Evaluation of Haematological and Biochemical Parameters of Juvenile Oreochromis niloticus after Exposure to Water Soluble Fractions of Crude Oil

The influence of water soluble fraction of crude oil from Afiesere oil field on water qualitycomponents and its consequent effect on haematological and biochemical parameters in juveniles of Oreochromis niloticus were evaluated. After a preliminary determination of the 96 h-LC50 of crude oil by probit regression was found to be 92.38 mg/l, fish were exposed to 4 sub-lethal concentrations (30, 45, 60 and 75% of the LC50 corresponding to 28, 41, 55 and 69 mg/l respectively) of the oil and a control. After 84 days of exposure, blood was collected and used in conducting haematological and biochemical analyses. Exposure of water to crude oil caused increased levels in chloride, conductivity, salinity, magnesium, biochemical oxygen demand, chemical oxygen demand, turbidity and Nitrate. The crude oil contaminated water resulted in a significant reduction (p<0.05) in the values of red blood cells, packed cell volume and haemoglobin. Although no definite trend in the values of computed haematological indices was observed, MCHC, however, decreased with increased concentration. Also, Glucose, ALP, ALT, AST, Urea and creatinine activities of all the affected set of fish, which have been exposed to the crude oil were significantly higher (p<0.05) in comparison to their respective control. Keywords: Crude oil, Afiesere oil field, blood, toxicity, water quality, Oreochromis niloticu

REPRODUCTIVE PERFORMANCE OF HATCHERY-BRED, WILD-CAUGHT BROODSTOCK, AND THEIR OUTBREED OF THE AFRICAN CATFISH Clarias gariepinus (Burchell, 1822)

This study was conducted to evaluate the reproductive performance of hatchery-bred and wild-caught broodstock of Clarias gariepinus. Thirty pairs of each hatchery-bred and wild-caught broodstock (15 females and 15 males) was used for the study. Induced breeding was carried out in four groups with three replications at a ratio of 1:1 by hypophysation method. Group A: hatchery-bred male and hatchery-bred female (HBM m + HBF f); B: wild-caught male and wild-caught female (WCM m + WCF f), C: hatchery-bred female and wild-caught male (HBF f+ WCM m) and D: wild-caught female and hatchery-bred male C. gariepinus (WCF f + HBM m). Results showed that egg diameter, sperm motility, sperm density, and male GSI were not significantly different (P>0.05) whereas ovary weight, sperm volume, fecundity, female GSI, and percentage fertilization were significantly higher (P<0.05) in hatchery-bred broodstock than wild-caught broodstock. Hatchability was significantly higher (P<0.05) in Group C and D than A and B. In conclusion, a better reproductive performance in C. gariepinus with an economic advantage could be recorded through the combination of wild-caught and hatchery-bred broodstock

Factors affecting feed intake in cultured fish species: A review

Feed expense constitutes the bulk of the whole cost of production in any intensive aquaculture setup in Nigeria. Consequently, feed and feeding stratagems are of paramount interest for feed utilization as well as profit maximization. However, the paucity of documents on the factors affecting feed intake in cultured fish is negatively influencing the efficiency of fish production from aquaculture. Hence, the major factors influencing feed intake by cultured fish are discussed. These factors include management practices, environment conditions, feed quality, inherent genetic factor and physiological condition of the fish. The review would help to increase basic knowledge on the nutrition (with emphasis on feed intake) of aquaculture species for improved management and productivity.Keywords: Nutrition, Aquaculture environment, Fish metabolism, Feed management, Feed quality, Feed intak

Evaluation of Haematological and Biochemical Parameters of Juvenile <i>Oreochromis niloticus</i> after Exposure to Water Soluble Fractions of Crude Oil

The influence of water soluble fraction of crude oil from Afiesere oil field on water qualitycomponents and its consequent effect on haematological and biochemical parameters in juveniles of Oreochromis niloticus were evaluated. After a preliminary determination of the 96 h-LC50 of crude oil by probit regression was found to be 92.38 mg/l, fish were exposed to 4 sub-lethal concentrations (30, 45, 60 and 75% of the LC50 corresponding to 28, 41, 55 and 69 mg/l respectively) of the oil and a control. After 84 days of exposure, blood was collected and used in conducting haematological and biochemical analyses. Exposure of water to crude oil caused increased levels in chloride, conductivity, salinity, magnesium, biochemical oxygen demand, chemical oxygen demand, turbidity and Nitrate. The crude oil contaminated water resulted in a significant reduction (p&lt;0.05) in the values of red blood cells, packed cell volume and haemoglobin. Although no definite trend in the values of computed haematological indices was observed, MCHC, however, decreased with increased concentration. Also, Glucose, ALP, ALT, AST, Urea and creatinine activities of all the affected set of fish, which have been exposed to the crude oil were significantly higher (p&lt;0.05) in comparison to their respective control. Keywords: Crude oil, Afiesere oil field, blood, toxicity, water quality, Oreochromis niloticu

Water soluble fractions of crude oil deteriorates water quality parameters and alters histopathological components of juvenile Clarias gariepinus

In this study, the water quality changes after the introduction of water soluble fractions of crude oil were monitored along-side the accompanying effects on histopathological changes in selected organs of juvenile Clarias gariepinus. After a preliminary short-term (96 hours) static toxicity tests, fish were exposed to four sub-lethal concentrations (30, 45, 60 and 75 % of the LC50 corresponding to 67, 101, 135 and 169 mg/l respectively) and a control group containing clean water using a semi-static renewal method for 90 days. Water quality parameters, heavy metals and total petroleum hydrocarbon (TPH) were determined using standard methods. After the exposure period, liver, brain and gill were harvested, labeled and prepared for photomicrography. Chloride, conductivity, salinity, magnesium, biochemical oxygen demand, chemical oxygen demand, total dissolve solids, turbidity and nitrate levels increased significantly (p&lt;0.05) with increasing concentration of water soluble fractions (WSF) of the crude oil. Temperature readings and phosphate levels were however not affected (p&gt;0.05). Values of TPH increased (p&lt;0.05) with increasing concentrations of the crude oil. All analysed heavy metals followed a direct proportional trend as their values increased (p&lt;0.05) alongside concentrations. Several histopathological alterations were found in the liver (sinusoidal congestion, atrophy of hepatocytes, hepatocellular degeneration and diffuse coagulation necrosis of hepatocytes), brain (vascular congestion and atrophy of neurons, neuronal necrosis, gliosis and loss of neurons) and gill (moderate loss of the secondary gill lamellae, moderate lamellae atrophy and moderate diffuse lamellae hyperplasia). The intensity of these lesions increased with increase in exposure dose.Keywords: Toxicity, Petroleum, Heavy metals, Water quality, Organs, Clarias gariepinus, LC5

Characterization of polycyclic aromatic hydrocarbons in mangrove sediments from Ifiekporo Creek, Warri, Nigeria

Abstract The occurrence and level of polycyclic aromatic hydrocarbons (PAHs) in mangrove sediment from Ifiekporo Creek in Warri, Delta State, Nigeria, were assessed in this study. The extraction of PAHs from the sediment samples was achieved using the PAH analytical test method (USEPA 8270). This method measures the individual concentrations of extractable PAHs in samples. The PAHs were quantified within the C11-C22 subgroup. The basic GC parameters for the analysis of polyaromatic hydrocarbons were analysed using a gas chromatography‒mass selective detector (GC‒MSD). The individual PAH concentrations in the mangrove sediment samples ranged from 850 µg/kg−1 to 3470 µg/kg−1. PAH source apportionment employing isomeric ratios and multivariate statistics indicated both pyrogenic and petrogenic source inputs in the sediment samples. The order of PAH homology in the sediment was 3-ring > 2-ring > 4-ring. The sediment samples were mostly dominated by LMW PAHs. The results of the ecological risk assessment in the study area indicate that there is low ecological risk associated with PAH exposure in sediment. These results provide data on the concentrations and compositional patterns of PAHs, which is useful for understanding the effects, sources, fates, and transport of PAHs in sediment in the study area, as well as for providing relevant information for environmental quality management and forensic studies