what can you keep with a blue lobster?

Personally I'd say any fish that is quick enough to swim away from it, or is not a bottom dweller. I'd recommend something a little more aggressive if you do get a bottom dweller, or mid to bottom dweller. In a 20g you should be able to get away with a couple of dwarf Gourami's, a school of bigger tetras, rainbowfish, or maybe even a betta since they're not bottom dwellers despite the fact that they're not fast (those fins might be tempting to the crayfish, although I've never seen mine nip any fins). To be honest with you it might be alright in your 55g with the goldfish and danios since they do well in cold water as well (as long as the goldfish don't sleep on the bottom). Choice is up to you, I don't think they're as aggressive as they're made out to be, but better safe than sorry.
 
My goldfish dont see too well and are always at the bottom sucking gravel, so Id rather not risk them. I do like gouramis I think thats a great idea.
 
small danios like zebra and pearls should be ok. a large snail might be as well. definitely no bettas they are easy targets
 
crays love snalls to eat big or small, well in my experience anyway. the only fish i have kept with my crays peacefully is guppies stay in the same caves, and i also have atleast 30 fry which the crays dont even bother with.
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Yeah snails probably wouldn't work, same with shrimp. I think you're right syddakydbettas might be too easy a target. What kind of cray do you have bullit?
 
i was told it was a blue cray when i bought it. only had a slight blemish of blue tho. but i have been told in here that its a yabbie..here is a few old photos. the colour is getting more noticeable now and brighter.

Photo-0011.jpg jhbjh.jpg
 
Nice looking crayfish. I think I will just use the 20g for a cray and to grow out endlers. If I lose a couple it wont be the end of the world since the oscar was going to eat them hehe.
 
Aah, now don't get me wrong, not (or at least not trying) to hijack this thread, but... I read about the snails getting eaten; Will this happen with nickle-quarter size snails and a dwarf (1.5-2") crayfish? Thanks...
 
I love your yabbie Bullit, looks like the ones from New Guinea with the red and blue (mostly blue though). They get big I heard, maybe 30cm or so. Should be quite a sight when he gets to that size.

Gordo, as long as they're going to be food anyway then why not. Just don't be surprised if you wake up one morning and find they're all gone, lol.

DP I think that since crayfish are such huge scavengers they'll eat anything they can get their hands on, including other crayfish the same size. The snails just won't be able to "run away" quickly enough from him and he surely won't have too much of a problem cracking their shells open or just digging them out of their shell for a nice snack. The snails might be able to make it as long as they stay away from the bottom of the tank, maybe, but crayfish are also amazing climbers too (mine's gotten to the top of my tank before, and I've heard of them getting out of the tank too) so I wouldn't put it past them to catch one hanging out in a plant or on top of a rock or even on the glass.
 
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