Clibanarius ambonensis Rahayu and Forest, 1992

Rahayu, D. L., 2003, Hermit crab species of the genus Clibanarius (Crustacea: Decapoda: Diogenidae) from mangrove habitats in Papua, Indonesia, with description of a new species, Memoirs of Museum Victoria 60 (1), pp. 99-104 : 99-100

Clibanarius ambonensis Rahayu and Forest

Clibanarius ambonensis Rahayu and Forest, 1992: 753 , figs 2b,

3c, d.

Material examined. Pulau Kamora, sandy mud, 20 Jun 2000, 3 females (2 ovigerous), 2.3–2.7 mm ( RCO 0102 ), and 23 Jun 2000, 1 male, 1.9 mm, J. Volosin ( PTFI) .

Diagnosis. Shield almost as long as broad. Ocular peduncles little shorter than shield, diameter 0.2 of peduncles; ocular acicles with 4 or 5 denticles. Antennular peduncles reaching slightly beyond base of cornea. Antennal peduncles not reaching completely base of cornea; antennal acicles not exceeding proximal margin of last peduncular segment. Chelipeds nearly equal; dorsolateral faces of propodi covered with dense small conical tubercles, dorsal margins of carpi each with single distal acute spine. Dactyls of second and third pereopods about the same length as propodi, 9 small spines on ventral margin.

Colour in life. Shield whitish with brown spots. Ocular peduncles bluish-white, dorsal surface with narrow dark brown longitudinal stripe; proximal part brown. Ocular acicles brown with bluish-white spines. Antennal peduncles bluish-white with dark brown longitudinal stripe on dorsal surface of fifth segment. Chelipeds brown with light blue spines; dactyls bluish-white with 2 longitudinal brown stripes on dorsal surfaces. Second and third pereopods bluish-white with brown longitudinal stripes on lateral surfaces: dactyls and meri with 3 longitudinal stripes, propodi with 4 longitudinal stripes, carpi with 2 longitudinal stripes.

Distribution. Ambon and Halmahera islands, Maluku, Indonesia, now extended eastward to the south coast of Papua.

Remarks. The present specimens agree well with the original description of the species by Rahayu and Forest (1992), except for one minor difference. The dactyls of the second and third pereopods of Papua specimens are slightly shorter than the propodi, while Rahayu and Forest (1992) described them as approximately the same length. Clibanarius ambonensis is recognisable by the number of longitudinal stripes on the ocular peduncles and second and third pereopods as described above.

Clibanarius ambonensis resembles C. striolatus Dana, 1852 . The shield of the two species is almost as long as broad; the ocular peduncles are stout, longer than the antennal and antennular peduncles; the dactyls of the second and third pereopods are approximately the same length as propodi. Live specimens can be distinguished by their coloration. The general colour of C. striolatus is yellowish green or brownish green with large brown longitudinal stripes on the second and third pereopods, while C. ambonensis is brownish blue or whitish blue with narrower brown longitudinal stripes on the pereopods. In addition, C. ambonensis possesses a longitudinal stripe on the dorsal surface of the ocular peduncles, which is absent in C. striolatus .