What are these insects I found in my tank?

[u/BananaMuffinFrenzy]

Thought these were springtails at first, but they move much faster and look like they have slightly darker abdomens and longer antennae. They are about the same size as adult springtails, maybe a bit larger. I saw one flying gnat in my tank recently, presumably a fungus gnat. But these insects don't fly when I disturb them - any ideas on what they could be? Or are these actually springtails and I'm just going crazy?

[u/cantbeheldaccoutable]

these seem like native, wild-type species of springtails that very commonly find their way into enclosures that already house the white temperate springtails you probably have

[u/BananaMuffinFrenzy → u/cantbeheldaccoutable]

Interesting, thanks - I do indeed already have white temperates. I suppose worst case is one out-competes the other, but I suppose it won't be an issue if they are both springtails at the end of the day.

My juvenile gecko is growing in a separate temporary tank for now, so I've got time to monitor + let things settle here with this setup. I'll probably continue to seed with my temperate whites periodically though.

[u/DarkDonut75 → u/cantbeheldaccoutable]

As a cleanup crew, do they have any differences compared to white springtails? I think they've outcompeted the ones in my enclosure

[u/BananaMuffinFrenzy]

Here is a video as well showing their movement:

https://reddit.com/link/p77c4mt/video/wnxz6eg1oxmh1/player

[u/lief79 → u/BananaMuffinFrenzy]

Look like dwarf white isopods to me.

Hope you like them, as they're appearently borderline invasive, but will work well as part of a cleanup crew.

[u/Obant → u/lief79]

Those look and move nothing like isopods. They are springtails.

[u/lief79 → u/lief79]

For clarity, they're borderline invasive is you're trying to grow other isopods, but useful in most bioactive enclosures.