Diversity and distribution of shallow water sponges (Porifera) in the coastal waters from Enayam to Kollam, south-west coast of India

Underwater surveys were conducted in the shallow coastal waters extending from Enayam to Kollam, southern India, covering six study locations viz., Enayam, Adimalathura,Vizhinjam, Varkala, Odayam and Paravoor to record the diversity of sponges. A total of 24 species of sponges were identified during the study which belonged to 20 genera, 14 families and 6 orders. Maximum species diversity was recorded at Enayam (11 species), followed by an equal number of species at Vizhinjam and Adimalathura (10 species). Five species of sponges were recorded at Odayam while three species were recorded at Varkala and only one at Paravur. Shannon diversity was high at Enayam, Vizhinjam and Adimalathura and the dominance plot also showed rich diversity of sponges in these three stations.The cluster results using Bray Curtis similarity Index indicated two clusters: stations Enayam, Vizhinjam and Adimalathura showed one cluster indicating similarity of species in these stations, while the stations Varkala, Odayam and Paravoor showed another cluster. The present study has indicated that the stations Enayam, Vizhinjam and Adimalathura are rich in diversity and abundance of sponges, compared to Varkala, Odayam and Paravoor.