Isolumes are the preferred light zone of an organism in the ocean in the preferendum hypothesis.[1] The preferendum hypothesis suggests that some organisms living in the mesopelagic zone, change their depth as light levels change in order to remain in their isolume.[2][1] Organisms prefer to remain within a certain light level for a variety of reason. Some organisms, like Sergestidae, Euphausiid,[1] and Palinuridae, use bioluminescence to camouflage their existence from predators and they change their depth as conditions change to stay in their isolume.[2] Zooplankton in Arctic and Antarctic regions will remain at the same depth for months at a time due to the long winters with little to no daylight.[3]
Organisms of the same species do not always exist in the same isolume and numerous factors can change what light levels an organism prefers to live within including age, sex, and competition for food.[1]
References
edit- ^ a b c d Widder, E. A.; Frank, T. M. (2001-04-23). "The speed of an isolume: a shrimp's eye view". Marine Biology. 138 (4): 669–677. doi:10.1007/s002270000504. ISSN 0025-3162. S2CID 85309237.
- ^ a b Yeung, Cynthia; Couillard, Theodore; McGowan, Michael (1993). "The relationship between the vertical distribution of spiny lobster phyllosoma larvae (Crustacea: Palinuridae) and isolume depths generated by a computer model". Revista de Biología Tropical. 41 (1): 63–67.
- ^ Hobbs, Laura; Banas, Neil S.; Cohen, Jonathan H.; Cottier, Finlo R.; Berge, Jørgen; Varpe, Øystein (February 24, 2021). "A marine zooplankton community vertically structured by light across diel to interannual timescales". Biology Letters. 17 (2): 20200810. doi:10.1098/rsbl.2020.0810. ISSN 1744-957X. PMC 8086989. PMID 33622076.
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