title: Cryopreservation of spermatozoa of black marlin, Makaira indica (Teleostei: Istiophoridae).
abstract: As a first step towards the development of a method for the cryopreservation of black marlin spermatozoa, this study investigated the effect of dimethylsulfoxide (DMSO) concentration and pellet size on post-thaw spermatozoal motility. Spermatozoa were recovered from the spermatic duct of testes retrieved post-mortem from four adult black marlin caught in the Coral Sea spawning grounds of Australia. Undiluted spermatozoa were stored on ice for 4 to 10 hours during transport to shore, then evaluated for motility after activation in seawater (1:10 v:v). Spermatozoa were prepared for cryopreservation in pellets by extension (1:3 v:v) in a defined fish Ringer's solution to give two final DMSO concentrations of 2.5% or 5.0%. Diluted spermatozoa were frozen directly on a dry ice block in pellet sizes of either 0.25 ml or 0.50 ml. Frozen pellets were thawed in a water bath at 40 degrees C for 60 seconds and assessed for post-thaw motility following activation in seawater. Spermatozoa recovered within 50 minutes of death and chilled on ice for 4 to 10 hours showed a mean (+/- SEM) motility immediately following activation of 91.6 +/- 7.9%. 50% of the spermatozoa remained motile for approximately 4 to 5 minutes. Following cryopreservation, mean motility declined significantly across all cryoprotectant and pellet size combinations (P < 0.001) but spermatozoa frozen in 2.5% DMSO showed higher motility than those frozen in 5.0% DMSO (P = 0.014). Pellet size had no effect on post-thaw motility (P = 0.179).
authors.affiliation: School of Animal Studies, The University of Queensland, Gatton, Australia. s373132@student.uq.edu.au
authors.forename: K M
authors.initials: KM
authors.lastname: van der Straten
authors.forename: L K-P
authors.initials: LK
authors.lastname: Leung
authors.forename: R
authors.initials: R
authors.lastname: Rossini
authors.forename: S D
authors.initials: SD
authors.lastname: Johnston
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004367:Dry Ice; D008297:Male; D010473:Perciformes; D012662:Semen Preservation / Q000379:methods*; D013081:Sperm Motility / Q000187:drug effects / Q000502:physiology; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology*
chemical_list: D003451:Cryoprotective Agents; D004367:Dry Ice; D004121:Dimethyl Sulfoxide