Mussel reefs in sub-littoral zone-An important habitat for infaunal and ichthyofaunal diversity

Abstract

A Sub-littoral mussel reefs harbours rich and diverse invertebrate communities. They utilize the reef complex as their habitat, rich feeding substrate and also as refuge from predation. Though the invertebrate diversity of the reefs is available, reports pertaining to their relation to dietary habit of reef fishes are lacking. A study was taken up at the sub-littoral mussel reefs occurring off Someshwara Coast (12⁰ 47’ 19” N 74⁰ 51’ 05”E) in Karnataka (eastern Arabian Sea) to ascertain the diversity reef as well as the fish fauna of the region. The invertebrate community of the reef was collected by quadrant sampling method. The details on fish fauna of the reefs were collected by visual census and also by using semi-structured interviews with local fishers. Detailed study was carried out to find the dietary relationship of the ichthyofauna with the diverse organism associated with the sub littoral mussel beds.  Apart from barnacles and mussels, the invertebrate community was dominated by polychaetes followed by amphipods and crablets. The major ichthyofaunal diversity includes fishes of the family Leiognathidae, Lutjanidae, Siganidae, Sciaenidae, Epinephelidae, Carangidae, Ariidae, Haemulidae, Cynoglossidae, and others. The information pertaining to the dietary habits of the fish assemblages were compared with the in-faunal and ichthyofaunal diversity of the reefs to bring out the importance of mussel bed habitat.