What are these critters?

[memorywrangler]

They have are pin-head sized (.32mm) and they just appeared in large numbers on the walls of several of my tanks.  They seem stationary, but their insides move some under the microscope.

Can anyone ID them?

 

[nabokovfan87]

cc @Biotope Biologist @modified lung any idea?

[BlueLineAquaticsSC]

Looks like water lice maybe.

[Chick-In-Of-TheSea]

I don’t know.. the photos don’t show legs. @Guppysnail, ever seen these? She seems to have a lot of miscellaneous knowledge about microfauna. Tagging @dasaltemelosguy just because he has a microscope 🤷🏻‍♀️

[Guppysnail]

On 3/7/2023 at 9:06 PM, Chick-In-Of-TheSea said:

I don’t know.. the photos don’t show legs. @Guppysnail, ever seen these? She seems to have a lot of miscellaneous knowledge about microfauna. Tagging @dasaltemelosguy just because he has a microscope 🤷🏻‍♀️

The first photo looks sort of something like a fish louse. I have never seen one in Person though so that is a total guess. 

@Biotope Biologist @modified lung @Colu

Edited March 8 by Guppysnail

[Colu]

On 3/8/2023 at 2:10 AM, Guppysnail said:

The first photo looks sort of something like a fish louse. I have never seen one in Person though so that is a total guess. 

@Biotope Biologist @modified lung @Colu

I don't think that a fish louse it doesn't have the legs and you don't usually get them in large numbers on the  glass of your aquarium it looks familiar but a can't place it hopefully  someone else can give a positive ID

Edited March 8 by Colu

[Guppysnail]

You may want to scroll through here. There are fabulous microscope shots of many tiny aquarium critters. You might find your. 

 

[Biotope Biologist]

Looks like an amorphous blob to me 😋 

 

It kinda looks like a rotifer but I’m not super well versed in limnology so I’m not entirely sure. Even if it is a rotifer there are something like 2000 species so that doesn’t narrow it down much.

[memorywrangler]

I got some better pictures.  I put a microscope slide in the aquarium for a couple weeks so I could look at one without scraping it off the glass.  It looks like the the things on the glass are eggs.  You can see the embryo moving in the gif.  But eggs of what?

I also found an adult something.  I'm not sure if they are related.

 

[Odd Duck]

Definitely doesn’t look like a fish louse but does appear to be some kind of microcrustacean. Seems likely to be fish food if the right fish comes along. 

[rockfisher]

I think it’s a Copepod. It so you would not want to get rid of them. Most are beneficial to your aquarium. They are detritivores, so it is beneficial to have them in the aquarium as part of the tank’s ecosystem. Copepods are also make a great snack for small fish.

[Biotope Biologist]

2nd photo is a water mite. Still have no clue as to what your amorphous blobs are beautiful pictures though!

 

maybe @modified lung has come across them? They do look like eggs of some sort of thing. It kinda appears the egg is upside down and the butt is moving while the grey blob at the bottom is the head. I can make out antennae.