Parasites or Good Bugs?

[Beverly]

At the end of October, we lost all the new fish we put into our 72 gal bowfront :cry: The tank is now being fed, but is going to be fallow for 8 weeks. Loss of fish was possibly due to velvet, internal parasites, or external parasites. We really don't know which, and it could be all of the above.

Had the flashlights out tonight and happened to see a strange looking bug swimming about near the front glass. Looked like some kind of isopod, but I couldn't say for sure what the heck it was. Caught it with the turkey baster and put it in a cup. Kept looking in the tank and found two more on the sandbed, one of which had just emerged from the sand. All three are now in the cup pending ID.

Here are the best photos of these bugs. They are about 1/8th of an inch in length. All three are walking about on the bottom of the cup and sometimes swimming around.

http://www.lostmymarblz.com/72gal-bug-1.jpg

http://www.lostmymarblz.com/72gal-bug-2.jpg

http://www.lostmymarblz.com/72gal-bug-3.jpg


Any idea if they are parasitic or just natural fauna to be found in a healthy tank?

TIA.

[Quinn]

I wouldn't trust those things for a second.

http://atiniui.nhm.org/presentations/ICC5/wetzer/sld003.htm

They look rather like the one on the bottom left.

I would doubt, however, that these are responsible for the death of your angels.

[Jason McK]

Check this out I think this is your guy a Marine pill bug.

http://www.museum.vic.gov.au/crust/pillbugs.html

Sounds harmless

J

[Aquattro]

I beleive isopods are carnivorous, so maybe put a bit of fresh fish in the cup and see what the do. If they eat it, rock them!

[Bartman]

Looks like an urchin larvae. Does it move forward with the round end or the pointy bits?

[Beverly]

Quinn,

I don't trust these bugs either, mostly because they are capable of swimming. If they were bottom feeders, they would have no need to swim anywhere because there is an almost endless supply of ocean bottom to live in/on.

These look like adults to me. Maybe their larvae could have had a hand in doing in my angels.

J,

Kind of looks like a harmless pill bug, doesn't it? They even roll up like a pill bug would. But there are thousands of isopod species, some detritus/dead-live algae eaters, and then there's the parasitic ones. There are so few diagrams and photos of the various species that, dang, I need to err on the side of caution here and suspect these bugs to be baddies.

Brad,

Judging from the research generated by the above links, plus a serious bunch of Google searches, I've found out the not all isopods are parasitic. But can't tell about these guys and I don't want to take any chances. Don't think I'll rock 'em though. Just put 'em in the freezer :evil:

Did add some frozen food with fish as a major component. The bugs didn't go near it at first, but are now eating it with gusto. I think a live fish would be a better test, but I don't think I'm going to set up a tank for that test. Hmm. Maybe I might, though....

Bartman,

The move in a forward manner, leading with the eyes.

Whatever they are, we're going to watch that tank like hawks with our flashlights. If they are parasitic, there is a period of time when they can live without hosts. After that, they will naturally die. May have to extend the fallow period to make sure that if these bugs are parasitic that they and their larvae are all gone before the new fish arrive. That's going to be a tall order, especially not knowing their life cycle and what the larvae look like :confused:

Thanks, all, for your input :smile:

[Beverly]

Well, I decided to set up a 5 gal on Sunday, put LR and a bit of sandbed from tanks that were healthy, put the bugs in it and got a green chromis to test the bugs for parasitism. Have also been adding more of the bugs from the infected tank when we find them. So far, the chromis is doing well.

Have marked the calendar for a 5 week quarantine time to give the bugs a chance to infect the chromis if they are indeed parasites.

Will post a follow up later.

[Quinn]

I thought all marine isopods were omnivorous...

Bev you should get a wee little nano and set up an isopod species tank.

[Beverly]

Quinn,

From the research I did on isopods, beginning with the two links provided, I discovered that some are parasitic, some are detritous eaters while others are live and dead algae eaters. Isopods are a mixed bag of feeders, basically.

Was looking in the 72 gal where the bugs originated last night. Did not see any of the bugs in the photos, but did see hundreds of way smaller bugs on the uncleaned glass. Most were on the glass, but some swam into the water column. These bugs were smaller than a pin head, but I am thinking they might be offspring of the bugs we caught for the 5g test tank. Will be looking for them over the next few nights to see how they grow, and possibly add some of these bugs to the test tank.

[Quinn]

I think what you're looking at there would be copepods.

[Beverly]

I think what you're looking at there would be copepods.

No, not copepods, which were also on the glass, unless immature copepods have the ability to swim. These little bugs sort of vibrated against the glass, while some swam into the water column, then back to the glass. I was watching some of our big transluscent-white flatworms approach the tiny bugs, thinking the flatworm would eat them, but it passed them by everytime. Gonna keep watching those itty bitty bugs over the next few nights to see what they grow up to be.

You know, while watching the tank over the last few nights, I've seen red swimming worms about 1/8" long and white swimming worms about 1/4" long. PLUS!!!!! We have found another hairy crab in that tank :eek: It doesn't have red eyes though and has not taken the bait in the glass of food we have set up to feed the tank. This crab is either very smart not to get caught in the trap or is not a predator.

[One_Divided]

Whatever they are, you should have no trouble finding a preditor for them.. Get a nice wrasse or something and I'm sure they won't last long!

[Beverly]

One,

If they are harmless detrivours, I don't want to get rid of them. Besides, wrasses eat every dang thing that'll fit into their mouths :evil:

Had a look at the 72's glass last night and the teeny tiny bugs have really grown over the course of a day. They have noticeable forked tails similar to the bugs we initially pulled out and put into the 5g test tank, so I'm thinking these pinhead sized bugs are babies of the bugs in the photos.

Looked in the 5 gal last night and found one original bug about twice as big as when we put the three of them in there. It was climbing the glass along one corner. Another of the three originals was on the sandbed.

I'm beginning to think these guys are harmless. I could suck up a few of the babies from the 72 and put them into the 5 to see what happens. Will probably do that tomorrow night.

[Quinn]

If you can catch that crab and hold onto him until the 6th, I will take him. Maybe he could hang out in a yogurt container submerged in the tank with holes in it to allow passage of water.

I did some research on isopods and found that the young hatch from eggs carried by the females and resemble adults but with one less pair of legs (six versus seven). Copepods, on the other hand, hatch as nauplii and grow into copepodids then finally into copepods. Copepods, throughout their life cycle, are able to swim.

Having said that, there are also parasitic copepods out there. Therefore what you are going to do with the ones you've been catching is up to you.

http://www.at-sea.org/missions/maineevent/docs/copprimer.html

http://www.wellfleetbay.org/pond/isopod.html

[Beverly]

Quinn,

If the crab can be caught, I'll save it for you. Have had a really yummy trap set for it the last few nights, but no crab in the morning. Doubt I will catch it :confused:

[Lofus]

I've noticed a bunch of these in my tank as well. I'm working on a fish trap to get them.

You might want to read this :
http://www.reefs.org/library/article/clarke_shimek.html

If the one you caught has small eyes you should be ok. If the eyes are bigger you could be infor it.

I'd also check the wetwebmedia.

[Beverly]

Lofus,

Good link. Scared the cr*p outta me. Did a Google search for more info on cirolanids.

Here's a photo, looks similar to my bug:

http://www.reefs.org/hhfaq/pages/picture_pages/faq_cirolanid.html

Here's another cirolanid photo that doesn't look like my bug:

http://www.tamug.edu/cavebiology/fauna/isopods/B_mayana.html

Here's a page on isopods:

http://reefkeeping.com/issues/2002-05/rs/index.htm

Photo from the above page says the way to ID parasitic isopods is by comparing eye sizes. Large eyes = parasite:

http://reefkeeping.com/issues/2002-05/rs/images/image004.jpg

Mine doesn't look like this:

http://www.museum.vic.gov.au/crust/mov1559i.html

Compare mine with these. I can't see any antennae on mine, though, but could be there:

http://tolweb.org/tree/eukaryotes/animals/arthropoda/crustacea/isopoda/accessory/caguide/plates/caplate07.html

http://tolweb.org/tree/eukaryotes/animals/arthropoda/crustacea/isopoda/accessory/caguide/plates/caplate08.html

Here's a discussion on RC:

http://reefcentral.com/forums/showthread.php?threadid=196239

Anyway, the best thing to do if I have parasitic isopods is to keep the tank fallow for 3-4 months, according to Dr. Ron. I was shooting for 2 months, but if 3-4 months is what it takes, then 3-4 months it will be :frown:

Thanks for the link, even though I'm not happy now :cry:

[Beverly]

Well, the chromis has been in the 5g test tank with the three mystery bugs for over a week now. No sign of infestation. Still not convinced these bugs are non-parasitic, though.

Sent the photos to the folks at wetwebmedia for ID. They couldn't tell me if they were parasites, either. However, they did mention a prolonged fallow period of 4-6 months in the event they, or their young offspring, turn out to be parasites. During this fallow period, the tank should not be fed any meaty foods. Dang, and I have been feeding mysis and other frozen meaty foods for the past 3 weeks :frown:

Would like opinions of what I could feed the tank instead. Some of my suggestions are nori, dulce, or plain old lettuce that has been previously soaked in SW to remove any pesticides. I also have Selco and Selcon that I am no longer using which I could feed the tank with. I'm sort of thinking the HUFAs in the Selco/Selcon would be enough "meat" for the parasites to live off, but am not sure.

Any and all suggestions would be greatly appreciated. TIA :smile:

[Beverly]

Just got a reply at RC from Dr. Shimek. He IDs these bugs as sphaeromatids, and they are scavengers :biggrin:

It's almost five weeks since the last fish died from velvet. I think I'm going to begin restocking soon, but with only one angel this time, though :frown:

[Lofus]

Good news Beverly!