Caligus elasmobranchi Boxshall 2018

Caligus elasmobranchi Boxshall, 2018 (Figs 26A–F) Hosts: Rhinoptera javanica Müller & Henle (Rhinopteridae: Myliobatiformes); Aetobatus narinari (Euphrasen) (Aetobatidae: Myliobatiformes); Carcharodon carcharias (Linnaeus) (Lamnidae: Lamniformes) Locality: Off east coast South Africa (Indian Ocean) Material examined: 5♀ Material collected: 6♀ from R. javanica; 1♀ from A. narinari; and 1♀ from C. carcharias Voucher material: 2♀ (SAMC-A099211) from R. javanica deposited in the Iziko South African Museum, Cape Town, South Africa. Adult female (Fig. 26A) genital complex slightly longer than wide; abdomen 1-segmented, longer than genital complex; antenna (a2) without proximal process, claw strongly curved; post-antennal process (pap) with slender, strongly curved tine (Figs 26B, C) and small protuberance (arrowed) at base (Fig. 26C); maxillule with dentiform posterior process (mpp) long, slender, slightly curved outwards (Figs 26B, C); sternal furca (sf) with long slender, slightly divergent tines (Fig. 26B); leg 1 last exopodal segment with 3 posterior pinnate setae (ps), terminal seta 4 (4) shorter than terminal spines (ts) 2–3 (Fig. 26D); leg 3 exopodal segment 1 distolateral spine (ds) straight, reaching beyond articulation between segments 2 and 3 (Fig. 26E); leg 4 long, almost reaching caudal rami (Fig. 26A), 3- segmented with I, III spines (arrowed) respectively, ornamented with numerous surface sensillae (s), terminal spines short (almost equal lengths), modified pecten on distomedial margin (Fig. 26F) (cf. Pillai 1985; Boxshall 2018). Remarks: Caligus elasmobranchi shares the structure of leg 4 (I, III spines), the pinnate setae on leg 1 last exopod segment and the 1-segmented abdomen with the C. macarovi -group, but not the remaining features. The body length of about 7 mm agrees with those previously reported (Pillai 1985; Boxshall 2018) as well as the very long legs 4. The small protuberance at the base of the post-antennal process was illustrated previously (see Fig. 88C in Pillai (1985) and Fig. 27B in Boxshall (2018)) although not mentioned in the descriptions. This represents a new report from South African waters while R. javanica, A. narinari and C. carcharias constitute new host reports. Additionally, this is the first report from Lamniformes since all previous reports were from Myliobatiformes and Rhinopristiformes (Pillai 1985; Boxshall 2018).