Developmental stages of Alebion lobatus Cressey, 1970 (Copepoda: Euryphoridae) found parasitic on the sandbar shark (Carcharhinus plumbeus (Nardo, 1827)) in the western North Atlantic, and a phylogenetic analysis of the genus Alebion Krøyer, 1863

Abstract

Three stages of copepodids, two preadults, and male and female adult Alebion lobatus collected from sandbar sharks (Carcharhinus plumbeus) in the western North Atlantic are described. Copepodids were found on the external body surface of hosts in hollows which were apparently formed by the absence of one to several placoid scales. A frontal filament was not observed in any developmental stage and the second antennae appeared to be the primary prehensile appendages. Two equally most parsimonious cladograms are presented as hypotheses of phylogenetic relationship for the eight known species of Alebion.