Gastroptychus iaspis Baba & Haig, 1990

Wicksten, Mary K., 2012, Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces 3371, Zootaxa 3371, pp. 1-307 : 143-145

Gastroptychus iaspis Baba & Haig, 1990

( Fig. 33K, L)

Chirostylus sp : Hart 1982: 166, fig. 65. — Wicksten 1982: 245; 1989b: 315.

Gastroptychus iaspis Baba & Haig 1990: 854 , figs. 1, 2.

Diagnosis. Rostrum short, triangular, terminating in narrow spine directed upward. Carapace slightly longer than greatest width. Lateral margins strongly convex in posterior 0.66 of carapace length; well developed anterolateral spine, row of inconspicuous lateral spines. Gastric region bearing 6 prominent spines arranged in hexagon, few additional, widely set spines. Mid-cervical groove located about halfway along carapace. One or 2 pronounced spines on anterior branchial region; cardiac region with pair prominent spines; posterior branchial region with short, widely set spines. Tergum of abdominal somite 1 with transverse row of 5–11 spines. Tergum of somite 2 with transverse row of tubercles, pleura with 1–5 small dorsal spines along anterolateral margin. Tergum of somites 3, 4 unarmed; pleura with 1–4 small posterior marginal spines or none. Tergum of somite 5 unarmed; pleura bearing 1–7 small spines on posterolateral margin, occasionally 1 or 2 small spines on pleural surface. Tergum of somite 6 with 3 prominent posterior marginal spines, 6 (occasionally more) dorsal spines; pleura usually unarmed, rarely with spines on lateral margin. barely reaching end of rostral spine; cornea dilated. Length of chelipeds about 5 times length of carapace excluding rostrum. Merus, carpus, palm with several regular longitudinal rows of spines. Pereopods 2–4 slender, merus and carpus with 6 rows spines, propodus with dorsal, mesial, dorsolateral spines in longitudinal rows, ventral margin with row of closely set movable spinules; length of dactyl less than 0.33 times length of propodus, with ventral spinules, terminating in acute corneous claw. Carapace length excluding rostrum: male 30.0 mm, ovigerous female 25.5.

Color in life. Anterior carapace bluish pink, laterally pale pink, white; spines orange. Antennules, antennae, eyestalk orange; cornea black. Chelipeds orange with white spines, fingers; pereopods 2–4 orange becoming paler on dactyls ( Hart 1982). A specimen from southern California was dark carrot-orange.

Habitat and depth. On abyssal muddy sand in northern part of range ( Hart 1982); hard bottom on Jasper Seamount ( Baba & Haig 1990); 600–1189 m.

Range. Southeastern Vancouver I., British Columbia, 48˚13'N ( Hart 1982) to Jasper Seamount off Baja California, 30˚25'N. Type locality Jasper Seamount, from 30˚ 25.6' N, 122˚43.7' W to 30˚ 25.5' N, 122˚ 44.3' W .

Remarks. This species is an important member of the Jasper Seamount community at the 600–1100 m depth interval, where it was usually seen on gorgonians and antipatharians (A. Genin, California Department of Fish and Game, pers. comm.) These crabs have been caught in baited fish traps off southern California, which suggests that they are scavengers ( Wicksten 1982b).