LAUSR

Abstract Coral reefs are one of the important habitats of marine biodiversity in shallow tropical waters as they sustain numerous crucial ecosystem services. This study provides the taxonomic account and sheds light on the habitat of Bryozoan species, which exclusively considers corals as its substratum for their growth and their role in reviving the depleting coral ecosystem. The systematic description of 12 coral associated bryozoans is, discussed here. Among the described 12 species, six of them, Parasmittina collifera (Robertson, 1908), Smittipora philippinensis (Canu and Bassler, 1929), Onychocella angulosa (Reuss, 1848), Plesiocleidochasma porcellanum (Busk, 1860), Robertsonidra argentea (Hincks, 1881) and Schizoporella errata (Waters, 1878) are reported for the first time in Indian waters. The survey was conducted during April 2013–April 2015 in Gulf of Mannar Marine Biosphere Reserve (GoMBR). Bryozoan species were, collected from the coral rubble and coral skeletal framework in the shallow waters (up to 5 m) and illustrated by scanning electron microscopy (SEM). A conclusion was drawn from this study, where Bryozoans, which colonise dead coral skeletal framework and rubble, can revive the depleting coral reef ecosystem as they play a major role in cementation and act as pioneer species in succession.