Ostracods in H. zosterae tank (1 Viewer)

[cacarnold3]

As many know, I have had an 8 gallon Hippocampus zosterae tank set up for a while. About a month ago, I noticed a lot of tiny white critters crawling all over the live rock. I immediately thought they were pods (especially since I had added pods to this tank several times). Well, they continue to multiply and are now at the point of even crawling on the seahorses themselves. The seahorses don't seem to be eating them. If they are, they are not keeping up with the rate that they are multiplying. I have been wondering why the seahorses were not keeping their population down so I bought a magnifying glass. With magnification, I could tell that they are not shaped like pods. They are not oblong and don't have any appendages on the back side of their bodies. These little guys are round like little balls with legs on the bottom. I then borrowed a mesoscope and (after finally getting it set up) have taken some photos to share. These appear to be Ostrocods of some sort and this is the first I have seen them.

If I can get a video of their movement, I will try to post it as well. These are really quick little guys. Occasionally they swim but mostly stay busy on the rocks. They also pile on top of one and other- not sure why they do this.

Here is the rock in the center of the tank. All of the white spots are these guys:


Another shot of the rock from a distance


Close-up of the pile of ostracods through the scope


Close up of the rock- notice the various sizes of the ostracods. Adults and juveniles both.

 

[BigRick]

https://www.google.com/search?q=ost...ssils.co.uk%2Fguides%2Fostracods.html;530;398


FLEAS

 

[Nemo_Nava]

I googled them since I don't know anything about them. Seem harmless everywhere I read, thoughts?

 

[Bakapuma]

I would freak out. That having been said one of two things will happen. They will run out of food and die off. Be prepared for water change. Or, the will cover everything in your tank until you intervene. I wager they will start to cannibilize each other then starve to death.

 

[cacarnold3]

https://www.google.com/search?q=ost...ssils.co.uk%2Fguides%2Fostracods.html;530;398


FLEAS

They certainly do look like fleas- but then again, pods aren't far off and we LOVE those. These guys actually are similar in appearance to a mollusk with the shells on both sides.

 

[cacarnold3]

I would freak out. That having been said one of two things will happen. They will run out of food and die off. Be prepared for water change. Or, the will cover everything in your tank until you intervene. I wager they will start to cannibilize each other then starve to death.

I was kinda freaking out when I saw them on the seahorses. I watched for a while and think they were just confusing the surface of the seahorse with a rock. They didn't appear to stop while on the zos. They were continually moving. That is not to say that they won't irritate the zos by doing so. I am going to post the same thread on seahorse.org and see if anyone will chime in.
I am also going to do a water change and remove some of them manually. I did so before but they just came back. Usually, I do water changes from the "sump" section of the tank (so as not to remove any baby zos).

 

[cacarnold3]

I googled them since I don't know anything about them. Seem harmless everywhere I read, thoughts?

There isn't a ton of information on them but, from what I read, most are harmless cleanup helpers. There are some places where I have read that there are a few types that are parasitic. The problem is how to determine which are which. Every indication leads me to believe that these are cleaning up the algae in the tank.

I also think that they might not be kept in check because of their shells. These seahorses are 1 3/4" max. Most are around an inch long and the babies are 1/4". Their snouts are probably not capable of eating the shell. That is just a guess. They do appear to try and perhaps they eat some of the juvenile ostracods.

 

[OceansX]

They must have an abundance of their food to maintain a large population,
so I am doubting they are parasitic or 100% carnivorous.

Maybe try placing some of these ostracods in another tank with larger mouthed fish?
Are you still running your Galveston blenny tank? That would be a lower risk test
than another seahorse tank.

I'll see if I can find someone who can identify the genus or species of Ostracod if
they were given a sample.

 

[cacarnold3]

It would be cool if they could be identified. I thought about borrowing a microscope to view them under as well. I might put some in another tank to see if they still populate- but I doubt they would. The blenny tank would be their only hope. They are actually a little pickier than other fish. They don't try to eat really small foods like roe or cyclopeze. Others have mandarins or wrasses in them so I am sure they'd be eaten.

 

[CCrescini]

I just showed the pics to one of our paleontologists. She said the general morphology sure looks like ostracods, but the pictures were pretty blurry. If you want to drop one in a film canister she would be happy to put it under the scope. She said it would just take a second of her time, and she would be happy to do it. She'd even give you a picture.

I'll be out of town next week, but if you're interested, I can get the sample from you next weekend.

Just let me know,
Chris

 

[cacarnold3]

Cool Chris. I'll get you some to take to her. Don't have a film canister... but I'll find something to put them in.

 

[cacarnold3]

It has been a while since the last post. Chris was kind enough to take some of the critters in question to his coworker for determination of what they are. They are in fact ostracods -probably Aurila. They couldn't get a photo at that time (because the camera was not hooked up the microscope they used) but hopefully I'll get a photo sometime and will add it to this thread.
These are still continuing to multiply in my tank (even with manual removal periodically).