Availability of cultivable prawn and fish seed in Cochin Barmouth area was assessed from June 1981 to April 1983 and it was found that postlarvae of Metapenaeus dobsoni, M. monoceros and Penaeus indicus were available almost throughout the year, with the peak during March-September. The maximum number observed was 5,25,024/net/hour in August 1981. M. dobsoni (50.80%), P. indicus (34.40%), M. monoceros (13.50%) and P. monodon (1.30%) were the constituent prawn species. P. indicus postlarvae were available in the catch in all months except December 1981, March-August showing the peak. P. monodon was present in limited quantities during the period February-June, the maximum number recorded being 13.248/net/hour in June 1982. The metapenaeids also showed the maximum numbers during the period March-September. Liza parsia was the only fish species found in any significant quantity, with a maximum number of 4,860/net/hour in November 1981. Fry and fingerlings of Chanos chanos and Mugil cephalus were found in appreciable numbers in the shallow inundated areas of the mangrove swamps, along with large numbers of Liza parsia