Spatial distribution of ectoparasites on the gills of the mullet,Liza macrolepis: the effects of pollution.
Spatial distribution of ectoparasites on the gills of the mulletLiza macrolepiscollected from two sites, the unpolluted reference site (Site I) and the heavily polluted North western arm of Visakhapatnam harbour (Site II), was analysed. Of the various ectoparasite species found on the gills of the mullet, onlyAncyrocephalus vanbenedeni(Monogenea) andDermergasilus varicoleus(Copepoda), occurred commonly at both the sites with more or less high prevalence and mean intensity.A. vanbenedeniat site I preferred gill arch 1 and posterior most and central sections, whereas at site II, it showed preference for gill arch 3, and posterior and proximal sections of the gill.D. varicoleusis highly specific in site selection. It preferred gill arch 1 and the anterior and distal parts at both the sites.Ergasilus rostralisfavoured gill arch 3 and anterior and proximal sectors, a safe place providing absolute protection from the environmental pollution. It is concluded that the distribution of various ectoparasites on the gills ofL. macrolepisis determined by the force of ventilation water current, the behavioral response of the parasite to the stress induced by pollution and the surface area of gill arches.
Department of Zoology, Andhra University, Visakhapatnam, 530 003 India.
Ruchika
R
Kumar
Department of Zoology, Andhra University, Visakhapatnam, 530 003 India.
Rokkam
R
Madhavi
Department of Zoology, Andhra University, Visakhapatnam, 530 003 India.
Bade
B
Sailaja
Ectoparasites; Gosthani estuary; Liza macrolepis; Mullet; Pollution; Spatial distribution