Assessment of length-weight relationship and condition factor of Synodontics omias (Cuvier, 1816) in River Komadougou, Northeast, Nigeria

Length-weight relationship and condition factor of Synodontics omias (Cuvier, 1816) was studied between June to November 2020 in River Komadougou, Northeast, Nigeria. A total of 350 fish species were collected from artisanal fishermen at selected landing sites within the study area. The morphometric and meristic characteristics examined varies whereas some meristic features such as pelvic and dorsal fin spine had a constant value of 1 each. The mean condition factor shows no significant difference (P 0.05) throughout the sampling period. A linear relationship was established W = -0.82L1.91 and significant at P 0.01 with b value indicating a negative allometric growth pattern.  The correlation coefficient (r2 = 0.7904) indicated that LWR model is reliable. This study provides baselines on length-weight relationship and condition factor of Synodontics omias in River Komadougou, thus further research should be encouraged on the water body for sustainable utilization, decision making and policy formulation

Aquaculture by-product meal as a fishmeal replacer in African catfish (Clarias gariepinus) diet: Effects on serum biochemistry, innate immune response, and oxidative stress markers

The effect of feeding aquaculture by-product meal (ABP) to African catfish (Clarias gariepinus) was investigated in a 56-day feeding trial using serum biochemistry, innate immune response, and oxidative stress markers as indices of assessment. Fishmeal protein in control diets was replaced at a rate of 15, 30, 45, and 60% by aquaculture by-product meal protein. Each experimental diet was randomly distributed into triplicate tanks containing catfish fingerlings (n = 15 fingerlings/replicate, 5.58±0.05 g). The primary haematological parameters (haemoglobin, packed cell volume, red blood cell count) and secondary haematological parameters (MCH, MCV, and MCHC) were similar with the control. The white blood cell count and its differential of the fish group fed ABP meal was numerically higher than control but not significant, except in fish fed D30T that had high lymphocyte count. The platelet count in all the dietary groups was similar. There was no significant variation in some of the serum biochemistry parameters: total protein, albumin, globulin and albumin/globulin ratio, urea, HDL-C and LDL-C. Creatinine values of the D60T fed group were significantly higher than all other dietary treatment groups including the control. Triglyceride's level was statistically similar with control up to 30% replacement level, while there were no significant variations in the cholesterol levels of the blood of C. gariepinus fed the different dietary treatments. Except for catalase, there were no significant differences in other oxidative stress biomarkers under study, primarily SOD, GSH, and GPx. Catalase enzyme activities of the fish group fed D30T were statistically higher than other fed groups. Some serum electrolytes, such as calcium and chloride ions of the differently fed fish groups, were not significantly different. Lastly, serum potassium ions were significantly higher among D60T fed group though statistically similar to D45T-fed group. No stress conditions were recorded among the dietary groups.  These results showed that the health status and immunity of African catfish were not degraded by feeding aquaculture by-product meal to the fish

Toasted Jatropha curcas seed meal in Nile tilapia (Oreochromis niloticus) diet: Effect on growth, economic performance, haematology, serum biochemistry and liver histology

The effect of dietary inclusion of differently timed dry heat-treated Jatropha curcas on the growth and economic performance of Nile tilapia, Oreochromis niloticus, was evaluated in a 56-day feeding trial. Five isonitrogenous and isolipidic dietary treatments (35% crude protein and 10% crude lipid) were made consisting of soybean meal (control) which was replaced by J. curcas seed meal toasted either 5 min or 10 min at 20 and 40% to make other four test diets. A total of 225 juveniles of O. niloticus were acclimatized for a week, weighed and allotted into five dietary treatments. Each treatment was replicated three times with fifteen fish per replicate. Fish were fed 5% body weight on two equal proportions per day for 56 days. Growth data were collected at two-week intervals. The results from the study indicated that there was significant difference (P0.05) in the different growth and economic performance parameters of fish fed CTR and fish fed D520T (5 min toasted, 20%). There was significant reduction in haematological and biochemical parameters of the blood of O. niloticus fed the different dietary treatments containing J. curcas seed meal. Based on economic and physiologic performance, soybean meal in Nile tilapia diet could be replaced up to 40% by 5-minute toasted J. curcass seed meal

Anemia macrocítico-normocrómica en el bagre africano Clarias gariepinus (Siluriform: Clariidae) expuesto a Paraquat en laboratorio

Introduction: Agricultural pesticides are among the main causes of pollution in aquatic ecosystems, and they can lead to physiological changes in fish. For example, blood alteration and damage to haemopoietic tissue can be associated with pathological conditions related to water. Objective: To describe the effects of certain levels of pesticide on a Nigerian fish species. Methods: Macrocytic-normochromic anaemia was induced in C. gariepinus at intervals of 1,7 and 14 days (sub-lethal concentrations of Paraquat: 0; 0,03; 0,05; 0,07 and 0,09mg/l). Results: Blood dyscrasias was observed with a significant (p<0,05) decrease in haemoglobin, haematocrit, red blood cells, white blood cells, lymphocytes and monocytes. Mean corpuscular volume (MCV), Mean corpuscular haemoglobin (MCH), Neutrophils, Eosinophil and Basophil increased significantly (p<0,05) with increasing concentrations of the toxicant while Mean corpuscular haemoglobin concentration (MCHC) remained normal. Conclusion: Sublethal concentrations of paraquat induced macrocytic-normochromic anaemia in the catfish C. gariepinus.Introducción: Los plaguicidas agrícolas se encuentran entre las principales causas de contaminación en los ecosistemas acuáticos y pueden provocar cambios fisiológicos en los peces. Por ejemplo, la alteración de la sangre y el daño al tejido hematopoyético pueden estar asociados con condiciones patológicas relacionadas con el agua. Objetivo: Describir los efectos de ciertos niveles de plaguicidas en una especie de pez de Nigeria. Métodos: Se indujo anemia macrocítico-normocrómica en C. gariepinus a intervalos de 1, 7 y 14 días (concentraciones subletales de Paraquat: 0; 0,03; 0,05; 0,07 and 0,09mg/l). Resultados: Hubo discrasias sanguíneas con una disminución significativa (p <0,05) de hemoglobina, hematocrito, glóbulos rojos, glóbulos blancos, linfocitos y monocitos, el volumen corpuscular medio (MCV), la hemoglobina corpuscular media (MCH), los neutrófilos, eosinófilos y basófilos aumentaron significativamente (p <0,05) con concentraciones crecientes del tóxico, mientras que la concentración de hemoglobina corpuscular media (MCHC) se mantuvo normal. Conclusión: Las concentraciones subletales de paraquat generaron anemia macrocítico-normocrómica en el bagre C. gariepinus