Quality Assessment of Wild Atlantic Sturgeon Semen under Conditions of Short-Term Storage

Short-term storage trials were conducted with semen of Atlantic sturgeon Acipenser oxyrinchus collected from a total of nine wild males during the 2008 and 2009 spawning seasons on the Hudson River. Semen samples were kept refrigerated (4 ± 1◦C) and stored in different gaseous atmospheres and storage extenders. The gaseous environments included oxygen, nitrogen, and air, while the extender treatments included modified Tsvetkova (MT), Park and Chapman (PC), and undiluted. Analyses of four response variables—percent viable sperm (viability), percent motile sperm (motility), curvilinear velocity (VCL), and ATP content—were determined on the day of arrival in the laboratory and then every other day for 7 d in 2008 and 21 d in 2009. The experiments were conducted in a split-split-plot design to examine dilution treatment, gas atmosphere, and repeated measures across days, and linear analyses of covariance models were fit to the data after appropriate transformation. Storage of sperm in an oxygen atmosphere was superior to storage in a nitrogen atmosphere for all variables. Storage of semen in 100% or 21% (air) oxygen in PC did not lead to differences among variables except for viability; viability was maintained at more than 95% through 13 d, decreasing to 88% and 94% on day 21 in 100% oxygen and air, respectively. During the last 5 d survival in an air atmosphere was better than that in 100% oxygen. Motility decreased during the 21 d of storage and the decline was greater in undiluted than in PC-extended semen, decreasing from 85% on day 1 to approximately 21% and 47%, respectively, on day 21. We conclude that for Atlantic sturgeon semen storage, PC is the extender of choice and semen viability can be maintained for up to 21 d with some expectation of successful fertilization. *Corresponding author: [email protected] Received October 30, 2010; accepted March 19, 2011