Culeolus herdmani Sluiter, 1904

Kott, Patricia, 2009, Taxonomic revision of Ascidiacea (Tunicata) from the upper continental slope off north-western Australia, Journal of Natural History 43 (31 - 32), pp. 1947-1986 : 1980-1981

Culeolus herdmani Sluiter, 1904

Culeolus herdmani Sluiter, 1904, p. 105 . Kott 2002, p. 63 and synonymy.

Distribution

Previously recorded ( Kott 2002): western Australia (off Collier Bay , Lacepede Archipelago , Cape Leveque ); New Caledonia; Indonesia; Philippines; Sea of Japan. New record: CSIRO 0507 western Australia ( Station 082-171, Imperieuse, 18.46 S 120.15 E, 80 m, Sled tow, 19.6.07, QM G328562 ) .

Although the new record is of a single specimen from 80 m, the previous records from north-western Australia are of from one to six specimens at depths from 400–500 m and the specimens from the western Pacific ( New Caledonia: Monniot C and Monniot F (1991)) were taken from 400–1000 m. It is known from soft bottoms and appears to be a relatively commonly occurring species .

Description

The species is readily identified by its long wiry-looking stalk extending from just ventral to the branchial aperture which is directed down toward the base of the stalk The sessile atrial aperture about one-third of the body length from the terminal (posterior) end of the body, is a transverse slit. The test is characteristically translucent and has small scale-like blisters, each with a small point in the centre. The body wall has circular muscles around each aperture and a few fine longitudinal bands radiate from each of the apertures. On each side of the body a narrow but conspicuous muscle band extends from one sides of the branchial aperture to the same side of the atrial aperture. The branchial tentacles are branched, the dorsal lamina has pointed languets, and the dorsal tubercle is a C-shaped slit with one horn in-rolled.

The species is remarkably uniform, without significant variations in its morphology. It has the usual geographic range recorded for the group of Indo-west Paciific species detected (in this survey) at intermediate depths. Like the sympatric stalked species, Pterygascidia mirabilis , it appears to be a common component of the fauna in this area and at this depth between the fauna of the continental shelf and that of the lower continental slope and abyssal depths.

The stalk of the present species is particularly long, thin and wiry, possibly anchoring the individual in soft sediments in habitats where currents affect its orientation and ensure that the open branchial aperture is presented to the oncoming currents, thus compensating for the lack of ciliated stigmata.