Ten species of the genus Alectona Carter, which are enlisted world over, form a dreadful group of pests of calcium secreting animals in the marine environment. These species were collected in the past from hard parts of Hexacorals, Octocorals, Hydrocorals and also from molluscan shells.In the present study A.wallichii(Carter) identified from the brown mussel (Perna indica Kuriakose and Nair) collected from Enayam, south west coast of India,forms the first record of A. wallichii from a shell, that too of the south west coast of India. Since the previous records of A. wallichi are from calcareous rocks and precious coral, it may be inferred that it has succeeded in migrating and establishing in a molluscan shell obviously in the absence of any precious coral communities in the Indian seas. With the present discovery of a species under the queer genus Alectona, the total number of valid Indian boring sponge species comes to 37.

Alectona wallichii, dreadful pest, new record, Enayam, southwest coast, India.