Trapped Under Ice - Metallica

For this month’s EUT, I was looking for an invertebrate in a new taxon. While I technically found one, “invertebrate” usually implies an animal. As to what it looks like… well… it looks like someone shoved a bottle of glitter up their nose, and then sneezed on a branch¹.
















This is a slime mold known only as Diacheopsis metallica. Despite appearances, it is a single-celled amoeba. Slime molds spend a large amount of the time as you would expect an amoeba to: gooping around as an individual cell, eating things smaller than itself. When things get rough the individuals band together, Voltron-syle, to search for food or water. This isn’t to say the cells form together into a multi-cellular creature. Instead, they form a gigantic, multi-nucleated cell that is able to pick up and move, slug-like, to a more favorable location. They also use this time to produce spores, which will spread if things don’t get any better.

Scientists have found this aspect of slime molds absolutely fascinating. In this form, slime molds can solve mazes. It will even re-create the Tokyo Rail map when food is placed at junction points. Computer scientists are researching how slime molds solve problems to help programs search, move, and problem solve more organically.

D. metallica is a cold-adapted slime mold that lives on the tops of mountains in scattered ranges throughout the world. While they hibernate as spores during the winter, they become active in spring. They use the melting snow to create the correct temperature and the right amount of water to create favorable conditions to eat and multiply.

While the IUCN doesn’t have this slime mold officially listed, they are beginning to worry about it. On their Species of the Day fact sheet, they say it “has a provisional listing of ‘Near Threatened’.” This is because global climate change is shrinking the snow-covered habitat that these glittery globules rely on. Individual conservation actions for a slime mold are near impossible to carry out, but trying to fix climate change is a good start.


¹My wife says this is something Ke$ha would do.

Gut Feeling

Well, this week I had intended to write about the African Wart Frog, which is both incredibly cute and unbelievably ugly at the same time. Alas, I couldn’t find enough information about it, so I had to find another amphibian to take its place¹. This one seemed to fit due to the fact that the WWF catalog that I mentioned in the last post was about “Wildlife Families.”

Image by Ella Tyler via EDGE

This is an image of the Southern Gastric-Brooding Frog (Rheobatrachus silus). In 2002, they were moved from their status as endangered to extinct². They looked like the typical grey and semi-aquatic frog, but their name gives away everything they were as parents. After mating, the female eats the eggs. Literally—there is no special mouth-pouch or anything like that; the eggs go straight into the stomach. This isn’t too much of a problem, since the female shuts down her digestive tract and does not eat anything from six to seven weeks. By this time, the frogs turn into froglets, and are ready to hop out of her mouth.

Living in Southern Australia, they were never found more than 12 feet from water. When they weren’t raising the kids, they’d eat all the insects they could catch. Their extinction is a mystery. The feral pigs that reside in the same habitat and the disruption of the water flow obviously couldn’t help, not to mention the problems that global climate change is causing all amphibians, what with more drought and higher UV levels. I suppose this makes the real mystery which one caused the most damage. If anyone was wondering why we care about the extinction of the Gastric-Brooding Frog, medical science will never know how the females turned off their stomach acid. Looks like I’ll have to stick with Nexium. Scientists have been on the lookout for them, but alas, none have been seen since 1981.

¹All right, it didn’t have to be an amphibian, but I really do try to be all-inclusive when it comes to the major taxa. Since it’s been about two months since the last amphibian, I thought it was time for another one.
²I was really trying to avoid using the past tense to make this a blow at the end, but the thought of writing three paragraphs without any forms of “be” seemed too difficult.

Third Eye Blind(ish)

The Tuatara (Sphenodon punctatus) is a reptile that is also grouped into the "living fossil" category (see footnote on the lungfish). They belong to order Rhynchocephalia, which has existed worldwide about 220 million years ago, and the tuataras themselves look about the same as they did 140 million years ago. They aren't exactly worldwide anymore, as they are confined to New Zealand, and being an island species is never good news in terms of population.

Image from Wellington Zoo

While superficially resembling lizards, there are various characteristics separating the two groups, such as lack of external ears, another set of teeth, and a developed pineal eye¹. This "third eye" may help in temperature regulation, circadian regulation, Vitamin D absorption, or something completely different.

Tuataras are nocturnal and able to function at much lower temperatures than most reptiles. They have long lifespans, taking 20 years to reach maturity and living up to 100 years. Like many predators, they subscribe to the idea, "Is it animal matter, smaller than my head, and easy to catch? Then it's food." Hunting by ambush, they will eat insects, lizards, eggs, and seabird chicks.

The endangerment of the tuatara starts out fairly textbook. After millions of years isolated on islands, humans interfere and begin habitat destruction, removing them from the New Zealand mainland. Europeans bring rats, which eat the eggs and the young. However, there is a newer problem facing the tuatara. Like many reptiles, incubation temperature determines the sex of the offspring. Too warm (above 71.6 degrees Fahrenheit for the tuatara) and the nest is all males, too cold (under 69.8 degrees) and the nest is all females. What happens when global warming comes into play? One female can only parent one litter at a time (and four years apart), so this hurts the population much more than if fewer males were being hatched.

There is hope for our spiny little friends. Breeding and release programs are working on bringing the tuatara back to the New Zealand mainland, with the help of rat-proof fencing. Various studies are being conducted to determine the extent of global warming's effect.

¹Though not near as developed as this guy's, who I came across while searching for images.