title: Chemical orientation of lobsters, homarus americanus, in turbulent odor plumes.
abstract: The lobster,Homarus americanus, relies upon its lateral antennules to make initial directional choices in a turbulent odor plume. To determine whether chemical signals provide cues for source direction and distance during orientation, we studied the search patterns of the lobster orienting within a turbulent odor plume. In an odor plume, animals walked significantly more slowly and most often up the middle of the tank; control animals (no odor present) walked rapidly in straight lines, frequently along a wall. Search patterns were not stereotyped either for the population of experimental animals or for individuals. Three different phases of orientation were evident: an initial stage during which the animals increased their walking speeds and decreased their heading angles; an intermediate stage where both the walking speed and headings were constant; and the final stage close to the source, where heading angles increased while walking speed decreased. During this last stage the animals appear to be switching from a distance orientation (mediated by the antennules) to a local food search (mediated by the walking legs) as evidenced by a great increase in leg-raking behavior.
authors.affiliation: Marine Biological Laboratory, Boston University Marine Program, 02543, Woods Hole, Massachusetts.
authors.forename: P A
authors.initials: PA
authors.lastname: Moore
authors.forename: N
authors.initials: N
authors.lastname: Scholz
authors.forename: J
authors.initials: J
authors.lastname: Atema