Observations on the distribution and seasonal fluctuations of Chaetognaths off Vizhinjam, Southwest coast of India

The distribution and seasonal abundance of Chaetognaths belonging to the genera Sagitta Quoy and Gaimard and Ptemagitta Costa collected during the cruises of Cadahin-VI between January and December, 1990 from three sectors off Vizhinjam, on the southwest coast of India, were studied in relation to hydrographic factors. Sagitta urfIata was the most dominant species for the greater part of the year and the present study revealed that this species is a continuous breeder with several peaks of intensive spawning. Species such as Sagitta farox. S. robusta and S. pacifca are recorded only during the premonsoon and later postmonsoon periods.