A study on the boring sponges infesting the brown mussel population of the outhwest coast of India was initiated in 1998, and bored shells collected from five major mussel fishing centres along the coast were analysed on a regular basis. It could be seen that out of 5,600 shells examined during 1998-2000 period, 997 shells were found infested with boring sponges registering an overall incidence of 17.8%, and this, when compared with 3-8 % noticed in natural molluscan beds was too high. The total number of boring sponge species recorded from mussel is nine, and these fall under two families and four genera, the most speciose genus being Cliona with five species. The Enayam centre accounted for all the nine species, and the two new infiltrants, Pione margaritifera and C. lobata formed a common factor with high specific incidence (%) in all the centres surveyed.

Brown mussel, dreadful sponge pests, southwest coast, India