Need help to identify... worms?

[Lukara]

I was feeding my fish this morning and I noticed 1 tiny white worm-like organism crawling down the back window of my aquarium. I only got about a minute to examine it since one of my platys gobbled it right up. Should I be worried? Anybody know what this could be?

Thanks,

Lukara

 

[OrionGirl]

Since you only got a glimpse, it's kind of hard to identify the critter. A helpful link:

www.sketicalaquariust.com (look for invertebrates and worms)

There are many organisms that can live in an aquarium. Some are okay, others pose a threat. Your critter may have been a hydra, a small worm of many specie, or a leach. Doubtful that is was a parasite, most likely harmless to adult fish. If you're concerned, your best bet is to find another one. Usually, if there's one, there's several, IME.

I've found leaches, daphnia, snails, baby guppies, ect in plants I purchased--they tend to be the best vector for introduction. If you've recently added a plant, this is probably what happened.

 

[wetmanNY]

Not to worry about. It was maybe a flatworm. If your Platy ate it and didn't spit it out, well and good. Fish are quite instinctive that way.

The other thing is, "if you can see it, --and it's not attached to a fish, of course-- it's not a parasite."

www.micrographia.com has some beautiful microscope photos of critters you might discover in the aquarium.

 

[OrionGirl]

I hate to argue...There are many parasitic critters that are visible and don't spend all their time attached to a fish. Leaches come immediately to mind. The parasites that you can't see are usually worse, but there are many worms that encyst in fish but are visible in a different life stage.

Of course, most of those are rare, but they show up occassionally, especially in gold fish and koi, or tanks that get feeders.

 

[wetmanNY]

Well you're right about leeches, Orion Girl. The only ones I've ever seen, though, that weren't attached to a fish have been among the blackworms, and those tiny ones are predators of blackworms rather than of fishes. Leeches don't switch off between worms as prey and fishes. Fish leeches are much more of a pond problem, wouldn't you agree? like fish lice and Lernaea and dragonfly larvae.

Dragonfly larvae also suck the fishes' blood and ignore the carcass. Yet we don't call them parasites. Because they're big? How big does a fish leech have to be before it's a predator? I don't know.

But I'm sure that none of the trematodes (and the encysting worms in fish are all trematodes) that encyst in fish have a visible egg stage. They may have juvenile stages developing in a copepod or a snail, but we can't see those free in the aquarium. Nematodes like camallanus and capillaria pass along as eggs or minute young, but they're far too small to see in that transient stage. Fluke hatchlings hunting for a host are microscopic. And all the other parasites are single-celled critters. Am I missing any?

...anyway I think you're right: it's too pat. I'll start saying "except for a small fish leech, if you can see it free in the aquarium, it's not a parasite."

Sorry to wind on... I simply feel people worry unnecessarily when they see a small invertebrate loose in the tank.

 

[OrionGirl]

I totally agree...Worms aren't a bad thing, just me being fussy. And there aren't many parasites that show up in the aquarium, but they are around. Non-parasitic worms are much more frequent. I have found leeches, but I know they were introduced with a lot of blood worms (not in my main tank!).

The reason dragonfly nymphs aren't considered parasites is they actually are predators. Parasites don't kill their host intentionally, death is usually a secondary reaction to the presence of the parasite. For example, maggots are not parasites, since they don't infect healthy flesh and never kill a creature. Tape worms don't directly kill their host, but may result in malnutrition/starvation, which can and does kill the host, as well making the host open to any number of other potentially deadly infections. The only time a parasite benefits from killing it's host is when it cannot go to it's next life stage without the host dying. Many examples of this--wasps that develop in caterpillars, worms that colonize a snails gut until forcing the snail to climb a stalk of grass and become bird food, etc. Tricky things, parasites!

Sorry--I realize this is way off topic. Parasites are a fascinating force of evolution, but not really applicable here.

 

[sunset]

Hopefully they wil just be planaria. I had those for a while once, and I just cleaned the tank out top to bottom, and that was the end of it. I guess they are pretty common, and if you had one you have thousands more, they multiply like crazy. Hopefuly thats all it was.