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.

Keywords: Celleporaria volsella, Encrusting bryozoa, Colombo port, Sri Lanka