Crater lake cichlids individually specialize along the benthic-limnetic axis

Kusche, H., Recknagel, H., Elmer, K. R. and Meyer, A. (2014) Crater lake cichlids individually specialize along the benthic-limnetic axis. Ecology and Evolution, 4(7), pp. 1127-1139. (doi: 10.1002/ece3.1015)

Abstract

A common pattern of adaptive diversification in freshwater fishes is the repeated evolution of elongated open water (limnetic) species and high-bodied shore (benthic) species from generalist ancestors. Studies on phenotype-diet correlations have suggested that population-wide individual specialization occurs at an early evolutionary and ecological stage of divergence and niche partitioning. This variable restricted niche use across individuals can provide the raw material for earliest stages of sympatric divergence. We investigated variation in morphology and diet as well as their correlations along the benthic-limnetic axis in an extremely young Midas cichlid species, Amphilophus tolteca, endemic to the Nicaraguan crater lake Asososca Managua. We found that A. tolteca varied continuously in ecologically relevant traits such as body shape and lower pharyngeal jaw morphology. The correlation of these phenotypes with niche suggested that individuals are specialized along the benthic-limnetic axis. No genetic differentiation within the crater lake was detected based on genotypes from 13 microsatellite loci. Overall, we found that individual specialization in this young crater lake species encompasses the limnetic- as well as the benthic macro-habitat. Yet there is no evidence for any diversification within the species, making this a candidate system for studying what might be the early stages preceding sympatric divergence.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Elmer, Professor Kathryn
• Authors: Kusche, H., Recknagel, H., Elmer, K. R., and Meyer, A.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Ecology and Evolution
• Publisher: John Wiley & Sons Ltd.
• ISSN: 2045-7758
• ISSN (Online): 2045-7758
• Copyright Holders: Copyright © 2014 The Authors
• First Published: First published in Ecology and Evolution 4(7):1127-1139
• Publisher Policy: Reproduced under a Creative Commons License