Meeting Abstract
Many marine vertebrates need to swim at high speeds to migrate, capture food, and escape predation. The thunniform mode is associated with high-speed swimming. Pelagic marine predators (e.g., tuna, swordfish, dolphins) swim in the thunniform mode, possessing a stiff fusiform body, narrow caudal peduncle, and sickle-shaped caudal propulsor. The literature is replete with records of maximal speeds for thunniform swimmers, but no comprehensive review has been undertaken to assess the validity of the claims. Differences in data collection (e.g., high-speed video, satellite transmitters, unreeling fishing line, boat observations) and subjective descriptions of swimming effort (e.g., burst, maximal, peak, cruise, steady, sustained, routine) have cast doubt on record values of performance. Data on swimming speeds of specialized perciform fishes (Scombridae, Istiophoridae, Xiphiidae) and cetaceans (Odontoceti, Mysticeti) were compiled from the primary literature dating from 1923 to 2015. Swimming speeds were categorized as either burst or sustained for each group. The distribution of speeds indicated that the highest performance (36.1 m/s) was displayed by swordfish (Xiphias gladius) and marlin (Makaira sp.), although the sources were questionable fishing reports. Similarly, the highest speeds (>15.0 m/s) for cetaceans were for a killer whale (Orcinus orca) and bottlenose dolphin (Tursiops truncatus) based on uncertain observations. There is wide variation of the distribution of swimming speeds reported for thunniform swimmers that is dependent on species, methodology, classification of performance, and motivation of the swimmer. Accurate information of speed capabilities for thunniform swimmers is necessary for application toward engineering biomimetic autonomous underwater vehicles with enhanced speed and efficiency.
