November-April), peaks of 3.8-4.9 IND/m² in April and May: Carretas-Pereyra coastal system on Gulf of Tehuantepec, Pacific, Mexico 14.

• For stocking density, stress, and substrate → D16.

• Inverse relation:
  • FARM: 14 day-old POST-LARVAE were stocked at 50-51 IND/m² in 0.8 ha ponds or at 61 IND/m² in 0.9 ha pond, at salinity of 15-19 ppt. After 111 days, no difference in FOOD CONVERSION RATIO (1.34-1.4) and in survival (80-82%) between densities. Tendency of higher final weight at lower 50-51 IND/m² density than at higher density (19.6-21.2 g versus 17.5 g) 71.
  • LAB: in 180 L tanks (0.5 m² bottom), BIOFLOC system with zero water exchange, POST-LARVAE with initial weight 0.003 g stocked at different densities. After nursing for 30 days under similar water parameters, no difference in survival (95.5-96.3%) or FOOD CONVERSION RATIO (1.0-1.1) but higher final weight at 1,500 IND/m² than 3,000 or 4,500 IND/m² stocking density (0.5 g versus 0.3 g). Lower survival (87.6%) and final weight (0.2 g) and FOOD CONVERSION RATIO (1.6) at 6,000 IND/m² than at lower stocking densities. After nursing POST-LARVAE for 35 days in second experiment, again higher final weight at 1,500 IND/m² than 3,000 or 4,500 IND/m² stocking density (0.9 versus 0.6 g). Lowest final weight at 6,000 IND/m² (0.4 g). Reducing stocking density for all conditions to 300 IND/m² and ongrowing for 20 days resulted in no difference in survival (93.3-98.1), final weight (3.6-3.8 g), and FOOD CONVERSION RATIO (1.2-1.5), indicating compensatory growth 60.
  • LAB: in 33 m² raceway covered with clear polyethylene sheeting, JUVENILES stocked at either 200 IND/m² (= 267 IND/m³) or 400 IND/m² (= 533 IND/m³) density.
    Experiment 1: after 86 days, higher weight gain (22.4 versus 17.1 g), growth rate (1.7 versus 1.3 g/week), and survival (80.9 versus 73.3%) in lower than higher density. Higher FOOD CONVERSION RATIO (1.9 versus 1.7) and production (5.1 versus 3.6 kg/m²) in higher density.
    Experiment 2: shared raceways: 40% JUVENILES at density of 100 IND/m² and 60% JUVENILES at 600 IND/m² in same water, separated by mesh barrier – overall density 400 IND/m². 80% JUVENILES at 100 IND/m², 20% at 600 IND/m², overall density 200 IND/m². After five weeks, higher weight in lower 100 IND/m² density (14.8 versus 11.0 g) – regardless of overall density in raceway. Indication that stocking density has higher influence on growth than water quality 61.
  • LAB: JUVENILES were stocked at 15, 25, 35, 45, 55, and 65 IND/m², in outdoor green water 800 L tank system, at salinity of 12.2 ppt. After 10 weeks, no difference in survival between different densities (93.4-100%). Higher weight gain at 35 and 45 IND/m² (11.3-11.8 g versus 10.6 g) than at 55 and 65 IND/m²; highest weight gain at 15 and 25 IND/m² (12.9-13.5 g). Lower FOOD CONVERSION RATIO at 35 and 45 IND/m² (1.4 versus 1.5) than at 55 and 65 IND/m²; lowest FOOD CONVERSION RATIO at 15 IND/m² (1.2) 62.
• No effect:
  • FARM: JUVENILES were stocked at 17, 26, 35, and 45 IND/m², in outdoor 0.1 ha production ponds, at salinity of 10.8-11.5 ppt. After 16 weeks, no difference in weight gain (20.7-25.3 g), FOOD CONVERSION RATIO (1.2-1.5), and survival (58-65.1%) between different stocking densities 62.

• For prevention of cannibalism by stark light contrasts → D3.
• For cannibalism and salinity → D4.

• LAB, ADULTS: males displayed three of mating stages (approaching from behind, crawling under tail, chasing) with other males 20 21 and immature females 20 without mating taking place, indicating that males recognise mature females and chasing here must have other reason – playing? Chasing of males was more frequent (76 versus 33 versus 12 times) than with mature or immature females 20.

• Injection with saline:
  • LAB, ADULTS: lower hatching rate (16.2 versus 31%) from females injected with saline solution than non-handled females. No difference in mean fecundity per female per spawn (48,483-52,000 eggs) and mean fertilisation rate (86.3-95.8%) 22. Not related to saline but stress due to handling? Further research needed.

• Confinement and air exposure:
  • LAB: JUVENILES in outdoor concrete tanks (1.4 x 1.11 m) at density of 20 IND/m² (30 IND/tank). After 38 d, JUVENILES were captured, confined (30 IND/6 L seawater) for 5 min, exposed to air for 10 s. Lower haemocyanin concentration 24 h after stress compared to control (82.3 mg/mL versus 96.2 mg/mL; 98.5 mg/mL at 1 h). Higher total proteins 1 h after stress (135.3 mg/mL versus 106 mg/mL control). Higher lactate and glucose levels in haemolymph 1 h after stress, back to normal 24 h after stress (lactate: 7.2 mg/mL at 1 h versus 5.7 mg/mL control, 5.4 mg/dL at 24 h; glucose: 56.2 mg/mL at 1 h versus 16.7 mg/mL control, 22.4 mg/dL at 24 h). Higher total haemocyte count (immune parameter) 1 h after stress (20.4x10⁶ haemocytes/ml haemolymph at 1 h versus 12.9x10⁶ haemocytes/ml haemolymph control, 13.9x10⁶ haemocytes/ml haemolymph at 24 h) 42.
• Confinement and chasing:
  • LAB: JUVENILES put in 20 L buckets and chased for 1 min. Increase in glucose in hemolymph not before 60 min after handling stress (15 to 45 mg/dL), thereafter decreasing to control levels between 120 and 240 min after stress. Increase in lactate in hemolymph at first sampling time 10 min after stress (3 to 11 mg/dL), with peak at 30 min after stress (17 mg/dL), thereafter decreasing to control levels between 120 and 240 min after stress. Decrease in total proteins in hemolymph not before 120 min after stress (from 87.5-90.5 to 77.7 mg/dL), back to control level at 240 min. The results indicate higher energy demand under stress 63.

• LAB: JUVENILES in concrete outdoor and plastic indoor tanks at density 20-22 IND/m² were stressed each morning by chasing them with a net, putting them in a cloth bag in a bucket with tank water, removing the bag, shaking it for 5 s. No treatment if >30% JUVENILES had moulted during the night to prevent mortalities. After four weeks repeated handling stress, increase in glucose (8.5 mg/dL versus 12.1 mg/dL in indoor tanks; no difference in outdoor tanks) compared to control group lower than expected. Together with missing difference in immunological parameters and most of metabolic parameters probably indication that JUVENILES adapted or acclimated to repeated stressor. Decrease in total lipids (205 mg/dL versus 180 mg/dL in indoor tanks; 297 mg/dL versus 207 mg/dL in outdoor tanks) and total proteins (no difference in indoor tanks; 122 mg/dL versus 111 mg/dL in outdoor tanks) in hemolymph probably indicate depletion due to higher energy demand under stress. Glucose probably better indicator for acute than chronic stress. For the latter, total proteins and total lipids (among others) seem to be better indicators 41.
• LAB: JUVENILES in outdoor concrete tanks (1.4 x 1.1 m) at density of 20 IND/m² (30 IND/tank). Each morning, JUVENILES were captured, confined (30 IND/6 L seawater) for 5 min, exposed to air for 10 s (duration increased by 5 s each week). After 30 days, lower weight than in control (11.6 g versus 12.8 g), higher number of total moults (49 versus 35), lower feed consumption (10.5 g versus 11.3 g), lower haemocyanin and total protein counts (haemocyanin: 73.6 mg/mL versus 82.9 mg/mL; total protein: 106.5 mg/mL versus 112 mg/mL), higher glucose level (23.3 mg/dL versus 14.2 mg/dL) 42.

• Ablation:
  • LAB: JUVENILES in circular tanks (1.5 diameter, 0.8 m high) at 16 IND/tank. Higher mortality in unilaterally (33%) and even higher in bilaterally (68%) ablated JUVENILES compared to control (2%). Higher glucose in unilaterally ablated males (ca 8 mg/dL versus 6 mg/dL) but lower in unilaterally and bilaterally ablated females (ca 5.8 mg/dL versus 8.2 mg/dL) compared to control. Decrease of glucose possibly due to catecholamines or serotonin. Higher lactate levels in females than males (6.5 mg/dL versus 3.5 mg/dL) and higher levels in unilaterally than bilaterally ablated JUVENILES, probably due to decrease in crustacean hyperglycemic hormone following ablation. In triglycerides, no effect of ablation on males but lower triglycerides in uni- and bilaterally ablated females than control females (ca 18-25 mg/dL versus 41 mg/dL); with unilateral ablation also lower than males (ca 18 mg/dL versus 22-30 mg/dL). Lower protein levels compared to control in males (ca 75 mg/mL versus 115 mg/mL) but higher in females (ca 135 mg/mL versus 78 mg/mL). No effect on cholesterol or total hemocyte count 58.
  • LAB, ADULTS: bilaterally ablated males were disoriented and observed swimming in circles at water surface. Mortality rate 85% after 56 days 23 (for details on the study → D30).

• Stunning rules: to minimise pain reactions and enhance welfare before slaughter:
  1. induce insensibility as fast as possible,
  2. prevent recovery from stunning,
  3. monitor effectiveness (observations, neurophysiological measurements) 72.

• Comparison of stunning methods in crabs: further research needed to determine whether this applies to L. vannamei as well.
  • WILD/LAB: rank of stunning methods in wild-caught edible crabs with ascending time until unconsciousness: electrical stunning < 20% KCL solution < heated water < CO2 < freezing < chilling. Details:
    a) Electrical stunning: stunning in aquarium between two steel electrodes: no loss of consciousness at 230 V for 1 s, but loss of appendages. three of four crabs lost responses at 400 V for 1 s. At 530 V for 1 s, three of 10 crabs still showed responses corresponding to anterior ganglion (eyes, antennae, antennules). Complete loss of consciousness at 230 V for 10 s. Four of 10 crabs fully recovered within 20 min. Complete loss of consciousness and no loss of appendages at two-stage stun of 530 V for 1 s, then 170 for 2 min. Two of 10 crabs fully recovered after 60 min, two crabs partly recovered.
    b) Bathing: when bathed in 17% NaCl solution, crabs struggled for 2 min, all reflexes present, albeit weak. In 5% KCl solution, 3 min struggle, abortion of experiment. In 20% KCl solution, no struggle, no reflexes within 1.5 min.
    c) Heated water: after placing crabs from 10-12 °C water into 37-41 °C water, four of five had lost visible responses at observation time 5 min after beginning of treatment, remaing one at second observations time at 10 min. Full recovery within 10 min when returning to 12 °C water. Placing crabs into boiling water is estimated to result in death within 2.5 min.
    d) CO2: in water saturated with CO2, gradually decreasing struggle. After 12 min, two of six crabs still weak responses.
    e) Freezing: after placing crabs in -40 °C freezer, appendages did not show responses after 20 min, eyes, mouth, and antennules after 30-40 min. No recovery when frozen for 60 min. After placing crabs in superchiller (-60 °C) for 3.2 min, no responses. Eye and antennule movements within one minute when returning to 12 °C, but irreparable damage in appendages.
    f) Chilling: after placing crabs on ice (0 °C), five of seven showed weak responses after 100 min. Full recovery within 10 min when returning to 12 °C water 73.
• Crustastun: further research needed to determine whether this applies to L. vannamei as well.
  • LAB: after stunning at average currents of 2.9-9.1 amps for 10 s (crabs) or 5 s (lobsters), edible brown crabs and lobsters lost sensory response to mechanical stimulation of the eyes and never recovered. This indicates that the stun ultimately led to death 74.
  • LAB: after stunning at 110 volt and 2-5 amps for 10 s, the crab Carcinus maenas and the Norway lobster Nephrops norvegicus lost spontaneous activity in the circumoesophageal connectives (main nerves of the central nervous system). N. norvegicus lost spontaneous activity in the ventral nerve cord and abdominal motor roots of the peripheral nervous system. Of 18 C. maenas, two showed sensory responses in the leg nerve and evoked force in the closer muscle of the Propodite/Carpopodite joint of an autotomised (i.e., naturally shed) leg but not in other legs of the same individual. This indicates that the stun halted activity in central and peripheral nervous system. Positioning of limbs in the stunner need further investigation to forego electrical current missing parts of the individuals 75.
  • LAB: after stunning at 110 volt and 2-5 amp for 10 s, no visible movement and no recovery in brown crab Cancer pagurus. In the European lobster Homarus gammarus, slight movements of mouthpart expodites and abdominal pleopods for few seconds before becoming immobile and never recovering. Increase in L-lactate level in haemolymph in C. pagurus (0.8 to 2.6 mM/L) indicates stress. No difference to increase of L-lactate level of individuals handled in the same way (emersion in air, sample taking, placement in stunner for ca 2 min) but not stunned (1.1 to 3.8 mM/L). Increase in L-lactate in H. gammarus (0.8 to 2.3 mM/L) indicates stress. No difference to increase of L-lactate level of handled but not stunned individuals (0.7 to 1.9 mM/L) 76.
  • LAB:
    a) Homarus americanus: after stunning lobsters (H. americanus) for 5 or 10 s, increased electric activity similar to epileptic phase in 21 of 26 individuals for 10 min. Only afterwards, decreasing electric activity. At 5 s stun, sensory transfer resumed weakly at 5 min after stunning, fully restored at 1 h after stunning. Restoration of sensory transfer took longer with 10 s stun. Phenotypically unconscious without reflexes for at least 30-45 min. Most of the individuals regained consciousness; mortality higher at 10 s stun. Transferring crustastunned H. americanus into hot water resulted in increased electric activity with 15-20 s delay compared to non-stunned lobsters. During cooking, 10 of 16 individuals stunned for 5 s, displayed movements of limbs and abdomen; fewer movements when stunned for 10 s. No difference in time until cessation of sensory transfer between crustastunned and non-stunned individuals (ca 150 s).
    b) Astacus leptodactylus: after stunning crayfishes (A. leptodactylus) for 5 or 10 s, increased electric activity similar to epileptic phase in six of 31 individuals for 5 min. Only afterwards, decreasing electric activity. Phenotypically unconscious without reflexes for hours. Sensory transfer resumed weakly at 10-15 min after stunning. Many individuals regained consciousness, suffering severe injuries when stunned for 10 s. Transferring crustastunned A. leptodactylus into hot water resulted in increased electric activity with 10 s delay and weaker amplitude compared to non-stunned crayfishes. Faster cessation of sensory transfer in crustastunned (41.2-46 s versus 79 s) than non-stunned individuals.
    c) Other crabs: after stunning Cancer pagurus for 10 s, three individuals died, another three were unconscious, displaying severe behavioural changes. After stunning Carcinus maenas for 5 s, one died, the remaining nine were unconscious for hours. Stunning for 10 s resulted in five deaths, unconsciousness for hours in the remaining five. Regaining consciousness faster when stunned for 5 s. Severe behavioural changes when stunned for 10 s 77.