Meeting Abstract
Recruitment is likely a significant bottleneck for lobster populations in the Gulf of Maine, as a result of intense predation on juveniles and limited availability of shelter in appropriate benthic habitats. During settlement, lobster postlarvae transition from a roving, exploratory planktonic lifestyle to a very cryptic, benthic one. Behavioral transitions during this stage are critically important for successful settlement, and may be influenced by a wide variety of developmental and environmental factors. During the postlarval stage (stage IV), we examined variation in settlement behavior as a function of age from hatching, age from metamorphosis, and early postlarval experience. The behavioral transition was surprisingly abrupt: the majority of postlarvae transitioned to benthic, cryptic behavior immediately after metamorphosis. There was no effect of early postlarval experience or developmental history on the timing of the behavioral transitions. We found clear evidence of a behavioral carry-over effect between the postlarval and early juvenile (stage V) stages, but not the one we predicted: juveniles with postlarval shelter experience took significantly longer to locate and settle into shelters. Juveniles with prior shelter experience may be more exploratory, or more selective about settlement location. Our results suggest that the behavioral transition from pelagic/exploratory to benthic/cryptic during the postlarval settlement stage is innate – tightly coupled to the molt cycle, but not strongly influenced by postllarval experiences or environment. However, postlarval experiences during the settlement stage do carry over and influence sheltering behavior during the first juvenile stage.
