Marine Ecology Research Papers - Academia.edu (original) (raw)

Fauna associated with selected seaweeds from intertidal areas of Vizhinjam coast was studied during November 2007 to May 2008. The environmental factors viz., Temperature, pH, Salinity, Nitrite, Nitrate, Phosphate and Silicate were also monitored during this period. Four morphologically different species of algae viz., Ceramium sp., Chnoospora minima, Padina tetrastromatica and Sargassum wightii were selected for this investigation. Totally four animal groups i.e., Sponges, Polychaetes, Crustaceans (Amphipods, Isopods and Decapods), and Molluscs (Bivalves and Gastropods) were encountered as associates of seaweeds. Maximum number of faunal associates was recorded from filamentous highly branched bushy red alga Ceramium sp. collected during Nov 2007 (564ind./100g ). In the case of coarsely branched alga C. minima, bearing narrow thallus, the associated fauna was maximum during May 2008 i.e., 414ind./100g. The leathery macrophyte S. wightii recorded a maximum of 366 ind./100g during March 2008. And the leafy thalloid, less complicated brown alga P. tetrastromatica showed the lowest faunal density, which recorded a maximum of 344 ind./100g during May 2008. Among the faunal population, amphipods recorded maximum density throughout the study period. The density of amphipod population was high in Ceramium sp. which varied from 17-418 ind./100g, followed by 97-405ind./100g in C. minima, 35-361 ind./100g in S. wightii and 17-216 ind./100g from P. tetrastromatica. Polychaetes were the second most abundant faunal associate of algae. The maximum density was observed in Ceramium sp. (38-209 ind./100g), followed by S. wightii (3-163 ind./100g), P. tetrastromatica (4-143ind./100g) and very less in C. minima. The third dominant group phytal fauna was molluscs, especially gastropods. Other groups, such as sponges, isopods, decapods and bivalves are uncommon and present occasionally. There was no significant correlation between environmental factors and fauna associated with seaweeds. The present study revealed that the morphology of algae plays a crucial role in the colonization of faunal associates.