||Open Marine Archive
|Phantom hunter of the fjords: Camouflage by counterillumination in a shark (Etmopterus spinax)|
|Claes, J.M.; Aksnes, D.L.; Mallefet, J. (2010). Phantom hunter of the fjords: Camouflage by counterillumination in a shark (Etmopterus spinax) J. Exp. Mar. Biol. Ecol. 388(1-2): 28-32. dx.doi.org/10.1016/j.jembe.2010.03.009|
|In: Journal of Experimental Marine Biology and Ecology. Elsevier: Amsterdam. ISSN 0022-0981, meer|
Etmopterus spinax (Linné) 1758 [donkerbuiklantaarnhaai] [WoRMS]; Marien
Bioluminescence; Deep-sea; Etmopterus spinax; Lantern shark; Midwater fish; Photophore
Many midwater animals emit ventral light to hide their silhouette in the water column. This phenomenon known as counterillumination typically requires fine control over light emission since it needs a luminescence that closely matches the properties of downwelling light (intensity, angular distribution and wavelength). Here we provide evidence that, although lacking complex structures of counterilluminating animals, the deepwater luminescent shark Etmopterus spinax could, in Norwegian fjords, efficiently cloak its silhouette from downwelling ambient light to remain hidden from predator and prey. This represents the first experimentally tested function of luminescence in a shark and illustrates how evolution can take different routes to converge on identical complex behavior.