Journal of the Marine Biological Association of India

Ecological characteristics associated with the polar erect bryozoans

Volume 51 Issue 2

Soja Louis and N.R. Menon

Abstract

Antarctic bryozoans are well known for their diversity. Over 300 species have been described from this unique ecosystem and new species continue to appear. During the Third Indian Antarctic Expedition,24 species of cheilomate bryozoans were collected. The most remarkable feature of majority of the species was a clear-cut coralline, fragile and thalloid morphology of the zoarium. Since this morphological feature was in striking contrast with the benthic bryozoans of the Indian Ocean, the possible reasons for the conspicuous difference in morphology were analyzed based on the ecological conditions prevailing in the mesobenthic regions of Southern Ocean in general and the coastal waters of the Antarctic continent in particular. The existence of different hydrological fronts influence the ecology of the waters of the Southern Ocean. The animals were collected from a depth of 200m where the hydrological conditions recorded were nearly hostile. This is accompanied by rarity of organic debris, microzooplankton and dead organic matter which form the source of energy for the microbenthos of the Antarctic. Therefore, the peculiar morphology of the bryozoan colonies could be an environment induced architecture ensuring and enhancing survival of the group in this hostile biological environment.

Keywords

Polar, benthic, erect, coralline, bryozoa

Date : 20-02-2010