Background and Objective: Adaptogens are plant substance that is known to enhance the productivity of animals mainly through their stress mitigating effects and hence the present study was undertaken with the main purpose to evaluate the effect of phytogenic feed additive (PHFA) on growth performance parameters in Litopenaeus vannamei under field conditions.Materials and Methods: The experimental shrimp for this study were post-larvae 10 (PL 10) and 112,000 shrimps were reared in two ponds (9.6×40×1.2m).One pond served as the control group and was fed with a basal diet, the other pond was considered as a PHFA group fed with a basal diet plus Phytocee TM (2 kg/ton).The water quality parameters such as dissolved oxygen, temperature, pH, total ammonia nitrogen and nitrites were measured every day.Salinity was measured every 3 days.Litopenaeus vannamei shrimps were fed with respective diets for 104 days. Results:The total body weight (kg), FCR and survival rate (%) exhibited by control and PHFA groups were 1, 108 & 1,145, 1.173 & 1.135 and 91.01 & 94.05, respectively.Results revealed that body weight (kg), FCR and survival rate (%) of L. vannamei were improved following the addition of PHFA at 2 kg/ton as compared to the control group.This could be due to the impact of individual ingredients which was already known to have adaptogenic, antioxidant and immunity-booster property.Conclusion: In conclusion, the addition of PHFA at the dose level of 2 kg/ton of feed could be recommended for the augmentation of the growth performance parameters of L. vannamei.
Background and Objective: In Nigeria, there is a paucity of information on the genetic similarity among wild Oreochromis niloticus species.Though there are assertions based on morphological observation, by fish farmers and some researchers of fisheries that most of these species in the wild are no longer pure and possibly hybridizing.Most molecular assessments are usually among tilapia species with limited sample coverage of O. niloticus species or of a lower marker.This was a preliminary investigation of the genetic similarity of Oreochromis niloticus from selected water bodies along the River Niger, in six states of Nigeria, using SSR markers.Materials and Methods: Similarity levels among Oreochromis niloticus from water bodies in six states in Nigeria were assessed using seven SSR markers with their various primers (UNH 208, 143, 104, 022, 119, 180 and 156), which were selected from the NCBI database.Only UNH 104, UNH143 and UNH 022 produced DNA amplifications.Phylogenetic representation using UPGMA cluster analysis produced a dendrogram with a total of 118 clusters grouped into 7 major clusters with up to 8 subgroups, indicating different degrees of variation and similarities.Results: Genetic similarities were observed at various coefficient levels, possibly due to hybridization.At the coefficient level of 1 or 100%, 39 clusters occurred with different samples on each cluster indicating they are genetically the same.Samples from South Delta (SSD), South West Oyo (SWO) and North West Kebbi (NWK) states were always present in each cluster at this coefficient level.A lot of migration is likely taking place among these fishes.The seven major clusters A, B, C, D, E, F and G at varying degrees of similarity 73, 67, 64, 59, 56, 48 and 44% showed the decreasing order of genetic similarity.Conclusion: These data supported the view that the very high similarity between tilapia from these water bodies stems from its highly prolific nature which may have led to a high probability of hybridization between species and strains.The genetic distance between strains may suggest that there are varying levels of genetic variability among O. niloticus in Nigeria water bodies under study.
Background and Objective: Fishmeal is considered the most expensive major source of protein commonly used in domestic animal feeds and in commercial aquafeeds.This study aimed to investigate the proximate composition, mineral contents and heavy metal contamination of the five most populous fishmeal available within the South-West of Nigeria.Materials and Methods: Samples were collected from commercial fishmeal whole sellers and analyzed accordingly.Proximate composition, mineral contents and heavy metal composition determined.Results: Results reveal significant differences (p<0.05) in the values obtained.For proximate composition, Carbohydrate, Crude Protein, Crude Fat, Moisture Ash and Crude Fibre contents ranged from 6.27±0.07-19.87±0.10,52.13±0.04-81.38±0.15,3.73±0.06-6.84±0.05,2.89±0.06-8.6±0.07,4.08±0.06-5.21±0.02and 1.65±0.02-9.3±0.14%among samples, respectively.Mineral contents (Na, K, Ca, Fe, Mg, P) for all five samples were significantly different at (p<0.05), while values of heavy metal contents revealed Cd, Pb, Hg, Cu, Zn and Cr concentrations ranging between 0.003±0.002-0.082±0.02,0.002±0.02-0.00,0.0016±0.00-0.0061±0.00,0.291±0.03-1.059±1.56,1.02±0.27-2.534±0.36 and 0.001±0.00-0.015±0.00mg kgG 1 , respectively.However, some values fell above the FAO/WHO permissible limit for heavy metals.Conclusion: It was concluded that more attention should be given to the sources of fishmeal used in feed production and constant monitoring of their chemical composition as not all fishmeal sold commercially are high-grade fishmeal.
Background and Objective: The water in Niger Delta, Nigeria has significant amounts of iron and manganese.To remove them, a precipitation procedure that involves potassium permanganate is required.In the end, the slush is empty into the aquatic environment without treatment, hence, we investigated the effects of the KMnO 4 , a major water treatment agent on Chrysichthys nigrodigitatus, a dominant freshwater fish in Niger Delta Nigeria.Materials and Methods: Fifteen Chrysichthys nigrodigitatus were self-bred and subjected to one-tenth of the range of KMnO 4 concentrations used for water treatment in Nigeria (0.50, 1.00, 1.50 and 2.00) mg LG 1 and a control.At the end of each experimental period, a fish is removed from each treatment and blood samples are taken from the caudal in anticoagulant-free centrifuge tubes and serum is obtained by centrifugation of blood at 3,000 rpm for 10 min.Similarly, on day 30th, immediately after collection of the blood, a fish from each treatment was dissected and the organs (brain, liver, gills and muscles) were excised, transferred to liquid nitrogen and kept at -25 o C until the analysis.The activities of glutathione s-transferase (GST) and acetylcholinesterase (AChE) in these organs were measured spectrophotometrically.Results: The slight increase in the activity of GST and the decrease in the activity of AChE demonstrated the incapability of the vital organs to neutralize the KMnO 4 generated in the oxidative stress condition and neurological impairment.Conclusion: These studies have proven that KMnO 4 suppresses AChE activity and has a dramatic impact on the antioxidant enzyme in C. nigrodigitatus.Therefore, sludge from water plants should be kept harmless before discharging into the rivers.
Background and Objective: Human-induced physical and environmental barriers especially hydropower dams and dense anoxic vegetation along riverine-lacustrine connectivity are known to isolate and fragment fish populations, leading to variation.This study explored possible morphological variations among populations of Barbus altianalis from Uganda with the intent to provide a more costeffective and reliable platform for elucidating the stocks under combined environmental and anthropogenic influence as a tool for improved fisheries management and conservation.Materials and Methods: Multivariate analysis of morphometric variables was performed to determine the morphological variation and discreteness among three populations of B. altianalis (N = 251) from the lacustrine (Lake Edward) and riverine (River Nile and Kazinga channel) systems in Uganda.Morphological variation was determined using a multivariate analysis of advanced truss and non-truss network systems on all individuals collected from commercial catches.Results: There was a significantly (p<0.001) higher level of heterogeneity among populations.Group means on the DFA1 showed that River Nile (-0.89) separated furthest from Lake Edward (0.79) and the Kazinga channel (0.68).River Nile had the highest number (80.5%) of individuals correctly classified while Lake Edward (67.2%) and Kazinga channel (60.5%) had more misclassifications between them, an indication that they could be much harder to separate.Conclusion: The observed patterns of variation were consistent with the geographical locations of the different water bodies, that the isolating mechanisms are subjecting the different populations to different selection pressure hence different phenotypic responses by the populations.
