Comparative Bioaccumulation of PAH and BTEX in Malapterurus electricus (Siluriformes: Malapteruridae) and its Enteric Parasite, Electrotaenia malopteruri Sampled from Lekki Lagoon, Lagos, Nigeria

Abstract

Contamination of Lekki lagoon by petrogenic chemicals such as polycyclic aromatic hydrocarbons (PAH) and benzene, toluene, ethylbenzene, and xylene (BTEX) has been widely reported. The study was aimed at investigating the bioaccumulation of PAH and BTEX in Malapterurus electricus collected from Lekki lagoon in Lagos, Nigeria. BTEX was analyzed in the intestine, water, and sediment samples using 8260B Agilent 7890B gas chromatograph coupled to a mass spectrometer (GC-MS). While PAHs were tested in the same media using a gas chromatograph coupled to a flame ionization detector (GC-FID). Histopathological analysis of the fish intestine was conducted using haematoxylin and eosin (H&E) stains. Parasite intensity, antioxidant enzymes, and lipid peroxidation activities were investigated in the fish. The parasitic infection detected in Malapterurus electricus was Electrotaenia malopteruri. The parasite showed weak and no depurative capacities for BTEX and PAH respectively. The decrease in superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) in conjunction with an increase in Malondialdehyde (MDA) characterized relatively higher susceptibility among the male fish. Varieties of tissue injuries increased with the standard length of the fish groups. Results suggest that lengthier and uninfected M. electricus were more susceptible to PAH in Lekki lagoon than the shorter and infected ones. The study demonstrated a promising tendency of the enteric parasite, E. malopteruri to depurate chlorobenzene, ethylbenzene, o-xylene, m+p-xylene, and 1,4-dichlorobenzene from the intestine of its host fish, M. electricus, while PAHs were poorly mediated by the parasite.

A comparative Study on Bioaccumulation of BTEX and Oxidative Stress Biomarker Response in Parasitised and Non -Parasitised Parachanna obscura (GUNTHER, 1861) from Lekki Lagoon, Lagos, Nigeria

“…Interestingly, Akinsanya et al, (2019) in a similar study reported that the parasite Wenyonia acuminata, infecting Synodontis clarias in the same study area did not bioaccumulate BTEX from fish. In another study by Isibor et al, 2020 the concentration of BTEX in the intestine of the Malapterurus electricus fish indicated that its enteric parasite Electrotaenia malopteruri significantly sequestered the toxicant's burden from the fish. Although the parasites were generally of low intensity in the fish, they, however, exhibited some ability to sequester chlorobenzene, ethylbenzene, o-xylene, m+p-xylene, and 1,4-dichlorobenzene from the intestine of the fish.…”

Bioaccumulation of organochlorine pesticides in the parasite Cosmocerca sp. (Nematoda: Cosmocercidae) and the amphibian host Amietophrynus regularis (Reuss, 1833) within Lagos metropolis, Nigeria

“…Insecticides cans should therefore be burned in a proper incinerator designed for organochlorine waste disposal. In cases where this is not possible, efforts should be made to bury the materials in an approved dump or landfill [ 30 ] where there is no risk of contamination of surface or groundwater [ 31 ]. The most important recommended guide to the handling of lindane is total compliance with the local legislation regarding the disposal of toxic wastes.…”