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Abstract Divergence in body shape is one of the most widespread and repeated patterns of morphological variation in fishes and is associated with habitat specification and swimming mechanics. Such ecological diversification is the first stage of the explosive adaptive radiation of cichlid fishes in the East African Rift Lakes. We use two hybrid crosses of cichlids (Metriaclimasp.×Aulonocarasp. andLabidochromissp.×Labeotropheussp., >975 animals total) to determine the genetic basis of body shape diversification that is similar to benthic‐pelagic divergence across fishes. Using a series of both linear and geometric shape measurements, we identified 34 quantitative trait loci (QTL) that underlie various aspects of body shape variation. These QTL are spread throughout the genome, each explaining 3.2–8.6% of phenotypic variation, and are largely modular. Further, QTL are distinct both between these two crosses of Lake Malawi cichlids and compared to previously identified QTL for body shape in fishes such as sticklebacks. We find that body shape is controlled by many genes of small effect. In all, we find that convergent body shape phenotypes commonly observed across fish clades are most likely due to distinct genetic and molecular mechanisms.
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Get unbent! R tools for the removal of arching and bending in fish specimens for geometric morphometric shape analysis
Abstract Geometric morphometrics is a powerful tool for studying fish body shape; however, body posture can be a hindrance to these analyses. Here I introduce new R language tools for correcting multiple types of bending of 3D data based on the TPS suite (geometric morphometric software) “unbend specimens” methodology. In a sample dataset of darters, these R tools adequately accounted for posture artifacts otherwise evident across multiple principal component axes. I hope these new tools will facilitate the incorporation of 3D landmark data into the comparative analysis of fish body shape.
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- Award ID(s):
- 2135927
- PAR ID:
- 10545804
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Journal of Fish Biology
- ISSN:
- 0022-1112
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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