Fertilization potential of cold-stored Fowler’s toad

Asynchrony of gamete release is problematic in amphibian captive breeding programs but can be overcome by short-term storage of spermatozoa. Hormonally induced sperm from the model species Anaxyrus fowleri were used to determine storage conditions for optimal fertilisation capacity. Sperm motility was measured over time, as a function of storage temperature (4°C or 22°C) and solution osmolality (7–40 mOsm/kg). Sperm at 40 mOsm/kg (spermic urine) stored at 4°C exhibited higher motility compared to 22°C. Also, sperm stored at 40 mOsm/kg retained higher motility compared to sperm stored below 15 mOsm/kg at both temperatures. Under optimal storage conditions (40 mOsm and 4°C) a 30% decrease in sperm motility occurred within 24 h, however, subsequent loss of sperm motility was lower (