Polyclinum vasculosum Pizon, 1908

Kott, Patricia, 2006, Observations on non-didemnid ascidians from Australian waters (1), Journal of Natural History 40 (3 - 4), pp. 169-234 : 195-196

Polyclinum vasculosum Pizon, 1908

Polyclinum vasculosum Pizon 1908, p 223 ; Kott 1992a, p 464 and synonymy.

Distribution

Previously recorded (see Kott 1992a): Western Australia (Broome, Shark Bay ); New South Wales (Arrawarra); Queensland ( Moreton Bay to Lizard I.); Indonesia?, Philippines, Hawaii, West Indian Ocean. New record: 17.605 ° S, 146.355 ° E, Great Barrier Reef lagoon south of Cairns .

Description

The colony is a naked, robust encrusting sheet growing over mud and calcareous debris including worm tubes. Zooids have black squamous epithelium anteriorly, and it is particularly conspicuous over the large rectangular atrial tongue, with a straight fringed outer margin, which is separated from the body wall just anterior to the atrial aperture by a narrow constriction. The large atrial tongues are inserted into the test over the common cloacal canals that converge to the common cloacal apertures. The systems are conspicuous. Gonads are in a sac posterior to the abdomen. Two or three larvae, each with a trunk 0.75 mm long and the tail wound three-quarters of the way around it are in the atrial cavity. They each have four median and four pairs of lateral ampullae and the usual antero-dorsal and postero-ventral clumps of vesicles.

Remarks

The robust colonies with black zooids and yellowish pigment in life and conspicuous common cloacal canals converging to the common cloacal apertures are common components of tropical rubble fauna. The species is an Indo-West Pacific tropical species.