Nesippus nana Cressey, 1970

Dippenaar, Susan M. & Jordaan, Bea P., 2012, Notes on the morphology and ecology of the adult females of Nesippus species (Siphonostomatoida: Pandaridae) with a key for identification, Zootaxa 3170, pp. 18-30 : 26-27

Nesippus nana Cressey, 1970

Material examined. Two adult Ƥ from the gill arches of Carcharhinus plumbeus (Nardo, 1827) caught off Richards Bay during February 2004.

Supplementary description of adult female. Mostly as described by Cressey (1970) with the following modifications or details: Caudal rami ( Fig. 9 A) bearing 5 obvious setae, all equally finely pinnate, 6th distomedial seta not observed. Adhesion pads ( Fig. 9 C) anterolaterally on dorsal shield obvious and conically shaped, adhesion pads at base of antenna smaller and less obvious with post-oral adhesion pads very pronounced boxing glove-like structures. Antenna ( Fig. 9 D) with 2 setae on terminal segment (one at base of claw, see Cressey 1970, Fig. 43) and one about midway on segment. Mandible ( Fig. 9 B) with 10 teeth. Leg 1 exopod with spines on outer margins of both segments without ‘accessory spinule’ (see Cressey 1970) but rather consisting of an inner spine surrounded by flesh with tip uncovered (similar to those of N. crypturus , see Fig. 4 D, but more covered and thus less sharp and pointy). Leg 4 ( Fig. 9 E) exopod with fine setules on medial margin, terminal spines (1 slightly more distolateral than others) of almost equal lengths (outer 2 slightly longer) with serrated margins and endopod with fine setules on distomedial margin.

Distinguishing characteristics. Fourth thoracic segment without lateral expansions, genital complex with anterolateral corners slightly tapering into narrow neck-like anterior region with shallow and broad median sinus posteriorly (see Cressey 1970, Fig. 39), prominent boxing glove-like post-oral adhesion pads ( Fig. 9 C), cephalon border bearing conspicuous papillae with short setules ( Fig. 9 F) and caudal rami with very finely (almost invisible) pinnate setae ( Fig. 9 A).

Ecological aspects. Nesippus nana exhibits a prevalence of 25% on its host with mean intensity and mean abundance of 2 and 1 individuals per host respectively.

This is the first report of N. nana from the east coast of South Africa.

Figures

FIGURE 4. Nesippus crypturus Heller, 1868, adult female SEM micrographs. (A) Cephalothorax, ventral; (B) Antennule, first segment; (C) Maxilla, calamus; (D) Leg 2, exopod; (E) Leg 4; Line drawing of (F) Mandible. Scale bars: A, 200 µm; B, C, E,

FIGURE 9. Nesippus nana Cressey, 1970, adult female. (A) Caudal ramus; (B) Mandible. SEM micrographs. (C) Cephalothorax, ventral; (D) Antenna; (E) Leg 4; (F) Cephalon border. Scale bars A, 50 µm; B, 10 µm; C, 200 µm; D, 100 µm; E – F, 20 µm.