Caligus affinis Heller, 1866

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 : 7-8

Caligus affinis Heller, 1866

Syn: nec Caligus affinis Kurian, 1961

nec Caligus cf. affinis: Kensley & Grindley, 1973 Differential diagnosis: Female genital complex and abdomen combined about 1.2 times longer than cephalothorax; body length 3.3–5.45 mm. Male body length 4.36 mm. Female genital complex without distinct postero-lateral lobes. Abdomen 2-segmented, first segment about twice as long as second. Male abdomen 2-segmented; first segment just shorter than second. Post-antennal process large and strongly curved in both sexes. Additional process present between post-antennal process and base of antenna in female. Sternal furca with strongly incurved tines and wide gape. Female maxilliped with smooth medial margin. Male maxilliped with large pointed process on myxal margin, opposing tip of claw. Exopod of leg 1 with seta at inner distal angle longer than longest spine but shorter than segment; no vestiges of posterior margin setae; first exopodal segment broad, with strongly convex posterior margin. Outer margin of second endopodal segment of leg 2 ornamented with denticles. Leg 4 with outer spine on second exopodal segment short, not reaching base of outer distal margin spine; outer and middle distal spines of similar length and distinctly shorter than terminal spine.

Material examined: none

Distribution: Mediterranean Sea.

Hosts: Sciaenidae : Umbrina cirrosa (Linnaeus, 1758) , Umbrina canariensis Valenciennes, 1843 .

Remarks: Brian (1935) gave a relatively good description of C. affinis based on a single female collected from the type host, Umbrina cirrosa , at Genoa. Cressey (unpublished) found and described in detail the same species on Umbrina canariensis from the type locality, the Adriatic Sea. The material reported by Kensley & Grindley (1973) as Caligus cf. affinis is not C. affinis . The body proportions of the adult female are different; the genital complex and abdomen are about twice as long as the cephalothorax, a vestigial seta is present on the posterior margin of the second exopodal segment of leg 1, and the proportional lengths of the spines on the exopod of leg 4 are not the same as in C. affinis . The South African material of Kensley & Grindley (1973) most closely resembles C. pagrosomi and C. temnodontis (see below). The plumose seta on the posterior margin of leg 1 exopod is more strongly reduced than in C. pagrosomi , and Özak et al. (submitted) tentatively attributed this material to C. temnodontis .

Caligus affinis is most closely related to the widely distributed C. epinepheli but can be distinguished from it by the shape of the sternal furca, with its more strongly incurved tines and wider gape, and by the strongly recurved post-antennal process of the female. Thus far C. affinis is only confirmed as parasitic on species of Umbrina in the Adriatic Sea.