How large is the world's largest fish? Measuring whale sharks Rhincodon typus with laser photogrammetry

摘要

Laser photogrammetry was found to be a promising new cost-effective technique for measuring free-swimming whale sharks Rhincodon typus. Photogrammetric measurements were more precise than visual size estimates by experienced researchers, with results from the two methods differing by 9.8 +/- 1.1% (mean +/- s.e.). A new metric of total length and the length between the fifth gill and first dorsal fin (r(2) = 0.93) is proposed to facilitate easy, accurate length measurements of whale sharks in the field