Dorsal Fin Edge Proportions and Their Relationship to Swimming Technique in Sharks

Benjamin Ronald Janitz,

Ashley Stoehr

Dorsal fins play a important function in elasmobranch locomotion by offering stability, decreasing roll, and enhancing swimming effectivity. Variation in dorsal fin geometry might due to this fact mirror ecological area of interest and swimming technique. This examine quantitatively compares dorsal fin leading-to-lagging edge ratios in three shark species with differing ecological roles: the spiny dogfish (Squalus acanthias), salmon shark (Lamna ditropis), and longfin mako (Isurus paucus). Using lateral-view pictures, dorsal fin main and trailing edges had been measured and expressed as proportional ratios to account for variations in total physique dimension. Results revealed substantial interspecific variation: the spiny dogfish exhibited essentially the most important modern proportion (137.5%), the salmon shark confirmed an intermediate ratio (116.67%), and the longfin mako displayed a symmetrical fin geometry (100%). These variations intently correspond to every species’ swimming conduct and habitat use. The elongated vanguard of the spiny dogfish enhances maneuverability at low speeds, the salmon shark’s reasonably prolonged vanguard helps high-speed pursuit and stabilization, and the longfin mako’s symmetrical fin promotes environment friendly cruising throughout long-distance migration. These findings show that dorsal fin morphology is an adaptive trait formed by hydrodynamic and ecological calls for, highlighting the practical relationship between fin geometry and swimming efficiency in sharks.