Environmental enrichment, sexual dimorphism, and brain size in sticklebacks. Issue 6 (12th February 2017)

• Record Type: Journal Article
• Authors: Toli, Elisavet A.; Noreikiene, Kristina; DeFaveri, Jacquelin; Merilä, Juha
• Is Part Of: Ecology and evolution. Volume 7:Issue 6(2017:Apr.)
• Page Start: 1691
• Page End: 1698
• Publication Date: 2017-02-12
• Subjects: brain size -- environmental enrichment -- fish -- phenotypic plasticity -- sexual dimorphism; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.2717
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Evidence for phenotypic plasticity in brain size and the size of different brain parts is widespread, but experimental investigations into this effect remain scarce and are usually conducted using individuals from a single population. As the costs and benefits of plasticity may differ among populations, the extent of brain plasticity may also differ from one population to another. In a common garden experiment conducted with three‐spined sticklebacks ( Gasterosteus aculeatus ) originating from four different populations, we investigated whether environmental enrichment (aquaria provided with structural complexity) caused an increase in the brain size or size of different brain parts compared to controls (bare aquaria). We found no evidence for a positive effect of environmental enrichment on brain size or size of different brain parts in either of the sexes in any of the populations. However, in all populations, males had larger brains than females, and the degree of sexual size dimorphism (SSD) in relative brain size ranged from 5.1 to 11.6% across the populations. Evidence was also found for genetically based differences in relative brain size among populations, as well as for plasticity in the size of different brain parts, as evidenced by consistent size differences among replicate blocks that differed in their temperature. Abstract : The impact of environmental enrichment on brain size and size of different brain parts was studied experimentally in multiple three‐spined stickleback populations. No enrichment effects were detected.