About Stingrays
Nov. 13th, 2007 06:34 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
livingdebI decided to research stingrays in preparation for hanging out with some of them in the Caribbean. I thought it might give me ideas of things to pay more attention to.
It turns out that it's not so easy to learn about stingrays. I could not find any books that are about nothing but stingrays, for example. Still I did learn a few things.
The easiest thing to learn is that stingrays almost never attack people, and if they do it's almost never a bad wound and the wound is almost always in your foot or ankle and the incident with Steve Irwin was a total fluke.
It's also pretty easy to learn that they are flat and like to hide by lying still on the bottom surface, even flinging sand over themselves to become less noticeable. If you step on it, it may reflexively attack with its stinger, which may then come out in your ankle. This does not kill the stingray, and it can grow a new one. This teaches people who find themselves around stingrays to do the "stingray shuffle," which is to drag your feet through the sand as you walk so that a surprised stingray will run away (which reaction also lets it live and even lets it keep its stinger).
I've been thinking that the stingray might be one of the most alien life forms I will ever interact with. But maybe it's not quite as alien as I thought. It's very closely related to the shark, with whom it survived the Cretaceous-Tertiary extinction. (I did find two books on sharks and rays.) Like the shark, it has a simple endoskeleton of calcified cartilage and it's a fish with gills. The big round parts are really just large pectoral fins. So, like me, it has bilateral symmetry and a backbone and it can swim underwater using its appendages and lie at the bottom of the pool, surprising people. It even has pretty good vision, although the top eyelid is fused to the eyeball (the bottom eyelid works fine).
However, its eyes are on top and its mouth is on the bottom, so it can't see what it's eating. That's weird, huh? Only I just realized that I can only see to within about a half inch of my mouth, unless I deliberately stick my lips out. So maybe that's not so odd anyway. Plus it has lips and can feel what it's looking for. And it has a good sense of smell and, from what I can tell, it can even sense things electrically. Electric eels do this sort of like bats use echolocation--they send out something and feel how it bounces back. So maybe they have something like that.
Another odd thing is that it is covered with tooth-like scales, like sharks are. Instead of little hairs. The same sorts of things are what grow into teeth, and it has more than one row of teeth, like sharks do. And one of them is what evolved into the stinger. Robin says that shark skin is like sandpaper, only it hurts more. I'm guessing that the stingrays we are going to be hanging with have a less sharp version. Still, it is more than a little strange that we are paying to hang around sharks that evolution has squashed into the cute and nonterrifying shape of pancakes.
So, while I am there, I'm going to pay attention to how sharp the skin is, what the eyelids look like, and how many fins and gills I can see, in addition to what I would have been paying attention to before, like how they swim, and what it feels like if they eat out of your hand.
It turns out that it's not so easy to learn about stingrays. I could not find any books that are about nothing but stingrays, for example. Still I did learn a few things.
The easiest thing to learn is that stingrays almost never attack people, and if they do it's almost never a bad wound and the wound is almost always in your foot or ankle and the incident with Steve Irwin was a total fluke.
It's also pretty easy to learn that they are flat and like to hide by lying still on the bottom surface, even flinging sand over themselves to become less noticeable. If you step on it, it may reflexively attack with its stinger, which may then come out in your ankle. This does not kill the stingray, and it can grow a new one. This teaches people who find themselves around stingrays to do the "stingray shuffle," which is to drag your feet through the sand as you walk so that a surprised stingray will run away (which reaction also lets it live and even lets it keep its stinger).
I've been thinking that the stingray might be one of the most alien life forms I will ever interact with. But maybe it's not quite as alien as I thought. It's very closely related to the shark, with whom it survived the Cretaceous-Tertiary extinction. (I did find two books on sharks and rays.) Like the shark, it has a simple endoskeleton of calcified cartilage and it's a fish with gills. The big round parts are really just large pectoral fins. So, like me, it has bilateral symmetry and a backbone and it can swim underwater using its appendages and lie at the bottom of the pool, surprising people. It even has pretty good vision, although the top eyelid is fused to the eyeball (the bottom eyelid works fine).
However, its eyes are on top and its mouth is on the bottom, so it can't see what it's eating. That's weird, huh? Only I just realized that I can only see to within about a half inch of my mouth, unless I deliberately stick my lips out. So maybe that's not so odd anyway. Plus it has lips and can feel what it's looking for. And it has a good sense of smell and, from what I can tell, it can even sense things electrically. Electric eels do this sort of like bats use echolocation--they send out something and feel how it bounces back. So maybe they have something like that.
Another odd thing is that it is covered with tooth-like scales, like sharks are. Instead of little hairs. The same sorts of things are what grow into teeth, and it has more than one row of teeth, like sharks do. And one of them is what evolved into the stinger. Robin says that shark skin is like sandpaper, only it hurts more. I'm guessing that the stingrays we are going to be hanging with have a less sharp version. Still, it is more than a little strange that we are paying to hang around sharks that evolution has squashed into the cute and nonterrifying shape of pancakes.
So, while I am there, I'm going to pay attention to how sharp the skin is, what the eyelids look like, and how many fins and gills I can see, in addition to what I would have been paying attention to before, like how they swim, and what it feels like if they eat out of your hand.