Six-Toed Anole

Ventral and dorsal view of polydactyl anole, click to enlarge.

As Rich Glor mentioned recently, we are in the second year of an experimental hybrid cross between two bark anole species.  Although we are still early in this year’s experiment, we have had about 50 eggs hatch and, surprisingly, two have had malformed forelimb digits. The first was missing two toes on one of its forelimbs and died a few days after hatching. The second (pictured above) hatched with six toes, but has been otherwise healthy. Each of these toes has an intact claw, and at least one has lamellae. The fourth digit (from closest to the body counting outwards) seems to lack the (expected) scansor and is permanently bent upwards.

Mats Olsson and colleagues (2004) found malformations in the limbs and jaws and kinked backbones in crosses between populations of Lacerta agilis. Of the over 800 hatchlings in last year’s F1 experiment, we found a few animals with malformed spines, but not a single animal with digit or jaw issues. It’s particularly interesting (to me at least) that these issues have manifested in the backcross generation, an issue I hope to investigate further as more animals hatch.

Polydactyly has been reported in captive-bred crested geckos (Correlophus ciliatus), but I couldn’t find anything about anoles. Has anyone else seen something similar in anoles? If so, please let us know in the comments.


About Anthony Geneva

Postdoctoral Fellow at Harvard University. I use a variety of evolutionary genetic approaches to ask questions about gene flow, adaptation and speciation.

3 thoughts on “Six-Toed Anole

  1. I have sen something similar on two individuals. We had 3 Chamaeleolis chamaeleonides that had malformed toe structure. One had only four digits. Used the limbs normally, but there was no visible sign that there was something wrong in the foot except that a toe on each foot was missing. Of two that were more similar to what you are describing, one had an extra front toe, and the other an extra back toe, only on one foot. One of the toes, I cant remember which, appeared to be coming out from the side of another toe, instead of from the palm. I have only seen these issues in chamaeleonides, though. All of the animals lived for 8-11 years if my memory is correct.

  2. Their parents may have had a similar grandparent (I’ll try to look this stuff up tomorrow and send you an email… I might also still have some pictures). The extra toe did look similar to that, but was more well defined as a toe with a small toenail. I’ll see what I can find tomorrow morning.

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