Caligus robustus Bassett-Smith 1898

Caligus robustus Bassett-Smith, 1898

Caligus robustus Bassett-Smith, 1898:357.—Pillai, 1985:345.—Cressey and Nutter, 1987:600.

MATERIAL EXAMINED.—Bassett-Smith (1898) described this species from 3 species of carangids and a species of Thunnus from Ceylon and Aden. Since then it has been recorded many times from the western Atlantic and Indian Ocean from carangid and scombrid fishes. Additional material has been collected by the author from Belize: Carangoides bartholomaei, Carangoides chrysos, Caranx hippos, Caranx ruber, Lutjanus apodus (1 immature male copepod); Florida: Caranx hippos; Philippines and Celebes: Caranx sexfasciatus, Alectis species; Borneo: Caranx sexfasciatus Quoy and Gaimard; Tutuila Island: Caranx sexfasciatus; and Revilligidado Island: Caranx melampygus Cuvier and Valenciennes.

FEMALE.—Body form as in Figure 168. Total length 4.7 mm, greatest width 1.98 mm. Cephalothorax about as long as wide and comprising about one-third of total body length. Lunules widely separated, space between them about twice lunule diameter. Genital complex widest posteriorly and longer than wide (1.2 × 0.82 mm). Abdomen 1-segmented and nearly 3 times longer than wide (length of genital complex about 1.2 times longer than abdomen). Caudal rami (Figure 169) longer than wide (0.84 × 0.39 mm) with usual 6 setae.

Second antenna (Figure 170a) claw recurved near tip; posterior process rounded and directed laterally. Postantennal process (Figure 170b) small with small distal process. Spiniform process of first maxilla (Figure 170c) with accessory process near tip. Sternal furca (Figure 171) basal portion about as long as tines; latter broad, slightly divergent, narrowing near tips.

Leg 1 (Figure 172) coxopod with patch of fine spinules; exopod first segment with a small spine at outer distal corner; second segment with small, subterminal spine, outer 2 terminal spines with fringe on medial and outer margins, tips naked, medialmost terminal spine naked and 3 well-developed medial setae; basal portion of outer margins of medial setae with stout setules followed by finer and shorter setules; setules on medial margins longer and more widely spaced. Leg 2 (Figure 173) exopod first 2 segments each with prominent, gently curved spine at outer corner (first spine slightly longer than second spine) and medial seta; last segment with 2 small outer spines followed by larger semipinnate seta and 5 terminal to medial pinnate setae. Endopod first segment with irregular row of setules and transverse row of spinules as in figure, medial margin with long seta; second segment with prominent patch of bristles covering most of proximal half and 2 medial setae; last segment with patch of bristles on basal portion, sclerotized, striated cresent-shaped process at outer distal corner, and 6 terminal setae. Leg 3 exopod (Figure 174) first segment with prominent sclerotized spine, fringed along outer margin and not reaching last segment; second segment with weak spine at outer corner and well-developed medial seta; last segment with 3 weak outer spines and 3 terminal setae. Leg 4 (Figure 175) exopod 3-segmented, outer margins of all 3 segments with double row of short setules; all exopod spines with similiar rows of fringe and all of about equal length.

MALE.—Body form as in Figure 176. Total length 2.65 mm, greatest width 1.37 mm. Cephalothorax 1.37 mm in length; genital complex 0.55 mm long and 0.48 mm wide. First abdominal segment 0.23 mm long and 0.48 mm wide, second segment 0.74 mm long and 0.67 mm wide. Caudal rami longer than wide (0.48 × 0.27 mm). Second antenna (Figure 177) with small adhesion pad at medial distal corner; last segment (claw) with naked seta on medial proximal corner sclerotized process beyond seta, tip of claw heavily sclerotized and bent at right angle.