Caligus antennatus Boxshall & Gurney 1980

Caligus antennatus Boxshall & Gurney, 1980 (Figs 14A – 15D) Host: Mustelus mustelus (Linnaeus) (Carcharhiniformes: Triakidae) Locality: Off west coast South Africa (Atlantic Ocean) Material examined: 3♀ Material collected: 3♀ from M. mustelus Voucher material: 1♀ (SAMC-A099205) from M. mustelus deposited in the Iziko South African Museum, Cape Town, South Africa. Adult female (Fig. 14A) genital complex wider than long; abdomen 1-segmented; antenna with spinuous proximal process (arrowed) (Fig. 14B), large conical process with concave tip (arrowed) and small subapical seta (s) proximally on terminal segment (Fig. 14C); post-antennal process with distal flange (arrowed) (Fig. 14D); maxillule with dentiform posterior process bifid, smaller tine (arrowed) basal to main tine (Fig. 14E), small triangular protuberance (arrowed) posteromedial to tip of dentiform process (Fig. 14F); maxilliped with prominent acuminate process (arrowed) basal on corpus (Fig. 15A); sternal furca small with parallel tines (Fig. 15B); leg 1 last exopodal segment with terminal seta 4 (4) distinctly longer than terminal spines (ts) (Fig. 15C); leg 4 3-segmented with I, III spines (arrowed) respectively (Fig. 15D) (cf. Boxshall & Gurney 1980; Kabata & Taureen 1984). Remarks: Caligus antennatus has only been reported from Acanthopagrus latus (Houttuyn) (Sparidae: Acanthuriformes) (Boxshall & Gurney 1980; Kabata & Taureen 1984). Therefore, this finding from an elasmobranch is unusual. Additionally, the habitus of the adult female differs slightly from that illustrated by Boxshall & Gurney (1980) (see Fig. 8A in Boxshall & Gurney (1980)) with the genital complex wider than long and the posterolateral corners of the genital complex slightly lobate (see Fig. 14A). Furthermore, the proximal process on the antenna is blunt ended rather than spinuous (see Fig. 14B). However, the distinguishing features of C. antennatus i.e. the structure of the antenna, post-antennal process, maxillule, maxilliped, sternal furca, length of leg 1 last exopod terminal seta 4 and structure of leg 4 (Boxshall & Gurney 1980; Kabata & Taureen 1984) all conforms to those of the examined specimens and thus they are identified as C. antennatus. This report constitutes a new species and host record off South Africa.