Improved Cryopreservation of Sperm of Paddlefish (Polyodon spathula)

Abstract

Experiments were performed to improve protocols for sperm cryopreservation of paddlefish (Polyodon spathula), a species for which there has been limited study. The first experiment was conducted to investigate the effects of two extenders (modified Tsvetkova’s extender: mT and modified Hanks’ balanced salt solution: mHBSS) in combination with methanol (MeOH) and dimethyl sulfoxide in two concentrations (5 and 10%) on the postthaw motility and fertilization rates of cryopreserved sperm. The highest postthaw motility (85 ± 5%) was observed when sperm were frozen using mT extender with 10% MeOH as cryoprotectant. Extenders (P = 0.0018) and cryoprotectants (P = 0.0040) each had a significant effect on the postthaw motility of paddlefish sperm. The highest fertilization (80 ± 3%) was found when eggs were fertilized with sperm frozen with mT extender in combination with 10% MeOH. However, there was no significant difference among fertilization rates when MeOH was used as a cryoprotectant in either concentration or in combination with either mT or mHBSS extenders. In the second experiment, 4000 eggs were fertilized with the pooled contents of five straws of thawed sperm (total volume of 1.25 mL) using mT extender in combination with 5% MeOH, and hatch rates as high as 79 ± 5% were observed. A third experiment was also conducted to clarify the role of MeOH concentration; however, no significant difference was found among fertilization and hatch rates when either 5 or 10% MeOH was used as a cryoprotectant. These results suggest that MeOH is a safe and reliable cryoprotectant for freezing of paddlefish sperm and obtaining viable postthaw sperm for consistent fertilization and hatch rates. Further, this experimental protocol is relatively simple and applicable for commercial hatchery production of paddlefish.

Cryopreservation and vitrification of fish semen: a review with special emphasis on marine species

“…; Horváth et al . , , ; Cabrita et al . ); also catfish like the African and European catfish ( Clarias gariepinus, Silurus glanis ) and carps like the common ( Cyprinus carpio ) and silver carp ( Hypophthalmichthys molitrix ) (Horváth & Urbanyi ; Suquet et al .…”

“…Among salmonids, these include rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta), brook trout (Salvelinus fontinalis) and charr (Salvelinus alpinus) (Lahnsteiner et al 1996;Cabrita et al 1998;Mart ınez-P aramo et al 2009). Other species of commercial interest which need protection are the sturgeons, such as beluga (Huso huso), sterlet (Acipenser ruthenus), pallid (Scaphirhynchus albus) Siberian, European and Russian (Aythya baeri, Acipenser sturio, Acipenser gueldenstaedtii) and the shortnose (Acipenser brevirostrum) (Glogowski et al 2002;Horv ath et al 2005Horv ath et al , 2006Horv ath et al , 2008Cabrita et al 2010); also catfish like the African and European catfish (Clarias gariepinus, Silurus glanis) and carps like the common (Cyprinus carpio) and silver carp (Hypophthalmichthys molitrix) (Horv ath & Urbanyi 2000;Suquet et al 2000;Jenkins & Draugelis-Dale, 2006;Alvarez et al 2008;Maisse et al 2008;Viveiros & Komen 2008;Cabrita et al 2010).…”

Cryopreservation of Persian sturgeon (Acipenser persicus) sperm: effects of cryoprotectants, antioxidant, membrane stabilizer, equilibration time and dilution ratio on sperm motility and fertility

“…MeOH is known for its rapid penetration of cells, but the details of its action as a CPA are not clear (Horvath et al . ). The adverse effects of Gly and EG at high concentration might be due to their toxic functions to cause damage to spermatozoa cells.…”

“…) and paddlefish (Horvath et al . ; Horvath, Urbányi, Mim, Bean, Gomelsky & Tiersch ; Linhart, Mims, Gomelsky, Cvetkova, Cosson, Rodina, Horvath & Urbanyi ) sperm. In most studies, DMSO has been reported the best CPA, probably due to its small molecular size, fast penetration into spermatozoa and by its interaction with the phospholipids of the sperm membrane (Suquet, Dreanno, Fauvel, Cosson & Billard ).…”

“…Previous studies have reported better sperm fertilizing ability in sturgeon cryopreserved with MeOH compared to DMSO (Cherepanov & Kopeika ; Horvath et al . ; Linhart et al . ).…”