please tell me if this is a Cirolanid isopod

[markush]

I cannot use the search funtion here and from what i have found on the net i believe this is a Cirolanid isopod. Can some one please help with identification? And if it is, is it truely as bad as they say it is?

[Blown 346]

Look slike it to me, Yes they are bad. They will feed off of your fish until it dies, and then move on to the next.

[ATJ]

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

[Henry Bowman]

Yup it is ! and yup, they are bad news. Just read an old post by Dr Ron Shimek that identifies them and describes how to trap them as well as what doesnt work for getting rid of them....

Edit: Just checked, the article listed above is the one I mentioned.

[scubajsm]

EEK!! Yes for sure. Seen very large one's while diving in Grand Cayman. Hope you don't have anymore....

[markush]

Originally posted by scubajsm
EEK!! Yes for sure. Seen very large one's while diving in Grand Cayman. Hope you don't have anymore....

Plenty more I’m sure...this is about the 6th I’ve seen and only the 3rd I’ve been able to net. If I’ve seen that many 2-3 mm bugs I’ll bet anything there are lots I haven't seen.

I'm in a bit of pickle guys, I set this tank up because my old tank has sprung its second small leak. I have fish that have to go into this new tank ASAP. This new tank was set up with sand and rock as part of a package of which I have gotten only half of the rock. I am waiting for the cycle to complete before accepting the second half. The vender assures me these are not the bad bugs. Is he telling me this so I don't raise a stink and accept the second half of rock or is he correct in that these may not be the type that will eat my fish?

[Blown 346]

Those are the type that will host from your fish, they will slowly kill the fish they are on, and once that fish dies they will move to the next fish.

[markush]

One more question before I make my decision. Will these things starve without fish present? I've read that some varieties will scavenge uneaten foods and invert molts.

At present I have about a dozen or so Porcelain crabs and an unknown amount of Gorilla and Stone crabs that came as hitchhikers. If I try to go with the starvation method I will accept the second half of the rock which would have corals that I would have to feed and a clean up crew that would contribute to the molts.

[ATJ]

From Shimek's article:

These final two groups of isopods, the Cirolanids and Aegids are so similar in appearance that it typically takes an expert to distinguish them on the basis of a few minor structural details. Not being an isopod expert, I will treat them together. These are flattened, streamlined crustaceans with a smoothly rounded or tapered and pointed front end. Their very large eyes are found laterally on the head and may occupy as much as half of the space of the head. They are strong, very fast swimmers and have no obvious trailing appendages. The thoracic legs are robust and end in very sharp gripping claws. Aegids differ from Cirolanids in several small details; probably the most evident is that both pairs of antennae are often evident and visible, IF you can find one that holds still long enough to observe that trait.
 
The taxonomic Family Cirolanidae is huge, consisting of several dozen genera, and probably many hundreds of species. Many of them are generally benign animals that are obligatory carrion-feeding scavengers. Some of these scavengers have been found in aquaria, and appear to be very well adapted to being part of "the clean-up crew." Many of the rest appear to be capable of scavenging when such food is available, but they will occasionally swim up into the water and attack fish, fastening on and sucking their blood. Finally, several species appear to be more-or-less obligate blood-sucking parasites of fishes, although some may be able to live for extended periods by scavenging some dead food. Within the last couple of years, some of these latter species have been seen in aquaria with alarming frequency. In many cases, these infestations appear to be the result of a pregnant female that enters the aquarium and then drops her brood of 10 to 30 young, all of which are immediately hungry for a nice meal of fish blood. A hobbyist will see the alarming sight of one or more fish with from one to twenty blood-sucking parasites on it. Often the isopods are nocturnal, and unless the aquarist is alert, they may not notice the parasites, as the bugs drop off the fish shortly after the lights go on and find shelter in the rocks. Prolonged exposure to such densities of blood suckers WILL kill fish.

The problem you have here is determining what species you have. Do you have the relatively benign "obligatory carrion-feeding scavengers"? Do you have scavengers that will occasionally latch on to the fish and get a meal? Do you have the species that are "more-or-less obligate blood-sucking parasites of fishes"?

The only way I think you will be able to determine is to put a sacrificial fish in the tank, as suggested below. If the isopods leave the fish alone, it is more likely they are obligate scavengers and would make a good addition to the tank. If the isopods attack the fish then you will need to remove them, and the sacrificial fish is the way to do it. As suggested below, choose something that is easy to catch.

The only way to rid an aquarium of these animals is to catch them all, which although tedious, is possible. Generally, this involves using a sacrificial fish, usually something easy to catch and moderately large. A yellow tang is a good choice for this because the fish's color pattern allows easy determination of the presence of the parasite. The other fish in the tank are collected and removed to a quarantine tank, and the "bait" fish is introduced. This fish is checked periodically and, if the parasites are seen on it, it is netted and removed to a flat surface where it may be immobilized with a wet paper towel. The parasite is removed with a pair of tweezers or forceps. The fish is then returned to the tank, and the procedure repeated. Often the parasites are nocturnal; consequently, the fish will have to be examined before the lights come on. The aquarium is probably free of the parasites if none are seen on the fish for a month or so after the last one has been collected.

As to the remaining live rock, in my opinion, it isn't going to make a whole lot of difference if you take it as you already have the isopods in the tank. The sooner you take it, the better, as you can deal with the isopods in one go, rather than cleaning up the tank and risk reintroducing them later.

[DaveJ]

Gorilla Crabs and Cirolanids......

Your LR supplier wouldn't be Tampa Bay Saltwater would it?

Regardless of who it is... those are nasty critters and any supplier who tells you otherwise doesn't deserve your business.

Give us an update when you can.

[markush]

I started a thread here http://archive.reefcentral.com/forum...readid=1115023 just before this one. I wish I had known there was a good chance my rock and sand would be infested with Cirolanids before i purchased. I watched the TBS vendor sight for about two months before i bought with no mention of these things. At least now there is an open dialog about them there, hopefully it will save a few people some grief. Please don't go in there with guns blazing, I feel that thread should stay open as long as possible

[DaveJ]

Originally posted by markush
I started a thread here http://archive.reefcentral.com/forum...readid=1115023 just before this one. I wish I had known there was a good chance my rock and sand would be infested with Cirolanids before i purchased. I watched the TBS vendor sight for about two months before i bought with no mention of these things. At least now there is an open dialog about them there, hopefully it will save a few people some grief. Please don't go in there with guns blazing, I feel that thread should stay open as long as possible

Dude they have been the source of more of these things than anyone for several years now.... the fact they are telling you they are not bad to have is just plain insane on their part.

Refused the shipment I hope???

[markush]

Quotes of replies to 2 different emails i sent expressing my concern that i thought i had Cirolanids and i had fish that had to go in ASAP. The second one is after i showed him the same pics i have posted here.

"if they do not look like the picture..not to worry....no big
deal....even if
they are the bad guys, they will not live.."


"they starve...plus it is not the bad one!"

The first part was already in place before i noticed these so i went ahead and had the second part shipped.