Egg chorion ultrastructure of Lophius species from the Mediterranean Sea

Abstract

Identification of fish eggs is one of the most difficult problems faced when working with ichthyoplankton. In marine teleosts the structure of the egg chorion is an indication of the systematic status of the species and it has a morphology which is species-specific; because of that some authors consider the possibility of use it in identifying eggs of different species. For this reason chorion surface and micropyle of unfertilized eggs of black anglerfish Lophius budegassa and white anglerfish Lophius piscatorius were examined by scanning electron microscopy. Lophius eggs are spherical. The chorion of both species was smooth, with pores distributed evenly over the surface. It consists of a thin outer zone and a thicker laminated inner zone. The micropyle is funnel-shaped, at the bottom of which is a circular aperture leading to the micropyle canal which traverses the entire chorion layer