Induced Spermiation in Wild Atlantic Sturgeons Held Captive Up to Six Years

Abstract

The ability to obtain gametes from male Atlantic sturgeons Acipenser oxyrinchus brought into captivity may be important to the success of future restoration efforts for this species. Atlantic sturgeons obtained as juveniles from the Delaware River and as sexually mature males from the Hudson River were held in freshwater at the Northeast Fishery Center, Lamar, Pennsylvania, from 1991 to 1997. After 4 years in captivity, three of three Hudson River fish were induced to spermiate by injection of common carp pituitary solution (CCP), luteinizing hormone-releasing hormone analogue (LHRHa), or a combination of both. Hatch rates were similar for eggs fertilized with a captive male's milt (3.1%) versus a wild male's milt (mean ± SD, 3.1 ± 0.5%). At 58 d posthatch, survival of the captive male's offspring (74.3%) was comparable to that of wild male's (61.9 ± 7.8%). After 6 years in captivity, two of five fish from the Delaware River were induced to spermiate by injection of CCP, and nearly all spermatozoa exhibited rapid forward motion. Results showed that feral male Atlantic sturgeons can be held in freshwater over a period of years for use as captive broodstock.