ID tiny clear bugs with black or brown innards

[dhof]

Reefing for about 1 year now. Have a pretty stable system with refugium and it has always had AMPLE copepods and Amphipods everywhere.

Tonight, my wife noticed these tiny black bugs over an old snail shell. Smaller than an Amphipod but larger than a copepod. Small enough you really can't see it without a 5x magnifying glass. They are all over the shells, and also scattered throughout the substrate.

I've recently added Berghia Nudibranchs to deal with aiptasia. I did not dip or QT the berghia. I also added a Royal Urchin, which i dipped in coral dip for 20 minutes or so prior to rinsing and putting it in.

I did try to search google and this forum, but really can't find anything similar. Picture provided is what they look like in a cheap microscope. While the clear part makes me think of an egg, they are wiggling around in the microscope slide, and not stationary. Inside the tank, they are definitely crawling briskly like an Amphipod speed over the shells. The speed that they move makes me fairly certain they are not a flatworm or anything like that. They also seem to zip around things in the fashion of an Amphipod (it's not like a random pattern of a flagella or anything like that). If I had to guess I'd say they have legs or dozens of little things moving them around.

Anyway, any ideas are appreciated!

Here's a video of them wiggling on the microscope slide. Note that they are truly crawling around things in the tank. I think they are wiggling because they are pinned against the glass and the water surface on the slide


Thank you!

 

[Ranjib]

#reefsquad

 

[saltyhog]

Man, I don't know but those are great pictures. Hopefully someone will have come across these sometime!

 

[DSC reef]

Baby stomatella? Very interesting for sure.

 

[reef lover]

A lil bump for more veiws..

 

[Lovemyreef2015]

I believe it's a type of copepod in the order Harpacticoida . There are over 400 genera with 3,000 species. I could be wrong but that's what it looks like to me.

 

[dhof]

Really appreciate the input so far. I looked up the stomatella and Harpacicoida a bit tonight. The stomatella seems unlikely because of the way these things move around and just how minuscule size they are. For their super tiny size they really do zip around a bit, it does not appear that they are 'slowly scooting' like I might expect from some sort of snail or worm. Its definitely movement more like a copepod zipping around looking for algae than the crawl of a snail or worm.

I would be pleased to find out these are some sort of Harpacicoida copepod. Nothing similar showed up on a google of Harpacticoida, but with that many genera and species, I'll go with that as the winning theory so far. Only thing that doesn't seem to match up is that they do not appear to have any sort of antenna or visible arms/legs protruding from them. Nearly all the pictures of various copepods seem to have 'alien antenna'. Now, I'm more of a physics guy than a biology guy, so maybe i'm assuming too much to think that all copepods would have some sort of antenna...

I tried to get some video and photos in the tank, but it's nearly impossible to maintain a focus on the iphone for things this small. In watching them move, they definitely move with the clear part of the egg shape at the front of where they are heading. The splotchy colored portion is always at the hind portion as they move about.

I noticed that a bunch of them were still stuck on a piece of paper at my desk near my microscope (24 hrs later). Certainly it was all dried up since I could see the block-grains of salt on the paper that had formed. The critters looked identical to the pictures I took of them wet (they didn't seem to degrade at all or burst from the drying process). I also see copepods and amphipods all dried up on the paper, and their arms/legs and antenna are clearly visible in the dried up specimens. So whatever makes up the exterior clear shell of these critters must be pretty solid and not just gel or something like that. Then, I used the tip of a scalpel to try to smash them. Mighty hard to do with my ape-like human hands, but I got the scalpel tip right over them and tried to smash them. They just slid over to the side of the scalpel and stuck to it (rather than getting smashed to smithereens by it).

Anyway, that's an update. Not sure I'm worried too much about these guys, but they are definitely interesting and my curiosity makes me want a solid ID.

 

[jack_aubry]

possibly an ostracod

 

[JasonK84]

I'm gonna have to watch how this thread goes. It's got me curious.

 

[4FordFamily]

Wow I’m stumped and this isn’t my forte but I am paying attention!

 

[jacksonjack]

Taragrade