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Plasticity in pigmentation induced by conflicting threats from predation and UV radiation

Hansson, Lars-Anders LU (2004) In Ecology 85(4). p.1005-1016
Abstract
In a variable and unpredictable environment, phenotypic plasticity in morphology or behavior may considerably improve an organism's protection against environmental threats and thereby its fitness. Here I demonstrate that common freshwater organisms, copepods (Crustacea), show a plastic response by adjusting pigmentation level in relation to two environmental threats: ultraviolet radiation (UV) and predation. The red pigment in copepods, astaxanthin, reduces damage caused by UV radiation, but makes the organism more conspicuous, thereby exposing it to higher predation pressure. In a field survey of six lakes sampled monthly for 16 mo, I quantified UV and predation threat, as well as copepod pigmentation level. The relative threat ratio... (More)
In a variable and unpredictable environment, phenotypic plasticity in morphology or behavior may considerably improve an organism's protection against environmental threats and thereby its fitness. Here I demonstrate that common freshwater organisms, copepods (Crustacea), show a plastic response by adjusting pigmentation level in relation to two environmental threats: ultraviolet radiation (UV) and predation. The red pigment in copepods, astaxanthin, reduces damage caused by UV radiation, but makes the organism more conspicuous, thereby exposing it to higher predation pressure. In a field survey of six lakes sampled monthly for 16 mo, I quantified UV and predation threat, as well as copepod pigmentation level. The relative threat ratio (UV/predation) was generally lowest during summer and highest during spring; this pattern was paralleled by pigmentation level among copepods. Moreover, the level of pigmentation among copepods in lakes with high predation pressure was lower than among those copepods in lakes with lower risk of predation. In a complementary experimental study performed under constant UV threat, calanoid copepods in the absence of predation threat responded with almost three times higher pigment levels, compared to those with fish present (caged). Hence, the correlative field survey and the mechanistic experiment together suggest that the level of pigmentation in copepods is an inducible and adjustable defense, governed by the aim to improve individual protection against prevailing threats from both predation and UV radiation. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Ecology
volume
85
issue
4
pages
1005 - 1016
publisher
Ecological Society of America
external identifiers
  • wos:000220766600012
  • scopus:8144230736
ISSN
0012-9658
language
English
LU publication?
yes
id
f1d63abb-a4bd-4fab-b232-33390248b47b (old id 136675)
alternative location
http://www.esajournals.org/esaonline/?request=get-abstract&issn=0012-9658&volume=085&issue=04&page=1005
date added to LUP
2007-06-28 13:44:13
date last changed
2017-11-12 03:54:16
@article{f1d63abb-a4bd-4fab-b232-33390248b47b,
  abstract     = {In a variable and unpredictable environment, phenotypic plasticity in morphology or behavior may considerably improve an organism's protection against environmental threats and thereby its fitness. Here I demonstrate that common freshwater organisms, copepods (Crustacea), show a plastic response by adjusting pigmentation level in relation to two environmental threats: ultraviolet radiation (UV) and predation. The red pigment in copepods, astaxanthin, reduces damage caused by UV radiation, but makes the organism more conspicuous, thereby exposing it to higher predation pressure. In a field survey of six lakes sampled monthly for 16 mo, I quantified UV and predation threat, as well as copepod pigmentation level. The relative threat ratio (UV/predation) was generally lowest during summer and highest during spring; this pattern was paralleled by pigmentation level among copepods. Moreover, the level of pigmentation among copepods in lakes with high predation pressure was lower than among those copepods in lakes with lower risk of predation. In a complementary experimental study performed under constant UV threat, calanoid copepods in the absence of predation threat responded with almost three times higher pigment levels, compared to those with fish present (caged). Hence, the correlative field survey and the mechanistic experiment together suggest that the level of pigmentation in copepods is an inducible and adjustable defense, governed by the aim to improve individual protection against prevailing threats from both predation and UV radiation.},
  author       = {Hansson, Lars-Anders},
  issn         = {0012-9658},
  language     = {eng},
  number       = {4},
  pages        = {1005--1016},
  publisher    = {Ecological Society of America},
  series       = {Ecology},
  title        = {Plasticity in pigmentation induced by conflicting threats from predation and UV radiation},
  volume       = {85},
  year         = {2004},
}