Fish Fanatic
May 7, 2013
Reaction score
UPDATE: Issue resolved with help from another member. The things in my tank were fresh water limpets, a tiny gastropod, nothing parasitic. Pictures below in responses, courtesy of @chris from hull.


Hey all,

I have this thing in one of my freshwater tanks that I have mostly ignored for a long time, but realize I need to identify for a host of reasons. I would take a picture, but it's impossible to get a decent image.

I have these little clear/opaquish oval things all over the glass of my tank. They are too abundant to be worth counting. They cover other surfaces too, but I mostly notice them on the glass. I usually just remove them when I want things to look pretty. Sometimes I have more than others, I THINK... occasionally I'll notice that they are everywhere if I just look. I don't think they are ever gone - for at least 2 years now. They do not move visibly (i.e. If I watch them, I don't see movement. It's possible they move slowly but that I just can't detect it easily. Over time locations vary, though, so they are moving or changing at some point or other). They are maximum of 1.5mm in size I think, or smaller, and vary in size. Imagine a clearish oval, with somewhat more opaque insides, including 1-2 little spot(s) that are slightly darker (the number of dark spots varies... if any have 3+, I didn't see them when I searched).

Of note, I have at least 4 species of snails in this tank. This tank has had some combination of snail life for over 3 years. The current snail inhabitants I can label are giant apple snail (pomacea canaliculata), ramshorn snail, and trumpet snail. There's another small snail that I don't know the identity of, that does not have the long extended shell of the trumpets and that seems to reproduce naturally. It's possible that theres more than one unidentified species, because they are small and I haven't had the motivation to remove any to do some great internet analysis. I've also had nerites, but have none currently. Only the ramshorn (3) and apple snail (1 - female) are not running around in great numbers. The fish in this tank are usually scaleless. I had a black ghost knife for a long time, and currently a golden dojo (for the past 5 months). Over the years there has otherwise been a lot of variation in fish/plant life... no plants currently per the giant apple snail (nom nom nom). Two of my former, male giant apple snails developed an inflamed genital condition, never reproduced, and died younger than expected (which may be irrelevant, but it was odd and something I'd never seen despite having seen a great portion of the life cycle of at least 100 of these guys).

Anybody have any idea of what these things could be? Could these be the sporocysts or metaceraria of flukes or some sort of parasite? I can answer additional questions, or ID from a picture on a website if you know how to look this up. From what I can tell, they do seem similar to what I see for parts of the life cycle of flukes, but the images I get are so varied and most of them are graphics so I'm having trouble making a comparison without a firm lead. I also realize that I could be COMPLETELY be going down the wrong direction.

Thank you so much! Any help is REALLY appreciated.
Last edited:
sorry can't help you ID but interesting read hope you get to the bottom on it. Wouldn't think it was flukes tho I've had them in my koi pond and wow you know you have them I lost a lot of fish due to secondary infection.
do they look like this


  • wp_ss_20170513_0003.png
    293.8 KB · Views: 241
  • wp_ss_20170513_0002.png
    243.1 KB · Views: 243
  • wp_ss_20170513_0001.png
    716.3 KB · Views: 246
Sorry for the late response. I was so relieved I forgot to respond! YES, they look just like that @chris from hull. After reading your response, I looked them up and took an even closer look at the things in my tank. They must be fresh water limpets. Wheeeew!! That is great news - that biodiversity is very welcome in my tank. Thank you SO much! I didn't come close to finding this out from the many searches I did prior to posting here, not for lack of trying! I'll be editing this post to contain those words if possible, to help out others in the future. :)

Most reactions