Sugar Magnolia said:
Incysor, I have an unidentifed crab in my tank (the 30), and have never seen it. I know it's there because I found a portion of it's molt - just an arm and claw, about a month ago. The claws look exactly like that guy there. Cramy colored shell with black tips on the claws. From what I understand the black tips indicate a "bad" crab.
Thankfully I haven't noticed any fish deaths. I did have a predatory whelk in the tnak that was taking out my nass snails, but I wonder if this elusive crab is also guilty.
Maybe I'll make a 20 oz soda bottle trap and see what I can catch.
I had one hitch hike in on a great mushroom rock when I had the 55 set up. It stayed in one hole, and didn't seem interested in the rest of the tank, and I couldn't see it too well, so I wasn't concerned. Then one day I walked by the tank and my cleaner shrimp was stuck butt-first in the hole. The crab had somehow got ahold of it and killed it. I took the rock out, and angled it around in a bucket with a light until I could get a little better look at him. Then I went in search of it. It seems there are several varieties of this black-tipped claw kinda crab, and they're ALL bad for your tank. I couldn't get it out of the hole so I ended up squirting isopropyl, (rubbing), alcohol in the hole. That will kill them instantly. It did the trick. I was able to fish the carcass out with a pair of forceps.
This one is more of a problem because it's bigger, and it's hole appears to be in one of the large rocks at the bottom of the aquarium. I'd have to essentially take all the rock out of the tank, and it's possible that I wouldn't find him. I'm gonna start trying to trap him out with a glass jar and some table shrimp tonight.
I also think I may have a mantis shrimp in my 75. I haven't seen it, or really any piles of empty crab/snail shells, but I occasionally hear popping coming from the tank at night, and 3 fish have gone missing recently. Both my catalina gobies, and my yellow headed jawfish.
Grrr.
Phishy, you wouldn't be coming home for the holidays would you? I think your isopod-hunting skills might come in handy. :?
B