Multiple paths to aquatic specialisation in four species of Central American Anolis lizards

Martha M Muñoz,Kristen E Crandell,Shane C Campbell-Staton,Kristi Fenstermacher,Hannah K Frank,Paul Van Middlesworth,Mahmood Sasa,Jonathan B Losos,Anthony Herrel

doi:10.1080/00222933.2015.1005714

Abstract

Aquatic anoles present an interesting ecomorphological puzzle. On the one hand, the link between habitat use and morphology is well established as convergent within the Caribbean anole radiation. On the other hand, aquatic anoles do not appear to form an ecomorphological group – rather, it appears that there may be several ways to adapt to aquatic habitats. We explore this issue by examining the ecology, morphology and performance of four species of Central American aquatic anoles belonging to two different lineages. Overall, we find that aquatic anoles overlap in multiple ecological and morphological dimensions. However, we do find some differences in substrate use, claw and limb morphology, and bite force that distinguish Anolis aquaticus from the other three species (A. lionotus, A. oxylophus and A. poecilopus). Our results suggest that A. aquaticus is adapted to climb on boulders, whereas the other species utilise vegetation in streamside habitats.

Highlights

The specialisation for life in aquatic environments has evolved in at least 11 lizard families and, as a group, aquatic lizards exhibit significant ecological, morphological and behavioural diversity (Pianka and Vitt 2003; Bauer and Jackman 2008)
Aquatic anoles do not appear to form an ecomorphological group – rather, it appears that there may be several ways to adapt to aquatic habitats. We explore this issue by examining the ecology, morphology and performance of four species of Central American aquatic anoles belonging to two different lineages
Aquatic specialisation in the genus Anolis is intriguing, as anoles are a classic example of ecomorphological specialisation, but it remains uncertain whether aquatic anoles, those from Central America, can be considered a single ecomorph (Leal et al 2002)

Summary

Introduction

The specialisation for life in aquatic environments has evolved in at least 11 lizard families and, as a group, aquatic lizards exhibit significant ecological, morphological and behavioural diversity (Pianka and Vitt 2003; Bauer and Jackman 2008). Some aquatics are only sometimes observed near water, whereas others spend most their time in aquatic habitats. In many cases, involved the evolution of novel behaviours (e.g. sprinting on water, as seen in Basiliscus and Uranoscodon superciliosus) and the evolution of specialised morphologies (e.g. laterally compressed tails in Sphenomorphus cryptotis and Varanus indicus; discussed in Bauer and Jackman 2008). Of the nearly 400 species of anoles, only 11 are known to have adopted the aquatic habitat. Anolis lionotus Cope, 1861 is the sister taxon to A. oxylophus and is distributed parapatrically in Panamá. The aquatic A. poecilopus Cope, 1862 is found in Panamá, though it is found in Colombia. The two Caribbean species, A. eugenegrahami Schwartz, 1978 and A. vermiculatus Cocteau in Duméril and Bibron, 1837, are found on the islands of Hispaniola and Cuba, respectively

Methods

Results

Conclusion