The Effect of Feed Supplementation with Fermented Red Seaweed (Kappaphycus alvarezii) on Growth and Survival of White Shrimp (Litopenaeus vannamei) Post-Larvae Culture

This study was aimed to investigate the effect of novel shrimp diet supplemention with fermented red seaweed Kappaphycus alvarezii on growth and survival of whiteleg shrimp (Litopenaeus vannamei) post-larvae culture. The research consisted of three consecutive steps: (1) preliminary study on Kappaphycus alvarezii fermentation, (2) feed formulation and proximate analysis, (3) performance test of commercial feed (C), commercial + 0.5% K. alvarezii (EF1), and commercial + 1.5% fermented K. alvarezii (EF2). Following 15 days of feeding, the highest biomass, specific growth rate and survival were achieved in EF2 treatment (1.60±0.21 g, 10.88±0.86%/d, 91.67±1.53%), significantly different from control (0.99±0.09 g, 7.72±0.63%/d, 47.00±5.00%) (p<0.05). Overall, this study suggested that the dietary supplementation of 1.5% fermented K. alvarezii can enhance the growth and survival of whiteleg shrimp during the nursery phase.

Effect of Salinities and Dietary Patterns toward Fullness of Gut and Gut Evacuation Time of the Newly Introduced Penaeus merguiensis Larvae

The gut capacity of shrimp larvae is minimal, and their digestion is often challenged by the inevitable fact that they tend to develop slowly during the zoea stage. Many studies approved that the digestive capacity of shrimp larvae could be improved by increasing the retention time of food in the intestine. Gut evacuation time and fullness of the gut are crucial parameters in assessing the growth of shrimp larvae, and the diet as well as environmental conditions indeed influence the activity of these parameters. Although many species of shrimps have a wide salinity tolerance, more specific research on salinity and its relation to the type of diet is necessary to find the optimum condition supporting the growth of shrimp larvae. By employing Penaeus merguiensis larvae, this study evaluates the effect of three nominal salinities (28, 32, and 36 ppt) and types of diets (Diet A: 100% live feed; Diet B: 100% FRIPPAK; Diet C: a combination of Diet A and Diet C, 50 % each) toward the fullness of gut and gut evacuation time of the newly introduced Penaeus merguiensis larvae culture. The result showed that the longest gut evacuation time and the highest percentage of gut's fullness were found in all Zoea reared with Diet A at salinity 28 and 32 ppt; Zoea-1 at 28 ppt with Diet A; Zoea-2 at 32 ppt with Diet A; Zoea-3 at 32 ppt with Diet A. Longer gut evacuation time would have an impact on the higher percentage of the fullness of gut. The higher fullness of the gut also indicates that the larvae have the best capacity to produce energy and achieve optimum growth.

Replacement of Artemia spp. with zooplankton in Penaeus vannamei larviculture

Supplying healthy and cost-effective postlarvae is critical to the success of the shrimp industry. Given the cost of Artemia in larvae culture, there is considerable interest in using alternative live feeds such as copepods. This study's objective was to evaluate five diets with different proportions of Artemia and copepods offered to Penaeus vannamei larvae. Biological factors such as growth, survival to postlarvae, and final weights were evaluated in conjunction with economic factors. The diets offered were: 1) 100% Artemia 2) 75% Artemia and 25% copepods 3) 50% Artemia and 50% copepods 4) 25% Artemia and 75% copepods and 5) 100% copepods. Concerning the biological response, there were no significant differences observed between the five treatments. The economic evaluation was based on a partial budget. It was concluded that there were no significant differences in survival or yields. However, the data collected in this experiment concluded that the treatment with 100% Artemia had higher annual net benefits due to the combined effect of survival rates and cost. These net benefits can vary in other repetitions, so it is recommended to experiment more times to observe differences in profits among diets.

Eficácia de anti-helmínticos no controle de parasitas gastrintestinais de ovinos no Alto Sertão da Paraíba, Brasil

<p>This project evaluated the efficiency of different anthelmintics on sheep gastrointestinal nematodes in the Alto Sertão of Paraíba state. Resistance test was conducted in two sheep farming units (P1 and P2) of Dorper and Santa Inês crossbreed sheep, which are located in Sousa microregion. Young and adult sheep of both sexes, were divided into five groups, being control group (G1), Ivermectin 0,08% (G2), Doramectin 1% (G3), Albendazole 10% (G4) and Levamisole Chloridrate 5% (G5). In P1 each group was formed by three young and three adult animals, while in P2 each group was formed by two young and three adult animals. Faeces samples were collected on the pre-treatment (D0) and post-treatment evaluation (D7, D14 and D21). In P1, the most efficient drug was Levamisole Chloridrate 5%, while the other drugs evaluated presented insufficiently active. In P2, Albendazole 10% and Levamisole Chloridrate 5% showed the highest percentages of efficiency to D7, D14 and D21. Also in P2, Ivermectin 0,08% and Doramectin 1%, to D7 and D14, were effective, with parasite reduction between 90-98%. Results obtained from larvae culture indicated that 100% of sheep helminth infections, in both farming units, were caused by Trichostrongyloidea superfamily, being Haemonchus spp.the most prevalent one (75,9%).</p>

Pathogenic Assay of Probiotic Bacteria Producing Proteolytic Enzymes as Bioremediation Bacteria Against Vannamei Shrimp Larvae (Litopenaeus vannamei)

Application of bacteria in bioremediation of shrimp culture ponds is one of the methods used to clean internal pollutants. This study aimed to evaluate the pathogenicity of extracellular proteolytic enzyme produced by the probiotic bacteria as bioremediation bacteria on vannamei shrimp larvae culture. There were five probiotic bacteria, which were successfully isolated from the sediments served as substrate in mangrove area. The isolated bacteria were coded in number as 13, 19, 30, 33, and 36. Pathogenic bacteria Vibrio harveyi was used as positive control. Pathogenic assay was carried out in two different bacterial concentrations, i.e. 10⁸ and 10⁶ cells.mL-1. The results showed that the lowest survival rate (SR) of shrimp larvae in positive control V. harveyi was 53 and 65%. Whereas isolates with the highest SR value (100%) were obtained from bacteria coded as 13 and 30. Isolates no. 19, 33 and 36 had SR of more than 90%. Total plate count (TPC) data showed that the bacteria increased significantly at the end of the study with an average increase value of 24%. The smallest TPC value was shown by bacterial isolate no. 19, while the largest was obtained from the isolate no. 13. These results suggest that all probiotic bacteria were not pathogenic to the vannamei shrimp larvae. Keywords: aquaculture, shrimp, bioremediation, pathogenesis, vibrio.