Ascidonia californiensis (Rathbun, 1902)

Wicksten, Mary K., 2012, Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces 3371, Zootaxa 3371, pp. 1-307 : 52

Ascidonia californiensis (Rathbun, 1902)

( Fig. 13A, B)

Pontonia californiensis Rathbun, 1902a: 902 ; 1904: 33, fig. 11. — Schmitt 1921: 38, fig. 23. — Holthuis 1951: 145, pl. 46, figs. a–i, pl. 47, figs. a–c. — Word & Charwat 1976 b: 169. — Standing 1981: 778. — Wicksten 1989a: 18.

Ascidonia californiensis . — Fransen 2002: 203, figs. 129–137.

Diagnosis. Rostrum about as long as first segment of antennular peduncle, flattened, without teeth. Carapace without teeth. Stylocerite short, blunt, first segment of antennular peduncle with very small distolateral spine. Scaphocerite oval in shape, blade about as long as inwardly curved lateral tooth. Pereopod 1 short, slender, chelate. Pereopod 2 more robust, unequal in size, shape; larger chela with 2 teeth closing against each other on dactyl, propodus; smaller chela without teeth, fingers slender, gaping. Pereopods 3–5 with hooked, biunguiculate dactyls. Abdominal pleura rounded, may be widely spread in ovigerous female. Telson with 2 pairs large dorsolateral spines, 3 pairs small terminal spines. Total length to 29 mm.

Color in life. Yellowish white or dull orange brown.

Habitat and depth. Subtidal rocky areas, commensal in ascidians, to 55 m.

Range. Carmel, Santa Cruz and Santa Rosa Is., off Palos Verdes Point , California . Type locality off Santa Cruz I., California.

Remarks. This symbiotic shrimp has been found in the branchial basket of the large solitary ascidian Ascidia vermiformis .