Zooplankton standing stock and diversity in the Gulf of Kachchh with special reference to larvae of decapoda and Pisces

Zooplankton characteristics of the Gulf of Kachchh including the major cree k systems of Nakti, Kandla and Hansthal were studied for monsoon, postmonso on and pre- monsoon periods. Zooplankton collections were made at 7 locatio ns. The area was very rich in zooplankton standing stock showing a variatio n of 0.59 to 185.50 ml/100m(3). The maximum biomass was at st 5-112.6 ml/10 0m(3) in monsoon; st 2 - 109.91 ml/100m(3) in postmonsoon and at st 1 - 88. 01ml/100m(3) in premonsoon. Similarly, the population maxima were 942 no/10 0m(3) during monsoon, 196 no/100m(3) in postmonsoon aid 8027 no/100m3 durin g premonsoon. Metapenaeus affinis, M. dobsoni, Penaeus indicus, Parapenaeop sis stylifera and P. hardwickii were the species of penaeid prawns present in the samples. Larvae of M. affinis were dominant in the creek and gulf du ring monsoon, whereas Acetes indicus dominated in the collections during pr emonsoon and postmonsoon. Among the fish larvae, majority of them were in t he early stages of development and the size varied from 1 nun to 5 mm. Bole opthalmus glaucus, Engraulis mystax, and Clupeids were the most common fish larvae present in this area. The major species of larvae of prawns and fis hes occurring in the gulf were compared with the adults caught from the are a. The environmental parameters like salinity, temperature, oxygen and nutr ients were taken to study the zooplankton population, its intensity and div ersity.