Anole Annals

One of the largest anoles, Anolis equestris (photo by Uwe Bartlett)

From the diminutive twig anole to the monstrous crown-griant anoles, Anolis lizards vary dramatically in their body size. Much research has focused on the patterns of body size variation among Caribbean species, how changes in body size are correlated with habitat differences among species, and rates of body size evolution upon invasion to new islands, yet an important question remains to be addressed in this body of literature, “how do anoles change body size?” S. Griffis and Dr. D. Jennings of Southern Illinois University at Edwardville are attempting to address this among Cuban anoles by searching for DNA sequence differences in known growth factories. But they are using what might be considered an unlikely model for lizard body size variation: dogs. Several years ago, Elaine Ostrander’s lab at the NIH uncovered that coding differences in the growth factors IGF were responsible for the body size variation in dogs. To a mechanist like myself, it was a surprise that this variation could be traced to coding differences in the genes, not to the levels of circulating growth factors. The authors of this poster are following Ostrander’s lead by looking for coding differences in genes involved with the IGF growth axis. But to keep their options open they are also collecting data on circulating hormone levels. When complete, if there are differences in the IGF growth axis contributing to differences in body size, Griffis and Jennings will find it.

Patterns of Convergence in the Body Shape of Squamate Reptiles

SICB 2015 is off and running and what better way to kick it of than with a lizard talk? Phillip Bergmann of Clark University filled the 8:15 time slot on day one with an intriguing evaluation of broad-scale body shape convergence among squamates. This is a perennial topic on Anole Annals due to the well-studied patterns of convergence among Anolis lizards and, indeed, Dr. Bergmann highlighted anoles early in his talk. He asked whether common functional (ecological) situations lead to body shape convergence at large scales. Rather than search for global patterns of convergence, Dr. Bermann used hypotheses specific to the transformations that occur when lineages transitioned into new habitats. As he pointed out, it is not surprising to find convergence in body shape occurring throughout squamate – after all, convergence is ubiquitous across the tree of life. He concluded his talk highlighting what he feels are some of the most pressing “Big Questions” regarding convergence which included the methods we use to detect convergence, the role of constraints in shaping convergence, and elucidating the mechanisms underlying convergence. Ultimately it was a thought-provoking talk both from the perspective of squamate organismal diversity and the topic of convergence more broadly.

Anolis allisoni displaying. Photo by Pablo Bedrossian

Sister WordPress blog pablobedrossian has a nice post with photos and videos of A. allisoni from Los Cayos Cochinos in Honduras.

Introducing Anolis alocomyos.

Gunther Köhler and colleagues have done it again!This time, they’ve taken Anolis tropidolepis  in Costa Rica and divided it into three species in the December 2014 issue of Mesoamerican Herpetology.

The back-story: the A. pachypus complex (as the authors refer to it, except using the generic name Norops) has in recent years been split in Panama into four species, but complex member A. tropidolepis remained intact in Costa Rica. These lizards are long-limbed, narrow-padded lizards found near the ground at high elevations.

Based on eight years of collecting, Köhler and colleagues now split the group in Costa Rica into three species that are somewhat genetically differentiated at the 16s mitochondrial gene and that differ in hemipenial morphology and to some extent in scalation.  One of the OTUs (operational taxonomic units), comprised of a single individual, has the mtDNA of one species and the hemipenis morphology of another and is interpreted as evidence of hybridization.

The paper includes interesting discussion of bar-coding and how one goes from degree of genetic differentiation to decisions on species delineation.

One highlight of the paper was the icon shown below, which occurred at the bottom of one of the pages at the end of the article without explanation. A quick look at the other two papers in the issue revealed that each has its own logo–nice!

Photo by Christopher E. Smith

Christopher E. Smith recently tweeted this photo of an eyelash viper consuming an anole. The photo was taken in Tortuguero, Costa Rica in 2008 and the incident is recorded on HerpMapper. He provided additional photos which show the anole more fully. It appears to me to be an A. limifrons, though the regenerated tail means that the usual tail banding is not present.

And two more, for good measure:

And Down the Hatch!

Photo by Christopher E. Smith

In going back through the AA archives, I’ve discovered that we previously posted a link to these photos in April, 2011! But here they are again for your renewed viewing pleasure.

Consumption of A. limifrons by eyelash vipers has been previously reported, including a lovely photo by Harry Greene in Lizards in an Evoutionary Tree. A quick Google Image search yields a number of photos, although I suspect most are in captivity.

Here’s an interesting one:

Photo from Many Creatures of Costa Rica

This, in turn, led me to The Many Creatures of Costa Rica blog, which has a whole series of photos of this predation event from La Selva in Costa Rica. The anole seems to be A. humilis. Here’s another from the series: