Two New Caligoid Copepods from Egyptian Fishes

Abstract

Material studied: Twenty-eight females collected from the gills of Lates niloticus (L.) during December 1952, and January-February, 1953. Holotype and 17 paratypes in the U. S. National Museum. Remaining paratypes in the author's collection. Female: Body elongate and slender (Fig. 1), total length (not including caudal rami), based on 5 specimens, 4.19 mm (4.09-4.40 mm). Carapace wider than long (0.735x0.905 mm), about 18% of the total body length, narrower than the genital segment and showing a U-shaped ridge on the dorsal posterior area. First 3 thoracic segments fused with the carapace. Fourth thoracic segment free, wider than long (0.118x0.288 mm). Genital and fifth thoracic segments fused (1.11 x 1.13 mm), cordiform, smooth except for the fifth legs, attachments of the egg sacs, and 2 chitinized knobs near the beginning of the abdomen. Abdomen 2-segmented, the second segment narrower, rectangular, and only about 6% of the total abdominal length. Length of 2 abdominal segments together 2.43 mm, first segment 2.28x0.591 mm, second segment 0.142 x 0.192 mm. Caudal rami (Fig. 2) elongate (0.131 x 0.070 mm), armed distally with 6 setae, the innermost and outermost much shorter than the middle 4. Frontal lunules (Fig. 3) relatively small. First antenna (Fig. 4) armed on the anterior margin of the second podomere with about 18 setae, some of them plumose, and on the distal region of the last podomere with about 14 naked setae. Second antenna (Fig. 5) a sharply curved, attenuated claw. Cuticular spine (first maxilla of Wilson, 1905, and maxillary hook of Leigh-Sharpe, 1934) minute (Fig. 6). Mouth cone containing slender mandibles, dentate near their tips (Fig. 7). First maxilla (Fig. 8) a chitinized spine, having near its base a lobe bearing 2 unequal setae. Second maxilla (Fig. 9) long and slender, ending in 2 unequal spines. Maxilliped (Fig. 10) with a stout base and a strong, curved, distal spine. Sternal furca absent. First leg (Fig. 11) uniramous, but with a small, 2-jointed, digitiform process on the base, perhaps representing a rudimentary endopodite. Distal podomere with 3 long, plumose, inner setae and 4 terminal spines. Second leg (Fig. 12) biramous, with the coxopodite and first podomere of the exopodite having a veil-like fringe of fine hairs. Outer margins of second and third endopodite podomeres expanded and pilose. Third leg (Fig. 13) biramous, the exopodite with 3 podomeres, the first with a strongly chitinized outer spine, the endopodite consisting of a single podomere. Outer margin of the base with a large veil-like fringe of fine hairs. Fourth leg (Fig. 14) uniramous, with a distal group of 3 spines, of which the innermost is nearly twice the length of the 2 outer spines which are subequal. Fifth leg (Fig. 15), visible in dorsal view, consisting of a small lamella bearing 3 setae and a single seta a short distance from the lamella. Egg sac (Fig. 1) 3.13x0.308 mm, containing about 42 eggs (30-49) and reaching well beyond the end of the abdomen. Male: Unknown.