Changes in structure of the frontal filament in sequential developmental stages of Caligus elongatus von Nordmann, 1832 (Crustacea, Copepoda, Siphonostomatoida)

Publisher Website
Google Scholar
Abstract
The frontal filament of larval and adult Caligus elongatus was examined using light and electron microscopy. No trace of a frontal filament was evident in eggs, nauplii, or young copepodids. The structure develops in older copepodids in a cuticular pocket in the cephalothorax. Upon infecting a fish, the filament extrudes and attaches permanently to the host. The subsequent chalimus stages inherit the filament. Before moulting, the "frontal organ" produces an extension lobe, which is attached to the old filament by each subsequent chalimus stage during the moult. The structure of the frontal filament is described and illustrated, as well as some details of the frontal organ. Some new terms are proposed for the elements of the filament and the organ. The suggestion is made that the life cycle of C. elongatus includes five, not four, chalimus stages.

This publication has 0 references indexed in Scilit: