Do Hatchery-Reared Blue Crabs Differ from Wild Crabs, and Does it Matter?

Abstract

Successful use of hatchery-reared juveniles to enhance recruitment-limited populations or severely depleted stocks is contingent upon their ability to survive and grow upon release into the wild. Hatchery conditions often result in juveniles that exhibit morphological, physiological, or behavioral characteristics different from their wild counterparts. Managers of stock enhancement or restocking programs need to assess whether any such deficiencies translate into differences in performance between hatchery-reared and wild juveniles in the field. If so, the deficits may be minimized through conditioning strategies. In this review, we summarize various aspects of the morphology and behavior of cultured and wild blue crabs, Callinectes sapidus, and compare our work on these crabs to studies on other invertebrates. We identify similarities and differences between cultured blue crabs and wild conspecifics. In some cases where differences existed, conditioning of the hatchery-reared crabs before release rapidly mitigated the defects, and, overall, any remaining differences did not translate into decreased survival. We conclude that there are no significant impediments to the fitness of hatchery-reared blue crabs used in release programs.

Keywords:

• stock enhancement
• restocking
• Callinectes sapidus
• blue crab
• conditioning
• hatchery methods

ACKNOWLEDGMENTS

We thank the many undergraduate students and technicians for their assistance in the field and laboratory experiments. Special thanks to M. Goodison, M. Kramer, and R. Aguilar for their assistance with laboratory and field studies. We also thank the researchers and technicians at COMB for raising the cultured crabs used in this study; in particular, B. Bystry, without whom this research would not have been possible. We are also grateful to two reviewers, whose comments and suggestions significantly improved the article. Funding for this research was provided to BCARC by NOAA, Phillips Seafood, the Maryland Watermen's Association, the Smithsonian Environmental Studies Program, and the Smithsonian Internship Program.