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