Extinction of the gastric-brooding frogs in Queensland Australia

Posted on December 21st, 2009 in Environment,Evolution,Science by Robert Miller
Gastric Brooding Frog

Gastric-Brooding Frog

It was a PBS program that alerted me to the extinction of a frog called the gastric-brooding frog. These animals reproduce by the female swallowing the fertilized eggs and keeping them in her stomach until the young emerge as fully formed frogs. The young fertilized eggs/tadpoles secrete an unidentified substance that stops acid production in the female’s stomach and shuts down her entire digestive system, converting it from a means her own  sustenance into a brood pouch. After the appropriate developmental period, lasting from 36-43 days, the little frogs, about 21 to 26 of them, come out of their mother’s mouth as fully formed and ready for action (see image). The delivery process apparently takes place in the water. Two different species of these frogs were known as the Southern and Northern gastric-brooding frogs, indigenous to Queensland Australia.  Now it appears that both species are extinct. They have not been seen in the wild since the 1980s and attempts to maintain them in captivity were not successful. Like most disappearing amphibians, the cause of this extinction is unknown, but the three leading hypotheses include global climate change, fungus infections and habitat destruction, all three of which can be related to human activity, including an increasingly understood global threat to amphibians from a fungus infection.

Species extinctions of course are part of evolution. But biologists have argued that we are in the early or intermediate phase of the sixth mass species extinction, with the last one taking place some 70 million years ago when the dinosaurs became extinct, quite likely from an asteroid which struck the earth in the Yucatan Peninsula. But the new extinction phase we are in now is entirely man-made and, if it should reach the dimensions of the dinosaur extinction, we need to act with an emergency plan: I would suggest, as one of our first actions, we put all of the Republicans on the last ice flow out of Antarctica. I will personally escort George Will to catch one of the earlier break-aways. It’s probably too late to organize and catch the last one out of the Arctic.

I have previously written on the disappearance of the Golden Toad in Costa Rica and commented more extensively on the problems facing amphibians globally. Having used amphibians for research during most of my career, I have watched in horror, as I see these animals depleted on a massive scale, for a variety of reasons, each of which can be traced to our incursions into their habitat or the changes we have helped to generate in the quality of their environment. Some of these changes, like those that might be attributed to global climate change, are not easily identified and require skilled and knowledgeable field biologists working with climatologists to figure out the problem, the stimulus for which is often species extinction or severe species decline. Even then our right wing detractors can and do claim that “it’s only a theory.” Unfortunately that criticism can be applied to every scientific dictum that we have, yet the predictability of these “theories” has generated some of the most astounding successes in our technological and scientific history.
One case in which I was personally involved, led to funding for one of our animal suppliers to move his aquatic amphibians (tiger salamanders in the aquatic phase) from a toxic site to a safer environment, at a cost of about $20,000. This emergency move was necessitated by the introduction of a nearby giant pig farm/factory,  which created a toxic waste dump that putrefied the surrounding water. These kinds of problems are happening all over the world and amphibians, because they are sensitive to both aquatic and land pollution, with delicate skin that can’t usually tolerate dry climate changes, are now serving front-line duty as our canaries in the mines of global climate change. What will the world do for entertainment if our little frogs and toads are eliminated? Will we only know Kermit the frog as a puppet and not the animal types from which he was dervied? Paris Hilton can’t last forever and neither can her front page replacement, Tiger Woods. Yet, what are we actually doing about it? If Copenhagen is any example of our state of readiness for action, we are not doing nearly enough and we are not doing it fast enough to save amphibians from large-scale extinction. But then, do we really care? If Rush Limbaugh can dismiss poor Americans as undeserving of healthcare, what would he say about the current and future state of our amphibians? Thanks to politicization of our policies related to global climate change and its impact on species extinction, our policy of “don’t ask, don’t tell” has gone way beyond gender preference in the military to include the animals whose abundance we once took for granted. How about a three minute inclusion in our evening news on “the species that we lost today.” A little video clip of a gastric-brooding frog giving birth to her little frogs coming up from her stomach and out her mouth should be competition for Paris Hilton, especially if it spills over onto Sesame Street–Kermit needs competition. If we had learned about the “substances” that the little tadpoles release to shut down the mother’s gastric secretions, we might have a new form of medication for the dreaded heartburn and its subsequent development into Barrett’s esophagus and/or esophageal cancer.

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