Leptoclinides minimus, Kott, 2005

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 : 2422-2424

Leptoclinides minimus sp. nov.

( Figures 2A,B , 14E )

Distribution

Type locality: Western Australia (Marmion Lagoon, coll. P. Berry, C. Brice, 10 November 1983, holotype WAM 30.84 ) .

Description

The holotype is a fragment of a white sheet with an even surface covered with minute, crowded, spicule-filled, flat-topped papillae. Stellate branchial apertures are surrounded by crowded spicules. Spicules are crowded throughout the surface layer of test and are in a thin layer on the base of the colony, but they are sparse elsewhere. Spicules are small (to 0.04 mm diameter), burr-shaped to stellate, with 17 or more conical pointed to roundtipped rays in optical transverse section.

Zooids are very small. The atrial aperture is posterior, almost sessile and two-lipped. Strong transverse muscles are in the interstigmatal bars, fine parallel thoracic muscles are in the pallial thoracic wall and a circular lateral organ is in the outer body wall on each side of the base of the short atrial siphon (opposite the interspace between the third and last rows of stigmata). Twelve stigmata are in the anterior row of the branchial sac and two coils of the vas deferens surround a circle of five to seven club-shaped male follicles. A large egg is outside the outer coil of the vas deferens.

Remarks

Despite their small size, these zooids are characteristic of the genus Leptoclinides . The few vas deferens coils is reminiscent of the dubius group, but the present species has a regular circle of testis follicles rather than the grape-like cluster in the dubius group of species ( Kott

2001). Leptoclinides carduus Kott, 2001 has few coils of the vas deferens and similar spicules but unlike the present species the spicules are crowded throughout the colony.

Figures

Figure 2. Leptoclinides minimus sp. nov. (WAM 30.84, holotype). (A) Thorax; (B) abdomen. Scale bars: 0.1 mm.

Figure 14. Scanning electron micrographs of the calcareous spicules of: (A) Leptoclinides decoratus (SAM E3257); (B) Leptoclinides dubius (WAM 1093.89); (C) Leptoclinides frustus sp. nov. (SAM E3255, holotype); (D) Leptoclinides kingi (WAM Z20557); (E) Leptoclinides minimus sp. nov. (WAM 30.84, holotype); (F) Leptoclinides pulvinus sp. nov. (QM G308742, holotype); (G) Polysyncraton galaxum (SAM E3250); (H) Polysyncraton glaucum (QM G308736).