Lissoclinum reginum Kott, 2001

Kott, Patricia, 2007, New and little-known species of Didemnidae (Ascidiacea, Tunicata) from Australia (part 4), Journal of Natural History 41 (17 - 20), pp. 1163-1211 : 1206-1207

Lissoclinum reginum Kott, 2001

( Figure 11E )

Lissoclinum reginum Kott 2001, p 319 and synonymy; 2004c, p 65 and synonymy.

Distribution

Previously recorded (see Kott 2001, 2004a, 2004b, 2004c): Western Australia (Port Hedland); Queensland (Capricorn Group, Swain Reefs, Lizard Island); Northern Territory ( Ashmore Reef, Darwin); Indian Ocean (Cocos Keeling Islands). New records: Queensland (Great Barrier Reef: 17.835 ° S, 146.695 ° E, 68 m, QM G308871; 16.955 ° S, 146.425 ° E, 55 m).

Description

The newly recorded colony (QM G308871) is a small, irregular scrap of an encrusting colony growing around weed. Clumps of spherical black cells are on each side of the branchial openings in the superficial bladder cell layer of the colony. The spicules, present throughout the test, are globular, to 0.03 mm diameter with occasional larger ones to 0.065 mm diameter. The rays are numerous, flat-ended rods. The common cloacal cavity is deep with clumps of zooids embedded in the test connectives that cross the common cloacal cavity between the basal and the surface test.

The other specimen has some lobes projecting from the surface and the basal test extends up into a central test mass. Dark pigment is in the basal or central test. Zooids are in clumps in test connectives that span the extensive common cloacal cavity between the central or the basal test and the surface layer where they branch to separate the thoraces from one another. The thoraces are large but contracted in all these specimens. They have a short oesophageal neck with a long, fine retractor muscle projecting from it and a large abdomen.

Remarks

The structure of the zooids is obscured by the poor condition of the colony and its identification is based on the form and size of the spicules and the disposition of the common cloacal cavities.

Figures

Figure 11. Scanning electron micrographs. (A) Trididemnum pigmentatum (QMG308842); (B) Trididemnum sibogae (QM G308893); (C) Trididemnum titanium (QM G308816); (D) Lissoclinum capsulatum (QM G308804); (E) Lissoclinum reginum (QM G308871); (F) Didemnidae?genus?species (QM G308889); (G, H) Didemnidae?genus?species [(G) QM G308888; (H) QM G308900].