PARENT SESSION
Poster Session #37: Invertebrate Ecology.
Thursday, August 9, 2001. Presentation from 10:30 AM to 12:00 PM. Exhibition Hall
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Spatial distribution and courtship behavior in the fairy shrimp Eubranchipus bundyi .
Roosa, Brian1, 1
ABSTRACT- Behavioral ecology of abundant species can provide important structural and functional information about a community. Eubranchipus bundyi is a widespread and abundant fairy shrimp (Crustacea: Anostraca) of temporary ponds. I studied how E. bundyi¿s spatial distribution depends on light, density and the presence of potential mates. Groups of 5 or 10 males or females, or 5 males plus 5 females, were placed in laboratory tanks and the spatial position of each individual recorded both in the dark and in the light. When the light source was located at the side of the tank, males and females alike displayed positive phototaxis, with no effects of density or gender. The same was true when the light source was placed directly above the tank, except that in the presence of males, females remained at the bottom rather than exhibiting phototaxis. Similarly, field observations indicate that males mate only in daytime, during which time they actively cruise high in the water, whereas mature females stay near the bottom litter until dark unless no males are around. This should expose males and females to different food and predator conditions, which potentially affect their abilities to redistribute in a drying pond and raises interesting questions about energetic tradeoffs. Data from field cage experiments shows that females tolerate much higher densities than males.
KEY WORDS: Eubranchipus bundyi, Fairy Shrimp, Anostraca, invertebrate behavior