Ecology of fouling bryozoans in Cochin waters

Abstract

An extensive study was conducted on the settlement and seasonal succession of fouling bryozoans in and around Cochin Harbour during the period 1965 to 1966; it was the first study of its kind performed in Indian waters. A total of 14 species was recorded from localities which were ecologically dissimilar. A distinct succession of species, mainly of a seasonal character, was observed. Seasonal succession usually occurs in localities where seasons are well marked, and where different species of animals with short life spans settle during particular times of the year. The study has shown that a distinct seasonal succession of bryozoans occurs in this locality; out of the 14 species which appeared on the panels not one species settled throughout the year. This was due to seasonal differences in the ecological conditions which prevailed in the area investigated. The significant seasonal influences on the incidence of bryozoans led to a categorisation of the species into the following patterns (a) typical brackish-water forms not encountered in purely marine localities; (b) typical brackish-water forms which may occur in marine localities; (c) typical marine forms never found in localities where low salinity conditions prevail.