No abstract

Delonix regia is commonly called Flamboyant or flame of the forest. The seeds were fermented, boiled, sundried and then ground into powdered meal. 40% crude protein based test diets containing Delonix regia seed meal D0 = 0%; D15 = 15%; D20 = 20% and D25 = 25% inclusion levels respectively were prepared. Red tilapia (Oreochromis niloticus) fingerlings of 6 weeks old were acclimatized for two weeks and then stocked in 12 hapas at 15 fish per hapa measuring 0.6 m × 1.2 m × 0.7 m placed in a concrete tank. Each diet was assigned to fish in a separate hapa in triplicate and administered at 3% fish body weight per day for 16 weeks. Fish weight and length were taken initially, bi-weekly and terminally. Water quality was monitored weekly. Number of fish at the end was recorded and survival rate, growth, feed utilization, fillet yield and blood parameters were determined. The data were subjected to the analysis of variance and mean separation (P= 0.05). Survival rate was highest in fish raised on D20 and least in D25 without any significant difference across the range. Mean growth performances, feed utilization indices and fillet yield were generally congruent between D20 and D25 with varying degrees of significant difference to other feeds. Results of blood assay did not depict harmful effects of the test diets indicating that the fish enjoyed some good measures of health. The gross performance of fish on D20 was optimal. It was therefore concluded that 20% dietary inclusion level of fermented, cooked and dried flamboyant seed was the best for the red tilapia (Oreochromis niloticus) post fingerlings.

Background: Crab shells lie wasted globally after the extraction of the edible soft tissues. Chitosan nanoparticles (CNPs) derived from these shells have the potentials to revolutionized aquaculture. Aims: Evaluated the effects of CNPs on water quality parameters, growth performance, feed utilization and survival rate of African catfish (Clarias gariepinus). Study Design:  The experimental diets were incorporated with chitosan nanoparticles at the rate of 0, 2.5 5.0 and 7.5 g kg-1 representing Treatments CNP00, CNP2.5, CNP5.0 and CNP7.5 respectively and replicated thrice. Place and Duration of Study: Department of Fisheries and Aquatic Environmental Management, University of Uyo, Uyo – Nigeria from August to November 2021. Methodology: We synthesized CNPs by ionic gelation method. Dried flour of FM, SBM, Wheat bran and yellow maize meal were analyzed for proximate composition used in the formulation of experimental diets. These were milled at 2 mm pellets, CNPs were dissolved in 0.3 liters of water and sprayed on the pellets. These were stored at 10% moisture content, in black polythene bags. Diets were fed to two hundred and sixteen fingerlings of African catfish (C. gariepinus) with mean body weight 23.86±3.11. Growth performance, feed utilization and survival rate parameters were calculated and statistically compared. Results: Ammonia was significantly (p<0.05) low in CNP7.5. The highest daily weight gain (6.98±0.81 g) was recorded in CNP7.5 while the lowest (1.02±0.01 g) was recorded in the control (CNP00). SGR, DWG, FCR, PER followed the same pattern. However, there was no difference in percentage survival rate. Conclusion: Chitosan nanoparticles supplemented at the rate of 7.5 g k-1 diet can give a better water quality, growth performance and feed utilization of C. gariepinus juvenile. Incorporation of CNPs in diet of C. gariepinus at a concentration of 7.5 g kg-1 is recommended for more profitable and sustainable culture of this fish species.