Keywords

geometric morphometrics, polymorphism, diversification, ecomorphological hypothesis

Abstract

Body and head shape in fish responds to environmental factors such as water flow rate, food sources, and niche availability. However, the way in which fish respond to these environmental factors varies. In Central Chile, multiple river and lake systems along the coast provide an ideal study site to investigate these types of shape changes. We use geometric morphometrics to characterize shape differences in Galaxias maculatus (Jenyns) between river and lake populations. Lake fish converge on a shape with a more fusiform body, narrower head, and larger eyes, while river fish have a more robust body, rounder head, and smaller eyes. These shape changes are consistent with a shift to zooplanktivorous foraging in lakes, as evidenced in other systems. Unlike some fish species that develop polymorphisms in body shape after colonization (e.g., benthic and limnetic forms), G. maculatus in lakes exhibit a monomorphic limnetic form.

Original Publication Citation

Mercer, Margaret; Searle, Peter C.; Cifuentes, Roberto; Habit, Evelyn; Belk, Mark C. 2020. "Morphometric Response of Galaxias maculatus (Jenyns) to Lake Colonization in Chile" Diversity 12, no. 6: 219.

Document Type

Peer-Reviewed Article

Publication Date

2020-05-31

Publisher

Diversity

Language

English

College

Life Sciences

Department

Biology

University Standing at Time of Publication

Full Professor

Included in

Biology Commons

Share

COinS