The motility, survival and fertilisation rates of Mekong giant catfish sperm were found to
depend on a number of factors, i.e. type of extender, sperm volume, cryoprotectant concentration,
cryopreservation and storage time. HBSS appeared to be the best extender for the fish sperm which,
when present in 1:6 (sperm:extender) ratio, gave the highest motility grades (3.3-4.0) and the highest
fertilisation rates at 2-ml volume. The percentage of live cells of the sperm kept in HBSS was also
Extender
Fertilisation rate (%)Maejo Int. J. Sci. Technol. 2010, 4(03), 417-427
426
highest (45.3%).A cryoprotectant (DMSO) concentration of 8% of the extended sperm was found to be
optimum. The highest fertilisation rate of MGC fresh sperm and MGC eggs was 47.1% while that of
one-year-cryopreserved sperm under the same conditions was 36.2%. Sperm cryopreserved for 2
weeks and 1 year gave a satisfactory fertilisation rates of 36.2 and 30.9% respectively with P.
hypophthalmus eggs.