Freshwater Snail (Viviparus sp); Its Potential to Use in Fish Feed Formulation

The present study was concerned with emerging culture systems of freshwater snail, (Viviparus sp) at the farmers level highlighting its potential to use in fish feed formulation. The study was conducted over a period of 7 months from May to November in Rupal Integrated Farm Chothrasia, Muktagacha Upazila of Mymensingh district, Bangladesh. Emerging culture systems of freshwater snail, its collection methods, proximate composition of snail mixed feed and comparative economic efficiency of snail mixed feed versus traditionally used fish feed were the focal points under the present study. The pond for freshwater snail culture was rectangular in shape with an area 4855㎡. The collection of snail from the culture ponds were carried out by the four methods. The production cycle was completed by 40-45 days following the harvest. The production of snail was about 4117 kg/10000㎡ in one cycle. Snail culture pond was used concurrently for rearing fry of carps (Labeo rohita, Catla catla, Cirhinus cirrhosus, Hypophthalmichthys molitrix etc), cat fish (Pangasius hypophthalmus). Two snail mixed feeds, one commercial feed and single rice bran were analyzed. The crude protein content, lipid content was higher in snail mixed feeds than commercial feed. The crude fibre content was lower in snail mixed feeds than commercial feed. Average cost for the production of snail mixed feed comparatively lower than the commercial feed. However, in terms of growth there was no significant differences occurred in both feeds

Mass culture of Moina macrocopa using organic waste and its feeding effects on the performance of Pagrus major larvae

Moina macrocopa (Straus, 1820), was cultured on different animal manures (i.e. chicken manure, Pig manure and cow manure) and food waste to detect the influence of these food sources on its mass production. Then M. macrocopa was used as feed for the rearing of Pagrus major larvae and its effects on their performance was studied. At first, the experiment was carried out for 21 days to identify the best culture medium for M. macrocopa. Food waste treatment resulted in higher density of M. macrocopa compared to other animal wastes. The percentage of unsaturated fatty acids was also significantly higher in the food waste treatment. Subsequently, we compared the effect of M. macrocopa cultured on food waste, Artemia and artificial diet on rearing the larvae of Pagrus major, red sea bream. The feeding time differed for each treatment, but the feeding number and amount were adjusted for all treatments. Results showed that larvae fed with M. macrocopa showed higher survival rates, growth rates, stress tolerance rate and DHA/EPA ratio than larvae fed with Artemia and artificial diet. The present results revealed that M. macrocopa cultured on food waste has an outstanding food potential and a probable substitute for Artemia. Keywords: Moina macrocopa, Food waste, Fatty acid content, Artificial diet, Pagrus major, Larva

Effects of different algae in diet on growth and interleukin (IL)-10 production of juvenile sea cucumber Apostichopus japonicus

Abstract The experiment was conducted to investigate the effects of different algae in diet on growth, survival, and interleukin-10 productions of sea cucumber. At first, a 9-week feeding trail was conducted to evaluate the growth performance and survival of the sea cucumber fed one of the six experimental diets containing ST (Sargassum thunbergii), UL (Ulva lactuca), UP (Undaria pinnatifida), LJ (Laminaria japonica), SS (Schizochytrium sp.), and NO (Nannochloropsis oculata) in a recirculating aquaculture system. The result showed that survival was not significantly different among the dietary treatments, and the specific growth rate (SGR) of sea cucumber fed the UL diet (1.58% d−1) was significantly higher than that of sea cucumber fed the other diets (P < 0.05), except for the LJ and NO diets. Secondly, interleukin (IL)-10 gene expression was determined where mice splenocytes were stimulated with 10 μg ml−1 of sea cucumber extracts for 2 h. The result showed that IL-10 gene expression levels were significantly increased in UL, LJ, and NO diets fed sea cucumber extracts compared to other experimental diets. The results suggest that dietary inclusion with Ulva lactuca, Laminaria japonica, and Nannochloropsis oculata algae may improve the growth of juvenile sea cucumber and could upregulate IL-10 gene expression in mice splenocytes. Such detailed information could be helpful in further development of more appropriate diets for sea cucumber culture