Sinking Factors and Average Densities of Florida Sharks as Functions of Liver Buoyancy

Observed variations in specific gravities of sharks of the same species were shown to be caused primarily by differences in buoyancy provided by the animal's livers. Shark livers vary greatly in content of low density oil with species, size, and physical condition of the shark. Procedures were developed for determining average densities (conventional specific gravities) and sinking factors (specific gravities referred to sea water at ambient temperature) of large sharks, either dead or anesthesized. Consideration of liver buoyancy permitted calculation of average values for densities and sinking factors of liver-free bodies from 13 species of sharks common to the eastern Gulf of Mexico.