New Zealand Journal of Marine and Freshwater Research abstracts

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Verification of the production of triploid grass carp (Ctenopharyngodon idella) with hydrostatic pressure

NIGEL H. McCARTER

Ministry of Agriculture and Fisheries P.O. Bo>; 951, Rotorua, New Zealand

Abstract Triploidy was induced in grass carp, Ctenopharyngodon idella, by pressure shocks of 5.6 X 10³ kPa 4 min after fertilisation. Pressure shocks induced ixiploidy in 95% of eggs. Fingerlings were tested for triploidy by karyotyping, flow cytometry, erythrocyte measurement, and using a Coulter counter. The mean erythrocyte cell volume, nuclear volume, linear measurements, and DNA content of triploid fish were 1.2 to 1.8X greater than measures of diploid fish with little overlap between the measures. The correlation between the test methods was high, and where there was disagreement, triploids were falsely classified as diploids. Measuring mean nuclear volume using a Coulter counter proved a rapid and accurate method of discriminating diploid from triploid fish.

Keywords Ctenopharyngodon idella; grass carp; aquatic weed control; triploids; sterility

New Zealand Journal of Marine and Freshwater Research, 1988, Vol. 22: 501-505 Crown copyright 1988Received 25 September 1987; accepted 22 January 1988

PDF file of entire paper: medium quality (409K); (scanned from paper original: notes about this process)

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