Freshwater bodies are being contaminated by the growing human population in many developing nations and one of the major contamination source is agricultural activities within the land used catchment. In this study the response of macroinvertebrates functional feeding group in response to agricultural activities in River Wanzum Niger state Nigeria was investigated. Four (4) sites were sampled base on anthropogenic impact in the river for a period of 24months (December 2021- November 2023). From the result of the physicochemical parameters measured, only turbidity and dissolved oxygen showed significant difference (p<0.05) between the sampling sites. All the physicochemical parameters measured in this study differs significantly (p<0.05) among the sampling months. A total of 2, 863 macroinvertebrates belonging to 33 families were identified. The family notonectidae was the most dominant taxa and the least dominant taxa were Teleganonidae and Hirudinidae. The macroinvertebrates were classified into shredders, collector-gatherers, collector-filterer, scraper and predators functional feeding group. There was significant difference (p<0.05) in abundance of the FFG as predators account for 72% abundance followed by scrappers 12%, collector-gatherer 8%, shredders 5% and the least FFG were the collector-filterer with 3% abundance in all the sampled sites. The CCA ordination plot has an eigen value of 0.047and 0.012 with 78.44% and 21.33% variance in dataset. The correlation between the functional feeding group and the physicochemical shows the shredders, collector-gatherer and collector-filterer were associated with site 1 and 4 which are the less perturbed station and were influenced by pH and dissolved oxygen. The scrapers were positively associated with CCA axis 2 which was influenced by temperature, depth, pH and nitrate in site 3 and the predators were negatively associated with CCA axis 2. Overall, this study shows that predators population increased with increased agricultural activities around river Wanzum.

One of the biological components that play a vital role in the ecological integrity of an aquatic ecosystem is zooplankton. These organisms are good indicators of stressors, especially anthropogenic stressors in their environment. Thus, there is a need to study the diversity in a diversified freshwater lake (Dangana Lake) in order to provide baseline information and knowledge on the status of the lake for proper and adequate water preservation and conservation. In addition to the zooplankton structure determination, the study also examined the physicochemical parameters of the Lake. Three sampling sites were identified with distinct characteristics where water and zooplankton samples were collected for physicochemical analyses and biotic identification using standard protocols. Sampling was conducted for a duration of eight months. The monitored physicochemical parameters, i.e., temperature, dissolved oxygen (DO), biochemical oxygen demand (BOD5) and pH revealed no significant difference (p>0.05) among sampling sites. However, significance (p<0.05) amongst sampling sites was recorded in electrical conductivity, nitrate and phosphate. Seasonally, there was a significant difference (p<0.05) among sampling months in all the monitored parameters. A total of ten species of zooplankton were recorded with four species each of rotifera and copepoda and two species of cladocera. The order of abundance of zooplankton population was rotifera (56.39%), copepoda (29.18%) and cladocera (14.42%). Zooplankton population was significantly (p<0.05) higher during the dry season than in the rainy season. The Canonical correspondence analysis (CCA) revealed a strong correlation between the zooplankton and physicochemical parameters. Ipso-facto, the lake exhibited spatiotemporal changes in zooplankton composition and physicochemical parameters during the sampling period.

The need to further ascertain the quality of fishmeal with biological indicators has poised this study to determine the biological characterisation of formulated diets with supplemented insect protein (variegated grasshopper and American cockroach). The diets (A–F) were prepared with local ingredients (A, 100% grasshopper meal; B, 100% fishmeal; C, 1:1 grasshopper:fishmeal; D, 1:1 cockroach:fishmeal; E, 100% cockroach meal; F, commercial diet). Samples of prepared diets ready to be stored for use were subjected to bacteria and fungi test. Diet F recorded the highest (4.60±1.10×10² cfu g^–1) total viable bacteria count. The highest (3.00±0.05×10² cfu g^–1) fungi count was recorded in diet A. Six probiotics bacteria were isolated from the diets. Lactobacillus delbrueckii subsp. bulgaricus was only isolated in grasshopper containing diets; as Pediococcus pentosaceus, Bifidobacterium longum, Mycobacterium marinum, Bacillus subtilisand, Lactococcocus lactis were only isolated in diets F, E, D, A and B respectively. Two pathogenic bacteria isolated were Streptoccoci pyogenes and Staphylococcus aureus. Aspergillus flavus and Penicillum sp. are the two species of fungi isolated from diet A, and diets C and E respectively. The diets with insect proteins were rich in probiotic bacteria than other diets may be considered to replace fishmeal in fish diet.

This study was conducted to investigate the stomach contents of two commercially important fish species (Tilapia zilli and Oreochromis nilocticus) from Wanzun River, Northcentral Nigeria using frequency of occurrence and volumetric methods between January to April 2019. Fish samples were collected monthly with help of Fishermen using various fishing nets and traps. One hundred (100) individual fish of each species were collected and their stomach contents were examined. The results obtained expressed in mean percentage indicated that out of the one hundred (100) individual fish of each species examined,Twelve (12%) fish had an empty stomach contents in Tilapia zilli, and out of the 100 samples examined, Seventeen (17%) fish had an empty stomach content in Oreochromis nilocticus. The stomach contents of both Tilapia zilli and Oreochromis nilocticus consist of detritus, insects, fish remains. Algae/protozoans plant materials and molluscs. Both fish species are omnivorous feeders and occupy the same ecological niche.The study reveals the importance of algae, fish, insects and plant materials as food for fishes and they form important part in the diet of the species examined.

The evaluations of insects’ protein as viable alternative protein source in fish diets are gaining more attention revealing that the protein has more comparative advantage than other protein sources. Therefore, this study was conducted to isolate and identify (using phylotypic and genotypic methods) bacteria isolates in the gastrointestinal tract (GIT) of African hybrid catfish fed supplemented grasshopper meal. Four feeding diets were adopted in this study; Diet A (conventional feed), Diet B (100% Grasshopper meal), Diet C (50% fishmeal and 50% Grasshopper meal) and Diet D (100% Fish meal). At the end of the 12- week experimental period, the fish were sacrificed for their GIT contents to determine bacteria diversity. In the catfish fed diet A, the bacteria isolates identified were Streptococcus pyogenes, Enterobacter aerogene, Staphylococcus aureus, Shigella flexneri, Escherichia coli, Leuconostoc latis and Klebsella pneumonia. In catfish fed diet B, Bacillus subtilis, Lactococcus bulgaricus, Lysinibacillus macroides, Lysinibacillus capsici, Stenotrophomonas pavanii and Lysinibacillus sp were isolated. Similarly, the fish fed diet C recorded the presence of Bacillus subtilis, Lactococcus bulgaricus, Lysinibacillus sp., Staphylococcus aureus, Lysinibacillus macroides, Stenotrophomonas pavanii and Enterobacter aerogene. The bacteria isolated in the GIT of fish fed diet D were Bacillus cereus, Staphylococcus aureus, Pedicoccus acidilactis, Escherichia coli, Salmonella typhi, Leuconostoc latis and Shigella flexneri.  Probiotic bacteria were more in fish fed with diets B and C, an indication that the different ratio of supplemented grasshopper meal is good for the fish, as they have the potentials to boost the fish immune system and improve the microbial balance of its gastro-intestinal tract.