How to Find and Kill Evil Hitchhikers

[SeaHorse_Fanatic]

Large starfish can be fish predators. What type was it? Google it to see if the one you bought is possibly the culprit.

[Canadbis]

Did something maybe come in on the GSP or other frags you have just introduced?
Maybe you added to much at once?

[Pier Pressure]

Okay just did further research on the brittle star as well as further research on the sea apples.

The only brittle star I could find that is "rumoured" to have eaten fish is a green one, and this thing is definitely purple. Plus fish bodies were not eaten or ravaged, so if the brittle star was preying on the fish I think their little bodies should have shown more evidence of same. The only thing we noticed on the dead fish was that their gills were a bit puffy.

The sea apples are one of the first thing that I put into the aquarium and they can be seen feeding daily - that is, one feeder tentacle after another is placed in their mouths, they are breathing out of their butts fine (cool feature, eh?) and they do not appear stressed at all. Their positioning within the tank did not change at all on the night of death in question.

I am going to try that bottle thingy tonight. If I come up with anything weird, or anything changes, I shall of course update this thread.

Canabis, that is exactly what I am thinking.

Karen

[dunl]

If the only sign of damage was puffy gills, I say it's not an animal. I know of no animal that kills others leaving puffy gills as the only evidence.

[mark]

Your test kits current, checking for the usual (NH3, Nitrates), salinity, no stray currents, no temp swings?

Checking the tank in the middle of the night with a red lensed light?

[Pier Pressure]

I am using two different test kits for the ammonia/nitrite thing, one is just about brand new, and they are reading nothing. The highest reading of those I got was after I found the dead fish and shrimp and then nitrite and nitrate was 0.3 so just above trace. Since then nothing. Salinity, PH, everything exact same that night as it was the next day and remaining steady.

I have to pick up a red lensed light this weekend and check out some night viewing. Where would a person get one of those?

After staring at the tank tonight until I am just about blind, I know for sure I have at least one of those gross bristle worm things. Red, about two inches long. Kinda looks like a centipede.

I am going to try the old bottle capture trick tonight and see what I come up with.

dunl, what DOES cause puffy gills? Any ideas?

This is a great site. Lots of support and lots of interest. Thank you!

[Canadbis]

It may take a few nights/weeks to catch something.
I still haven't caught these two crabs that I have found molts of.
I have given up.

[Ruth]

With that many fish etc. dieing in that short of period of time I highly doubt that it is a predator hitchiker. Particularly since you say they had no other marks on them other than puffy gills.
A couple of possibilities come to my pea brain. Did you by any chance have a power outage or loose circulation for a period of time? Do you run a skimmer and perhaps shut it off overnight. The reason I ask is because when I had a breaker trip and lost circulation overnight in one of my tanks I lost 4 fish (out of 7) and it was from lack of oxygen in the water. For the most part the fish I lost were large however on very large one (my Naso Tang)survived. Some fish are way more suseptable to an oxygen drop.
The next thing to explore is water quality. I know you tested yours but could you please let us know what brand of test kit you are using and what your #'s for Ammonia, Nitrate, Nitrite, PH, calcium, alk/dkh, and magnesium are. Sometimes it can be an inbalance in chemestry however I do not suspect this in your case.
Of course the last thing is some kind of disease that only effected some of your livestock and that list is way too long and complicated to try and guess at.

[Johnny Reefer]

If the gills, and only the gills, were affected.....and since fish breathe through the gills by passing water over the gills.....it appears to me to be a water quality issue of one sort or another, be it a toxin or whatever. My guess is a toxin from the Sea Apple(s). To borrow a line from "Reef Invertebrates" by Calfo & Fenner: "Sea Apples (Cucumarids) are definitely more difficult to keep in captivity. They also include some of the few species in this class (Holothuroids) actually toxic enough under duress in practical applications to kill fishes (the toxin is harmful to few if any invertebrates). .......... It is very important to note that if the Cucumarid is ultimately stimulated to exude toxin, all fishes in the system are at risk of sudden death."
Sea apples are a big risk. Especially in a small system such as yours. I won't even keep one in my 180.

HTH and cheers,

[ludwig9393]

Hi,
can someone please identify what kind of crab is this? I just put the rocks in my tank and this hitchhiker come out. Is my future livestocks safe with this on the same tank?

sorry but thats the best shot i can get.


many thanks!