The indiscriminate use of inorganic fertilisers to boost plant productivity has resulted in negative consequences in aquatic ecosystems. The effects of chronic exposure to NPK (15:15:15) fertiliser at 0.40, 0.80 and 1.60 g l −1 on the haematological and biochemical responses of Clarias gariepinus were determined under a static renewal bioassay for a period of 56 days in April-June 2013. There was a reduction in haemoglobin levels, mean corpuscular haemoglobin and haematocrit, while mean corpuscular haemoglobin concentration increased in exposed fish compared to the control. There was a significant difference (p < 0.05) between the levels of the parameters examined in exposed fish and the control. However, a mixed trend was observed in the leucocyte differentials. In addition, glucose, alanine aminotransferase and aspartate aminotransferase levels were significantly increased while protein levels were reduced (p < 0.05) in the plasma throughout the exposure period. Prolonged exposure of C. gariepinus juveniles to NPK can lead to physiological dysfunction in the fish.
Fingerlings of Tilapia zillii (5.20 gm ±0.03) were exposed to sap extract of Euphorbia tirucalli at concentrations of 6.00, 3.00, 1.50, 0.75 and 0.38 mg-1 with control as 0.00 mg-1 for 96 hours. The static bioassay showed that the 96-hour LC50 was 1.20 mg with lower and upper confidence limits of 0.78 and 1.85 mg respectively. Erratic swimming, loss of balance, respiratory distress, air gulping was observed before eventually death of the fish. Opercular ventilation and tail fin counts increased with increasing concentrations of the sap extract. Histopathological examination of the gills and liver revealed damages to these organs which were directly proportional to the concentration of the sap extract while those in the control tanks remained unchanged. Phytochemical analysis of the sap extract showed the presence of alkaloid, tannin, saponin, cardiac glycoside, rotenone, phenols, volatile oil, balsam and steroids. Water quality parameters monitored showed no significant difference (P>0.05) in temperature and pH while there was significant difference (P>0.05) in values obtained in dissolved oxygen, free carbon oxide and alkalinity. The implications of the findings as they affect the exposed fish and the aquatic ecosystem are discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.