Correlating Fast-Start Performance to Morphology in Juvenile Bluegill


Meeting Abstract

P2.44  Saturday, Jan. 5  Correlating Fast-Start Performance to Morphology in Juvenile Bluegill GERRY, S.P.*; BISACCIA, M.; ELLERBY, D.J.; Fairfield University; Fairfield University; Wellesley College sgerry@fairfield.edu

Adult bluegill exhibit variation in their morphology and swimming performance based on habitat. The littoral form has a deeper body with fins located farther from the center of mass to aid in maneuvering among the vegetation. Pelagic bluegill have a streamlined, fusiform body shape associated with efficient steady-swimming. Additionally, this body shape is associated with greater fast-start performance based on peak velocity, acceleration and turning rates. This is significant since fish that perform faster-starts should have greater fitness because they are better able to evade predators. Juvenile bluegill of both body forms hatch in the littoral habitat and remain there until they are less susceptible to predation in the open water. It is not known if the variation in morphology and fast-start performance present in adult bluegill is also present in the juveniles or if there is a relationship between morphology and performance in juvenile fish. Therefore, we captured 100 juvenile bluegill over a range of size classes from 1-80 g. We analyzed their fast-start performance from high-speed video recordings and measured functionally relevant morphological variables including fin areas, body area and body depth. The smallest bluegill showed no association between morphology and performance. Body depth and the areas of the median fins are each negatively correlated with fast-start performance in larger juvenile bluegill (Pearson, p < 0.05). This divergence in form and function, as bluegill increase in size, may be related to a shift in foraging behavior between littoral and pelagic habitats. Juveniles with streamlined bodies and increased fast-start performance are better suited to sustained swimming, an advantage when capturing zooplankton and escaping predators in a pelagic environment.

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