Didemnum ternerratum Kott, 2001

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 : 2452-2453

Didemnum ternerratum Kott, 2001

( Figure 16F )

Didemnum ternerratum Kott 2001, p 241 and synonymy; 2004b, p 2501.

Distribution

Previously recorded (see Kott 2001, 2004b): South Australia (Great Australian Bight, Kangaroo I., Wright I., Ward I.); Victoria (Western Port). New record: Tasmania (Port Davey, SAM E3240).

Description

The newly recorded colony is a tough white slab with an even smooth surface. Stellate spicules are crowded throughout. They are to 0.06 mm diameter and have 15–17 short conical rays in optical transverse section. Despite the relatively numerous rays, their bases are not especially crowded together. The common cloacal cavity is a relatively shallow cavity at thoracic level. Zooids are small with about seven stigmata per row in the anterior part of the branchial sac. Gonads were not detected in this specimen.

Remarks

The sympatric temperate species D. jucundum Kott, 2001 , D. lissoclinum Kott, 2001 , D. ossium Kott, 2001 , and D. patulum ( Herdman, 1899) generally have larger spicules with fewer rays.

Figures

Figure 16. Scanning electron micrographs of the calcareous spicules of: (A) Didemnum incanum (SAM E3238); (B) Didemnum leopardus sp. nov. (QM G308719, holotype); (C) Didemnum moseleyi (WAM 175.93); (D) Didemnum plebeium sp. nov. (WAM 155.93, syntypes); (E) Didemnum stragulum (WAM 162.93); (F) Didemnum ternerratum (SAM E3240); (G) Trididemnum amiculum (SAM E3263); (H) Trididemnum areolatum (QM G308746).