Lund University is celebrating 350 years. Read more on lunduniversity.lu.se

Menu

Javascript is not activated in your browser. This website needs javascript activated to work properly.
You are here

Iso-luminance counterillumination drove bioluminescent shark radiation.

Author:
  • Julien M Claes
  • Dan-E Nilsson
  • Nicolas Straube
  • Shaun P Collin
  • Jérôme Mallefet
Publishing year: 2014
Language: English
Publication/Series: Scientific Reports
Volume: 4
Document type: Journal article
Publisher: Nature Publishing Group

Abstract english

Counterilluminating animals use ventral photogenic organs (photophores) to mimic the residual downwelling light and cloak their silhouette from upward-looking predators. To cope with variable conditions of pelagic light environments they typically adjust their luminescence intensity. Here, we found evidence that bioluminescent sharks instead emit a constant light output and move up and down in the water column to remain cryptic at iso-luminance depth. We observed, across 21 globally distributed shark species, a correlation between capture depth and the proportion of a ventral area occupied by photophores. This information further allowed us, using visual modelling, to provide an adaptive explanation for shark photophore pattern diversity: in species facing moderate predation risk from below, counterilluminating photophores were partially co-opted for bioluminescent signalling, leading to complex patterns. In addition to increase our understanding of pelagic ecosystems our study emphasizes the importance of bioluminescence as a speciation driver.

Keywords

  • Zoology

Other

Published
  • ISSN: 2045-2322
Dan-E Nilsson
E-mail: dan-e.nilsson [at] biol.lu.se

Professor

Functional zoology

+46 46 222 93 45

+46 70 623 10 64

B-B312

4

Research group

Lund Vision Group

Projects

Doctoral students and postdocs

Phd Students, main supervisor

Postdocs

Downloads & links