Food and feeding of Phallusia nigra, Savigny, 1816
Divta T Dharan, G Prasad
Ascidians are conspicuous and important members of shallow benthic community. Ascidians belong to phylum Chordata and class Ascidiacea. Phytoplankton and other organic particles in suspension constitute the bulk of the food of the many species of ascidians. The present study was carried out to analyze the stomach contents of solitary ascidian Phallusia nigra to identify the diet components on seasonal basis. The highest value of index of preponderance was shown by sand particles (54.69%) followed by micro flora (24.78%), meio fauna (13.63%), miscellaneous (4.86%) and macro fauna (2.034%). The percentage of feeding intensity was highest (27.64%) for heavy fed group and lowest value was reported for empty fed group (11.79%). P. nigra has been found to be an unselective suspension filter feeder which mainly feed upon large quantity of mud and micro flora (Cosinodiscus sp, Navicula sp and Prorocentrum sp) and macro fauna were less frequent than meiofauna.