ID some microscope images of little black bugs

[reefiness]

Hey guys, so since taking my fish out of my DT and putting them into the HT, ive begun noticing some more detail in my tank, or it could be that theres less predation going on.

anyway, the sides of my tank are totally covered in copepods and clusters of snail eggs. the other day im looking at the sand bed for the tubes from the nassarius snails which always stick out, and i notice black specs all over the sand. have no idea what it is, so i decided to take out the good old microscope. I was hoping it was more copepods, but it doesnt seem like it. I tried taking some pics through the lens with my phone camera, but im not too sure they're good enough to help ID with... but here they are

 

[reefiness]

so the total right is a baby amphipod it seems like. second from right is a copepod, and the other 3 things are the little black things in question. they almost look like little clams with some green/yellow and black matter inside them.
they also each have about 3-5 little filament hairs coming off of them.

 

[reefiness]

ok, so the first picture i took was looking at a specimen i preserved in grain alcohol.

currently looking at a live one, those "hairs" are legs

 

[reefiness]

i took a video if someone can tell me how to upload it

 

[reefiness]

heres a close up

 

[reefiness]

https://drive.google.com/file/d/0B6QtmVQphwClb0lvLThFbWxLVFk/view?usp=sharing

This link should get you access to the video... i think

 

[reefiness]

anyone have any idea what these are? I've never seen them before in such quantities which is worrying me. they are probably at a density of about 20-30/sq.in. on the substrate.

 

[salpet]

they look like mussel larvae

 

[reefiness]

with legs? did you look at the video i linked to?

 

[sgdcover]

How tiny are they? As small as sand grains? Or can you measure in mm? Are the dark areas a shell?

 

[reefiness]

they are about the size of a small sand grain. I have a crushed coral base in my tank now and i see them crawling on the shells. I cant measure them in mm... its less than 1.

to me it looks like the dark areas are under the shell... it seems to me like its some sort of mite with a shell over his body, but i dont know what that would be.

 

[sgdcover]

Yeah that's tiny! I found this but I didn't see anything that matched except for maybe some type of arthropod.

Found this: http://reefkeeping.com/issues/2008-12/feature/index.php and this: http://www.wetwebmedia.com/crustidfaqs.htm

 

[reefiness]

eh... i dont think it looks like any of them

 

[reefiness]

closest thing ive found so far is a barnacle cyprid, but i still dont think thats it

 

[reefiness]

Well I got the answer... I emailed a marine ecologist from my undergrad and she said its an ostracod aka clam shrimp. I have no idea how they got into my tank, or how long they've been there, but i just noticed them, and from what i can read, they are pretty indifferent.

 

[sgdcover]

An ostracod... never heard anyone refer that. Nice addition to the tank's biodeversity

 

[reefiness]

I had never heard of it either, nor had i ever seen anything like this. thats why i went to an expert.

 

[thirty6]

^^ nice resource you found. Good thinking

 

[mysterasuarez]

Wow. It's amazing the biodiversity that's found in this hobby.