Journal of Aquatic Sciences

Histopathological responses in liver, brain and gills of Oreochromis niloticus juveniles exposed to water soluble fractions of crude oil

2024-02-08T11:58:03+00:00

Aquatic pollution has been shown to induce different changes ranging from biochemical alterations in single cells to changes in whole populations. In this study, qualitative analyses of liver, brain and gills histopathological parameters were evaluated in Oreochromis niloticus after exposure to water-soluble fractions of crude oil. After preliminary short-term (96 hours) bioassay, fish were subjected to four sublethal concentrations (30, 45, 60, and 75 % of the LC₅₀ corresponding to 28, 41, 55, and 69 mg/l respectively), and a control group using a semi-static renewal method for 90 days. After the exposure period, the liver, brain and gills were harvested, labeled and prepared for photomicrography using standard procedure. Results showed atrophy and necrosis of hepatocytes and degeneration of hepatopancreas in the liver. The histopathological alterations in the brain included mild congestion of cerebral blood vessels, widespread vacuolation of neuropil, necrosis and atrophy of neurons. In the gills, congestion of capillaries, atrophied and necrotic lamellae were detected. Overall, the study revealed that histopathological biomarkers can be relied upon as a suitable tool for accessing long-term impacts of crude oil spillage in the aquatic environment. Therefore, an immediate multi-agency response approach for efficient and effective management of oil spills is recommended.

Potential of cattle hair meal based diet as fishmeal replacer on physiology of Clarias gariepinus juveniles

2024-02-08T12:22:20+00:00

The Cattle hair meal (CHM) has the potential of usage as a dietary protein source in fish nutrition due to the qualitative nutrients present in it and the enormous quantity generated at abattoirs worldwide. This study investigated the inclusion of CHM in diet of Clarias gariepinus as fishmeal replacement. Catfish juveniles with average weight of 5.86±0.14g were stocked in 15 plastic tanks at 21fish/tank in completely randomized design. The experimental fish were fed with 40% crude protein diet at 0%, 25%, 50%, 75% and 100% inclusion of CHM at 3% body weight for duration of 8 weeks. Growth performance, carcass quality, haematology, digestive enzymes, gut morphology and histology of C. gariepinus were assessed. Growth parameters differed significantly (P<0.05) among treatments with similar responses in carcass composition. The blood parameters, digestive enzymes and intestinal morphology also showed variations among treatments. Histological observation revealed that only diet with 25% CHM inclusion showed no alteration in tissues of kidney, liver and intestine. This study recommends usage of CHM up to 25% as replacement for fishmeal in C. gariepinus diet.

Toxicity evaluation of single and multiple mixtures of some facial cosmetics on mud catfish (Clarias Gariepinus) fingerlings

2024-02-08T12:44:08+00:00

Astronomical discharge of facial cosmetic products into the aquatic environments exposes aquatic organisms to these pollutants. Eight facial cosmetic products such as Milani Powder, Ponds Primer, Zikel Powder, Zaron concealer, Glam gal’s foundation, Maybelline foundation, L.A Girl concealer and Milk of Magnesia were evaluated for relative acute toxicity (single and joint action) against Clarias gariepinus in static laboratory bioassays. Single action toxicity data were statistically analysed based on Probit, while the Synergistic Ratio and Concentration - Addition analysed joint action. Results of acute toxicity (single action) based on 96hrLC₅₀ values showed that Milani Powder (184.14 mg/l) was the most toxic, followed by Ponds Primer (230.95 mg/l), Zikel powder (233.58 mg/l), Aaron concealer (384.47 mg/l), Glam Gals’ foundation (421.83 mg/l), Maybelline foundation (565.32 mg/l), L, A Girl concealer (587.75 mg/l) and Milk of Magnesia (2218 mg/l) in descending order of toxicity. Joint action toxicity evaluation of the binary, trinary and quaternary mixtures subjected to the Synergistic Ratio and Concentration showed that binary mixtures tended towards synergism and antagonism in varied ratios and combinations. The ratio of toxicity units for all mixtures interaction tended to synergism and could be dangerous to the biota. Therefore, strict regulation standards should be enforced to protect the environment and make eco-friendly alternative ingredients that can be incorporated into these products.

Comparative assessment of heavy metal levels in crabs, periwinkles and oysters obtained from Eyaa Creek, Upper Bonny Estuary, Onne, Nigeria

2024-02-08T12:54:33+00:00

This study examined heavy metals in some aquatic organisms [crabs (Callinectes amnicola), periwinkles (Tympanotonus fuscatus) and oysters (Crassostrea gasar)] from Eyaa Creek, Onne, in southern Nigeria. Samples were collected from four stations monthly for three months. Characterization of the environment was via physico-chemical properties, while heavy metal analysis was by Atomic Absorption Spectrometry. Physico-chemistry results indicated: temperature; 30.2 – 30.7^oC; pH: 6.7 – 6.8; dissolved oxygen: 6.1 – 6.3 mg/l; electrical conductivity: 18.8 – 20. 8 mS/cm; total dissolved solids: 4698.5 – 6212.0 mg/l; salinity: 11.1 - 12.4 PSU and turbidity: 3.7 - 4.7 NTU. ANOVA showed insignificant difference (p>0.05) between stations indicating homogeneity of the area assessed. Mean metal concentrations (mg/ kg) in the organisms were cadmium: 0.18 ± 0.09 - 0.60 ± 0.08; chromium: 0.41 ± 0.14 – 0.78 ± 0.08; iron: 12.1 ± 6.9 - 20.2 ± 7.7; lead: 0.31 ± 0.2 – 0.91 ± 0.05. Chromium and lead values were above permissible values of FAO/WHO and EU but cadmium fell within and above the limits. Principal component analysis did not show a clear pattern with organisms’ feeding habit but discriminated based on metal concentrations. In conclusion metal concentration in periwinkles>crabs>oysters which was related to their feeding habits in terms of sediment and pelagic affiliations.

Acute toxicity, behavioural and histological changes in juvenile clarias gariepinus exposed to atrazine

2024-02-08T13:03:47+00:00

The study determined acute toxicity, behavioural changes and histological effects of atrazine on juvenile Clarias gariepinus. The experiment involved exposing groups of fish to different concentrations {0.00 (control), 3.75, 6.25, 8.75, 11.25 and 13.75mg/l} of atrazine and monitoring fish mortality, physicochemical parameters of the test water and behavioural changes in the fish. The histological assessment of liver and gills was also carried out on dead fish to examine possible changes in their structural makeup in comparison to the organ extracted from the control. Acute toxicity test was conducted using standard methods and fish mortality was monitored for 96 hours. The physico-chemical parameters such as temperature, pH, dissolved oxygen, total dissolved solids and electrical conductivity in the test solutions were monitored using standard procedure. The study revealed that there was no mortality in the control group, which had no atrazine, while mortality rates increased with increasing concentrations of atrazine. The highest percentage mortality (83.33%) was recorded at the highest concentration of 13.75mg/l. The 96- hour lethal concentration (LC₅₀) value of atrazine computed based on logarithm was 8.84mg/l. At exposure to acute concentrations, fish showed abnormal behaviour such as restlessness, loss of colouration, respiratory stress, erratic swimming and instant death. Histological effects observed on the gills exposed to atrazine included interstitial haemorrhage, deformed primary and secondary lamella, lesion, blanketing and blood congestion. Liver tissues showed necrosis and vacuolation of hepatocytes. Dissolved oxygen level in the test solutions that contained atrazine reduced drastically and this might have induced death in fish recorded in the study. Inference from the study revealed that atrazine may be toxic to aquatic organisms, particularly juvenile C. gariepinus.

Assessment of the physico-chemical parameters and prawn species in Ase River, Delta State, Nigeria

2024-02-08T13:10:06+00:00

The study was conducted to determine the physico-chemical parameters and prawn species available in Ase River at Ndokwa East L.G.A. of Delta State, Nigeria. Water samples were collected for nine (9) months from January to September, 2023. Samples were collected with plastic bottles at the deepest part of the river, they were labelled and kept in ice-chest box and transported to the laboratory for further analysis. Analysis of the water parameters followed standard procedure. Dissolved oxygen, electrical conductivity, temperature and pH were measured in-situ while other variables: (total dissolved solid, nitrate, carbonate, biochemical oxygen demand, and hardness) were determined in the laboratory. Prawn samples were collected from artisanal fisherfolks who used traditional basket valve traps made of bamboo to harvest. All protocol followed standard procedure. Results showed the mean dry season water temperature (27.9 ± 0.22 mg/l), carbonate (1.02 ± 0.02 mg/l) and BOD (2.23 ± 0.05 mg/l) which were significantly different (p < 0.05) and higher than the mean results for the wet season which were 26.6 ± 0.03 mg/, 0.86 ± 0.05 mg/l and 1.79 ± 0.10mg/l for temperature, carbonate and BOD respectively. Prawn species obtained and their percentage prevalence were Macrobrachium vollenhovenii (41.8%), Macrobrachium macrobrachion (36.5%) and Macrobrachium potamalpheops (21.7%). Results from the study showed that the variation in physico-chemical parameters influenced the abundance of prawn species found in the environment. It is recommended that government agencies carry out fisheries extension education which could help the artisanal fisherfolks in sustainable harvest practices.

Cost effect and growth responses of Clarias gariepinus juveniles fed local and commercial feeds in tarpaulin ponds

2024-02-08T13:19:34+00:00

This study evaluated growth performances, survival rates, and cost-effectiveness of using locally formulated feed compared to three commercial feeds (Skretting, Bluecrown and Top). 4,000 Clarias gariepinus juveniles were sorted and stocked at 500 each into 8 tarpaulin ponds. Feeding duration was 56 days and fish were fed twice daily at 5% of body weight. Assessments of growth parameters, water quality, and cost analysis were done following standard procedure. The results showed that Skretting had the highest average weight gain (171.80g) followed by the locally formulated feed (140.73g) then, Top feed (140.50g) and the Bluecrown (134.77g). Skretting also had the best feed conversion ratio (FCR) of 1.48 followed by local feed which had 1.66, Top feed (1.75) and Bluecrown (1.80). The results of economic evaluation revealed that locally produced feed was found to be significantly (P<0.05) cheaper than the commercial feeds, costing ₦129.82 to produce 140.73g of fish flesh at ₦536.7/kg. this was followed by Bluecrown (₦206.13 to produce 134.77g at ₦820/kg), Top feed (₦212.60 to produce 140.50g at ₦833.33/kg) and Skretting (₦377.92 to produce 171.80g of flesh at 1,400/kg). There were no significant differences (P>0.05) in survival rates and the water parameters in the culture ponds. While Skretting was best in promoting fish growth, locally formulated feed proved to be cost-effective and an economically competitive option.

Assessment of fish logistics and supply value chain in some fishing camps along River Escravos route to some markets in Warri Metropolis, Nigeria

2024-02-08T13:27:38+00:00

The study examined empirical solutions to fish logistics and supply value chain network from selected fishing camps to markets in Warri South, Delta State, Nigeria. Issues relating to high cost of transporting fishes and fisheries products from fishing camps to major markets, poor logistic practices, physical handling and packaging of fishes during transit, are major determinant in the final market price of fish, and also play critical role in the immediate physical satisfaction of the fish consumer. In this study, 100 questionnaires were distributed to fishermen, boat drivers and distributors, eighty (80) questionnaires were returned. Multiple regressions were used for the analysis with statgraphic software version 16.0. The results of the study showed that there was a statistically significant relationship (P < 0.05) between transportation cost of fish and perceived price of fish at a great extent with p-value of 0.01 which is less than alpha level of 0.05. Results also showed that significant relationship existed in the integration of logistics services and this promotes the economic value of fish at a moderate extent at 0.01 which is less than 0.05 alpha value. Finally, recommendations were made for policy implications.

Automotive gas oil effects on performance of Clarias gariepinus: Implications of oil spills in the Niger Delta, Nigeria

2024-02-08T13:33:50+00:00

Water pollution, which is sometimes caused by the spilling of crude oil or commercial petroleum fuels (CPFs), is a major environmental problem that causes toxic effects in aquatic ecosystems. Hence, the effects of varied concentrations of Automotive Gas Oil (AGO) on aquatic species (Clarias gariepinus) was investigated. A total of 250 juveniles of C. gariepinus (mean weight 3.3g) were procured and used for the experiment. Fish samples were divided into five groups and assigned to different AGO concentrations (0mg/l (control), 5mg/ l, 10mg/l, 15mg/l, and 20mg/l) in a laboratory condition for a period of 14 days. Each treatment was split into 3 replicates, containing 14 juveniles of C. gariepinus each. A 20-liter capacity holding tanks filled with de–chlorinated bore hole water was used for the experiment. The effects of exposure to AGO pollution levels on proximate composition, and freshness of test organisms were investigated following standard procedure. Data collected were subjected to analysis of variance (ANOVA) and test of significance was by Duncan Multiple Range Test. From the results there was no mortality recorded for fish exposed to all treatments. However, AGO pollution levels significantly affected (p>0.05) proximate composition, and fish freshness. There were no significant differences (p<0.05) in freshness of fish among the control group, 5mg/l and 10mg/l AGO levels. Moisture (5.88-7.95%) and fat (11.09- 21.25%) contents, energy (282.73-424.58Kcal) and carbohydrate (16.03-28.40%) levels of fish decreased with increase in AGO pollution level. The study concluded that C. gariepinus is a good bio-indicator for AGO polluted aquatic environment. The results of the present study implied that fish populations in Niger Delta polluted waters are negatively impacted in terms of quality and quantity. Measures to stop pollution of water bodies by AGO and other refined crude products are recommended by the study.

Effects of onion peel wastes on nutritional and organoleptic quality assessment of smoked Clarias gariepinus

2024-02-08T13:44:20+00:00

The wastes from onion usually litter sales outlets in various markets across the country. Onion (Allium cepa) peel wastes (OPW) was assessed for its chemical content, nutritional and organoleptic quality on smoked catfish (Clarias gariepinus) stored for a duration of 8 weeks at room temperature. The OPW at concentrations of 0g, 2.5g and 5g (T0, T1 and T2 respectively) were sprinkled on the fish samples before and after smoking. Samples of OPW and fish were analyzed chemically for proximate composition, and determination of organoleptic quality according to standard method by panel of 20 on a 9-point hedonic scale. Nitrogen free extract (43.26%) constituted the highest analyte of the OPW. This was followed by ash (32.95%); crude fibre (11.45%); moisture content (6.69%); crude protein (4.40%) and ether extract (1.25%). The composition of fish preserved with OPW was significantly different when compared with the initial and final carcass analysis of the control group. The analysis revealed crude protein in T0 (49.84%), T1 (36.91%), T2 (43.13%); ash in T0 (7.70%), T1(14.05%), T2 (8.20%) while ether extract T0 (8.65), T1 (5.55%) and T2 (7.76%). In terms of organoleptic assessment, all the mean values of the fish samples were above 5 which indicated that they were not disliked. The control fish, T0 (0.0g/0.5kg) had superior taste, 7.95%; appearance, 7.60%; aroma, 7.45%; texture, 7.60% and acceptability, 7.85%. this was followed by T2 (5.0g/0.5kg) with no significant variation (p < 0.05) among the test samples. Inference from the study showed that OPW at 5g can be used to preserve smoked fish without change in quality, sensory and organoleptic assessment for 8 weeks.

Formalin in imported frozen fish products in Bayelsa State, Nigeria: effects of heat treatments on the concentration and health risk assessment

2024-02-08T13:52:57+00:00

Fish make up an essential component of daily diets due to their nutritional composition. In this study, formalin concentration in imported fish products in Bayelsa State, Nigeria, was undertaken. The effect of household heat processing treatments on the formalin concentrations, and the potential risk associated with consumption of these fish products, were evaluated. Fish products of different species were obtained from wholesale and retail outlets, and were prepared as raw, cooked, fried and smoked samples. Formalin was extracted from the prepared fish samples using a mixture of acetone and dichloromethane, and quantified using GC-MS. The average daily intake (ADI) of formalin was used to estimate potential health risk. Results showed low concentration of formalin in the raw fish samples, while heat processing treatments (frying and boiling) significantly elevated formalin concentrations. The formalin concentrations of heat processed fish samples with respect to the raw samples followed the order: smoked < raw < boiled < fried; and raw < smoked < boiled < fried for wholesale and retail products respectively. However, all formalin concentrations were below guideline values. The ADI of formalin were below established guideline values, suggesting that the intake of formalin in fish before and after household heat processing treatments may not pose significant risk to consumers of the imported frozen fish products.

Bacteria associated with Periophthalmus papilio and Bostrychus africanus from creeklets of the New Calabar River, Rivers State, Nigeria

2024-02-08T14:01:47+00:00

The study investigated the bacteria associated with two species of gobies (Periophthalmus papilio and Bostrychus africanus) from two Creeklets; Iwofe and Bakana of the New Calabar River. Determination of bacterial loads, species characterization and composition in fish parts (skin, intestine and gills) were done using standard microbiological procedures. Results revealed a total of eight bacterial species: Bacillus subtilis, B. licheniformis, B. megaterium, Staphylococcus aureus, Escherichia coli, Micrococcus sp, Pseudomonas sp and Proteus sp. The total viable counts of bacterial isolated from Periophthalmus papilio revealed 6.4 × 10⁷ and 9.2 × 10⁷ cfu/g from the skin, 4.8 × 10⁸ and 2.2 × 10⁸ cfu/g from the intestine and 5.2 × 10⁷ and 7.1 × 10⁷ cfu/g from the gills in Bakana and Iwofe Creeklets respectively. The total heterotrophic bacterial counts of Bostrychus africanus showed 2.5 × 10⁷ and 8.5 × 10⁷ cfu/g from the skin, 2.8 × 10⁸ and 1.5 × 10⁸ cfu/g from the intestine and 1.5 × 10⁷ and 6.0 × 10⁷ cfu/g from the gills from Bakana and Iwofe Creeklets respectively. Bacillus subtilis, Staphylococcus aureus and Escherichia coli had the highest frequency of occurrence (20%) while Pseudomonas and Proteus sp. occurred twice (5%). Analysis of variance (ANOVA) on the data showed that there was no significant difference at p ≥0.05 between the bacteria isolated from the two fish species collected from Iwofe and Bakana Creeklets. Some bacterial flora (Bacillus sp) isolated in the present study composed of potential pathogenic organisms of public health interest. Thus, the cooking process applied to fishes before consumption should employ temperatures that can eliminate these pathogens.