Distaplia pallida Kott, 1990

Kott, Patricia, 2006, Observations on non-didemnid ascidians from Australian waters (1), Journal of Natural History 40 (3 - 4), pp. 169-234 : 187-188

Distaplia pallida Kott, 1990

( Figure 8H )

Distaplia pallida Kott 1990a, p 121 .

Distribution

Previously recorded (see Kott 1990a): South Australia (Great Australian Bight, Gulf St Vincent); Victoria (Portsea); New South Wales ( Byron Bay ); Tasmania (Tinderbox). New records : Tasmania ( Port Davey , 5–7 m, SAM E3273 ) .

Description

The colony is a firm, jelly-like translucent cushion with conical lobes protruding from the upper surface. Zooids are arranged in circular to long oval systems around sessile common cloacal openings. Sometimes the common cloacal apertures are long slits between two apparently parallel rows of zooids, and at each end the opening extends into narrow slits in the roof of the common cloacal canal that expose the atrial apertures directly to the exterior. The translucent internal or basal test contains criss-crossing posterior stolons of the zooids. About 12 stigmata are in each row in the branchial sac and the stomach has about 10 broad, parallel external folds. Gonads were not detected in the newly recorded specimens, although in previously recorded specimens they are reported to be in the gut loop. Photographs show colonies as pale blue, although they are beige in preservative.

Remarks

The species is distinguished from other species with circular to longitudinal systems by its relatively few branchial stigmata, broad stomach folds, and gonads in the gut loop (see Kott 1990a).

Figures

Figure 8. In situ images of: (A) Pseudodiazona claviformis (SAM E3280); (B) Pycnoclavella tabella (SAM E3290); (C) Stomozoa australiensis (SAM E3285); (D) Sigillina exigua (SAM E3300, syntype); (E) Distaplia australiensis (SAM E3294); (F) Distaplia australiensis (SAM E3295); (G) Distaplia florida (SAM E3293); (H) Distaplia pallida (SAM E3273).