Effects of experience with shelter in hatchery-reared juvenile European lobsters Homarus gammarus

Abstract

Hatchery-reared lobsters will be highly dependent on shelter after release, and the ability of training to enhance quick shelter-seeking behaviour was investigated. Single, emergent-phase lobsters were released in tanks, either with or without shelter present, to determine whether the lobsters reached the shelter position by chance or not. They were recovered after two days and re-released into either identical tanks or tanks without shelter. All lobsters were observed for at least 10 min after each release; walking direction from the release position and time elapsed before they entered the shelter were recorded. In additional treatments, some lobsters were exposed to a mock predator, in the form of a series of short touches, and times before they reached shelter were compared with those of lobsters not so touched. Hatchery-reared lobster juveniles adapted to new environments and shelters. Experienced juveniles were quicker to find shelter. Time to reach shelter decreased in touched lobsters. Search time increased in experienced lobsters after removal of shelter.