The swell shark (Cephaloscyllium ventriosum) is a fascinating fish that can be found in tropical waters of the Eastern Pacific. This animal can double the size of its stomach by swallowing water when feeling threatened. They are also biofluorescent, allowing mates and conspecifics to be able to find each other.

Art and facts by @Squidtoons

[Edited by Isabelle McDonald]

Reference:

Gruber, D. F., Loew, E. R., Deheyn, D. D., Akkaynak, D., Gaffney, J. P., Smith, W. L., Davis, M. P., Stern, J. H., Pieribone, V. A., & Sparks, J. S. (2016). Biofluorescence in catsharks (Scyliorhinidae): Fundamental description and relevance for elasmobranch visual ecology. Scientific Reports, 6(1). https://doi.org/10.1038/srep24751