title: Density-dependent compensatory growth in brown trout (Salmo trutta) in nature.
abstract: Density-dependence is a major ecological mechanism that is known to limit individual growth. To examine if compensatory growth (unusually rapid growth following a period of imposed slow growth) in nature is density-dependent, one-year-old brown trout (Salmo trutta L.) were first starved in the laboratory, and then released back into their natural stream, either at natural or at experimentally increased population density. The experimental trout were captured three times over a one-year period. We found no differences in growth, within the first month after release (May-June), between the starved fish and the control group (i.e. no evidence of compensation). During the summer however (July-September), the starved fish grew more than the control group (i.e. compensation), and the starved fish released into the stream at a higher density, grew less than those released at a natural density, both in terms of weight and length (i.e. density-dependent compensation). Over the winter (October-April), there were no effects of either starvation or density on weight and length growth. After the winter, starved fish released at either density had caught up with control fish in body size, but recapture rates (proxy for survival) did not indicate any costs of compensation. Our results suggest that compensatory growth in nature can be density-dependent. Thus, this is the first study to demonstrate the presence of ecological restrictions on the compensatory growth response in free-ranging animals.
authors: Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden. fred.sundstrom@gmail.com
authors: L Fredrik
authors: LF
authors: Sundström
authors: Rasmus
authors: R
authors: Kaspersson
authors: Joacim
authors: J
authors: Näslund
authors: Jörgen I
authors: JI
authors: Johnsson
mesh_terms: D000818:Animals; D049628:Body Size / Q000502:physiology*; D017753:Ecosystem; D005508:Food Deprivation; D011156:Population Density; D045483:Rivers; D012621:Seasons; D014337:Trout / Q000254:growth & development*
references: Domest Anim Endocrinol. 2000 Aug;19(2):121-32
references: 11025191
references: Evolution. 2005 Jul;59(7):1560-9
references: 16153041
references: Proc Biol Sci. 2005 Mar 22;272(1563):601-7
references: 15817434
references: Biol Rev Camb Philos Soc. 2011 Feb;86(1):97-116
references: 20394607
references: Trends Ecol Evol. 2001 May 1;16(5):254-260
references: 11301155
references: Oecologia. 2002 Feb;130(4):496-504
references: 28547250
references: Proc Biol Sci. 2006 May 22;273(1591):1281-6
references: 16720403
references: Biol Rev Camb Philos Soc. 1960 Aug;35:324-63
references: 13785698
references: Horm Behav. 2003 Sep;44(3):222-32
references: 14609544
references: Comp Biochem Physiol A Mol Integr Physiol. 2010 May;156(1):1-18
references: 20060056
references: Ecol Lett. 2010 Aug 1;13(8):998-1007
references: 20545728
references: J Fish Biol. 2010 Jun;76(10):2342-69
references: 20557596