Resurrection of Perissopus galeorhini (Yamaguti, 1936)with notes on the genus Perissopus Steenstrup and Lutken, 1861 (Copepoda: Pandaridae)parasitic on sharks

JORGE ALEJANDRO ETCHEGOIN; IVANOV, VERÓNICA A.; TIMI, JUAN TOMAS

Systematic Parasitology

Año: 2001 vol. 50 p. 31 - 39

Recently collected copepod parasites on the narrownose smooth-hound shark Mustelus schmitti Springer revealed enough similarities with Perissopus galeorhini (Yamaguti, 1936) to be considered conspecific. Comparison of these specimens with the types of P. oblongus (Wilson, 1908) showed that P. galeorhini and P. oblongus are distinct species. Therefore, P. galeorhini is considered a valid species rather than a synonym of P. oblongus, as it has been treated since the revision of Cressey (1967). Descriptions of P. galeorhini from M. schmitti and type-material of P. oblongus are provided along with a discussion on their taxonomic status. P. galeorhini differs from P. oblongus in features relating to the anterior margin of cephalothorax, the dorsal plates of the third pedigerous segment and details of the segmentation and armature of the appendages. In addition, an amended diagnosis of Perissopus Steenstrup & and Lütken, 1861 is given, including characters not previously considered by Cressey (1967) such as: the dorsal plate of segment 2 can be small, widely separated, covered by the posterior end of the lateral processes of the cephalothorax and not always extending to the posterior border of the plates of segment 3; and the rami of legs 3 can be 2-segmented.