Meeting Abstract
48.5 Tuesday, Jan. 5 Variation in Behavior of Larval Lobsters as a Function of Population, Parentage, and Development Time SHUTTARI, N*; JACOBS, M.W.; Boston University; Woods Hole Oceanographic Institution nidas@bu.edu
Variation in Behavior of Larval Lobsters as a Function of Population, Parentage, and Development Time Shuttari N and M.W. Jacobs Woods Hole Oceanographic Institution Boston University nidas@bu.edu Offspring of the lobster Homarus americanus hatch as swimming larvae and grow through three molt stages in the plankton. At the fourth molt, the larvae metamorphose into a postlarval settlement stage and swim down to the benthos. We studied substrate selection behavior over time during this critical stage as a function of age from metamorphosis, age from hatching, population of origin, and maternal parentage. Settlement behavior was tested in a large mesocosm where postlarvae were offered a choice of sand, small rocks, large rocks, or artificial PVC shelters. We measured behavior of individual postlarvae during timed 5 minute trials, and also released groups of labeled postlarvae into the mesocosm for overnight settlement trials. We found that settling behavior varied strongly as a function of age from metamorphosis. In overnight mesocosm experiments, the proportion of postlarvae found crawling in the open decreased throughout the settlement period, while the proportion found sheltering in large rocks or PVC shelters increased. We expected the proportion found swimming to be inversely proportional to the proportion found sheltering, but interestingly swimming behavior peaked in the middle of the settlement period. These results suggest that attraction to the bottom during settlement is decoupled from sheltering behavior. Settlement behavior was similar overall between parents and populations, but preliminary analyses suggest that Rhode Island postlarvae increase sheltering behavior earlier than Georges Bank postlarvae, suggesting that variation in settlement behavior is influenced by both genetics and environment.
