A 16‐day experiment was designed to find the best combination of water temperature (27, 30, 33°C) and daily duration of food availability (12, 18, 24 h) for larval tench (Tinca tinca) growth and survival. Larvae with an initial mean size of 5.7 mm total length (TL) and 0.7 mg wet body weight (BW) were stocked at 15 L⁻¹. Larvae were fed in excess with live Artemia nauplii with the period of food availability lasting 12, 18 or 24 h daily. The largest final larval size was recorded at 27 and 30°C in groups fed for 24 h a day (17.7 and 17.9 mm TL, 76.1 and 77.7 mg BW, respectively). The combination of the highest temperature and the longest daily food availability was the only set of conditions under which final larval survival was affected (95.4% survival; 98.7–99.9% under all other conditions). The combination of water temperature of about 28.6°C and continuous food availability is recommended as the optimum combination for rearing T. tinca larvae under controlled conditions. Providing continuous food supply to fish larvae under aquaculture conditions was also advantageous in helping to mitigate the effects of slower growth relative to developmental progress, which can occur at high water temperatures. However, should one wish to limit the daily feeding period to 12 h per day, the use of a water temperature between 27.4 and 27.9°C would be the best solution.

Failing to initiate first feeding during the transition from endogenous nutrition to exogenous feeding will lead to starvation of fish larvae. However, little is known about the mechanism of first feeding selection of fish. Golden mandarin fish larvae (3 d after hatch, 2.05 ± 0.03 mg) were fed with four different foods for 7 d, including the following: M – Megalobrama amblycephala (prey fish larvae as natural food); S – surimi of M. amblycephala; A – Artemia (zooplankton); and MA –mixed M. amblycephala with Artemia (mixed food). Larvae fed with the mixed food achieved an appropriate balance between high survival and good growth through elevating the expression of growth genes (GH, IGF‐I, and IGF‐II) and fatty acid synthesis genes (FAD and ELO). Growth performance of fish fed with MA reared at different salinities (0, 5, and 10 ppt) was examined. The salinity of 5 ppt produced the best growth performance of the three salinity levels tested. Fish larvae adapted to high‐ or low‐salinity environments through increasing the expression of lipolysis genes (HSL, LPL, and HL). Therefore, both food type and salinity affect the growth, survival, and lipometabolism of golden mandarin fish larvae during initial feeding stage, and mixed food and 5 ppt salinity improved its survival and growth.

"Se llevó a cabo un estudio experimental en tres fases, a fin de evaluar el efecto de alimento natural exógeno sobre la respuesta productiva, condición nutricional e inmune, y calidad post cosecha del camarón blanco del pacifico Litopenaeus vannamei, durante la pre-engorda superintensiva. En la primera fase se evaluaron 4 grupos zooplanctónicos (rotiferos, copepodos, Artemia e insectos acuáticos) en 4 densidades, sobre el desempeño productivo y calidad del agua del sistema. En la segunda fase se evaluaron dos medios de cultivo alternativos, uno agrícola y otro acuícola, para la producción de las microalgas Nannochloropisis oculata y Chaetoceros muelleri, las cuales a su vez fueron evaluadas como alimento para Brachionus rotundiformis, Acartia sp. y Calanus pacificus. En la tercera fase se evaluó la sustitución parcial y total del alimento formulado, por alimento natural exógeno (insectos), en la respuesta productiva, condición nutricional e inmune y calidad post cosecha de juveniles de camarón, EI medio a base de fosfato monoamonico fue similar al medio Guillard F2 en la producción de biomasa de N. oculata. Sin embargo, microalgas en un medio con Nutrilake generaron mayor producción de rotíferos (l32.5±6.35 r/ml) y fecundidad (1.25±0.09 huevos/hembra) comparado con el control (111.5±9 .29 r/ml y 0.67±O.12 huevos/hembra, respectivamente). Se encontró que la inclusión de alimento natural exógeno tuvo efectos positivos en la respuesta productiva del camarón y no hubo efectos adversos significativos en la calidad del agua. Camarones alimentados con insectos acuáticos a1canzaron 4.97±0.50 g, con una sobrevivencia de 86.67%. Camarones alimentados con rotíferos alcanzaron 3.40±0.07 g, con una sobrevivencia de 92.42%, mientras que el control alcanzo 2.18±0.31 g, con sobrevivencia de 62.12%. La sustitución parcial al 50% del alimento formulado por insectos acuáticos, resulto en biomasa similares al control, una mejor sobrevivencia y un factor de conversión de alimento significativamente menor (l.44±0.06). Se presentó una tendencia en la que la cantidad de hemocitos se incrementa en función a la cantidad de alimento natural. Los conteos mas bajos de hemocitos y mas altos de profenol oxidasa se presentaron en el tratamiento con alimento artificial. Se estableció que hay una mayor cantidad de proteína y menor cantidad de glucosa, colesterol y triglicéridos en la hemolinfa de camarones que recibieron alimento natural..." | "A three-phase experimental study was conducted to evaluate the effect of natural feed on the production response, nutritional an immune condition, and post harvest quality of white shrimp, Litopenaeus vannamei, in a super intensive nursery phase. In the first phase 4 zooplankton groups (rotifers, copepods, Artemia and aquatic insects) were evaluated at 4 densities, in terms of productive performance of shrimp fed on them, and water quality of the system. In the second pha e, 2 alternative mediums: 1 agricultural and 1 aquaculture fertilizer, were evaluated for the production of the micro algae Nannochloropisis oculata and Chaetoceros muelleri, which were also evaluated as feed for Brachionus rotundiformiss, Acartia sp. and Calanus pacificus. In the third phase, the partial and total replacement of formulated feed by exogenous natural feed (insects) was evaluated in terms of production response, nutritional and immune condition and post harvest quality of shrimp. The use of mono ammonic phosphate medium for the production of N. oculata generated similar results to the use of Guillard F2. Microalgae in a Nutrilake fertilized system produced higher number of rotifers (132.5±6.35 r/ml) and fecundity (1.25±0.09 eggs/female) when compared with the control (1 11.5±9.29 r/ml y 0.67±0.12 eggs/female, respectively). Inclusion of natural exogenous food had a positive response in terms of production, with no apparent negative effects in terms of water quality. Shrimp fed with aquatic insects attained a final test weight of 4.97±0.50 g, and survival of 86.67%. Rotifer fed shrimp had a mean final weight of 3.40±0.07 g, and a survival of 92.42%. Mean [mal weight for control shrimp was 2.18±0.31 g (survival = 62.12%). A 50% formulated feed substitution for aquatic insects resulted in a similar final biomass to the control, better survival and a significantly lower food conversion rate (l.44±0.06). Hems cite count increased as the level of natural feed increased in the treatments. This is a reflection of the immune state of the organism. Low hem cite and high prophenol oxidase levels were present in the control (artificial feed) treatment. There was a higher protein and lower glucose, cholesterol and triglyceride levels in the hem lymph of shrimp receiving natural exogenous feed..."

Pós-Larvas do camarão Litopenaeus vannamei, na fase de PL9-10 e PL25-26 foram aclimatadas à água doce (0,0 ‰), objetivando promover cultivos em regiões interioranas. Para isso, foram realizados dois experimentos conduzidos em aquários com capacidade útil de 44 litros e densidade de estocagem de 11,36 pós-larvas/L. No experimento 1, foram testadas diferentes concentrações de cal hidratada (0,018 g a 0,031 g) e 2 dietas, formuladas à base de ração comercial para camarão e biomassa de artêmia. No experimento 2, foram testadas 5dietas com diferentes concentrações de biomassa de artêmia (0% a 100%), inseridas em rações de peixes e camarões. No final do processo de aclimatação, a sobrevivência das póslarvas variou de 40,44% a 98,04%. Concluiu-se que pós-larvas do Litopenaeus vannamei podem ser aclimatadas à água doce e que o aumento da concentração de cal e de artêmia na ração melhoraram significativamente (p<0,05) os parâmetros zootécnicos da espécie.<br><br>Litopenaeus vannamei postlarvae with 9-10 (PL9-10), 25-26 days old (PL25-26) were acclimated to freshwater (0 ppt) for the purpose of attending the inland cultures. Two experiments were conducted in 44 liter aquariums with stocking density of 11.36 postlarvae/L. In experiment 01, different concentrations of hydrated lime (0.018 g a 0.031 g) and two diets, formulated with commercial shrimp ration and artemia biomass, were tested. In experiment 02, five diets, withdifferent concentrations of artemia biomass (0 to 100%) inserted in fish and shrimp rations, were tested. At the end of the acclimatization process, the postlarvae survival varied from40.44 to 98.04%. Results showed that Litopenaeus vannamei postlarvae can be acclimated to freshwater. Also, the increase of lime concentration and the artemia biomass in the ration improved (p<0.05) the zootechnic parameters of the species in a significant way.