Experiment 1: Den sharing behavioral training
16 conspecific lobster pairs were assigned to social and asocial treatment groups. Lobsters in the social treatment group were given a high quality food reward if they exhibited den sharing behaviors. Lobsters in the asocial treatment group were given high quality food rewards if they did not exhibit den sharing behavior.
This experiment indicates that lobster den sharing behavior is plastic in the laboratory setting.
Experiment 2: Conspecific odor attraction
We next explored if the den sharing training experiment was successful using a Y-maze trial to test conspecific odor attraction of the lobsters. We expected that the training experiment would influence the social lobsters to choose to be with each other in the Y-maze based on conspecific odor. We also expected that the training experiment would influence the asocial lobsters to not be on the same size of the Y-maze.
Ultimately, den sharing in the lab was not correlated with conspecific attraction. This was another indication that lobster den sharing behavior was plastic.
Experiment 3: Field study of lobster environmental behavior
36 lobsters from Burnt Point in the Florida Keys were tagged and allowed to roam in a hexagonal field. Substrate composition and conspecific density was recorded by divers on the reef.
Den sharing in the field was not correlated to lobster density but was correlated to the substrate type, specifically with hardbottom substrate. Hardbottom substrate may provide more opportunities for den sharing because of the presence of solution holes.