Evidences of possible influences of methylmercury concentrations on condition factor and maturation of Lophius vomerinus (Cape monkfish)

Abstract

Muscle and liver tissues of Lophius vomerinus off the coast of Namibia were analysed to investigated the influence of MeHg on the biological parameters of L.vomerinus by (i) determining if the variability in total MeHg concentrations is influenced by length, maturity status and sex, and (ii) assessing if there is a relationship between biological indices (Condition factor (K), Gonadosomatic Index (GSI) Hepatosomatic Index (HSI)) and MeHg concentrations. Correlations between total MeHg concentrations and fish length, K and HSI were observed. A weak positive correlation was observed between total MeHg and GSI for combined sex. Total MeHg concentration in tissues of L. vomerinus is significantly dependent on the maturity stages (p < 0.05). K was significantly inversely correlated with total MeHg in tissues of L. vomerinus. The evidence presented in this study suggests that MeHg in L. vomerinus tissues could be detrimental to both its physiology and population dynamics.

Keywords: Condition factor; Gonadosomatic index; Hepatosomatic index; Lophius vomerinus; Methylmercury.