Tag: toepad

An Update on Taking Toepad Pictures

0C7FAAF7-83FB-46AE-9B5E-D0F68041B2EA

I’ve taken more than four hundred toepad pictures using the new macro photography technique I introduced  in an earlier post and I’ve learned a few tricks that I want to share in this update.

First and foremost, I highly recommend this approach. For those of you looking to capture a lot of toepad data, particularly in the field, this kit is way faster and more portable than using a flatbed scanner and the images I’m getting are at least as sharp.

forefoot

A few tips:

  • Petri dishes work great as a clear platform to place the lizard feet on. I found that the 60 mm diameter dishes were much easier to balance atop the lens (~40 mm in diameter) than the larger dishes I’d originally shown.
  • I cut and taped a scale bar to one edge of the petri dish so I wouldn’t have to worry about juggling a lizard and a tape measure.
  • Make sure you have several petri dishes – they scratch fast – and keep some ethanol and a kimwipe close at hand.

IMG_6314

  • The app that lets you remotely trigger your iPhone is absolutely maddening. Do not download it. I’m not even going to relink the name. Instead, I suggest a much more stable alternative: connect your phone to your computer with the USB cable, open QuickTime Player, select File > New Movie Recording and click the down arrow next to the record button. This will give you the option to select your attached iPhone as a recording device. This live-view is far more stable and less frustrating. *Windows and android users I’m afraid I haven’t had an opportunity to sort out a solution for those platforms. If you know of something that works, please include in the comments!

Screen Shot 2017-08-21 at 3.47.58 PM

Unfortunately, through the live view all you can see is whether the lizard is in position. You cannot remotely trigger the shutter this way. That means you’ll need a second pair of hands to help. I found it worked best when my partner was in charge of putting the ID tag in the frame after I’d placed the lizard foot and then pushing the volume button on the side of the phone to trigger the camera shutter.

  • Lighting is really important. I suggested a headlamp in the previous post providing an oblique light source through the diffuser around the lens. I tried using a microscope fiber optic light source but I was really unhappy with the “warmth” of the light. I found that the white-LEDs in my headlamp produced a much more realistic looking image (see above). Also, make sure you don’t have any light sources above/behind the subject. Backlighting confuses the camera’s auto-contrasting and results in dark and sometimes unfocused images.

red dewlap

Evolution 2015 Recap

Logo for the Evolution 2015 conference.

Evolution 2015 is officially over and we have all sadly left beautiful Guarujá,  Brazil. There were a lot of great talks and posters and a great representation of South American students and researchers. For coverage on the conference as a whole, check out #evol2015 on twitter! The herps were few and far between (I only saw 2 in my 16 days in Brazil!) but the posters and talks on herps were numerous. Unfortunately, anoles were poorly represented at Evolution this year with only three anole talks and a couple of others that briefly highlighted anoles. If you weren’t able to make it to Brazil, I’ve got the recap for you here.

click to read more about Travis Hagey's research

A glimpse at the variation in gecko toepads

Starting off in one of the first sessions was a talk by Travis Hagey titled “Independent Origins, Tempo, and Mode of Adhesive Performance Evolution Across Padded Lizards.” Although his talk was mostly about geckos, he did shine the spotlight on anoles for a few minutes. He focused on the phylogenetic pattern of toepad adhesion in pad-bearing lizards: geckos, skinks, and anoles. Specifically he looked at how clinging ability (measured as angular detachment – check out one of his videos showing this) varied within and among clades. Unsurprisingly, he found that anoles don’t cling nearly as well as geckos. He also demonstrated that gecko toepad diversification best followed a Brownian motion model with weak OU and anole toepad diversification was best fit by a strong Ornstein–Uhlenbeck process. In other words, gecko toepads diversified slowly over a very long period while anoles were quickly drawn towards an optimum over a short time-period. Travis concluded that these patterns explain why there is a large amount of diversity in gecko toepads but not in anole toepads.

Next up was Joel McGlothlin, who also gave a non-anole talk titled “Multiple origins of tetrodotoxin‐resistant sodium channels in squamates.”

How Many Lamellae Are on this Toepad?

One of the age old questions in anole morphology is at what point do you stop counting lamellae on the toepad?

Without giving any more information on various techniques or methods, I thought it would be interesting to ask the AA community their personal opinions. Below I have attached a flatbed scan of a toepad. Could people please fill out the corresponding poll below, and I will present the results in a follow up post!

alt text

Lamellae numbered 1-51 on the 4th digit of an Anolis lizard hindfoot

Powered by WordPress & Theme by Anders Norén