Anole Annals

Check out this piece in the New Scientist, which picked up on our images of Anolis embryos and Thom’s awesome research!

Embryo of Anolis longitibialis, a trunk-ground anole from the Dominican Republic.

The readers of this blog do not need to be convinced that anoles are an amazing model system in evolutionary biology. New and exciting research often finds its way to the Anole Annals. Here we’ve learned about emerging trends in Anolis genomics, speciation, and comparative phylogenetics, to list just a few. In recent years, Anolis has also become a model system for developmental biology. For example, a recent study by Dr. Thom Sanger demonstrated that the diversity of limb dimensions among ecomorphs have evolved from similar developmental mechanisms.

This summer I worked a bit with Thom to learn how to stage Anolis embryos using his handy staging series as a guide. The goal of the project was to determine the stage at which female anoles laid eggs under two treatment conditions – a hot treatment (32°C) and a cold treatment (20°C). I had females from three populations of A. cybotes (55, 700, and 1400 meters in elevation), one population of A. shrevei (2450 m), and one population of A. longitibialis (100m). Unfortunately, I was unable to collect very many eggs despite letting the experiment run for six weeks. I did, however, manage to get several beautiful embryos, which I have imaged and staged. Here I’ll provide some pictures and give a few shorthand methods for staging Anolis embryos.

Anole Classics: Licht and Gorman (1970) on Anole Reproductive Cycles

By Jonathan Losos

On November 28, 2011

In Classics from the Literature

Reproductive cycle of Anolis trinitatis, from Licht and Gorman (1970).

All anoles lay only a single egg at a time, but that doesn’t mean that no variation exists among species in reproductive cycles. Still the most comprehensive study of this topic is Licht and Gorman’s (1970) comparison of nine populations of seven species throughout the Caribbean (downloadable as part of AA’s “Classics in Anole Literature” Initiative—pdf contributions welcome!). They found that reproductive activity was most constant through the year in the two southernmost species examined, A. trinitatis and A. griseus from St. Vincent. In the remaining species, both sexes showed some degree of seasonal fluctuations, although reproductive activity by at least some individuals occurred in almost all months. The authors considered rainfall to be the primary factor driving variation in reproductive activity, although in a later paper, they reconsidered and suggested that seasonal temperature cycles were probably more important.

Despite the ease with which such data could be collected, relatively few studies in the past four decades have followed up on this work. One such study on a Colombian anole was featured in AA recently, but for the most part, little work of this sort has been conducted in recent years. Who knows what surprises await an anole comparative reproductive biologist?

Recently AA asked George Gorman for some thoughts on this work, and he provided the summary below of the several papers he and Paul Licht wrote in the first half of the 1970’s on anole reproductive cycles:

Licht and Gorman. 1970. University of California Publications in Zoology 95:1-52.

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Comparing the Environment of Native and Introduced Brown Anoles

By Jonathan Losos

On November 27, 2011

In New Research

Geographic range of natural and introduced populations of Anolis sagrei. From Angetter et al. (2011).

The Cuban brown anole, Anolis sagrei, is indisputably the most successful of all Caribbean anoles. Not only is it found throughout almost all of Cuba at low elevations, but also everywhere in the Bahamas, on many islands in western Cuba, and even on the coast of Central America. Not surprisingly given its natural colonizing ability, the brown anole is the anole most widely introduced by humans as well, now established not only in Florida, but also on many islands in the Caribbean, as well as Taiwan, Hawaii and, most recently, Costa Rica.

What is surprising is how widely the brown anole has spread in North America. As the map above indicates, invasive populations have moved to areas much farther north than the species’ most northerly outpost in the Bahamas. One would think that Cuban anoles—or even Bahamian ones—would not be adapted to conditions in Georgia because environmental conditions are so different from those in Cuba.

To examine this idea, Angetter et al. conducted a species distribution modeling exercise to compare the environmental conditions that characterize the brown anole’s native range with that of its introduced range.

Thanks-giving Far from Home

By Daniel Scantlebury

On November 25, 2011

In Notes from the Field

Initially skeptical of my ambitions, a group of security guards celebrate the capture of a massive Anolis baleatus.

Part of any field-based research program are the random, unimagined discoveries that develop into fascinating side projects. (I’m sure that statement made my advisor’s blood pressure swell a tad). One such “discovery” I’ve been a part of during my adventures in the Dominican Republic are the existence of maggot infestations inside the mouths of crown giant anoles. Another crucial component to field research are the memories you take home with you – I mean the ones you’re not even sure you believe yourself when you tell your friends and family because they are just too random, bizarre and wonderful to be possible. And that January night when Miguel Landestoy, Anthony Geneva, and I first glimpsed these writhing maggots in the mouths of giant anoles certainly qualifies… (Cliff notes: Cipro and solenodon).

Challenges and Resources for the Post-genomic Era of Anole Research

By Thomas Sanger

On November 24, 2011

In New Research, Research Methods

The Anolis carolinensis genome represents the first annotated squamate genome and provides a valuable resource for those interested in anole morphology, development, physiology, systematics, and behavior (yes, even behavior!). Since the release of the original A. carolinensis draft genome in March 2007, no fewer than 20 papers have mined it for a deeper understanding of the amniote genome and its evolution. Many more labs are currently developing tools and resources for functional genomics and we can expect a number of exciting advancements in coming years. But with increased genomic information comes the need for community-wide organization and discussion about how to handle, store, label, and communicate these data. These well-known hurdles have each been faced in other communities. In addition, the community of Anolis researchers can also expect new challenges due to the number of comparative studies being conducted among populations and species (compared to research being done within relatively homogeneous strains or lines). To handle at least a few of these challenges, the Anolis Gene Nomenclature Committee was formed, comprised of researchers from diverse biological disciplines and representatives from public genomic databases. Culminating nearly two years of discussion, the first publication from this group is now available online (for free!) from BMC Genomics, outlining basic guidelines for the terminology and symbols used in future work on anole genomics. This paper represents an evolving document and is presented here to elicit further discussion.

Skeletal Anomalies – Curious Case of the Asymmetrical Sacrum

By Emma Sherratt

On November 24, 2011

In Natural History Observations

Back in September, we saw an Anolis carolinensis with a bizarre skeletal anomaly, the zig-zag tail. Several readers commented that this was quite a common trait, especially among captive lizards. I wanted to continue this theme with a curious Anolis cybotes specimen I found while CT scanning.

This image of a volume rendering of the skeleton shows a typical A. cybotes male pelvis, where the ilia articulates with the sacral vertebrae (denoted by arrow).

Now, the image below shows R186747, a male A. cybotes collected by Luke Mahler in the Dominican Republic. The lateral process of the first tail vertebrae has been adopted to form the sacrum on the left side, while the right remains standard, and the right side of the pubis appears to have an old healed fracture.

My First Field Expedition

By Asa Conover

On November 23, 2011

In Notes from the Field

Miguel Landestoy's "Tank"

Hello everyone! My name is Asa Conover, I am a student at Stuyvesant High School in New York, and this is my first post on AA. This summer I accompanied Martha Muñoz and Maureen Stimola on their trip to the Dominican Republic to investigate thermoregulation at different altitudes. I did elementary fieldwork with anoles when I was 8. On a family trip to Naples, Florida, I caught a bunch with my hands. I was too sad to part with them when we left so my dad permitted me to take a few home (I apologize to any who frown upon this). At home we set up a proper terrarium with a small tree and a heat lamp. Shortly afterwards, as we were replacing the mulch, we found an egg. This was the first of many. The anoles bred rapidly and before they became too many to handle, we sent them all back to Florida with a neighbor.

Honey Holes and Rare Anoles

By Daniel Scantlebury

On November 22, 2011

In Notes from the Field

Saludos desede la República Dominicana!

Male Anolis fowleri

I’m just past the middle of a 6 week trip to the eastern half of Hispaniola to collect specimens and ecological data for geckos of the genus Sphaerodactylus as part of my thesis work. I’m here for the most part with photographer, naturalist, and fellow adventurer Miguel Landestoy. We’ve had a number of ups and downs already and I figured it is time to share some photos from one of our first nigths in the field when we stumbled upon a honey hole of rare anoles. Since Anolis fowleri is such a rarely seen and poorly known beast, here are some photos of a pair and their habitat. (sorry to keep this post short, but I’m here for geckos after all and am completely exhausted)

Another Anolis Sagrei Sighting in Savannah, Georgia

By Allison DeVan

On November 22, 2011

In Introduced Anoles

This past weekend, I came across one A. sagrei perched on a building in Savannah, Georgia. It appears that this introduced lizard’s invasion is spreading north from Florida.

Curly Tail Lizard Attempts to Consume Anole

By Rich Glor

On November 22, 2011

In Natural History Observations

Leiocephalus macropus attempts to consume a juvenile A. jubar in southwestern Cuba. Photos copyright R. Glor 2000.

Anole Annals has a long, gut-wrenching history of posting photographs of our favorite lizards being consumed (or at least partially consumed) by other organisms, including snakes (1, 2, 3), birds (1, 2, 3), other anoles (1, 2), a frog, a spider, and even a plant. As far as I can tell, however, we have yet to post any images of anoles being eaten by one of their fiercest predators across the northern Caribbean: Curly-tailed lizards (Leiocephalus). Curly-tails are notorious anole predators and can have a profound impact on anole abundance and behavior (see for, example, Losos et al. 2004). The photos above were taken in southeastern Cuba and show Leiocepalus macropus killing and attempting to eat a juvenile Anolis jubar. Manuel Leal initially spotted the Leio plucking the young anole off a tree trunk. Although the Leio successfully killed the anole and got it part way into its mouth, it seemingly wasn’t able to swallow its intended prey (at least not until we interrupted the event).