Leptoclinides tuberculatus, Kott, 2004

Kott, Patricia, 2004, New and little-known species of Didemnidae (Ascidiacea, Tunicata) from Australia (part I), Journal of Natural History 38 (19), pp. 731-774 : 737-738

Leptoclinides tuberculatus sp. nov.

( figure 3 A–C)

Distribution. Type locality: Queensland (Shelburne Bay, 22 m, encrusting red gorgonian, coll. AIMS Bioactivity Group, 9 April 1994, holotype QM G308540; 11 April 1994, paratypes QM G308536, G308539).

Description. These encrusting colonies are thin with conspicuous but irregular spicule-filled small papillae to larger tuberosities projecting from the surface. Sometimes only sparse spicules are present in the remainder of the test but in other colonies they are present throughout, albeit they are most crowded in surface and basal layers. Primary common cloacal cavities surrounding large clumps of zooids are deep, leaving only a thin layer of basal test in the floor of the cavity which sometimes becomes posterior abdominal. In life, colonies are dark, and are either mottled brown and white, or blue. In preservative, black pigment, which is scattered through the test, is seen only between the opaque white surface excrescences and the colonies all appear mottled (or piebald). The black pigment is in minute spherical cells, which are particularly crowded in the roof of the common cloacal canals. Spicules are robust, stellate, to 0.08 mm diameter, with 11–13 sturdy, conical, pointed rays in optical transverse section. Sometimes rays appear to be broken off at their base. The ray length / spicule diameter ratio is 0.3.

Zooids are small. The branchial siphon is short with six lobes around the aperture. The atrial aperture is on a relatively short posteriorly orientated siphon. About eight stigmata are in each of the four rows. Six coils of the vas deferens surround about five male follicles. The larva is not known.

Remarks. This species has been taken only from Shelburne Bay, and on red, branching, gorgonian colonies. Nevertheless, it is likely to have a wider range in the tropics.

Like the present species, Leptoclinides cuspidatus ( Sluiter, 1909) colonies are mottled blue and white or dark blue, lack a superficial bladder cell layer, have dark pigment beneath the surface spicules and around the common cloacal cavities and six coils of the vas deferens. However, L. cuspidatus has larger (to 1.25 mm diameter or more) spicules, many with chisel-shaped rays and it lacks the surface tuberosities of the present species.

The spicules and lack of surface bladder cells resemble L. brandi Kott, 2001 but the stigmata and the colony surface are different.

Figures

FIG. 3. Leptoclinides tuberculatus: (A) vertical section through colony (QM G308540); (B) zooid (QM G308536); (C) spicules (QM G308539). Leptoclinides variegatus (SAM E2908): (D) spicules. Scales: (A) 1.0 mm; (B) 0.1 mm.