Lissoclinum diversum Kott, 2004b

Kott, Patricia, 2005, New and little-known species of Didemnidae (Ascidiacea, Tunicata) from Australia (Part 3), Journal of Natural History 39 (26), pp. 2409-2479 : 2465

Lissoclinum diversum Kott, 2004b

( Figure 17H )

Lissoclinum diversum Kott 2004b, p 2508 .

Distribution

Previously recorded (see Kott 2004b): Western Australia (Dampier Archipelago). New record: Western Australia ( Shark Bay , WAM 153.86 ) .

Description

The newly recorded colony is an extensive, hard sheet with spicules crowded throughout. The upper surface of the preserved specimen is even but rough, with some low concentric ridges around the apertures and some long, low corrugations between them. Large, sessile common cloacal apertures are randomly distributed on the surface. The branchial apertures are small openings in the spicule-filled test that sometimes look more like slits than circular or stellate openings. The spicules are small (to 0.035 mm diameter) and burrlike with flat-tipped rod-like rays or almost globular with rounded rays or stellate with conical tips in a basal shaft.

Thoraces cross the shallow, horizontal common cloacal cavity in separate test sheaths and abdomina are embedded in the basal test. Zooids are a brownish colour but there are no separate large pigmented cells around them. Ten stigmata are in the anterior row on one side of the branchial sac. The gut loop is vertical and there are two testis follicles and a straight vas deferens.

Figures

Figure 17. Scanning electron micrographs of the calcareous spicules of: (A) Trididemnum dispersum (WAM 1044.89); (B) Trididemnum nobile (SAM E3262); (C) Trididemnum pigmentatum (QM G308714); (D) Lissoclinum agriculum sp. nov. (WAM 179.93, syntypes); (E) Lissoclinum bistratum (WAM 1018.89); (F) Lissoclinum clavatum sp. nov. (SAM E3260, holotype); (G) Lissoclinum coactum (WAM 120.90); (H) Lissoclinum diversum (WAM 153.86).