Cryopreservation of sperm of
red snapper (Lutjanus campechanus)
K.L. Riley, Ch.G. Holladay, E.J. Chesney, T.R.
Tiersch-2004
Aquaculture, 238: 183-194
Abstract:
Interest in the culture of snappers (family
Lutjanidae) has developed throughout the world because of declines in wild
stocks combined with a consistent high demand and market value. Some
snappers, such as the red snapper Lutjanus campechanus have proven to
be difficult to spawn and culture in captivity. As part of a larger study to
improve propagation techniques for red snapper, procedures were developed
for the collection, handling, and commercial-scale cryopreservation of
sperm. Utilization of cryopreserved sperm in spawning of red snapper allows
efforts to be focused on maintaining female broodstock, monitoring ovarian
development, and increasing efficiency during the strip-spawning process.
Red snapper were collected during the 2000 and 2001 spawning seasons (May to
August) off coastal Louisiana by hook and line. Testes were surgically
removed and sliced to release sperm. Sperm were collected in 50-ml
centrifuge tubes and diluted 1:3 (v:v) with calcium-free Hanks' balanced
salt solution. Dimethyl acetamide, dimethyl sulfoxide, methanol, and
glycerol were evaluated as cryoprotectants. Dimethyl sulfoxide produced the
smallest reduction in motility of sperm cells in acute toxicity trials and
produced the highest motilities after thawing (71±16%) in initial
cryopreservation trials. During the 2-year study, sperm samples from 20 red
snapper were frozen using commercial-scale cryopreservation methods
developed for dairy bulls. Although sperm motility after thawing was
typically greater than 80%, comparison with fresh samples revealed a
significant difference in motility (P=0.048). Refrigerated and
cryopreserved sperm samples with motilities above 80% were used in
fertilization trials. Fertilization rates were variable among females
(11–85%), although results with refrigerated (non-frozen) and
cryopreserved sperm were highly correlated (r=0.85). These results
demonstrate that refrigerated and cryopreserved sperm were each effective
for the artificial fertilization of red snapper eggs.
(Aquaculture Research Station, Louisiana Agricultural
Experiment Station, Louisiana State University Agricultural Center, Baton
Rouge, LA 70803, USA, e-mail: kriley@hboi.edu)