Caligus temnodontis Brian, 1924

Boxshall, Geoff A & El-Rashidy, Hoda H., 2009, A review of the Caligus productus species group, with the description of a new species, new synonymies and supplementary descriptions, Zootaxa 2271, pp. 1-26 : 21-24

Caligus temnodontis Brian, 1924

Syn: C. mauritanicus var. temnodontis Brian, 1924 C. cf. affinis: Kensley & Grindley, 1973

Differential diagnosis: Female genital complex and abdomen combined about 1.2 times longer than cephalothorax; body length 3.61–5.48 mm. Male body length 2.52–3.85 mm. Female genital complex ( Fig. 7 A) about 1.5 times longer than wide, narrowing to waist-like region anteriorly, lacking distinct posterolateral lobes: abdomen 2-segmented, first segment about three times longer than second and ornamented with transverse striated cuticular markings. Cephalothorax lacking striated lateral borders. Male abdomen 2- segmented ( Fig. 8 A); second segment about 1.6 times longer than first. Female antenna with distal claw only slightly curved ( Fig. 7 B). Male antenna with complex apical claw ( Fig. 8 C). Post-antennal process sexually dimorphic, larger and more strongly curved in male (cf. Figs 7 B, pap; 8B, pap). Additional rounded process present between post-antennal process and base of antenna in female ( Fig. 7 B). Posterior process of maxillule tapering evenly ( Figs 7 B, 8B) in both sexes; with tiny blunt accessory process in male ( Fig. 8 B, mxl). Sternal furca with straight to slightly incurved tines ( Figs 7 C, 8E) and with transverse thickenings of body surface either side of furca ( Fig. 8 E). Female maxilliped with smooth medial margin. Male maxilliped with 2 pointed processes on myxal margin ( Fig. 8 D), larger, proximal process opposing tip of claw and with slight concavity (possibly a pore) at tip. Exopod of leg 1 with seta at inner distal angle shorter than segment and about as long as middle spine on distal margin; posterior margin with single plumose seta about half length of adjacent seta ( Fig. 8 F). Outer margin of second endopodal segment of leg 2 ornamented with typical setules. Leg 4 with robust first exopodal segment bearing single marginal setule; second segment with well developed spines in both sexes, increasing in length towards terminal spine ( Figs 7 D, 8G).

Material examined: 13 female and 6 male syntypes labeled Caligus mauritanicus var temnodontis , in two vials deposited in the collections of the Museum National d’Histoire Naturelle in Paris, registration numbers, MNHN Cp. 281 and Cp.282.

3 adult females and 1 male collected from P. saltatrix caught off Mapelane, South Africa, on 30 August 1975 by R. van der Elst: stored in collections of the Natural History Museum, London Reg. Nos. 1979.899- 903.

5 adult females collected from P. saltatrix caught off Durban, South Africa, by R. Bray: stored in collections of the Natural History Museum, London Reg. Nos. 1984.129.

4 adult females collected from P. saltatrix caught off Sodwana, Natal, South Africa, by R. Bray: stored in collections of the Natural History Museum, London Reg. Nos. 1984.133.

Distribution: Eastern South Atlantic.

Host: Pomatomidae : Pomatomus saltatrix (Linnaeus, 1766) (as Temnodon saltator and as Pomatomus

saltator ).

Remarks: In his survey of the parasitic copepods of Mauritania Brian (1924) described a new species, Caligus mauritanicus , from a range of hosts. Brian noted that this form resembled C. productus and C. haemulonis in the apparent absence of the three large plumose setae from the posterior margin of the distal exopodal segment of the first swimming legs. In his original description, Brian (1924) established C. mauritanicus n. sp. and two distinct varieties which he named, n. varietas miniscula and n. varietas temnodontis . He distinguished the former from ‘la forme typique’ on the basis of its smaller size and small differences in the relative proportions of genital complex and abdomen. He distinguished the latter on the basis of differences in body shape, in the shape of the post-antennal processes (‘hamuli ou secundae maxillae’) and in the form of the spines on the distal margin of the first leg exopod. We consider that these three varieties represent three distinct species: the typical form of C. mauritanicus is synonymized above with C. dakari and the variety miniscula was synonymized above with C. haemulonis . The variety temnodontis is, in our opinion, a valid species characterised by the presence of a small plumose seta on the posterior margin of the distal exopodal segment of leg 1. It shares this character state with C. dakari but the leg 4 differs from that of C. dakari which has a distinctive shape to the distal exopodal segment. The females of these species can also be distinguished on the basis of size, body proportions and the shape of the antennal claw and postantennal process.

South African Caligus material from the type host, Pomatomus saltatrix , in the collections of the Natural History Museum, London is identifiable as C. temnodontis , and this species has recently been reported from P. saltatrix in the eastern Mediterranean (Özak et al. submitted).

We consider that the material identified as Caligus cf. affinis by Kensley & Grindley (1973) is also, most probably, C. temnodontis .

Figures

FIGURE 7. Caligus temnodontis Brian, 1924 female. A. genital complex and abdomen, ventral view; B. antenna, postantennal process (pap) and maxillule (mxl), ventral view in situ; C. sternal furca in situ; D. leg 4. Scale-bars: A = 500 μm, B = 250 μm, C = 100 μm, D = 200 μm.

FIGURE 8. Caligus temnodontis Brian, 1924 male. A. genital complex and abdomen, ventral view; B. frontal margin of cephalothorax with lunule, antenna, post-antennal process (pap) and maxillule (mxl) in situ, ventral view; C. detail of antennal claw armature; D. maxilliped, with inset showing detail of myxal margin; E. sternal furca; F. second exopodal segment of leg 1 showing distal armature; G. leg 4. Scale-bars: A = 500 μm, B, D, G = 250 μm, C = 50 μm, E, F = 100 μm.