ascidian Aplidium sp., possibly A. vastum

This ascidian Aplidium sp. is a colonial ascidian in the family Polyclinidae and could be Aplidium vastum [2].

Aplidium vastum is found throughout Antarctica and the Antarctic Peninsula from 100 to 300 meters depth [1,3]. A. vastum colonies are massive, spherical or egg-shaped, from six to twenty centimeters in diameter [1,4]. The spherical colonies of A. vastum have zooids opening all around the surface and their test (covering) may be impregnated with sand [1,4].


This photo of the Aplidium sp. colony above shows its size relative to other organisms.

1: Antarctic Ascidiacea; Monographic Account of the Known Species Based on Specimens Collected under U.S. Government Auspices, 1947-1965. Kott, Patricia. Washington, DC : American Geophysical Union, 1969. Antarctic Research Series. Volume 13; 2: Patricia (Kott) Mather, personal communication, 1999; 3: Memoires du Museum National d'Histoire Naturelle. Nouvelle Serie. Serie A, Zoologie 125:1-168, plates, 1983; 4: Bulletin du Museum National d'Histoire Naturelle. 3e Serie. Number 510. Zoologie 351:3-18, 1978

Text ©Peter Brueggeman. Photograph ©Steve Alexander. Photographs may not be used in any form without the express written permission of Steve Alexander.