To freedom!
So, the traps in the swamp yielded a few really good finds: two sirens, and this guy, the two-toed amphiuma. It's a good thing that swamp housed so many cool herps, or I'd never forgive it for trying to swallow me.
The major distinguishing characteristic among amphiumas are the toe numbers: there are one-, two-, and three-toed amphiumas. Amphiuma means is the two-toed amphiuma, and if you look at those tiny little appendages below its head, those are its arms. It has both arms and legs, each with two toes. Two tiny, tiny toes.
All members of the family Amphiumidae have these ridiculously small arms, gill slits, and laterally compressed tails, all of which indicates that they are entirely aquatic, and the fact that they retain these traits into adulthood indicate that they are obligate paedomorphs. They are nocturnal; they hang out in burrows during the day and hunt at night. They are quite active hunters, but I will get to that later; right now, I want to talk about their slime. Amphiumas produce huge, really off-putting quantities of mucus. It's super gross, but also super cool, because they can use this mucus to estivate: when it becomes too dry, they hunker down in a nasty little mucous cocoon, retaining moisture and waiting out the drought. They also use it to retain moisture for trips on land. They can use their tiny arms to scoot themselves along on land, really slowly. Here is a video of an amphiuma doing that.
Amphiumas have to get on land for reproduction. Amphiumas have internal fertilization, and they do it kind of like birds, with the cloacal kiss: they get right up next to each other and the male deposits a spermatophore (or maybe just sperm in non-packet form) into/onto the female's cloaca. Eggs are laid on land, in hollow logs or some other suitably burrow-y place, and the female attends the eggs until they hatch.
Totes adorbs.
So, about amphiumas as predators. They eat aquatic crustaceans and insects and I think small fish as well—anything that will fit in their mouths and not kill them. Here is a pretty cool video of an amphiuma eating a crawdad, and then dealing with the fact that it just put an angry, pincer-bearing thing inside its body.
Amphiumas live in the southeast, in swamps and sometimes in rivers, but mostly in swamps. Swamp water isn't totally stagnant, of course, but it's definitely not moving at, like, river-like speeds, and so it's not as well oxygenated as river water. Additionally, amphiumas have gill slits, but not external gills. This should make no sense: the amount of oxygen available to an organism via its gills is a function of the concentration of oxygen around the gills and the surface area of the gills, but these guys have, like, no gill surface area. Small gills are very disadvantageous in a swamp, and yet, these guys have gill slits, not even proper gills. This is because they have these awesome lungs, which provide them with just over half their oxygen; they breathe really infrequently and give the oxygen a really long time to diffuse, and so make really good use of each breath. So, that is pretty cool.
These guys are pretty angry; they can bite super hard, and the one we caught looked super pissed-off the whole time, although that's also kind of what amphiumas look like by default. According to Wikipedia and one comment on an article I'm going to link, amphiumas can make a high-pitched cry when they feel threatened, but I haven't seen that anywhere else, so if someone can verify that from personal experience or otherwise solid knowledge, that would be awesome.
Check these things out!
- There's an amphiuma article on TetZoo! You guys, I believe I have told you this already, but I love TetZoo.
- The source of the amphiuma videos. These are all three-toed amphiumas, Amphiuma tridactylum, rather than two-toed ones.
2 comments:
They're the only salamanders with internal gills!
that video of amphiuma walking is precious!! their limbs are more efficient than i expected
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