Cnemidocarpa completa Kott, 1985

Kott, Patricia, 2008, Ascidiacea (Tunicata) from deep waters of the continental shelf of Western Australia, Journal of Natural History 42 (15 - 16), pp. 1103-1217 : 1196-1198

Cnemidocarpa completa Kott, 1985

( Figures 15A, B )

Cnemidocarpa completa Kott 1985, p. 124 .

Distribution

Previously recorded (see Kott 1985): Victoria (Bass Strait, Deal I.); New South Wales (Arrawarra). New record: Western Australia CSIRO SS10 / 05 (Zuytdorp, Stn 110, 06.12.05, 106 m, QM G328141 ) .

Although formerly known from Bass Strait and north almost into subtropical waters on the eastern seaboard of the continent, the new record suggests a range around the southern half of the continent, possibly extending across the southern coast and north to Shark Bay.

Description

The newly recorded specimen is 1.9 cm long, contracted and almost cylindrical with a terminal branchial aperture and the atrial aperture on a thick, anteriorly directed siphon about one-third of the distance down the dorsal surface. The external surface is wrinkled around the apertures although elsewhere it is smooth with sparse sand embedded in the test. About 12 conspicuous branchial tentacles surround the aperture with rudimentary ones alternating. Although the siphon linings are slightly irridescent neither spines nor scales were detected. Four wide folds are on each side. At least six internal longitudinal vessels are between the folds and up to 18 are crowded on the folds in this contracted specimen. Four long, crowded, convoluted, loosely attached and sometimes overlapping but more or less parallel gonads are on the right side of the body. The posterior half of the left side of the body is damaged. The stomach is long, lined with fine parallel longitudinal folds but the remainder of the gut and the gonads were not detected. A few endocarps are on the body wall between the gonads.

Remarks

Although it is not in good condition, the specimen is identified on the basis of its lack of siphonal armature, its long, crowded, convoluted gonads, long stomach with fine longitudinal folds in the lining and gut and gonads attached to the body wall by ligaments rather than embedded in it. The relatively few gonads in the newly recorded specimen may be associated with its small size, although it has more internal longitudinal branchial vessels between the folds than previously reported.

Figures

Figure 15. Cnemidocarpa completa (QM G328141): A, external view; B, internal view, right side showing branchial sac cut away to display gonads. Stolonica aluta (QM G328460): C, external view of a single zooid; D, pallial wall showing gut and gonads on left side. Pyura scortea (QM G328138): E, external view. Molgula elva sp.nov. (WAM Z27525): F, detail of branchial infundibula; G, internal view showing body organs and muscualture. Scales: A, E, 0.5 cm; B–D, 0.2 cm; F, 0.5 mm; G, 1 mm.