This study compared the condition factor and nutrient composition of two sexes of the African catfish (Clarias gariepinus) from the wild and cultured sources in Zobe Dam and Ni’ima Farm, respectively, in Dutsin-Ma, Katsina State, Nigeria. For this, 20 wild and 20 cultured, with equal sex representation (total n=40). The condition factor (K) of the wild fish was statistically higher (males: 1.71 ± 0.03; females: 1.69 ± 0.04) than the cultured fish (males: 1.52 ± 0.05; females: 1.56 ± 0.02). This shows that the wild fish had better overall well-being and energy reserves than the cultured ones. The proximate analysis was conducted (for dry matter, crude protein, crude fibre, lipid, ash, and nitrogen-free extract), and there were no significant differences in most of the parameters of the sources and sexes except the ash content of the cultured fish, which was higher, and the wild fish possessed higher lipid and nitrogen-free extract. The male fishes showed slightly higher crude protein and lipids than the females. In conclusion, it was observed that the cultured and wild C. gariepinus fish had similar nutritional value, although the cultured fish had better minerals and the wild fish had more lipid from natural foraging. These findings will provide the basis for sustainable development of feed formulation, processing and management to enhance the quality of the cultured fish as well as assist the aquaculture sector of Dutsin-Ma, Katsina State, Nigeria, amid growing protein demand.

Pesticide residues pose a significant risk to aquatic ecosystems, fauna and human health. Yet, the physiological impact on aquatic organisms, especially fish exposed to pesticide residues in the dry season, remains unexplored, and even data on chronic exposure to pesticide residue mixtures under natural environmental conditions remains scarce. This study evaluated the immune, haematological and growth responses of Oreochromis niloticus exposed to cotton field effluents under in-situ conditions during the dry season in the Batran water reservoir. A 56-day experiment was conducted during the dry season using a 2 x 1 design (pen culture system x two environments). The Batran water reservoir in Benin's cotton basin (effluent-exposed site) was used as a test (polluted) environment, and a concrete tank at the Station de Recherche et d'Innovation en Aquacultures (SRIA) of the University of Parakou represented the controlled environment. The results revealed that O. niloticus exposed to the polluted environment showed significantly lower macrophage activity compared to the control (p > 0.05). The haematological analysis showed elevated eosinophil and heterophil levels in the polluted environment compared to the controls (p < 0.05). On the growth parameters, generally, O. niloticus exhibited higher growth performance in the polluted environment compared to the control, with a significant difference only with the final average weight (83.61 +/- 16.61 g; 69.44 +/- 5.73 g, respectively) (p < 0.05) at the end of the experiment. These findings imply that the absence of pesticide application during the dry season at Batran likely reduced pollutant-induced physiological stress, thereby enhancing growth despite comparable immune metrics. These findings suggest the need to contextualise aquaculture management strategies within seasonal agrochemical use cycles, as non-application periods may offer critical recovery intervals for farmed species.

This study examined the morphometric features and growth patterns of Oreochromis niloticus in Tiga Dam and River Wudil, Kano State, Nigeria. A total of 60 fish samples were collected over a period of three months (June to August 2024), with 10 fish per month from the two water bodies. The data was analyzed for length-weight relationship and condition factor, and the parameters were compared between the two water bodies using a T-test, with significance at P<0.05. The results showed marginal but not significant differences (P>0.05) in length, weight, and condition factor between the two populations. River Wudil had a slightly higher average length (13.16 ± 0.16 cm), while Tiga Dam had a slightly higher average weight (42.27 ± 1.91 g) and condition factor (1.94 ± 0.05). The length-weight relationship demonstrated strong positive correlations, with R² values of 0.70 for Tiga Dam and 0.77 for River Wudil. The growth exponents indicated negative allometric growth, meaning the fish become slimmer as they grow longer. The condition factor values suggested that the fish in both populations are in good condition. This study offers valuable insights into the growth patterns and health of the O. niloticus populations, supporting fisheries management and conservation efforts. Regular monitoring, conservation initiatives, and further research are recommended to ensure the sustainability of these populations.

This study was carried out to evaluate the nutritional compositions and microbial load of some frozen marine fish species sold in Kano State, Nigeria. A total of 81 samples comprising 27 each of Atlantic herring (Clupea harengus), Atlantic mackerel (Scomber scombrus) and Atlantic horse mackerel (Trachurus trachurus) were purchased from three sampling areas: Bichi, Dambatta and Gwarzo. They were analysed for proximate, mineral compositions, and microbial load using standard procedures. Results indicated that the highest crude protein content, 21.51% was recorded in T. trachurus from Dambatta, while the mineral composition revealed that C. harengus recorded the highest sodium content, 1.69 mg Kg-1, from Bichi. The highest free fatty acids 2.07 ± 0.18% was observed in T. trachurus from Gwarzo. The results of the microbial population elucidated that T. trachurus had the highest Salmonella spp. count of 4.22 x 106cfu g-1 from Dambatta. The Escherichia coli of 3.22 x 106cfu g-1 recorded in S. scombrus from Dambatta was the highest. All the microbial loads parameters were affected by the species, but not the collection station. The microbial load recorded in this study did not exceed the recommended limit of x106 to 107cfu g-1 of bacteria load safe for human consumption. The study therefore recommends T. trachurus as the best for consumption in the study area, due to its higher protein composition and the lowest microbial load.

Background. Disease outbreaks are considered to be a significant drawback in aquaculture development globally which leads aquaculturists to indiscriminate use of antibiotics. Objective. To assess the status of antibiotics use, farmers’ knowledge of risks associated with antimicrobial resistance (AMR), and disease occurrence in fish farms in Katsina state, Nigeria. Methodology Semi-structured questionnaires were administered to the active and accessible fish farms in the state, The data collected were presented and analyzed using descriptive statistics and binary logistic regression. Results: Most of the respondents were male (87.5%), aged 31 to 40 years and average of 7 years in operation. The majority (78.1%) use antibiotics for curative purposes, and the dominant usage frequency was occasional (28.1%). Majority (75%) of the respondents noted that antibiotics are readily available and moderately priced (46.9%) while the method of addition to water (37.5%) was the most frequently. Fish cure™ (37%), Aquaceryl plus™ (26%) and Oxytetracycline (10%) were the most commonly used antibiotics in the state. Most of the respondents (65.6%) are aware of the risks associated with AMR for fish but many of them (56.2%) are not aware of possible risks associated with consuming fish with antibiotic residue. Disease occurrence is very high (78.1%) among the farms in the state, with the majority (59.3%) having experienced outbreaks between one and three times. Despite the small scale of fish farming in the state, the mean economic loss due to disease outbreaks stood at ₦594, 605.3±0.21 (USD 371.63). The logistic regression model revealed that years in operation is the major factor influencing the use of antibiotics (P=0.072) and the occurrence of fish diseases (P=0.055) in fish farms in the state. Implication: Antibiotics is highly used in fish farms in the state without prescription by the veterinary experts and the majority of the farmers are not aware of risk associated with consuming fish with antibiotic residue. Conclusion.The study collectively provide a foundation for informed decision-making, targeted interventions, and future research directions in the realm of sustainable and responsible aquaculture practices in Katsina state.

Organochloride pesticides remain widely used in Africa, despite their potential public health issues. This study assessed the organochloride pesticides (OCPs) residues in water and silver catfish from Ajiwa Reservoir. The concentrations of OCPs in water and fish samples were determined using GC analysis, while One-way analysis of variance (ANOVA) was used to compare the means for each parameter among the selected stations (Kadaji, Gamji and Kundu waje). Significantly higher concentrations of Aldrin (2.66±0.44ngL-1), Diedrin (1.71±0.38ngL-1), Endrin aldehyde (2.31±0.22ngL-1), Endrin ketone (2.56±0.22ngL-1), beta-BHC (1.70±0.66ngL-1), gamma- BHC (0.85±0.30ngL-1) and delta- BHC (1.19±0.47ngL-1) were found in the gills of fish from Kadaji. Also, significantly higher Endosulfan (2.24±0.70 gL-1), Methoxychlor (2.63±0.95gL-1) and p,p'-DDE (1.77±0.34ngL-1) were found in the muscles of fish from Gamji. In contrast, Diedrin (2.111±0.59ngL-1) and Endrin aldehyde (3.84±0.86ngL-1) were significantly higher in the fish muscles from Kadaji. The OCPs in the water were not significantly different among the stations except Alpha-BHC (1.50±0.63 ngL-1). The study revealed the presence of various organochlorine pesticides in the fish tissues and the water, indicating a possible bioaccumulation in the fish. Although all the organochlorines were not above the safety level, however, it is not impossible that this might lead to possible health issues in the future

The fertilization of eggs may be delayed during induced fish breeding due to unforeseen circumstances. It is, therefore, necessary to know the optimal delay period and explore short-term storage options that can extend the viability of the eggs in such instances. In two studies, African catfish Clarias gariepinus eggs were obtained from broodstocks induced using ovaprim® hormone at 0.5ml/kg. A batch of the stripped eggs was then exposed in triplicate to atmospheric oxygen for 0, 1, 2, 3, 4, 8 and 12 hours post-stripping (HPS). In contrast, another batch was stored for 8 hours using sole and combined methods of “refrigeration”, “addition of extender” and “aeration”. The eggs were then fertilized using fresh sperm in all instances. In both experiments, egg characteristics, breeding parameters, and biometric parameters of hatched fry were recorded. Results showed a size reduction in the eggs as the time of exposure to atmospheric oxygen increased. Also, the fertilization and hatchability of eggs were similar to 4HPS; beyond this threshold, the value declined significantly to zero. However, the hatched fry’s biometric parameters showed no significant difference among treatments (P<0.05). The second study showed a poor breeding performance of eggs stored in all the different storage methods tested. Meanwhile, egg sizes and biometric parameters of the few hatched fry show no significant difference among the treatments (P<0.05). It was therefore concluded that the fertilization of stripped C. gariepinus eggs should not be later than 4HPS to optimize the breeding performance of the fish.

Indigenous knowledge, attitudes, and practices (KAP) about fish parasitic and water quality parameters are poorly understood, such information is essential for preventive and sustainable management of water bodies. A community based cross-sectional study was carried out to assess the knowledge, attitudes, and practices (KAPs) of the resident communities of Warwade reservoir on water quality and fish parasites. One hundred and twenty questionnaires were administered to the respondents from the three randomly selected locations (Warwade, Zuwan-hawa and Tsauni-arewa) around the water body. The data was presented using descriptive statistics. The result showed that most of the respondents were aged between 21-30 years, representing 31.67%. Gender participation indicated that 66.67% of the respondent were male. The respondents in this study had a good level of knowledge on changes of the water quality of the reservoir, with a mean score of 68.33% with 75% of the participants had insufficient knowledge of entering pollutant/sewage into the reservoir. Some believed (41.67%) the pollutants are from agricultural and domestic wastes. Majority of the respondents (84.17%) had insufficient knowledge of fish parasites, while 75% strongly believed fish parasites is harmful for health. Majority (60%) of the respondents had sufficient knowledge that eating undercook fish/raw can result in acquiring fish parasites while 87.5% of the respondents had bad attitude and practice of washing their clothes in the reservoir and 81.66% swim/bath/paly around the reservoir. The study recommended health education activities in the communities, in order to change the perception of risks associated with changes of water quality and...

Growth pattern and condition factor are important indices for management of fisheries resources, and comparing these between water bodies could provide a more robust information and not just stand alone status of fisheries stock. This study examined the length-weight relationship and condition factor of Clarias gariepinus populations in Tiga dam and River Wudil, Kano State, Nigeria, with the aim of understanding the healthiness of the stocks and adaptability of the fish to different aquatic ecosystems. Over a six-week period, 60 C. gariepinus were collected from the study areas and analyzed for length, weight, and condition factor. Measurements were taken following standard protocols. Total length (TL) was measured from the tip of the snout to the caudal peduncle, while body weight was measured using a top-loading electronic balance. The length-weight relationship was estimated using linear regression and the condition factor was calculated using the length and weight measured. Statistical analysis revealed that C. gariepinus from River Wudil had slightly higher mean length and weight values, whereas C. gariepinus from Tiga dam had a slightly higher condition factor. The growth pattern showed negative allometry for the two water bodies, with C. gariepinus from Tiga dam exhibiting a slightly higher growth exponent. This study demonstrates the adaptability of African catfish to different aquatic environments and underscores the importance of ecosystem-based management approaches to ensure the long-term sustainability of these fish populations.

ABSTRACT Socio-economic status has a huge impact on fishing methods as it influences participation, fishing practices, gears and methods used. It is necessary to understand the socio-economic status and fishing methods used by the artisanal fisherfolks in order to have an insight and information on the sustainability of the water bodies. This study was therefore carried out to assess the socio-economic status and fishing methods used by artisanal fisherfolks on water bodies in Katsina State. The study used a two-stage sampling procedure to select three water bodies, one each from each of the three agro-ecological zones in the state, and then select 145 fisherfolks from the three water bodies based on the proportion of fisherfolks in the three water bodies. A well-structured questionnaire was administered and descriptive statistics was used to analyse the data. The socio-economic data revealed that 63% of the respondents are below the age of 40 years, primary school education with a percentage of 44% as the dominant educational status. The majority of the respondents has a maximum household size of seven, while 47% have between one and ten years of fishing experience. Fishing is the main occupation of 65.5% of the respondents, with 57.9% of them earning less than a maximum of 100,000 naira annually. Passive fishing method only represents the dominant method with 55.2%, while the factors considered in selecting fishing gears by the fisherfolks are led by the size of the water body, followed by fish size and shape. The study revealed that the socio-economic status of the fisherfolks is low, and this is corroborated by the passive fishing method dominating among them. The study recommends that the fishing communities should further utilize their associations to secure interventions and trainings that could help increase their practices and subsequently their socio-economic status.

The species of cichlids are easily misidentified due to their morphological similarities. This study, therefore, was designed to discriminate the cichlid species inhabiting Zobe reservoir using a molecular approach. Samples of different cichlid species were collected from the reservoir between August and November 2022 and identified using their morphological features following the field guide to Nigerian freshwater fish. Fin clips of two samples from each of the species were fixed in 100% ethanol and the DNA was extracted. The mitochondrial cytochrome oxidase (CO1) gene area was amplified (using the FishF1 and FishR1 primer pair), purified and sequenced to reveal the identity of the species. Morphologically, the result revealed the presence of four species, namely: Oreochromis niloticus, Oreochromis mossambicus, Sarotherodon galilaeus, and Coptodon zilli. The genetic identity of the samples agreed with the earlier attempt made at morphological discrimination except for O. mossambicus which matches the partial and complete genome of Oreochromis aureus, hence, solving misidentification. The phylogenetic tree of the CO1 genes constructed using MEGA 11 software reveals the species were grouped independently into the three different genera of the Cichlidae family (i.e., the Coptodon, Oreochromis and Sarotherodon). This study affirms the need for molecular confirmation of morphologically identified cichlids in Nigeria. Keywords: Cichlids, DNA Barcoding, Identification, Phylogeny, Polymerase Chain Reaction

Blood preservatives (anticoagulants) prevent blood from clotting while ensuring that the concentration of the component to be analysed stays constant prior to the analytical procedures. The study was aimed to evaluate the effects of different anticoagulants, such as ethylenediaminetetraacetic acid (EDTA), fluoride oxalate, sodium citrate and lithium heparin, on the haematological parameters of African catfish (Clarias gariepinus). Forty fish were obtained and separated into four groups representing the four treatments. Blood samples were collected from ten fish from each group and stored in separate anticoagulant laden bottles. Lithium heparin was used as control in this experiment. Each sample was processed, and values of the parameters were recorded. The RBC, haemoglobin, and PCV of the anticoagulants used were similar as no significant difference (P > 0.05) was revealed among the treatments. The heterophil levels of fluoride oxalate treatment group was significantly higher than control, this in turn led to an increase in HLR (heterophil-lymphocyte ratio). Therefore, the haematologic alteration observed in this study, which include heterophilia associated with fluoride oxalate anticoagulant, should be put into consideration when making a choice of anticoagulants for haematological analysis in C. gariepinus.

Fish species are important aquatic models utilised in ecotoxicology studies; however, most of these species are found in temperate countries. In this chapter, we reviewed native fish species in Nigeria that are utilised for ecotoxicology studies. A search of the literature was conducted using Google Scholar search engine from anytime until November 7, 2023, resulting in a total of 45 articles that were included in this review. The commonly used native Nigerian fish species in laboratory and field-based (biomonitoring) ecotoxicological studies are the African sharptooth catfish Clarias gariepinus, the Nile tilapia Oreochromis niloticus and the Guinean tilapia Coptodon guineensis. These fish species have been demonstrated to be valid models to study biomarkers of exposure to and effects of toxicants including pesticides, effluents, heavy metals, hydrocarbons, pharmaceuticals, plant and sediment extracts. They serve as bioindicators of stressors or pollutants in biomonitoring programmes with indices ranging from cellular (nuclear abnormalities, haematological effects) to tissue and organ histological alterations, oxidative stress indices as well as individual/population level effects (such as behavioural changes). We recommend targeted studies on the culture exploitation of other native Nigerian freshwater, brackish and marine fish species as well as ratification of C. gariepinus and O. niloticus as globally recognised model fish species for use in ecotoxicological studies.

Effects of processed duckweed meals as a replacement for toasted soybean meal in the diets of Oreochromis niloticus fingerlings were evaluated. Sun-dried and blanched duckweed meals were used to replaced toasted soybean meal in at 25, 50, 75, and 100% each. Feed Solution Software (version 2022) was used to formulate nine iso-nitrogenous diets at 32% crude protein. 27 Hapa nets of 1 m2 each were used for the feeding trials for six months. Ten fingerlings of Oreochromis niloticus were stocked per Hapa and fed 5% body weight three times per day. The best mean weight gain (460.59 g), viscerosomatic index (9.90) and feed conversion ratio (1.82) were recorded in the fish fed 75% blanched duckweed meal while the fish fed 100% sun-dried duckweed meal and 100% blanched duckweed meal recorded the poor mean weight gain, viscerosomatic index and feed conversion ratio of 401.69 g and 394.03 g, 6.49 and 6.36, 2.06 and 2.10, respectively. The cost-benefit evaluation revealed that 75% blanched duckweed meal gave the highest net profit (₦3,682) and lowest incident cost (₦6.49). This study revealed that soybean meal can be replaced with 75% blanched duckweed meal in the diet of Oreochromis niloticus without any inauspicious effects on the growth and nutrient utilization, and will reduce the cost of production and maximize profit.

The nutrient recovery potentials of the plants Ocimum basilicum and Corchorus olitorius in a polyculture aquaponic system were evaluated. Two treatments of polyculture aquaponics (fish + crayfish + O. basilicum; and fish + crayfish + C. olitorius) and a conventional recirculating aquaculture system (RAS) as the control (fish + crayfish) were set up in triplicates, randomly. The fish and crayfish were stocked at 75 fish:50 crayfish per treatment while three seedlings of each plant were placed in each planting cup. There were five plant throughs with each having 14 planting holes, making a total of 70 planting holes per treatment. The water quality parameters, growth performance and nutrients uptake of the fish, crayfish and plants were determined after 14 weeks observation. The results showed that the dissolved oxygen, electrical conductivity, total dissolved solids and nitrates in the culture tanks of both plant treatments were significantly higher than recirculating aquaculture system treatment, especially from eight weeks and above. The fish and crayfish in the O. basilicum-polyculture aquaponic system had higher final weight gain, 53.6 g and 14.8 g respectively, while higher survival rate (97.33 ± 0.77 and 82.67 ± 2.9, respectively), and lower feed conversion ratio (2.46 ± 0.06 and 2.68 ± 0.04, respectively) were observed in the RAS treatment, although there were no significant differences (P > 0.05) across treatments. The yield of O. basilicum (274 g m−2) was significantly higher than C. olitorius (213 g m−2), while the N-uptake by O. basilicum (128.4 g culture unit−1) was significantly higher than C. olitorius (102.2 g culture unit−1). However, there were about 37–41% of N, 38–41% of P and 44–48% of K after harvest which is an indication that aquaponics polyculture system can either accommodate more plant troughs (increase plant densities) or more planting cycle of the herbs.

The study was conducted over a period of fifty-six (56) days to investigate the effects of different colours of culture tanks on the water quality, growth, and feed utilization of Nile tilapia (Oreochromis niloticus) juveniles. O. niloticus of mean body weight of 8.5g were stocked and fed twice daily with a commercial diet containing 42% crude protein. The experiment had four treatments based on tank colours; white, green, black and blue coloured tanks. Some water quality indices were assessed once in a week while the fish were weighed at the end of the experiment to compute the performance indices. The data were presented using mean and standard error and comparative analysis was done using one way ANOVA at 95% confidence interval with Duncan multiple range test as the follow up test. The water quality parameters examined during the study were not significantly different among the treatments. All the selected water quality parameters were within the acceptable range for tropical fish culture. While there was no significant difference in final weight, weight gain, percentage weight gain, and specific growth rate among the treatments, black tanks showed slightly higher values with 10.89±0.89 g, 2.54±0.94g, 30.47±11.43%, and 0.47±0.16%/day, respectively. Higher feed intake and FCR were recorded in green tank (10.08±0.61 g and 7.92±2.70 respectively) and the least was observed in black tank (9.32±0.12g and 4.23±1.51). The percentage survival of the fish was different significantly among the treatments (P<0.05). Fish reared in white background showed the highest survival (100%) which was different significantly from all other treatments. The blue and black tanks showed slightly higher values of viscerosomatic index and hepatosomatic index with 7.22±1.00% and 2.02±0.25%, respectively, while black and white tanks had the least values with 4.44±1.11% and 1.64±0.15%, respectively. The results showed that O. niloticus juveniles can be reared in all the tanks with no negative implication on their performances. However, black and white tanks showed better potential towards improved growth and feed utilization, while white tank led to better survival rate and tended towards better well-being as indicated by the skin pigmentation and hepatosmatic index. Therefore, rearing of O. niloticus juvenile in white tank is recommended over other colours.

A 56-day experiment was undertaken to assess the influence of water changing frequency on the water quality, growth performance and physiological status of African catfish, Clarias gariepinus juveniles. There were three treatments with different water changing regimes, every two days, every four days and once a week. Nine plastic tanks were stocked with ten African catfish (10.39±0.36 g) each in triplicates for the three treatments. The fish were fed at 5% body weight daily. Selected water quality parameters were examined twice a week, while growth performance and physiological parameters were measured at the end of the eight weeks. pH, temperature and nitrate-nitrogen were not different significantly among the treatments. The highest total ammonia-nitrogen (0.55±0.01 mg L-1 ) was observed in the treatment with water changes once a week, and it was significantly higher than the treatment with water changes every two days. Both total dissolved solids and electrical conductivity were also different among the treatments. Growth performance improved with decreased frequency of changing water; weight gain, specific growth rate and yield were all higher significantly in the treatment with water changes once in a week compared to every two days. Nutrient utilization, survival and body indices were not different significantly among the treatments. Higher glycogen and healthier livers were noted in the treatment with water changes once a week. The result established that changing the water once a week for fish stocked up to 20 Kg m-3 may confer more advantages on the fish and lead to improved performance.

This study examined the status of fish farming in Katsina State with a view to understanding the current practices, management, operation, and constraints to its sustainable development. All the active and accessible fish farms in the state, thirty-two in number were visited and data was collected through the administration of structured questionnaires. The data were analyzed and presented using descriptive statistics; frequency and percentage. The result showed that most of the respondents were male (87.5%) with a mean age of 41 years. The majority of the respondents (59%) are graduates of higher institutions and married (75%) with a mean household size of nine. Most of the respondents (56.3%) were owners of the farms with the majority of them (59.4%) gaining knowledge of fish farming on the job. The production technique and species cultured indicated that monoculture of African catfish (Clarias gariepinus) accounts for 84.4% with concrete tanks being the most used culture facility (34.4%). The majority of the respondents (62.5%) had grow-out units with 68.8% of their culture system being stagnant renewal. Most of the respondents (90.6%) had two sources of water with 71.9% never carrying out any water quality management. The high cost of feeding was adjudged a major constraint by the respondents, while disease infestation, inadequate technical expertise, marketing, and inadequate capital were classified as minor constraints. There is a gradual development in aquaculture production in the state, especially in terms of practices, operation and management, although, the development appears to be at a slow pace.

The experiment was performed to check the lethal toxicity of aqueous extract of Calotropis procera on Clarias gariepinus juveniles. A range finding test was done and the concentrations for the definitive tests were determined. A total of 150 African catfish juveniles of average weight 9.37±0.08g were randomly selected and distributed into four treatments in triplicates of 20mg/L, 40mg/l, 60mg/L, 80mg/L concentrations and a control (0.00) using a static bioassay test over a period of 96 hours. Behavioral responses observed during exposure of the fish to lethal concentrations included erratic swimming, air gulping, haemorrhage, loss of equilibrium and sudden death. All data obtained were summarised using descriptive statistics for the mortality, water quality parameters, growth performance and nutrient utilization. While one-way analysis of variance (ANOVA) was used to assess differences in means among the concentrations and Duncan multiple range tests was used to separate the means, where there was a difference. Physico-chemical water parameters and haematological parameters showed various significant difference among the treatments (P< 0.05). C. procera at higher concentrations of 40mg/L and above was highly toxic to fish, which led to erratic behavior and mortality.

The species composition, size distribution, condition factor and growth pattern of cichlids from Zobe reservoir Dutsin-Ma, Katsina State was investigated between August and November 2022, with a view to understanding the distribution and well-being of cichlids in the water body. One hundred (100) cichlids were sampled from two (2) major landing sites (Makera and Garhi) of the reservoir, the fish were identified and separated before being transported in an ice box to the laboratory Biology Laboratory of the Federal University Dutsin-ma. At the laboratory, the length was measured to the nearest centimeter using a ruler while a sensitive weighing scale was used to measure the weight in grams. The results showed that four species were identified; Oreochromis niloticus (40), Oreochromis aureus (21), Sarotherodon galilaeus (21) and Coptodon zilli (18). The mean total length and weight were significantly higher (P<0.05) in O. niloticus compared to other species. The least was observed in O. aureus although it was not different significantly compared with C. zilli and S. galilaeus. The condition factor (K) of >1 was obtained in all the species with O. niloticus having the highest value of 2.26 which was significantly higher than 1.48 observed in O. aureus. All the species showed negative allometric growth, however, C. Zilli and O. aureus were very close to isometric growth with b values of 2.96 and 2.85 respectively. Although negative allometric growth was observed in all the species, the K values of >1 showed that all the cichlids in the Zobe reservoir are healthy and in good biological condition