supply of good quality desi magur ( clarias batrachus ) / singhi ( heteropneustes fossilis ) and lime under air breeding fish culture during the year 2018-19 at different blocks in the murshidabad district of west bengal . , a ) desi magur ( clarias batrachus ) / singhi ( heteropneustes fossilis ) : good quality healthy magur / singhi seed . b ) delivery size 3 inches @ 24000 nos . / ha in oxygen pack . c ) only pure variety , no hybrid variety will be allowed . ( to be identified from the structure , skull & skin colour ) . , 1 ) supply of good quality lime stone ( calcium carbonate - caco3 ) or burnt lime ( calcium oxide - cao ) 2 ) the materials should be solid , semi dust , purely in dried conditions in sealed pack . 3 ) in case of lime stone , calcium carbonate should be not less than 98% . 4 ) in case of burnt lime , calcium oxide should not be less than 89% . 5 ) burnt lime should neither be over burnt nor under burnt .