Jesús T. Ponce-Palafox

The effects of salinity and temperature on the growth and survival rates of juvenile white shrimp, Penaeus vannamei, Boone, 1931

The growth and survival of Penaeus vannamei postlarvae was measured at temperatures of 20, 25, 30 and 35 °C and salinities of 20, 30, 35, 40 and 50%.. Groups of 30 animals were used in each combination of conditions, in triplicate. The results clearly show that juveniles of this species have their best survival between temperatures of 20 and 30 °C and salinities above 20%.. Best growth was obtained between temperatures of 25 and 35 °C, with little difference being noted among salinities. Survival and growth coincide best at around 28 to 30 °C and 33 to 40%.. Calculated overall production was shown to be best in these conditions. The results demonstrate a high coincidence between the experimentally determined optimum conditions for production and the prevailing conditions in the coastal environment from which the animals originated.

Growth Characteristics of the Australian Redclaw Crayfish, Cherax quadricarinatus, Cultured in an Indoor Recirculating System

Abstract The redclaw crayfish has been cultured in ponds since about 1990. As interest in redclaw has expanded, some culturists have begun to ask about culture potential in areas where pond culture may not be feasible. This study was conducted to determine growth characteristics of redclaw crayfish in an indoor, closed-system culture unit. Redclaw crayfish of two initial sizes, small (0.3±0.1 g) and medium (6.9±2.9 g) were cultured in tanks (1 m2) for five months. Temperature was maintained at 29±1.0°C, and the photoperiod was set at a 12:12 light:dark cycle. Survivals ranged from 65% to 70%. Final mean weights for the two size groups were 5.0 g and 29.0 g, respectively. Redclaw crayfish growth was much lower in this study than has been routinely reported for redclaw crayfish growth in outdoor ponds but not much different from what others have reported for other crayfish species cultured in indoor tanks. Factors that might cause the reduced growth include inadequate diet, density effects, and pheromones.

Effect of the initial stocking body weight on growth of spotted rose snapper Lutjanus guttatus (Steindachner, 1869) in marine floating cages

Spotted rose snapper were stocked at body weight sizes of 24.5 �} 3.7 g, 55.4 �} 3.5 g, and 110.2 �} 4.6 g in three replicated marine floating cages of 100 m3 and reared for 153 days at Santa Cruz de Miramar in Nayarit, Mexico, to determine the appropriate stocking body weight size. Caged snapper were fed twice a day with commercial pellets containing 35% crude protein during the first three months and 25% during the last two months, respectively. The water temperature of cages ranged from 25.6 to 32.3��C. Mean survival ranged from 67.5 to 74.7%. Stocking body weight sizes of snapper exerted significantly different (P.0.05) effects on the final biomass. The maximum mean weekly weight gain was 12.8 g week-1 in cages with the 110.2 �} 4.6 g body weight size. These results suggest, as a good strategy, the introduction of snappers with a total weight of 110 g for grow out in marine cages culture.

Growth of fresh-water prawn Macrobrachium tenellum (Smith, 1871) juveniles fed isoproteic diets substituting fish meal by soya bean meal

Growth parameters (standard length, weight, specific growth rate and daily we ight gain) of prawn Macrobrachium tenellum juveniles fed 40% crude protein isoproteic diets substituting fish m eal with soya bean meal at various levels (20, 40, 60, 80 and 100%) were evaluated for 45 days under laboratory conditions. Experimental diets were compared with a 100% fish meal based di et. Total survival was recorded for all the treatments at the end of the experiment. There were no significant differences (p � 0.05) for all the growth parameters among the dietary treatments. The initial mean weight (0.36 ± 0.10 g) increased almost three times (1.00 ± 0.13 g) after 45 days. The final specif ic growth fluctuated from 1.82% BW/d for the 60% soya bean meal inclusion diet, to 2.62% for the 100% fish meal diet. The mean final survival was 91.66%. Growth performance of M. tenellum juveniles was not affected by the dietary soya bean meal levels tested.

A response-surface analysis of the relative importance of the temperature, salinity and body weight on the respiratory metabolism of the white shrimp Litopenaeus vannamei (Boone, 1931)

We used a response-surface analysis to determine the importance of different factors affecting the resting routine metabolic rate (QO2) of the white shrimp Litopenaeus vannamei. The oxygen consumption rates were estimated using a multi-factorial design with 28 combinations of different salinities (15, 20, 25, 30, 35, 40 and 45 psu) and temperature (20, 25, 30 and 35 °C) values. The response-surface analysis produced a quadratic function showing that temperature more profoundly affects the oxygen consumption rate. Response-surface curves were generated to predict the optimal conditions resulting in oxygen consumption to better understand the successful growth of this species.

Efecto de diferentes combinaciones de temperatura y salinidad sobre el consumo específico de oxígeno en el camarón blanco Litopenaeus vannamei

The combined effect of different temperatures (20, 25 and 30°C) and salinities (15, 25, 35 and 45 psu) on the specific oxygen consumption (CEO) in Litopenaeus vannamei was determined. For this, CEO of 248 organisms of different body sizes (0.31 to 15.85 g) was measured. The CEO decreased when shrimp weight increased in all treatments without presenting a definite pattern when the salinity increased; even though all the combinations of temperature and salinity did not statistically show slopes significantly different in the regression models for CEO and organism weight relationships. The slope values suggest that at 20°C there is high energy expenditure at 15 psu, and at 25°C the highest energy consumption occurs at 45 psu. Whereas at 30°C, the lowest energy consumption occurred combined with the lowest salinity (15 psu). This may indicate that the isosmotic condition (point of lowest energy expenditure) tends to change with temperature, which may imply that the shrimp can be cultivated at high temperature (30°C) and at low salinities (15 psu) without increasing energy expenditure.

A Modified Chamber Designed for Estimation of Digestibility in Shrimp

Abstract The science of the feeding and nutrition of crustaceans is still in development, and producers and feed manufacturers need better understanding of the digestibility of various nutrients. The most widely used method of determining digestibility in vivo in fish is based on the measurement of chromium oxide (which is incorporated into the diet) in feces. To use this method, it is essential to have an efficient means of collecting feces in the aquatic environment. In shrimp, this presents some difficulties because of their benthic feeding and coprophagic habits. This paper describes the development and testing of a low-cost modification of the “Guelph” system used for fish that allows the collection of feces from shrimp. The system performed extremely well and had clear advantages over the basic siphon system. The importance of having an easy and efficient method of collecting feces for in vivo assays is discussed.

Annual reproductive cycle and growth of the pen shell Atrina maura (Pterioidea: Pinnidae) on sand-bottom culture in the Ensenada Pabellones lagoon system, Gulf of California, Mexico

Abstract The reproductive cycle and growth of the pen shell, Atrina maura, which was cultured in the Ensenada Pabellones lagoon system, Gulf of California, from March 2008 to March 2009, is described in this article. Histological techniques and the condition index were used to determine its reproductive condition. The sex ratio was 0.57 females:1.72 males within the population studied. There were no differences (χ2, p < 0.05) in shell length (SL) between males and females. The mean length of the sampled specimens ranged between 50.99 ± 4.86 mm and 218.16 ± 8.87 mm. The histological results confirmed that A. maura is a gonochoristic organism that presents synchronic development of the gonads. The maturity and spawning phases were observed throughout the study period, with the exception of March and May 2008. The frequency of the gonad development stages obtained per month suggests that this species reproduced two times annually, with one important reproductive period from June to September, a minor reproductive period from November to February, and two resting periods as follows: July to August and January to February 2009.

Stocking Density for Nursery Production of Redclaw Crayfish, Cherax quadricarinatus, in a Recirculating System

Redclaw crayfish, Cherax quadricarinatus, early juveniles were reared at different stocking densities in a closed recirculation system using 12-L plastic containers as rearing tanks. Initial stocking densities were 1.0, 1.5, 2.0, 2.5, and 3.0 per liter (66, 89, 111, 133, and 156 crayfish/m2, respectively). Rearing period was 42 days. Each density was tested with five replicates. Shelter (0.112 m2) was added to double the surface area of rearing tanks. Animals were fed ad libitum twice a day with a commercial diet containing 35% crude protein. There were no significant differences (P < 0.05) in length and specific growth rate (SGR) among stocking densities. Final weight and daily weight gain, however, were significantly higher at the density of 66 per m2 (1.0 per liter). Total biomass at harvest increased with density. Survival was affected by stocking density from day 28 onward, decreasing with density from 62.7 ± 7.6% obtained at 66 crayfish/m2 to 44.85 ± 8.18% at 156 crayfish/m2.

Color of Raw, Frozen, and Smoked Fillets of Rainbow Trout (Oncorhynchus mykiss) Fed Diets Supplemented with Astaxanthin and Saponified Red Chilli (Capsicum annuum) Extracts

ABSTRACT Rainbow trout (Oncorhynchus mykiss) were fed diets supplemented with astaxanthin and saponified red chilli extracts. Raw fillets resulted in a decrease of lightness (L*), hue (h*) and chroma (C*) values, and in an increase of redness (a*) and yellowness (b*) values as diet feeding time increased. Frozen fillets showed a decrease in L* and h* values and an increase in a*, b*, and C* values, and exhibited differences of color (ΔE*) between 2.4 to 11.0 units depending on freezing time, when trout were fed diets containing 200 g.kg−1 (SC200) and 250 g.kg−1 (SC250) of saponified red chilli extracts compared with that obtained from feeding the trout a diet containing 100 g.kg−1 (CP) astaxanthin. During the smoking process, L* and a* values were not significantly different (p ≥ 0.05), and b*, h*, and C* values increased significantly (p < 0.05) with all the experimental diets. The astaxanthin containing diet produced fillets with a more reddish-pink color than the rest of the experimental diets.