Light scattering by selected zooplankton from the Gulf of Aqaba

Y. L. Gagnon, N. Shashar, E. J. Warrant, S. J. Johnsen

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Light scattering by zooplankton was investigated as a major factor undermining transparency camouflage in these pelagic animals. Zooplankton of differing transparencies - including the hyperiid amphipod Anchylomera blossevillei, an unknown gammarid amphipod species, the brine shrimp Artemia satina, the euphausiid shrimp Euphausia diomedeae, the isopod Gnathia sp., the copepods Ponteila karachiensis, Rhincalanus sp. and Sapphirina sp., the chaetognath Sagitta elegans and an enteropneust tornaria larva - were illuminated dorsally with white light (400-700 nm). Spectral measurements of direct transmittance as well as relative scattered radiances at angles of 30°, 90°, 150° and 180° from the light source were taken. The animals sampled had transparencies between 1.5% and 75%. For all species, the highest recorded relative scattered radiance was at 30°, with radiances reaching 38% of the incident radiance for the amphipod A. blossevillei. Scattering patterns were also found to be species-specific for most animals. Relative scattered radiances were used to estimate sighting distances at different depths. These calculations predict that all of the examined zooplankton are brighter than the background radiance when viewed horizontally, or from diagonally above or below at shallow depths. Thus, in contrast to greater depths, the best strategy for detecting transparent zooplankton in the epipelagic environment may be to search for them from above while looking diagonally downwards, looking horizontally or looking from below diagonally upwards. Looking directly upwards proved to be more beneficial than the other viewing angles only when the viewed animal was at depths greater than 40 m.

Original languageEnglish
Pages (from-to)3728-3735
Number of pages8
JournalJournal of Experimental Biology
Issue number21
StatePublished - 1 Nov 2007
Externally publishedYes


  • Backscattering
  • Model
  • Sighting distance
  • Transmittance

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Physiology
  • Aquatic Science
  • Animal Science and Zoology
  • Molecular Biology
  • Insect Science


Dive into the research topics of 'Light scattering by selected zooplankton from the Gulf of Aqaba'. Together they form a unique fingerprint.

Cite this