Flip or flop? Behavioral response to stranding in fish representing six teleost orders

Aquatic and amphibious fishes produce a variety of behaviors when stranded on land, including a ballistic movement called a tail-flip jump. Although recent studies have examined jump performance (distance) in several cyprinodontiform species, less is known about the diversity of behaviors produced by teleosts when stranded on land. Here, seven species from four major teleost lineages (individual n = 4–12) were manually stranded in a terrestrial arena for two-minute trials. From videos of the trials, the number of jumps, flops (movements <1 body length), displacement (total and mean), latency (time to onset of movement), and percent time moving were quantified for each individual. A principal components analysis of these variables was used to define four “behavioral spaces:” species that produced effective displacement and spent the majority of the trial period moving (Danio); species that produced less effective displacement and spent the majority of the trial period moving (Pseudomugil); species that produced less effective displacement and spent little time moving (Umbra); and species that produced effective displacement, but spent little time moving (Kryptolebias). Based on the literature and metabolic data collected for this study, it appears that the ability to extract oxygen from air (vs. water) predicts the amount of time spent moving when stranded on land. Air-breathing fishes appear to adopt a “wait and see strategy,” while species that lack the ability to breathe air move immediately and frequently, likely an attempt to return to the water as quickly as possible.