Aplidium panis, Kott, 2008

Kott, Patricia, 2008, Ascidiacea (Tunicata) from deep waters of the continental shelf of Western Australia, Journal of Natural History 42 (15 - 16), pp. 1103-1217 : 1159

Aplidium panis sp. nov.

( Figures 10A–C )

Distribution

Type locality: Western Australia CSIRO SS10 / 05 (Albany, Stn 22, 118.2940E 35.3350S, 100 m, 22 November 2005, holotype WAM Z27513, QM G328115 ) .

Description

The holotype is a sessile vertical cone about 8 cm high. The external surface is a hard crust of crowded sand grains. Only occasional clumps of sand are present internally in the otherwise translucent test. A cluster of small, red vesicles is embedded in the test in the vicinity of each zooid. The arrangement of zooids in the test is obscured by their contraction and withdrawal. Zooids have a large atrial lip projecting from the body wall anterior to the opening, which is on a distinct siphon. Stigmata are in 18– 20 rows, although the number per row was not determined. The small short stomach has five longitudinal folds in its wall. Male follicles are in two rows in the posterior abdomen.

Remarks

Although the colony is a similar shape to some of Aplidium crateriferum sp. nov., it lacks the latter species’ characteristic surface common cloacal apertures on chimneylike protrusions projecting up from deep depressions over the common cloacal cavities. The distribution of sand (which, in the present species, is crowded only in the surface) also helps to distinguish this species from other sandy Aplidium spp. (such as A. tuberosum sp. nov.) with sand crowded throughout the colony, only five stomach folds and separate atrial lips.

Figures

Figure 10. Aplidium panis sp. nov. (QM G326115): A, colony outline; B, thorax and abdmen; C, posterior abdomen. Aplidium solidum (QM G328064): D, zooid with larvae being incubated. Scales: A, 1.0 cm; B–D, 0.5 mm.