Marian seems to have 6 jointed legs, a couple of feelers on her wide end, which I think is her head, and a row of fine hairs running down her sides all the way to her pointed end. She’s kind of transparent, but if you had a whole lot of them, they’d probably look tannish.
Anybody have a clue as to what she is? She came in a clump of red ludwigia freshwater plants that I got for my betta fish.
She’s apparently an arthropod. Looks vaguely shrimp-like, but straighter, slender. She’s about an inch long and swims quite well.
Oh ick. Double ick. I wish no harm to Marian, but can’t you just take her outside and wish her good luck? Yuck. Arrrgh. Bugs. Creepy crawly. Get it outside!!!
Your critter sounds like some type insect larva or crustacean. The six legs, the ability to swim well and the large size makes me think it might be a large water beetle larva. Among the larger water beetles, large dytiscid larvae;
are known as water tigers for their ability to overwhelm large prey, up to and including small fish slightly larger than they are. They are also noted with having a venom that puts them in the running for most painful bite among the insects. They inject the venom through their large fangs, digesting their prey from to inside, as they also suck up the digested innards back through their fangs in till the prey is just a hollow skin.
I read your account of the fish food going to the read end of the critter in a different thread. That is probably just surface tension. Dytiscid larvae breathe though a spiracle on the tip of their abdomen. There is a fringe of hair around the spiracle to help it break through the surface tension when the larva comes up to breathe.
But, you can’t keep something if you don’t know what it eats! Hence, my concern for finding out what she is.
Just after posting this thread, I noticed that she has a pair of really fine, sharply pointed jaws. Much like those on an ant lion. She was opening and closing them, hanging off a leaf like she was expecting something to swim by or stalking around peering beneath leaves.
It occurred to me that she might eat smaller insects, so I tried feeding her a few frozen bloodworms. She became attentive as soon as they touched the water. One was dangling from the surface. She made a grab for it and missed, then angled around had another go at it. Got it that time, dragged it over to a leaf, and . . . lo and behold . . . began sucking stuff out of it.
The bloodworm was dark red, but now looks nearly transparent and Marian went from being transparent to . . . a nice cheery pink.
I guess this tiger bites people, right? Because how else would we know it has the most painful bite among insects? Apparently the bitten insects don’t live to talk about it afterwards. So, Lamby, do you think you would want to be a little bit careful with the water tiger? Is this the sort of thing that people should be selling in red ludwigia freshwater plants? Shouldn’t the plants be inspected? What if someone gets bitten?
As far as babysitting, gee, I’d love to help out but I’m booked. Permanently.
You’re welcome! Lambchop, I’m impressed you are not offended by large carnivorous insects. Most of the herbivores I’ve met on the net have been timid creatures, yet you assertively go by the name of a cut of meat, when you are clearly more than intelligent enough that consuming you would be a grotesque act of cannibalism!
As far as getting bitten by water tigers, it happens rarely enough that it is not an issue in the aquarium trade. The only fellow I’ve ever met that was bitten had accidentally pinned a 2 inch monster to the bottom of a stream trying to capture a stickleback minnow. It zapped his little finger. His hand swelled up and was in pain for a week! They usually simply swim off to avoid tangling with something much larger than they are. The real problem is if too many get into an outdoor small fish breeding facility and eat the stock.
When it gets to the size to pupate, it will need the right conditions to pupate under and will then mature into a really big water beetle. If I remember correctly, it needs a mud beach to crawl out on and perhaps some small rocks and bits of plant material to make a cocoon out of, but I’m not 100% sure on that.
I will ask Ding, the guy that got bitten! and see if he knows where they pupate.
Oh lord, this is all we need. I can only hope the most painful bite-giving insect does not have to be bigger than a ..uh…breadbox say, to pupate. Mercy! Here’s hoping too that really big water beetles aren’t cannibals who eat intelligent assertive lamb chops!!!
Poor Ding! I’d never dare to capture a fish again.
As adult predatory water beetle doesn’t have the right mouthparts to inject venom, they just bite. The mental image of an epic battle between Lambchop and a giant water beetle is rather humorous, though!
The most painful venom known is produced by the scorpion fish. It doesn’t damage the pain nerve endings. It simply sends the pain nerve cells into overdrive. The fish inject it with hollow defensive spines. It is so painful; otherwise unflappable Nordic fishermen have been known to cut off their own fingers to escape the pain.
Ding is one of the bravest, most skilled fellow entomologists I’ve met. He simply has great respect for insects that can sting or bite. He routinely grabs wasps and large bees by the wings, so he can place them in insect killing jars without getting stung, himself.
Went looking for more pics of monstrous water insects to terrorise you all with, and I found that BugGuide is CLOSED! Finito. Kaput. What a major bummer.
