Cybicola buccatus (Wilson C. B. 1922)

Pseudocycnoides buccata (Wilson, 1922)

Pseudocycnus buccata Wilson, 1922:79.

Cybicola elongata Pearse, 1951:365.

Pseudocycnopsis buccata (Wilson).—Yamaguti, 1963:172.

MATERIAL EXAMINED.—125 collections containing 667 10 from the gill filaments of following hosts and localities: Scomberomorus sierra from Peru, Colombia (Pacific), Panama (Pacific), Costa Rica (Pacific), Gulf of California, Baja California; S. concolor from Gulf of California, California; S. regalis from Brazil (north coast), Surinam, Gulf of Venezuela, Virgin Islands, Haiti, Cuba, Florida (Atlantic); S. maculatus from Mexico (Vera Cruz), Florida (west coast), Alabama, United States east coast (several localities from Florida to Cape Cod); S. brasiliensis from Brazil (Rio de Janeiro to north coast), Trinidad, Panama (Atlantic), Costa Rica, British Honduras, Mexico (Mazatlán); S. cavalla from Brazil, Trinidad, Cuba, Gulf of Mexico, Cape Cod.

FEMALE.—Body from as in Figure 92a. Total length 5.14 mm. Greatest width 1.20 mm. Thoracic segments bearing legs 2 and 3 free. Genital segment comprising about 60 percent total body length; ventral surface with a patch of spinules between bases of leg 3, 3 patches of spinules between leg 4 setae, and another patch distal to leg 4 setae. Considerable variation of total length occurs in this species and this will be considered in a separate study by the first author and B. B. Collette. Abdomen (Figure 92a) somewhat wider than long (652 × 493 μm). Caudal rami about twice as long as wide (362 × 188 μ), bearing 2 short terminal setae. Entire body covered with dense, fine hairs. First antenna (Figure 92c) 7-segmented, no ornamentation on first segment, remaining segments with short, naked setae as indicated in the figure. Second antenna (Figure 92d) a simple claw with 2 short, stout setae on inner edge of claw. Mouth tube (Figure 92e) without surface ornamentation. Mandible with 6–7 teeth. First maxilla (Figure 92f) bearing 3 setae at tip. Second maxilla (Figure 92g) similar to that of P. armatus except no patch of spinules on basal segment. Maxilliped (Figure 93a) with a short, heavily sclerotized claw (Figure 93b), basal segment with a thumblike process at inner proximal corner as in P. armatus.

Legs 1–3 rudimentary. Leg 1 (Figure 93c) rami 1-segmented; exopod with 5 short terminal spines; endopod bearing a short terminal spine; both rami covered with dense hairs and difficult to study. Leg 2 (Figure 93c) rami 1-segmented; basipod with a well-developed seta at outer distal corner; exopod bearing 4 terminal spines; endopod with 1 easily visible spine, 2 very short spines, and spinules as in the figure. Leg 3 (Figure 93c) reduced to a short knob bearing a short spine. Leg 4 represented by a lateral seta on anterior genital segment.

Egg string long.

MALE.—Body form as in Figure 93d. Total length 1.88 mm. Greatest width 0.55 mm. Thoracic segments bearing legs 2 and 3 incompletely separated. Genital segment about twice as long as wide (1.04 × 0.53 mm); abdomen (Figure 93c) nearly twice as wide as long (259 × 147 μm) with a ventral patch of spinules near each outer distal corner. Caudal rami (see Figure 93e) about twice as long as wide (123 × 64 μm), bearing 2 prominent lateral setae, 2 small lateral setae and a terminal spine, ventral surface covered with spinules. First antenna as in female. Second antenna (Figure 93f) similar to female except claw longer and more pointed. Mouth tube (Figure 94a) with 3 patches of spinules on labrum. First maxilla (Figure 94a) with 2 stout setae at tip, setae relatively longer than in female. Second maxilla as in S. armatus except no spinules on basal segment. Maxilliped (Figure 94b) with 2-segmented claw and spinules on proximal inner corner of base.

Leg 1 (Figure 94c) biramous, each ramus 1-segmented and not distinctly articulated with basipod; basipod with a patch of spinules and a triangular process and a seta at outer distal corner; exopod with patches of spinules and spinulose lobes in distal third, 2 short spines at tip; endopod modified as a curved, heavily sclerotized process, lobed at tip and most of its length enclosed in a membrane (compare with P. armatus). Leg 2 similar to P. buccata except exopod inner 3 spines smaller and distal half with widely spaced spinules; endopod with 2 distinct patches of spinules. Leg 3 (Figure 94d) reduced to a spinulose process with a short spine at tip.