Freshwater fisheries ecology encompasses the intricate interactions among fish species, their aquatic habitats, and human activities

Clarias gariepinusfish were treated with 2 ppm, 150 ppm, and 100 ppm of potassium permanganate, hydrogen peroxide, and formalin respectively. After a 70-day culture period, growth and hematological indices were measured. Data were subjected to one-way ANOVA and the mean were separated using the New Duncan Multiple range test at p ≤ 0.05. Results indicated that fish treated with potassium permanganate had the highest weight gain (5.31 ± 1.66 g) while the least (3.70 ± 0.28 g) was recorded in fish treated with hydrogen peroxide. The control fish had the highest (1.91 ± 2.28) feed conversion ratio while the least (1.47 ± 0.41) was recorded in catfish fingerlings treated with potassium permanganate. White blood cells were more (6.23 ± 0.25) in fish treated with formalin and lowest in control fish. Hemoglobin values were similar in control fish (12.45 ± 2.03) and potassium permanganate(13.09 ± 0.98) treated fish. Apart from PCV that decreased in fish treated with H2O2 and formalin, other red blood indices increased significantly (p ≤ 0.05) against the control. Potassium permanganate appeared to have the least negative effect on the fish. The study, therefore, recommends the use of potassium at 2 ppm for treatments in catfish fingerlings aquaculture.

Feed plays an important role in the development and sustainability of the aquaculture industry. Feedstuffs are either of plant or animal origins. Some plants despite their potentials are underutilized in fish feed industry. The cost effectiveness, availability and sustainability potentials of these plants coupled with their nutritional composition make them fit to compete favourably well with the commonly utilized plants. Leaves and seeds of plants such as Moringaoleifera, Gliricidiasepium, Leucaenaleucocephala, alfalfa, sweet potato, velvet bean, cucumber, squash, broad bean, papaya, azolla, water hyacinth, duckweeds, etc. have been discovered to possess the requirements needed for use as a feedstuff in the fish feed industry. This paper therefore reviewed extensively; the potential use of various plant products as ingredients in fish feed industry.

High cost of feeds is a major problem to fish farming in Nigeria. In this study, the growth performance of African catfish (Clarias gariepinus) fed graded levels of plantain peels (PPM) as a replacement for maize was investigated. Five diets were formulated and maize meal replaced at 0 %, 25 %, 50 %, 75 % and 100 % in PPMD1, PPMD2, PPMD3, PPMD4 and PPMD5 respectively. The feeding trial lasted for 56 days. Data collected were subjected to one-way ANOVA test. Results showed that fish on control diet (PPMD1) were significantly (p > 0.05) highest in weight gain(7.34 ± 0.09g)while the least weight gain was recorded among PPMD5 fish. Similar trend was observed in specific growth rate (SGR), feed conversion ratio (FCR) and protein efficiency ratio (PER). Packed cell volume (PCV), Haemoglobin (HB), Red blood cell (RBC), Mean corpuscular haemoglobin cell (MCHC), and Lymphocytes (20.67 ± 0.33, 7.77 ± 0.03, 1.80 ± 0.06, 35.57 ± 0.47, and 84.00 ± 0.58 respectively) were significantly highest (p<0.05) in PPMD4. MCV was highest in PPMD1 and lowest in PPMD4. MCH was significantly higher (p<0.05) in PPMD1 and lowest in PPMD3. White blood cells (WBC) was significantly highest (p<0.05) in PPMD3 and Neutrophils was significantly highest (p<0.05) in PPMD5. It was concluded that PPM compares favorably with maize and an optimum inclusion level 25% (PPMD2).

Three ageing reservoirs in Ekiti State, Nigeria (Ureje constructed in 1958, Egbe in 1982, and Ero in 1989), were comparatively assessed to evaluate fish assemblages and their conservation relevance. Despite the absence of formal fisheries governance, all three reservoirs supported temporally stable fish communities with low overall diversity. A core assemblage of six species dominated across sites, while species richness increased from seven species in the small urban Ureje reservoir to nine species in the larger and more rural Ero reservoir. Four native species that have become locally scarce in surrounding river systems (Heterotis niloticus, Parachanna obscura, Hepsetus odoe, and Hyperopisus bebe) persisted at low but consistent abundance. Aquatic environmental variables remained within suitable limits for freshwater fishes, and trophic structure appeared intact across the reservoirs. Catch density was substantially higher in the urban reservoir compared to the rural systems, reflecting spatial differences in fishing intensity. Overall, the findings demonstrate that small tropical reservoirs can function as important freshwater habitats that sustain fish biodiversity and fisheries production in modified landscapes.