Toxins in Gray Treefrog Metamorphs

[opistoglyph]

Thank you for the links!

On the possibilty of pollutants, kind of slim. The amphibians in the pond, plus the uneaten metamorphs from the cage are all acting healthy. Plus, people sneaking on MY property? I was the biggest breeder of venomous snakes in the northeast for 20 years. Everyone around here is convinced that I keep stuff running around loose in my yard (don't know WHO would start rumors like that!) for protection. When I had the big mammals and valuable birds, I had a perimeter fence, now I don't even need one- paranoia does the trick. Scared neighbors are good neighbors.

No sign of illness in the one survivor from that group of babies, or other babies from different groups that didn't eat yesterday. I might try a couple of survivor metamorphs on a couple baby watersnakes and see the result- which wouldn't be conclusive being a different species and all, just interesting to note..

[LilyPad]

Why would you continue to "experiment" and kill off more snakes when you saw the results of the first round? I'm not a expert in reptiles and amphibians, and I agree that it is odd you would post this on a forum where frogs are beloved pets, but just coming from a rational, common sense standpoint, why would you want to kill more snakes in such a traumatic way?

[opistoglyph]

These same snakes, had they not been born in a cage in my collection, would have been born on my property and eating the same foods. Observation wise, it would be interesting to note whether the same toxicity problem is noted in Natrix in the same location as the Thamnophis. Both Thamnophis and Natrix have dozens to a hundred young apiece, and 99% die in the wild in their first few weeks, much like amphibians.

And when do the toxin levels change or drop? Or the tolerances of the predators build up to suitable levels? The whole concept that amphibian toxins change at various stages is brand new to me after 52 years in this field, and I'm willing to bet others that read this may find it interesting. Much less the fact that a severely road injured gray treefrog could pump out enough toxin to incapacitate a 200 lb man capable of surviving black forest cobra bite without antiserum, (plus the other nasty effects I had from it).

There have been many recent years when both ribbons and watersnakes had very low populations, most had presumed predation by night and blue herons, much like half the turtles in the US that are disappearing, as well as many amphibians. These birds are at pest levels now. If the problem actually relates to a change in toxins in young treefrogs locally, it certainly would be interesting to note it. This is not the first time I've raised these species and fed them wild caught food before they got large enough to switch over to scented pinkies, and I'm almost certain gray treefrog metamorphs were in the mix, so this is kind of interesting to me and local wildlife people. Our state people know almost nothing about amphibians or reptiles.

I have entomologist friends who object to my feeding insects to my amphibians as well, including species thought previously to be toxic that are accepted quite well. I know many amphibian people who feed pinkie mice to large salamanders and even larger mice to various frogs (though they are not acceptable as a regular diet item and may be bad for them, the hobbyists often brag about it). Many people like mice. I know many people who feed feeder fish of several species to amphibians. Many people like fish.

Wasn't looking for sympathy or approval, just intellectual dissemination. I see pictures of people with treefrogs on their faces, handled by their children, and think back to my stressed gray treefrog accidental toxin ingestion and shudder. If the young are more toxic or have a different toxin, that might be handy for hobbyists to know. Some keepers of aquatic salamanders load their tanks up with tadpoles for food- might save them a loss of a valued specimen. Likewise, a lot of reptile enthusiasts are also members here, and it might be a cautionary tale for them as well.

And lastly, the few specimens of extremely numerous amphibians and reptiles Iwould sacrifice in the pursuit of this knowledge are nothing compared to the deaths of thousands of larval amphibians kept and raised by hobbyists who have never bought a water test kit or studied filtration or understood oxygenation of the container and population dynamic who are thrilled to have a few specimens survive while hundreds died needlessly. Studying toxic animals, breeding endangered species for zoos and release programs, designing release programs and captive colonies is what I do, and sometimes you gotta break a couple eggs to make that omelette and understand all the variables.

Sorry if I offended you in any way.

[Rae]

Why would you continue to "experiment" and kill off more snakes when you saw the results of the first round? I'm not a expert in reptiles and amphibians, and I agree that it is odd you would post this on a forum where frogs are beloved pets, but just coming from a rational, common sense standpoint, why would you want to kill more snakes in such a traumatic way?

Glad to see that I wasnt the only one wondering this ... but I had no idea that Grey tree frogs could be poisonous.

[SkeletalFrog]

Knowledge for its own sake is generally worth it. Pretty much all modern medicine and technology can be traced back to "I wonder what happens if I do this?" For all we know, these could be a parallel system to the Brodie's garter snakes, which have already increasing not just our understanding of evolution and ecology, but also yielded novel insights about sodium channels in neurons, which in turn has countless medical applications.

Opisthoglyph, personally, I'd actually hang on to those metamorphs, with the goal of breeding them and actually setting up an experiment with proper design and enough statistical power to quite possibly be publishable. Maybe get several dozen ribbon snake litters next year, and randomly assort them into groups that are fed the offspring of these metamorphs, some wild-caught tadpoles you gather next year (both greys and other species for an additional control), and some wild-caught tadpoles from a different location many states away. I'd also freeze some tadpoles for chemical assays (I suspect the author of the poster I linked to would be keen on doing some of the chemistry on such a potent toxin).

The number required is tricky, but with some clever stats could probably be reduced. Unfortunately, this is a perfect case for non-parametric statistics, which I'm not particularly familiar with.

Still, I'd save those metamorphs, as their offspring could be a key to determining whether these are inherent toxins like toads or acquired through dietary sources like dart frogs.

[opistoglyph]

Thanks. I was almost loathe to say that I went out and collected some for the state wildlife pathologist- I've intellectually stimulated him here and there a few times over the years. There is the possibility that my man-made ponds, though the soil on my property is nearly identical to that in vernal pool areas and woodland ponds locally may also have introduced an element that has influenced this...

My toxic hero, Thomas Eisner (an entomologist/toxicologist, but a good Cornell contact to get things to the right people) has passed away, as have many of my capable friends over the years, but the state wildlife guy loves a mystery. The negative side would be allowing state guys on my property to do collecting <sigh>.

I brought him chytrid infected frogs four summers ago when it hit our area first time. He asked me how I found them and deduced what they were suffering from. I said that I saw adult green frogs hopping around in the sun on hot roads during the day acting disoriented and spastic (for the first time in my life). I assumed that since the fungus irritated the skin in early stages, it had the effect to make the frogs spread the fungus this way, traveling to new ponds, DRIVEN to new places, much like rabies causes the infected animal seek out another victim. After testing, yes they were infected, but I seem to be as yet the only one who has noted this phenomenon. Though chytrid has now moved through twice in this region, populations generally bounce back in one year, so I am assuming some level of resistance in individuals. I read about it constantly, provide specimens when I can.

Always new things. Too much to learn, but fun while you do. I'm sure you would laugh, but I was shocked to find out after years of keeping and breeding caecilians, that many of them have strong toxins- none of the literature I had read mentioned it. And yet I have several species of snakes that eat them (all of which readily switch to scented substitute prey items- much like mud snakes will eat a sponge rubbed on an amphiuma, or a rainbow snake would eat a rock with eel mucus on it- young ribbons aren't that easy to switch until they're 12" plus) and again wonder about that predator/prey relationship- acquired immunity? genetic? fascinating.

A pleasure corresponding with you, you've given me much to plan and consider. My facilities are not sufficient for this type of work, just observational. I do captive breeding. If no one can breed it naturally, I do. If people can't keep it alive, I do. Bugs to birds, not attached to any one group or species, I find them all worthy of the effort necessary to help others work with them and save them for future generations.

[Jennifer]

Hi, i was reading what you were saying about the toxins on the grey tree frog. I caught a grey tree frog in august and kept it as a pt. About two days ago i came in contact with the toxins on my lips. They have been burning for two days now. It is quite uncomfortable. I have no other symptoms. Any opinion about what i could do? Is there something natural i could rub on or eat to stop the reaction? Its kind of scarey because i do now realize the severity of handling and owning this tree frog now.

[Shiro]

Go to the doctor. If it's been burning for two days, there is something wrong and it needs treated.