Effect of bio-organic fertilizer and agro-industrial residue on the growth and reproduction of cyclopoid copepod, Oithona rigida (Giesbrecht, 1896)

Production of live feed for larval development of aquatic species is crucial in the aquaculture industry. The cultivation of cyclopoid copepod, Oithona rigida can enhance the growth performance and nutritional quality of fish and crustacean larvae. Hence this study was conducted to evaluate the different dietary regimes containing swiftlet waste, soybean meal, rice bran and microalgae (Nannochloropsis sp.) on the growth and productivity of O. rigida. The results showed that rice bran and Nannochloropsis sp. additives produced the best outcomes in terms of specific growth rate (0.109±0.002 and 0.104±0.001 day -1) of O. rigida., protein content (66.83±2.25 and 72.08±2.02%), and lipid content (21.98±1.41 and 18.09±1.18%) respectively. A mixture of rice bran and Nannochloropsis sp. (41.62%) as dietary additives also improved the polyunsaturated fatty acids (PUFAs) content of O. rigida as compared with mono diet applied such as rice bran (28.16%) and Nannochloropsis sp. (31.35%). The use of rice bran as food additives for O. rigida has shown a comparable result with the Nannochloropsis sp., in terms of the growth, survival, reproduction and dietary value. Thus, rice bran and Nannochloropsis sp. was marked as the best feeding regime for the cyclopoid copepod, O. rigida as potential characteristics for mass culture in aquaculture hatcheries

Effect of mono and binary diets on growth and reproduction of cyclopoid copepod

This study compared the efficiency of different diets on the growth, survival and reproduction of the cyclopoid copepod Apocyclops ramkhamhaengi as a potential live food species for fish larvae and crustaceans in aquaculture. The experimental diets consisted of four mono diets (chicken manure, palm kernel cake (PKC), Tetraselmis sp. and Nannochloropsis sp. (control) and two binary diets (chicken manure + PKC and Tetraselmis sp. + Nannochloropsis sp.). The experiment was carried out for 15 days and the population growth, specific population growth rate, survival and reproductive performance (hatching time, hatching rate, generation time, life spawning times, daily offspring production, lifespan and sex ratio) were used to assess the responses of A. ramkhamhaengi to different food types. The diets were given at the concentration of 500 mg L-1. Population growth (10.18±1.84 ind mL-1; p = 0.245) and survival (126.16±23.27%; p = 0.370) of copepods were not significantly affected (p = 0.245, p = 0.370; p > 0.05) by the mono and binary diets. However, the reproductive performance of the copepods was significantly affected by the diets used (p < 0.05). Among all the diets used, the mono diets; Tetraselmis sp. produce the highest population growth (10.59±1.93 ind mL-1), survival (130.35±25.77%) and reproduction (e.g. hatching rate, 84.01±6.02%) compared with other mono and binary diets. The present study indicates that organic fertilizers used in this study are able to substitute microalgae as an alternative feed and assists in the production of A. ramkhamhaengi as live food for marine larvae in hatcheries

Production Performance of <i>Moina macrocopa</i> (Straus 1820) (Crustacea, Cladocera) Cultured in Different Salinities: The Effect on Growth, Survival, Reproduction, and Fatty Acid Composition of the Neonates

Salinity is a known factor in shaping population dynamics and community structure through direct and indirect effects on aquatic ecosystems. Salinity changes further influence food webs through competition and predation. The responses of Moina macrocopa (Cladocera) collected from Setiu Wetland lagoon (Terengganu) was evaluated through manipulative laboratory experiments to understand the ability of M. macrocopa to tolerate high salinity stress. Specifically, the fatty acid composition, growth, survival, and reproduction of this cladocerans species was examined. Sodium chloride (NaCl) as used in the treatments water with the concentration 0, 4, 6, 8, 12, and 15 salinity. Fatty acid levels were determined using Gas Chromatography and Mass Spectrophotometry (GC-MS). The results indicated that optimal conditions produced the highest fatty acid content, especially the polyunsaturated fatty acid content, such as EPA (eicosapentaenoic acid), ALA (alpha-linoleic acid), ARA (arachidonic acid), and DHA (docosahexaenoic acid). Furthermore, M. macrocopa survival was best at salinity 0, with a percentage of 98%, whereas the opposite occurred at salinity 15, with approximately 20% of viable animals surviving. Besides, M. macrocopa also showed the highest reproduction rate at salinity 0 (e.g., average initial age of reproduction, 4.33 ± 0.58 days) compared with other salinities level. Interestingly, the difference in growth at different salinities was not evident, an unusual finding when considering adverse effects such as osmoregulation pressure on the organism. Based on the results, we conclude that M. macrocopa can only tolerate salinity below salinity 8 and cannot withstand stressful environmental conditions associated with salinities above 8

Effect of diet on productivity and body composition of Moina macrocopa (Straus, 1820) (Branchiopoda, Cladocera, Anomopoda)

In the aquaculture of fish and crustaceans, the indoor culture of M. macrocopa constitutes a requisite to produce a more effective feed for the larviculture of the cultured commercial species. The present study examined the efficiency of different diets on population density, survival, and productivity of M. macrocopa. The cladocerans [Cladocera: currently largely referred to as Diplostraca] were fed and enriched with seven diets, including Chlorella sp., agro-industrial residues (rice bran and soybean meal), bio-organic fertilizer (chicken manure and swiftlet waste), canola oil and artificial micro pellets. The diets were provided at a concentration of 500 mg/l for each diet. The M. macrocopa fed on rice bran had a higher population density, survival, productivity, and a promising higher nutrient quality than the test groups fed on the other dietary treatments used. This study has covered the most important aspects of nutritional requirements to produce live feed organisms, which would provide a comprehensive data set for an alternative solution of the best feed for M. macrocopa propagation and their utilization in hatcheries