The Caryophylleadae cestodes, Wenyonia spp Woodland, 1923 Bioaccumulates High Quantities of A Specific PCBs Congener in the Fish Host, Synodontis clarias (Linnaeus, 1758), with Histopathological Alterations as Biomarker Response

Document Type : Original Article

Authors

1 1- Department of Zoology, University of Lagos

2 Department of Marine Sciences, University of Lagos

Abstract

One hundred and fifty samples of Synodontis clarias were collected,and subjected to parasitologic  examination.They were analyzed from three stations of the sampling site (Epe axis of Lekki Lagoon). Out of the total number of specimens examined from the three stations, 56 (37.33%) were infected. The total infected individuals from the three stations had 30 (20.0%) males and 26 (17.33%) females while the non-infected individuals for all the stations had 64 (42.67%) males and females. Also, in this study, Synodontis clarias were infected with two (2) species of parasites the Cestodes (Wenyonia spp) and Nematode (Raphidascaroides spp) which is common among family Mockokidae. The concentration of Polychlorinated biphenyl in the fish tissue, parasite, sediment and water collected from the sampling site were also analyzed . The PCB congeners 8, 18, 28, 44, 77, 81, 123, 153, 156 detected in the water and sediment sample of all the 209 PCB congeners were also reported. The findings presented in the study showed more of the lower chlorinated PCB congeners in the water sample than in the sediment, Synodontis clarias and parasite sample from the three stations in the Epe axis of Lekki Lagoon. The concentration of PCB congeners in the parasite was high in Oribo and Ikosi (549.53 ppb and 569.95ppb) sampling station while it is low in Imode (57.77ppb) station. There was high quantity of PCB 81 found in the parasite but not found in the fish host.The fish samples collected from Oribo had the high concentration of congeners 28, 18, 44, and 52 among other detected, while fish samples collected from station Imode had the high concentration of 44,18,8 and 28 and the fish samples collected from station Ikosi also had the high concentration of PCB 44, 18, 8 and 123 respectively. However, the concentration of PCBs level found in the fish tissue was above W.H.O limits of 200 part per billion (ppb) in Oribo and Ikosi ((607.42ppb and 325.43ppb) sampling station while the concentration was below in Imode (188.61ppb) sampling station and hence the Synodontis clarias in Oribo and Ikosi is not safe and edible for consumption. Laws enacted to protect our Aquatic environment should be enforced.However, the study showed a need for continuous pollution assessment study of aquatic organisms and its environment.

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