Anti-Predator Behavior of Captive-Reared and Wild Juvenile Spiny Lobster (Jasus edwardsii)

Abstract

Early juvenile lobsters reared in captivity may loose anti-predator behaviors displayed by their wild counterparts. To test this hypothesis in juvenile spiny lobsters (Jasus edwardsii), we conducted a series of experiments in which recently settled pueruli were reared in captivity under differing levels of predation risk. After one year in captivity, these lobsters were exposed to a predator in a tank or released into the wild to assess their ability to recognize and respond to predation. We found that lobsters raised without predators significantly reduced their movement activity outside shelters when subsequently introduced to a predator compared with juveniles raised with predators (F_1,45 = 4.33, p < 0.05). This apparent over-compensation may be necessary for lobsters to learn the appropriate anti-predator response. Lobsters raised without predators and released into the wild displayed the same types of behaviors as resident wild lobsters. Released lobsters spent more time defending and fighting amongst themselves than the wild lobsters (G = 13.006 > χ² _0.05,2 = 9.488), but they displayed the appropriate anti-predator responses when approached or attacked by a predator. Our results show that juvenile spiny lobsters habituate to the absence of a predator when reared in captivity for long periods, but display an innate ability to recognize and effectively respond to predators when encountered in a hatchery environment or in the wild.

Keywords:

• stock enhancement
• activity
• captivity
• anti-predator behavior
• lobster

ACKNOWLEDGMENTS

We thank John Hunt for his superior boat driving skills and several anonymous reviewers for their constructive feedback. This research was supported by the Rock Lobster Enhancement and Aquaculture Subprogram of the Fisheries Research and Development Corporation of Australia and New Zealand's Foundation for Research, Science and Technology contract number CO1X0209. All experiments complied with national and institutional animal ethics and current laws of New Zealand.