Author: Jonathan Losos Page 100 of 133

You never know where you'll find a two-tailed lizard in the Bahamas

Two-tailed–or occasionally even three-tailed–lizards are not all that uncommon. The way it usually happens is easy to explain. Most lizards can lose their tails and regrow a new one.  The way they do this is that in the middle of each vertebra in the tail is a zone of weakness (called a “breakage plane”), pre-made to easily fracture. At the same point, the muscles are arranged to pull apart, and the blood vessels to easily split and clamp down, losing little blood. When this happen, the signal goes out–don’t ask me how–and new tail construction begins.

But occasionally it doesn’t quite work like this. The tail is only partially broken, and doesn’t come off, but enough is broken that new tail growth begins. The result: two tails, the old, still attached one, and the newly grown one.

Now, one more point: new tails do not regrow the original vertebrae, made of bone. Rather, they grow as one long, cartilaginous rod. So, one can easily tell the new tail from the old one.

In any case, that’s how I understood things. When we caught the beauty pictured above, I thought “let’s x-ray the tail to illustrate how this happens for our viewing audience back home.” And boy was I surprised. Take a close look–both tails are composed of cartilage–no bones there.

Now, you’re probably thinking: “Big whoop. It lost its tail, regrew it, then partially broke the regenerated tail, leading to the production of a second one.” Well, you’re probably right, but it’s not supposed to happen that way. Regenerated tails do not have breakage planes and other adaptations for detachment. They’re not supposed to be lost and regrown. Can anyone explain to me what’s going on here?

BK. Photo by John Rahn

Previous posts (1, 2, 3) have discussed the effect of Curly-tailed lizards (Leiocephalus carinatus) on brown anoles in the Bahamas and elsewhere. To summarize briefly, the effect is this: curly-tails eat brown anoles. Lots of them. The survivors move up into bushes to get away.

Such slaughter may seem of academic interest when it occurs in far-flung Caribbean ports, but soon–already!–Florida denizens can see the carnage up close and personal. The reason: curly-tails have been introduced to the east coast of Florida and seem to be spreading fairly rapidly.

This is all preamble to a series of photographs that AA reader John Rahn has sent in. John lives in Hobe Sound, Florida  (on the coast, north of Miami and West Palm Beach) and enjoys watching and photographing lizards on his back patio. He commented that “I love watching their antics. They are actually quite interesting and are great subjects to practice shooting (photographing).There’s another on my patio (editor’s note: “another” refers to  the A. distichus  he mentioned, along with a photo, in a comment), a girl with great markings and a red head, and this big boy.”

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Anole Annals has a long tradition of promoting knowledge of honorary anoles (e.g., here). A little while ago, we had a post on non-anole dewlaps featuring Otocryptis and now we continue what will become a series of sporadic posts on the Asian branch of the anole fan club (Hey! That was a pun, in case you missed it).

Thanks to Sameera Suranjan Karunarathna’s posting on the Facebook “Professional Herpetologists” page, I’ve become aware of several interesting articles on the behavior of the Asian dewlap-bearing agamid lizard, Otocryptis wiegmannii.

The first paper is on the territorial behavior of this species. The description sounds like anoles in some ways—dewlap deployment is a major feature—but different in others, such as the ability of the dewlap to change colors and the way in which the lizards launch themselves at each other after approaching bipedally. Here’s the heart of the description:

“At once both males ran towards each other bypedally about 1 m and stood by their hind limbs for about another 1 minute (Fig. 3b). After that, there was about 1 m distance between them. During this period they were expanding and compressing their dewlaps rapidly approximately four to six times per minute and kept the dewlap expanded for approximately 1 second. Theirtails were lifted up and they appeared suddenly with black and white bands that became more prominent. The body colour was distinct with yellow, black, white and green. Their heartswere fluttered fast and both lizards breathed deeply.

Struggling