Meeting Abstract

45.3  Sunday, Jan. 5 10:45  New methods for assessing scaling and body condition in several shark species IRSCHICK, DJ*; HARTOG, K; ESCONTRELA, D; HAMMERSCHLAG, N; University of Massachusetts at Amherst; Rosenstiel School of Marine and Atmospheric Science, University of Miami; Rosenstiel School of Marine and Atmospheric Science, University of Miami; Rosenstiel School of Marine and Atmospheric Science, University of Miami irschick@bio.umass.edu

Sharks represent one of the most important apex predators in marine ecosystems, yet relatively little is known regarding how body shape scales with size in various species, especially large species (e.g., Tiger Sharks). One of the primary limitations is the lack of museum specimens for a wide range of shark specimens of various sizes, which therefore limits the ability of scientists to analyze variation in body shape. Further, there are no established methods for assessing condition in sharks, despite the obvious importance of this measure for a wide range of ecological questions, and for conservation more generally. For example, recent studies have shown that large apex sharks migrate long distances into deep ocean waters, yet there is little work addressing how variation in condition among different individuals translates into variation in the ability to move long distances. We developed methods for measuring various kinds of body and fin shape from a range of individuals of different sizes for four different shark species captured live, and then released (Tiger shark, Bull shark, Blacktip shark, and Reef shark). We show how scaling with size in various fin and body shape measures differs dramatically among these different species, and we also present a new method for measuring condition in these sharks, which we believe could be widely used in the broader arena of marine ecology and conversation.