Lawnmower Blenny Necropsy

[disc1]

So, my lawnmower blenny died. I really liked that fish. He was doing awesome until the day before yesterday. I noticed he wasn't very active. He looked a little thin and pale. He just looked sick. Yesterday morning he looked a little better, at least he was swimming around, and after work yesterday he looked almost as good as new. Suddenly I noticed a large black/purple spot (looked just like a fresh bruise on a human) in his mid section. Well, it took about ten minutes for him to die from there. Just all the sudden.

So I took him out and did a little necropsy to see what happened. I made a cut like I was going to fillet him, so I could see his insides. His belly was completely full of blood and it looked like his intestines had ruptured. I found several large grains of sand in there. I had noticed him picking algae off the sand, but had figured this to be natural behavior. I don't know if the sand was his problem or not, but something surely burst his guts open.

I don't guess I really had a question with this. Just wanted to share my story. I am intersted in any comments you have.

 

[Girly Gears]

Do you have a pistol shrimp in your tank? That sounds like the kind of damage they would cause. If you hear any loud clicking noises and have a lot of disappearances of live stock, you probably need to trap one!

 

[Sk8r]

Pistol shrimp or mantis. Google them. The blow causes that kind of injury, and they are a frequent hitchhiker.

 

[disc1]

This tank has been up for several months and the lawnmower and a firefish have been in there for over two months. I haven't seen or heard any evidence of a mantis, but that doesn't mean it's not in there. Do you guys have any good advise on luring them out into the open?

Since the fish looked sick the day before, I'm leaning towards something internal. I also haven't seen any issue with any other fish or snails or hermits. But sure can't rule it out. Guess we'll have to see how the firefish does over the next little bit.

 

[Sk8r]

A firefish, unfortunately, is very likely to be a mantis or pistol victim. Go to the mantis forum and ask how to detect and trap one: they are often salable: if you do catch one, take it to your lfs for credit.

 

[disc1]

Well, I know this sounds cold hearted, but there's no way I would ever catch the firefish out of the tank. So I will just let things alone and see if he disappears. I still kind of doubt the mantis idea though. I would think a mantis would have made a meal of some hermits by now. The tank has been stocked for a few months now. The hermits have been there since september. Is that not a safe assumption? Should I still be hunting a shrimp?

 

[TheH]

I think a mantis shrimp is unlikely. Especially if there was nothing noticeable on the outside of the fish. Additionally, the mantis would have probably returned to finish off and consume the injured fish.

This reminds me of a post in which a foxface rabbitfish was found to have large amounts of sand in it's belly upon dissection after an unexplained death.