Ascidia conifera Hartmeyer, 1909

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 : 1968-1969

Ascidia conifera Hartmeyer, 1909 –1911

(Figure 2A–B)

Phallusia conifera Hartmeyer, 1909 –1911, p. 1404 (nom. nov. for Ascidia spinosa Sluiter, 1904, p. 34 . Not Ascidie spinosa Quoy and Gaimard, 1834, p. 615 < Pyura spinosa, Kott 2005, p. 168 )

Ascidia conifera: Monniot C. and F. 1989, p. 231.

Ascidia ornata Monniot F. and C., 2001, p. 306

Distribution

Previously recorded: Indonesia, Philippines; new records: western Australia CSIRO05 / 07 ( Station 017-018, Onslow 11.6.07, 20.21 S 115.13 E, 95 m Beam trawl, QM G328567 ; Station 125-060 Sled tow, Lacepede, 15.81 S 121.16 E, 90 m, 1.7.07, QM G326572 ; Station 188-038, Ashmore, 12.44 S 123. 60 E, 400 m, Beam trawl, 17.05.07, QM G328555 .

The species has been recorded from 73–400 m.

Description

Only the three specimens (QM G328555) are entire, the bodies remaining with the test. The largest specimen is about 4 cm long and about 3 cm deep. It has a rectangular body with a terminal branchial aperture and the antero-dorsal atrial aperture about one-third of the body length down the dorsal surface. Both the lobed apertures are sessile. Other newly recorded specimens consist only of the empty and damaged tests, sometimes with the branchial aperture turned to the right and posteriorly, although both apertures are almost sessile, with a fringe of short, narrow, finger-like processes around the margin of each opening. The outer surface of the firm translucent test has evenly spaced mamilliform to cylindrical processes, about 5 mm apart, each containing a cluster of terminal branches of a test vessel and with a sharp terminal point in the centre of its terminal surface. Internally, both branchial and atrial apertures are on short siphons with circular muscles. Longitudinal muscles extend down each side of the body, although on the left these do not extend posterior to the gut loop and there are some transverse muscle bands across the mid line that may be associated with terminal branches of the longitudinal muscles.

A small dorsal tubercle with a simple C-shaped slit turned anteriorly is behind the branchial tentacles at the top of a double dorsal lamina. The dorsal gland and ganglion are about halfway between the atrial and the branchial apertures Conspicuous and well-spaced longitudinal muscle bands are on each side of the body. The branchial sac has about eight stigmata per mesh. The gut forms a tight double loop in the postero-dorsal corner on the left, the elliptical stomach occupies most of the proximal limb and its internal wall is finely pleated. Crowded, branched, ovarian tubes spread through the pole of the loop to the lateral side of the gut loop and branched male follicles crowd over and obscure the mesial side of the loop. A thick oviduct emerges from among the ovarian tubules in the pole of the primary loop and can be seen between the two limbs of the loop. It opens near the anus at the base of the bilabiate anal aperture just inside the atrial opening. The rectum is swollen.

Remarks

Ascidia conifera: Monniot C. and F., 1989, taken from off the Philippines in depths 73–110 m, has mamillated, transparent test and does not appear to be different from the present species in any significant respect, having longitudinal muscle bands missing only from over the gut, a small dorsal tubercle with a simple U-shaped slit, an elliptical stomach with a finely pleated lining, testis follicle overgrowing the rectum and other parts of the gut loop and the dorsal ganglion separated from the dorsal tubercle. Ascidia ornata Monniot, F. and C., 2001, taken from 13–20 m off the Philippines , also is similar, having, in addition to its mamillated test, a swollen rectum. These sympatric species appear to be conspecific with the types of the present species from Indonesia .

Ascidia papillosa Tokioka, 1967 from Japan has a papillated test like the present species, but a larger gut loop, less finely pleated stomach and a mesh of muscles on the right side of the body, unlike the longitudinal bands of the present species.