Mystery Critters… Tell Me They’re Great

[PlasticOcean]

Found easily a hundred, probably more of these crawling around the tank today. Almost the size of sand grains so didn’t notice them before.

They’re able to scale any surface but fall off the glass quickly - so I don’t think snails. If you look closely, you’ll see what appear to be little black legs, similar to crab legs. It looks like a shell with legs to the naked eye.

But I understand hermit crab larvae don’t have shells. So what could these be?

Any thoughts?

 

[bluemon]

Can't see the video but probably copepods. Good guys

Edit: photo just loaded. Don't seem like coepods. Seems like small cowries in terms of shape. You said they have legs though? Probably some kind of isopod then?

If they are falling off the glass, I'd say that leans towards snails. I've seen more snails fail to climb up glass thn I've seen small crustaceans

 

[PlasticOcean]

Yea sorry, the videos won’t load.

They’re not like any copepod species I’ve seen. They appear to have a true shell of some kind and don’t appear motile or able to swim in any way. They crawl, side to side more than anything, although they can climb the rock or algae encrusted glass. They appear to have a speckled “shell.”

 

[bluemon]

Yea sorry, the videos won’t load.

They’re not like any copepod species I’ve seen. They appear to have a true shell of some kind and don’t appear motile or able to swim in any way. They crawl, side to side more than anything, although they can climb the rock or algae encrusted glass. They appear to have a speckled “shell.”

Yea, the photos didn't lead until after I made my comment. Edited it after looking at photos. Can you post a video on YouTube? It'd be hard to id without video

 

[JoJosReef]

Following.
@ISpeakForTheSeas @EeyoreIsMySpiritAnimal @vetteguy53081 any ideas?

 

[bluemon]

Maybe a marine ostracod?

Not sure what the scale of the picture is though.

 

[PlasticOcean]

For scale, those white specks beside the critters in question are grains of Caribsea Bimini Pink reef sand which have a grain size of: 0.5 - 5.0mm

 

[bluemon]

Can you manage to take a picture of their undersides?

Whether it's when they are on the glass, or if you want to suck some of them out onto a clear cup and take a Pic from underneath

 

[PlasticOcean]

I’m thinking marine ostracods for the win!

Had not heard of those but they fit the description perfectly. Bivalve like shell, walking appendages, around 1mm or so in size, and speckled shell.

You folks are amazing!

Let me know if you want me to put one under the microscope tmrw.

Cheers

 

[vetteguy53081]

Found easily a hundred, probably more of these crawling around the tank today. Almost the size of sand grains so didn’t notice them before.

They’re able to scale any surface but fall off the glass quickly - so I don’t think snails. If you look closely, you’ll see what appear to be little black legs, similar to crab legs. It looks like a shell with legs to the naked eye.

But I understand hermit crab larvae don’t have shells. So what could these be?

Any thoughts?

These are not ostracods which are tiny and referred to as glass shrimp but appear to be collanista snails which are the size of a pea or smaller and reef safe but do breed easily

 

[bluemon]

These are not ostracods which are tiny and referred to as glass shrimp but appear to be collanista snails which are the size of a pea or smaller and reef safe but do breed easily

It seems there are some species that are big enough to be the size of the smallest grains of sand that OP is referring to.

And OP also seems adamant that these little buggers are not snails and have legs

 

[ISpeakForTheSeas]

Let me know if you want me to put one under the microscope tmrw.

Cool find - I agree that these seem to be ostracods; neat find, and I personally would love to see some microscope pics of one of your specimens.