02877nam a2200205Ia 4500999001700000003000400017005001700021008004100038082002100079100001800100245012700118260007700245300000800322502000900330520212100339700002202460856005602482942001202538952012102550  c27820d27820OSt20220323110110.0140128s9999    xx            000 0 und d  a639.2bJAY/ST PG  aJayasree P S   aStructure and the seasonal changes of the macrobenthic community in relation to the hydrography of a prawn filtration pond  aPanangadbDepartment of Fishery Hydrography, College of Fisheries c2009  a129  bMFSc3 aPresent study was carried out in the prawn filtration pond of the College of Fisheries adjacent to Cochin backwater to find out the seasonal variation of macrobenthos and to correlate them with the seasonal variation in hydrographical parameters and sedimentary characteristics of the pond. Fortnightly samples for hydrographical parameters, sedimentary characteristics and biological studies were collected during the period from October 2007 to September 2008. Hydrographical parameters like salinity, water temperature, turbidity, pH, total alkalinity, hardness, nutrients, dissolved oxygen, primary production, chlorophyll – a and transparency were observed.

	Polychaetes, tanaids, amphipods, bivalves and gastropods were the benthic groups obtained. Prawn juveniles and cumaceans encountered very rarely, during the study period were grouped as ‘others’. Among these gastropods, tanaids and polychaetes were the dominant forms. In the culture field, benthic populations were maxi                                                                                                                                                                                                 mum during post monsoon months and showed a decreasing trend during pre monsoon and with the onset of monsoon it further decreased. Gastropods were the most dominant group observed during pre monsoon, forming 80% of total macrobenthos. Tanaids were the second major group and they were the dominant group during the post monsoon period forming 54% of total macrobenthos. Polychaetes were the third major group and constituted 35% of total macrobenthos during monsoon season and they were the second maximum during that period. In the culture field benthic abundance was found to be mainly influenced by substratum characteristics. Among the different hydrographical parameters studied for seasonal variation, water temperature, pH, primary production and chlorophyll were found to be significantly different. Among the sedimentary characteristics studied for seasonal variation, sediment pH was found to be significantly different.
  aRaman N N (Guide)  uhttp://krishikosh.egranth.ac.in/handle/1/5810043174  2ddccTH  00102ddc4070aKAUCLVbKAUCLVcTHESESd2014-03-18l0o639.2 JAY/ST PGp172880r2014-03-18 00:00:00w2014-03-18yTH