PRODUCTION OF GASTROPODS IN LAKE BIANDANTANG Ⅱ.ANNUAL PRODUCTION OF PARAFOSSARULUS STRIATULUS

The production of Parafossarulus striatulus in Lake Biandantang was calculated by using four method.The results were:178.07 mg穖-2穉-1 of dry weight shell free or 4998.40 mg穖-2穉-1 of wet weight with shell by size-frequency method;174.5 mg穖-2穉-1 of dry weight shell free or 4898.20 mg穖-2穉-1 of wet weight with shell by removal summation method;174.5 mg穖-2穉-1 of dry weight shell free or 4898.20 mg穖-2穉-1 of wet weight with shell by Allen curve method;178.14 mg穖-2穉-1 of dry weight shell free or 5000.40 mg穖-2穉-1 of wet weight with shell by instantaneous growth method.The corresponding P/B ratios are 4.3,4.4,4.4,4.5, respectively. Therefore,the results by the four methods are in well agreement,which might be of great significance in the estimation of invertebrate production.