Nesippus tigris Cressey, 1967

Material collected. From the nasal cavities of G. cuvier caught off Richards Bay during August 2005 (1 Ƥ); Salt Rock during April 2006 (4 Ƥ); Ballito Bay (29°32’S 31°14’E) during June 2006 (16 Ƥ); Umdloti during May 2006 (10 Ƥ); Brighton Beach (29°56’S 31°10’E) during January 2006 (3 Ƥ); Amanzimtoti during June 2006 (3 Ƥ); Winklespruit (30°06’S 30°51’E) during January 2000 (4 Ƥ) and June 2006 (33 Ƥ); Scottburgh during November 2005 (20 Ƥ) and January 2006 (2 Ƥ); Hibberdene (30°34’S 30°34’E) during August 2005 (3 Ƥ); Umzumbe (30°32’S 30°37’E) during September 2005 (42 Ƥ); Umtentweni (30°43’S 30°28’E) during October 2006 (6 Ƥ); Trafalgar during February 2005 (18 Ƥ); T. O Strand (31°02’S 30°14’E) during January 2000 (4 Ƥ) and February 2005 (2 Ƥ). From C. carcharias, caught off Richards Bay during December 2003, 1 Ƥ.

Supplementary description of adult female. Mostly as described by Cressey (1967) with the following modifications or details: Caudal rami (Fig. 7 A) broad, bearing 6 small naked setae. Adhesion pads anterolaterally on cephalothorax small, triangularly shaped, those at base of antenna small, post-oral adhesion pads most prominent and protruded (Fig. 8 A), similar to those in N. orientalis and N. crypturus, but less pointed. Antennule, first segment armed with at least 16 naked setae of varying lengths and 3 knob-like proturberances, second segment with 2 aesthetascs, 6 naked setae (1 on outer margin, 5 terminally) and a small protuberance. Mandible (Fig. 7 B) with 12 teeth. Calamus of maxilla (Fig. 8 B) robust (compared to other species), slightly curved, with rows of thin serrate membrane; canna much shorter than calamus, naked, thumb-like and curved; crista a blunt, naked, seta-like protrusion. Legs 1–3 with short stubby setae that are not constricted at their bases (Fig. 8 C). Leg 4 (Fig. 8 D), exopod with 4 spines (3 terminally and 1 distolaterally), distomedial spine longest, other 3 of mostly equal lengths, endopod unarmed.

Distinguishing characteristics. Fourth thoracic segment laterally expanded, genital complex broad anterolaterally without neck-like anterior region and with median sinus posteriorly (see Pillai 1985, Fig. 49J and Cressey 1967, Fig. 325), triangularly shaped adhesion pads anterolaterally on dorsal shield and protruded post-oral adhesion pads (Fig. 8 A), robust maxilla calamus (Fig. 8 B) compared to other species, setae on legs short and stubby (not constricted as in some other species) (Fig. 8 C), caudal rami broad, armed with 6 small, naked setae (Fig. 7 A). Ecological aspects. Nesippus tigris exhibits 75% prevalence on G. cuvier with mean intensity and mean abundance of 10 and 8 individuals per host respectively.

This is the first report of N. tigris from C. carcharias.