Reduction of sexual dimorphism in stream-resident forms of three-spined stickleback Gasterosteus aculeatus

Sexual dimorphism in geometric body shape and external morphology was compared between marine and stream‐resident forms of three‐spined stickleback Gasterosteus aculeatus collected from North America and Japan. Some aspects of sexual dimorphism were shared between ecotypes: males had larger heads th...

Full description

Saved in:
Bibliographic Details
Published in:Journal of fish biology 2012-01, Vol.80 (1), p.131-146
Main Authors: Kitano, J., Mori, S., Peichel, C. L.
Format: Article
Language:English
Subjects:
Animals
Body Size
ecology
Ecosystem
evolution
Female
Freshwater
Gasterosteus aculeatus
geometric morphometrics
Male
Rivers
Sex Characteristics
sex chromosome
sexual selection
Smegmamorpha - anatomy & histology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Sexual dimorphism in geometric body shape and external morphology was compared between marine and stream‐resident forms of three‐spined stickleback Gasterosteus aculeatus collected from North America and Japan. Some aspects of sexual dimorphism were shared between ecotypes: males had larger heads than females with no significant effect of ecotype on the magnitude of sexual dimorphism. By contrast, a significant sex‐by‐ecotype interaction was found for body depth. Males tended to have deeper bodies than females in both forms, but the magnitude of sexual dimorphism was reduced in stream‐resident forms. Although females were generally larger in standard length and had larger pelvic girdles, significant sexual dimorphism in these traits was not consistently found across populations or ecotypes. These results suggest that some aspects of sexual dimorphism were shared between ecotypes, while others were unique to each population. The results further suggest that ecology may influence the evolution of sexual dimorphism in some external morphological traits, such as body depth.
ISSN:0022-1112
1095-8649
DOI:10.1111/j.1095-8649.2011.03161.x