First Record of Cheilostome Encrusting Bryozoan, Celleporaria volsella from Coastal Waters of Sri Lanka

Abstract

Sri Lanka is an Island country with very high faunal diversity. Yet, many species remain to be uncovered due to lack of interest on biodiversity in the marine environment. Therefore, it is imperative to carry out comprehensive studies to unveil these mysterious organisms from our coastal waters. Biofouling community is one such group that needs due attention in terms of taxonomy and distribution. Bryozoans are diverse and widely spread group owing to their long history; dating back to early Ordovician Period. Yet, inconspicuous and poorly known to most part of the world. Although most are marine, these colonial invertebrates occur in fresh water habitats as well. They comprise the major component of fouling communities growing on substrates. Therefore, the present study was designed to investigate the diversity of encrusting bryozoans in Colombo Port. Biofouling assemblages were collected from eight sampling locations using settlement collectors based on those developed by the Center for Research on Introduced Marine Pests (CRIMP). The collectors were suspended in four different depths. The first set was 1 m below the water surface and others settled in 1 m increments. Monthly samples were collected from October 2014 to July 2015 from both replacing and permanently settled collectors. Specimens were identified microscopically observing fine morphological features. Findings of the present study demonstrate presence of taxonomically diverse bryozoan community in Colombo port. Among other bryozoans the remarkable finding was the record of colonies of Celleporaria volsella found in all the sampling locations. This is the first record of C. volsella from Sri Lankan coastal waters. C. volsella is very rare encrusting colonial bryozoans of the family Lepraliellidae, sub-order Flustrina, and order Cheilostomatida originally described from Solomon Island, Anusha Islands and Florida Islands. C. volsella can be distinguish from close relatives of the genus from size and shape of the primary orifice with pair of spiny processes, large suboral avicularia and elongate vicarious avicularia with a smooth, truncated spatulate distal rim.