Open AccessThe energetics of ‘airtime’: estimating swim power from breaching behaviour in fishes and cetaceans
Author(s) -
Lewis G. Halsey,
Gil Iosilevskii
Publication year - 2019
Publication title -
journal of experimental biology
Language(s) - English
Resource type - Journals
eISSN - 1477-9145
pISSN - 0022-0949
DOI - 10.1242/jeb.216036
Subject(s) - energetics , limiting , fish <actinopterygii> , biology , maximum power principle , fishery , power (physics) , muscle power , ecology , physics , thermodynamics , mechanical engineering , medicine , engineering , physical medicine and rehabilitation
Maximum swimming behaviour is rare in the laboratory or the wild, limiting our understanding of the top-end athletic capacities of aquatic vertebrates. However, jumps out of the water - exhibited by a diversity of fish and cetaceans - might sometimes represent a behaviour of maximum burst effort. We collected data on such breaching behaviour for 14 fish and cetacean species primarily from online videos, to calculate breaching speed. From newly derived formulae based on the drag coefficient and hydrodynamic efficiency we also calculated the associated power. The fastest breaching speeds were exhibited by species 2 m in length, peaking at nearly 11 m/s; from this length, as species size decreases the fastest breaches become slower, while species larger than 2 m do not show a systematic pattern. The power associated with the fastest breaches was consistently about 50 W/kg (equivalent to 200 W/kg muscle) in species from 20 cm to 2 m in length; this value may represent a universal (conservative) upper boundary. And it is similar to the maximum recorded power output per muscle mass recorded in any species of similar size, suggesting that some breaches could indeed be representative of maximum capability.