Oratosquillina perpensa

Oratosquilla perpensa (Kemp, 1911)

Squilla oratoria var. perpensa Kemp, 1911:98 [part]; 1913:70, pl. 5: figs. 57–59 [part].

Squilla oratoria var. inornata.—Holthuis, 1941:248 [part; not Squilla inornata Tate, 1883].

Squilla perpensa.—Lee and Wu, 1966:49.

MATERIAL.—Tung Kang, S Formosa [Tung Chiang, Taiwan]; trawled; S. Lee nos. 97, 169; 5 Sep 1965: 1 , TL 68 mm, 1 , TL 82 mm (RMNH 517S). Same loc.; Lee and Wu no. 180; 9 May 1965: 1 , TL 66 mm (USNM 125061). Hong Kong [Hong Kong Island, 22°15′N, 114°11′E]; G. Dennys, leg.; lectotype: 1 , TL 97.5 mm (ZSI). Data same; paralectotypes: 13 , TL 73–93 mm, 13 , TL 77–97 mm (ZSI 4851–72/9). Data same; paralectotypes: 1 , TL 92.5 mm, 1 , TL 88 mm (USNM 143577). Java, Indonesia; Bleeker, leg.: 1 , TL 70 mm (RMNH 70S). Off Irrawaddy delta, Burma; 15°20′N, 94°55′E; 20 fms (37 m); Investigator, leg.; paralectotypes: 1 , TL 64 mm, 1 , TL 63 mm (USNM 143575).

DESCRIPTION.—Size moderate, total length of adults less than 100 mm. Body appearing smooth, actually very rugose when dried or viewed under magnification.

Eye (Figure 11b) moderate to small, cornea bilobed, set obliquely on stalk. Eyes not extending beyond end of first segment of antennular peduncle. Corneal indices 363–429.

Antennular peduncle almost as long as carapace. Dorsal processes of antennular somite produced into acute, occasionally spiniform lobes directed anteriorly.

Rostral plate (Figure 11a) broader than long, quadrate or trapezoidal in shape, appearing short, apex flattened. Median carina absent.

Anterior width of carapace about half median length, not so long as carapace and rostral plate combined. Anterolateral spines (Figure 11a) strong, extending to or slightly beyond base of rostral plate. Median carina interrupted at base of anterior bifurcation, branches of bifurcation distinct. Intermediate carinae turning toward but not meeting laterals anteriorly, not extending to anterior margin.

Dactylus of claw with 6 teeth, outer margin strongly sinuous. Dorsal ridge of carpus (Figure 11c) undivided. Inferodistal angle on outer face of merus with sharp spine.

Exposed thoracic somites (Figure 11d) each with submedian and intermediate carinae, those of fifth somite poorly developed. Lateral process of fifth somite with anterior lobe produced into long, slender spine, directed anterolaterally, posterior lobe smaller, triangular. Lateral process of sixth somite bilobed, anterior lobe slender, triangular, apex sharp, posterior lobe larger, triangular, apex sharp but not spiniform. Lateral process of seventh somite bilobed, anterior lobe smaller than that of sixth somite, triangular, apex sharp, posterior lobe larger, triangular, apex sharp but not spiniform.

Submedian carinae subparallel on fifth abdominal somite. Abdominal carinae spined as follows: submedian 5–6, intermediate 4–5, lateral 3–6, marginal 1–5.

Telson flattened, slightly longer than broad. Prelateral lobe subequal in length to margin of lateral tooth. Denticles (Figure 11e) rounded or subquadrate, unarmed, 3–4, 7–9, 1. Ventral surface with long postanal keel.

Uropod broad, proximal segment of exopod shorter than distal, with 8–11 (usually 9) movable spines on outer margin, distalmost not extending to midlength of distal segment. Lobe on outer margin of inner spine of basal prolongation (Figure 11f) small, erect, prominent, narrower than adjacent spine, margin concave, apex rounded or angled.

COLOR.—Body appearing dusky, with concentration of pigment dorsally. Median carina, gastric grooves, and anterior margin of carapace dark, other carinae outlined by more diffuse lines of dark pigment. Lateral margin of rostral plate dark. Merus of claw with diffuse dark band dorsolaterally, propodus with distal patch of dark chromatophores. Exposed thoracic and all abdominal somites with dark posterior line, submedian and intermediate carinae faintly indicated by lines of dark chromatophores; lateral carinae flanked mesially by curved, dark line. Median carina of telson with anterior and posterior dark patches, bases of marginal teeth dark. Proximal segment of uropodal exopod with middorsal dark line, inner half of distal segment dark. Distal half of endopod dark. Basal prolongation of uropod with longitudinal patch of dark pigment on inner, ventral surface.

MEASUREMENTS.—Males, TL 64–93 mm; females, TL 63–97.5 mm. Other measurements of female lectotype, TL 97.5 mm: CL 20.6, anterior width 10.3; cornea width 5.1; antennular peduncle length 19.8; rostral plate length 2.7, width 3.1; telson length 17.8, width 16.3.

DISTRIBUTION.—Known with certainty from localities between southern Taiwan and Burma, including Tung Kang, Taiwan, 40–50 fms (73–91.5 m) (Lee and Wu, 1966); Hong Kong (Kemp, 1911, 1913); Java, Indonesia (Holthuis, 1941); and off the Irrawaddy delta, Burma, 20 fms (37 m) (Kemp, 1913).