Caligus inopinatus n. sp. (Copepoda: Siphonostomatoida), with comments on intrageneric groupings in the genus Caligus Müller, 1785

Caligus inopinatus n. sp. (Copepoda: Caligidae) is described and illustrated. It is parasitic on Sphyraena flavicauda (Pisces: Teleostei: Sphyraenidae) taken off Eilat, Red Sea. The influence of the host on the morphology of Caligus spp. parasitic on carangids is discussed. The author concludes that the morphological similarity among these species is an expression of their genetic relationship, rather than the effect of the host influence, although as a general proposition such influence cannot be excluded.