sperm of the following neotropical characiformes fish species were tested for cold storage: brycon lundii, piaractus mesopotamicus, leporinus elongatus, leporinus friderici, prochilodus lineatus and prochilodus marggravii. each sperm sample was split into two aliquots. the first was placed into a plastic bag with air or oxygen and the second, in a plastic tube with air. the samples were maintained at temperatures between 1.7-4.9 oc. the rate of sperm motility was estimated using a 50 mm nacl solution as the activating solution. the shortest sperm storage duration (7 h) was recorded for l. friderici, when the sperm motility rate reached ~ 30%, whereas the longest duration (20 h) was obtained with the sperm of p. lineatus. a fertilisation test using prochilodus marggravii sperm refrigerated for 8 h yielded 88-90% of viable embryos. the refrigerated storage method could be of practical applications, especially in fish reproductive management at hatchery stations.