reptiles

Tuesday, August 10, 2010

Cleared and Stained

cleared and stined

Caiman latirostris — a crocodile

Some of our specimens, recently discussed in our post about specimens as snapshots in time, take on a unique role after entering the museum's collections. Certain reptiles, amphibians and fishes undergo a process called clearing and staining, which helps scientists look into the critters.

After being turned translucent by a digestive enzyme called Trypsin (found in the bellies of many vertebrates including us), dyes are added.  Bones and hard tissue are stained red with a chemical called Alizarin, and soft tissues are highlighted by adding Alcian blue. 

The contrasting colors help scientists study the morphology - the skeletal and skin structures - of an animal.  As an example, they prove especially useful for studying frog skulls, which undergo a peculiar dance of morphological change as frogs mature. 

Wednesday, January 13, 2010

A Reptilian Present

holding a bat

Today is my birthday. It is also Linda Trueb’s birthday. I don’t know if she knows that we are birthday buddies.

So, I celebrated my birthday out in the field on Mt. Palali.  It was a wonderful birthday. I always think that the food at camp is delicious, but I think the food was extra good today with chicken and rice for breakfast, beef stew for lunch and the grand finale of the biggest batch of spaghetti I’ve ever seen! And the cake! How can I forget the cake? Arvin and Rafe hiked down into town yesterday to replenish our food supply and they came back with a birthday cake for me! How lucky I was to actually have a birthday cake out in the middle of the rainforest on an isolated mountain in the middle of Luzon!

One of the town officials hiked up to join us for the spaghetti and cake. He smiled at me and said “This year you celebrate your birthday with Philippinos!...And one Mexican!”

I also want to mention I had quite an adventure last night. We went to a new stream to look for different species we haven’t collected yet. This stream was full of murky, dark waters and was surrounded by fields of tall grass that stirred up feelings of claustrophobia. When I had fallen behind the boys and the local guide and I was navigating this hellish stream all by myself, my knees actually started shaking I was so scared. Fears of pit vipers and God knows what else I could come across in the murky waters filled my mind (Enteng and JB brought back a good-size eel from one the streams around the camp less than a week ago). Did I mention this was nighttime and all I had for light was my headlamp? Anyway, I continued forward and finally managed to catch up with the boys and the guide. To my relief, the stream opened up to more forest-like the surroundings. We were still following the narrow stream in a single-file. Herping in a single-file wasn’t working out very well for me, being that the guide in the front was catching all the frogs, the boys in the middle collecting the few herps that the guide missed, and me in the back desperately trying to spy anything else that was missed by both the guide and the boys. And at one point, I noticed a fern-like plant hanging over the stream. I remember noticing Enteng the other night checking big leafs on plants for frogs and lizards so I decided to try the same thing. On the second leaf I pulled down, I found a skink from the genus Eutropis. I was so surprised I yelled to the boys “I found a skink!” The boys yelled back “Don’t just tell us! Catch it!” And I did! First reptile on the trip for me. Later, we proceeded to scale a waterfall that was also very exciting.  We returned to camp that night with a good amount of specimens and an adrenaline rush.

—Allie

Thursday, June 21, 2012

The oldest Batesian trick in the book

I’m proud to say, a few days ago at Camp Putik, I fell for the oldest trick I the book.  Million of years of evolution and selection pressures exerted by predators have produced many flavors of harmless animals which avoid predation by “mimicking” noxious, toxic, foul-tasting, or venomous co-distributed species.

Thus, back in Kansas, the harmless Regal Frittillary Butterfly (Speyeria idalia) are the same brilliant shades of red and brown as the toxic Monarch Butterfly (Danaus plexippus) and birds apparently cannot tell the difference and avoid eating them both.  The “mimic” benefits from the predator education on the part of the “model.”

Of course individuals of the mimic species (the harmless beneficiary of this trick) and the model (the species that packs the dangerous punch) are not actually engaged in conscious or active mimicry strategies.  Rather, it’s the predators who are born with innate, evolved, “instincts” to avoid brightly colored “warning” patterns that exert selection pressures by eating the harmless, drab colored individuals and avoiding the brightly colored ones.   Thus, the brightly colored variants disproportionately pass on a greater proportion of their genes to the next generation and, through time, the population as a whole becomes more brightly colored—and “mimics” the venomous model.  This all according to the famous Batesian Mimicry hypothesis of evolution of aposematic coloration.

In any case, last week as we enjoyed a few sips of rum late at night in camp, a brightly colored, banded snake crawled past our feet through the mud.  At a glance, I identified it as a Philippine coral snake (Calliophis intestinalis).  We very carefully captured it with sticks and gloves and only after it was in the bag did we realize we had before us the harmless example of Boie’s Dwarf Snake Calamaria lumbricoides.

I don't mess around with venomous reptiles.  In contrast to what you see on TV, most herpetologists who study venomous reptiles avoid touching subjects, never pin snakes behind the head and hold them in their hands, and in general, don't take chances.  In my book, every snake-wrangling cowboy made famous on the Discover Channel is living on borrowed time; eventually the odds will catch up with all of them. Given that handling venomous reptiles is part of my job description, I’m determined not to be a snakebite statistic…I lost a friend ten years ago to a krait bite in Burma, and I’d rather be safe than sorry.  Meanwhile, I have to admire the exquisitely precise coral snake mimicry achieved by Boie’s Dwarf Snake. —Rafe

Tuesday, June 12, 2012

The oldest Batesian trick in the book

I’m proud to say, a few days ago at Camp Putik, I fell for the oldest trick I the book. Million of years of evolution and selection pressures exerted by predators have produced many flavors of harmless animals which avoid predation by “mimicking” noxious, toxic, foul-tasting, or venomous co-distributed species.

Thus, back in Kansas, the harmless Regal Frittillary Butterfly (Speyeria idalia) are the same brilliant shades of red and brown as the toxic Monarch Butterfly (Danau plexippu) and birds apparently cannot tell the difference and avoid eating them both. The “mimic” benefits from the predator education on the part of the “model.”

Of course individuals of the mimic species (the harmless beneficiary of this trick) and the model (the species that packs the dangerous punch) are not actually engaged in conscious or active mimicry strategies. Rather, it’s the predators who are born with innate, evolved, “instincts” to avoid brightly colored “warning” patterns that exert selection pressures by eating the harmless, drab colored individuals and avoiding the brightly colored ones. Thus, the brightly colored variants disproportionately pass on a greater proportion of their genes to the next generation and, through time, the population as a whole becomes more brightly colored—and “mimics” the venomous model. This all according to the famous Batesian Mimicry hypothesis of evolution of aposematic coloration.

In any case, last week as we enjoyed a few sips of rum late at night in camp, a brightly colored, banded snake crawled past our feet through the mud. At a glance, I identified it as a Philippine coral snake (Calliophi intestinali). We very carefully captured it with sticks and gloves and only after it was in the bag did we realize we had before us the harmless example of Boie’ Dwarf Snake Calamaria lumbricoide.

I don't mess around with venomous reptiles. In contrast to what you see on TV, most herpetologists who study venomous reptiles avoid touching subjects, never pin snakes behind the head and hold them in their hands, and in general, don't take chances. In my book, every snake-wrangling cowboy made famous on the Discover Channel is living on borrowed time; eventually the odds will catch up with all of them. Given that handling venomous reptiles is part of my job description, I’m determined not to be a snakebite statistic…I lost a friend ten years ago to a krait bite in Burma, and I’d rather be safe than sorry. Meanwhile, I have to admire the exquisitely precise coral snake mimicry achieved by Boie’ Dwarf Snake. —Rafe