Here’s something you don’t see every day. More on these guys soon.
- Anolis annectens. Photo by J. Losos.
No flies on you guys–this remarkably obscure anole was quickly identified. So, what’s its claim to fame?
Well, we have to backtrack to Anolis onca for a minute. Faithful AA readers will recall that A. onca is the only anole lacking a subdigital toepad. For this reason, at one point it was placed in its own genus, Tropidodactylus. However, in 1974 Ernest Williams described a new species in Breviora based on a single specimen found in a jar of A. onca in the Field Museum in Chicago. At that time, Anolis was characterized by having expanded scales under phalanxes ii and iii of the toe, whereas Tropidodactylus, of course, had none (phalanxes are the bones in a toe–humans have three per finger, for example). What was remarkable was that the new specimen had expanded scales under phalanx ii, the Anolis condition, but only keeled scales under phalanx iii–it was intermediate between the two, hence the specific name annectens. Here’s an image from Williams’ paper and a photograph of an annectens toe.
From Williams (1974).
Anolis annectens foot. Note the lamellae under only one toe bone. Photo by J. Losos.
The term “retrograde” comes from Williams’ paper and refers to the idea that A. annectens and A. onca illustrate a morphocline in toepad reduction–halfway gone, then all the way gone. Incidentally, recent molecular studies confirm that the two species are sister taxa.
Amazingly enough, A. annectens occurs in the same general region as A. onca, near Lake Maracaibo in Venezuela. In 2007, Tito Barros and colleagues reported in Tropical Zoology on the collection of an additional 22 specimens of A. annectens, confirming that the one individual wasn’t a freak. They also provided information on coloration, geographic distribution (it still hasn’t been found in sympatry with A. onca) and some data on ecology.
Since we were in the area any way, we decided to go and look for them after collecting data on A. onca. By “we,” I mean Tito Barros, Gilson Rivas, several students of theirs, and Rosario Castañeda. Anthony Herrel was busy back at the field lab conducting performance trials (sprint speed, bite force), and I was on assignment finding discarded cardboard boxes to make a proper racetrack.
The weather was beastly hot, about 110 degrees Fahrenheit, with no wind. Here’s what Rosario had to say:
On a recent trip to Grand Cayman I was interested in the UV reflecting dewlap of Anolis conspersus. The dewlaps of these lizards appear blue to our visual system but are maximally reflective in the ultraviolet. While anoles have 4 cone types (ultraviolet, blue, green and red sensitive), humans have only 3 and cannot see UV light so to understand what these lizards look like in the UV, we have to use specialized camera equipment. The photo to the right shows what a displaying A. conspersus looks like to our camera system when imaged in the human visual spectrum as commercially available digital cameras also have only three channels corresponding to the three human cone types. Presumably if we were also able to see in the ultraviolet as many other animals can, our cameras would be designed with a separate channel for ultraviolet.
These images of the lizard in the UV show clearly the regions of the dewlap and that are highly UV reflective and the pattern of UV reflectance in other areas. One somewhat interesting finding is that while the dewlap scales are highly reflective across the human visual spectrum (which is why they appear white to our eyes) they reflect very little UV light. The lower photo is a monochromatic image (both the red and blue channels in this camera are sensitive to UV so the raw image appears purple) that makes it a bit easier to see brighter areas as white. Note how bright the dewlap appears relative to the reflectance standard, when imaged in the human visual spectrum a similar monochromatic image of the dewlap would appear very dark. I believe this shows the potential value of UV photography when studying Anolis dewlap patterns. While the UV nature of the A. conspersus dewlap is uniform, it’s likely that other species have patterns visible in the UV we’ve previously missed. We have also used this UV photography setup in SE Asia to image Draco flying lizards and other species, some of which have patterns that are visible only in the UV band. The goal of this project is to make a camera system with pixel channels similar to the four cone types found in Anolis lizards and birds to image whole organisms and really “see” the patterns organisms experience with their visual system as they would see them. As Anolis visual pigments and their associated oil droplets appear to be fairly conserved, this seems to be achievable.
Another surprise (to me) was the large number of A. conspersus on Grand Cayman using lights at night to feed. I’ve spent many months doing fieldwork in SE Asia and Central America and can’t recall seeing this sort of thing with other diurnal lizard species, but on Grand Cayman it was quite common in A. conspersus. I observed one A. conspersus male chase away a Hemidactylus that got too close to the light, showing that the anoles at least occasionally displaced the group I typically associate with feeding around lights. A check of the literature shows this has occasionally been documented on other Caribbean islands, but as far as I can tell no one has published on this in mainland species. What diurnal lizard species have others observed using lights to feed at night?
During a recent trip to the interior of Colombia (March 2013), we spotted this large striking anole. It was located just outside the town of Barichara, on the ancient Camino Real trail to Guane. Average elevation of this area is approximately 4,200 feet. Can anyone help identify this species and gender?
As it was early in morning, the anole had just begun to bask in the morning sun. It had probably not thoroughly warmed its body yet, and made for an easy capture! We examined, photographed, and released unharmed. -Marc Kramer, DVM (Miami, FL)
Read all about in Janson Jones’ latest anole post over on Dust tracks on the web and more on the ever dangerous broad-headed skinks at this recent post.
Better Janson than a brown anole
Green anole (Anolis carolinensis). Photo courtesy of Karla Moeller.
Ensembl Release 71 includes many updates for Anolis carolinensis, including the addition of the Arizona State University (ASU) Anole Genome Project annotation recently published in BMC Genomics (Eckalbar et al., 2013). This release includes an updated Ensembl gene set and aligned RNA-Seq data from a number of tissues, including embryo, lung, liver, heart, dewlap, skeletal muscle, adrenal gland, ovary, and brain, which have been added to the track viewer. These RNA-Seq data from individual tissues and from the ASU reannotation or the “Anole Genome Project” can be viewed just below the Ensembl gene tracks, as in this example.
Rob Heathcote posted this photo as a comment on Sean Giery’s post on bird predation on anoles, but the photo is so spectacular that we need to make sure everyone sees it.
A few years ago I asked an ornithologist friend of mine what urban birds such as starlings and house sparrows ate. His answer was that it was probably a mix of bottle caps, cigarette butts, and McDonald’s French fries. I’m only partially satisfied with that answer, and so try to keep an eye on what urban birds eat wherever I go.
Since moving to Miami four years ago, I’ve observed several cases of birds consuming anoles. After watching a Common Grackle feed an anole to a fledgling a few days ago, I thought I’d compile and share these observations with AA readers.
Is this an embarrassment of anoles? Image from petparadise.info.
For natural history students, professionals and enthusiasts some of the most entertaining, albeit fairly useless, facts are the collective nouns used to describe a group of organisms. From taxon to taxon, collective nouns are literary (a murder of crows), descriptive (a prickle of porcupines or a sneak of weasels), mundane (a shoal of sticklebacks), and even absurd (an aurora of polar bears).
When I first read the headline of Jonathan’s latest dispatch to the New York Times Scientist at Work blog, An Embarrassment of Anoles, I briefly thought that anoles had their very own collective noun. But alas, I was wrong and a group of anoles isn’t (yet) referred to as an embarrassment.
In a quick flurry of googling I found words for groups of various amphibians and reptiles: crocodiles (bask), cobras (quiver), iguanas (mess), frogs (knot), toads (knot), salamanders (congress) and lizards (lounge), to name a few. But nothing for anoles!
Does anyone know of a collective noun for anoles or, failing that, have a suggestion?
Twin embryos of A. apletophallus dissected from a single egg that failed to hatch.
During my research project on A. apletophallus I dissected many eggs that failed to hatch but I was very surprised to discover two embryos in this egg. The female had mated in the wild and laid many normal single embryo eggs before and after this one. Twin embryos have been observed in other lizards (e.g Agama agama (Herptelogica 1967,23:57), leopard geckos and bearded dragons) but I did not find any previous report in anoles. Thought it my interest the AA readers. Anyone else seen this?