COLD STORAGE OF SPERM FROM THE AXOLOTL, AMBYSTOMA MEXICANUM

The development of reproductive methodologies such as techniques for storage of sperm can be valuable for conservation management of endangered amphibians. For example, storage and preservation of genetic material can assist in transferring genes from natural populations to cultured breeding colonies and can assist in increasing genetic exchange among distinct populations. For salamanders, collecting spermatophores and their subsequent cold storage is a useful method of increasing genetic variation and assisting in propagation efforts. In this study, I examined the influence of temperature on the short-term viability of sperm from spermatophores of Axolotls (Ambystoma mericanum) salamanders for spermatophores stored at 0 degrees C, 3 degrees C, and 6 degrees C. Sperm remained viable for 28 d when stored at 0 degrees C (45.0% +/- 31.2%), 3 degrees C (61.7% + 12.6%) and 6 degrees C (40.0 +/- 45.8%). The percentage of viable sperm cells fluctuated through time (individual spermatophores assayed on days 0, 7, 14, 21, and 28), and was not significantly different. Additionally, the percentage of viable sperm cells in the three storage temperatures were not significantly different, and neither this factor nor the interaction of time x temperature resulted in a significant difference in the percent of sperm that were viable. Overall, the ability to store spermatophores for 28 d for A. mexicanum (critically endangered in nature) may prove useful for optimizing protocols for a range of endangered species.