New crayfish, is this Marmokreb?

[Dark Jester]

Yep, they curl their tails and will spend all their time hiding for a few weeks when reproducing. They won't eat much (if at all) while they are brooding. If you have a substrate they can move around, and a cave to hide in, they'll likely block off the entrance to the cave and stay hidden the whole time.

Hatch times and growth rates depend greatly on water temperature. I took some siblings from one brood and stuck a few in a tank at room temp ~65 degrees and some in a heated tank at 78 degrees, and when the ones at 65 were about 1/2" at 3 weeks, the ones at 78 were just over an inch. Same feeding schedule and foods. Pretty big gap there. Gestation time can be anywhere from 20-40+ days depending on temp. Warmer is faster. Max size is around 3" for the main body + tail. Claws will extend beyond that. They'll reach max in around 3-4 months at ~75 degrees.

Good luck with them.

 

[akaEric]

How do u indentify if a cray is a marble cray

 

[Dark Jester]

How do u indentify if a cray is a marble cray

It's just a distinctive look. They are usually a brown/tan color (though they can go blue or red/orange), and their shells have a 'marbled' look to them, with lighter spots splashed around. Usually have dark lines running down the tails. Since they're genetic clones, they all look alike. External environmental factors can alter their coloration though.

Until another thread here a few days ago, I wasn't aware of any others that looked like Marmorkrebs, but it appears Procambarus Fallax could be mistaken for one. IMO, that would make P. Fallax a likely suspect for being one of the original Marbled Cray's parents.

I'm not 100% sure on the one in this thread being a Marbled Cray. Might just be the camera flash, but this one looks a lot lighter than the variations I have seen so far in mine, and the pattern on the carapace looks a bit different. I haven't seen any with the white coloration in the tails like this one. I can't say it's not Marbled either though. If it shows up with baby crays with no other adult present, I guess that's the proof either way.

 

[Cohazard]

I'm guessing it's not now because it ate two of my smaller marbled crays, and I read that they don't cannibalize.

It's just a distinctive look. They are usually a brown/tan color (though they can go blue or red/orange), and their shells have a 'marbled' look to them, with lighter spots splashed around. Usually have dark lines running down the tails. Since they're genetic clones, they all look alike. External environmental factors can alter their coloration though.

Until another thread here a few days ago, I wasn't aware of any others that looked like Marmorkrebs, but it appears Procambarus Fallax could be mistaken for one. IMO, that would make P. Fallax a likely suspect for being one of the original Marbled Cray's parents.

I'm not 100% sure on the one in this thread being a Marbled Cray. Might just be the camera flash, but this one looks a lot lighter than the variations I have seen so far in mine, and the pattern on the carapace looks a bit different. I haven't seen any with the white coloration in the tails like this one. I can't say it's not Marbled either though. If it shows up with baby crays with no other adult present, I guess that's the proof either way.

 

[Dark Jester]

Sorry to hear that. That would probably confirm it isn't Marbled, but not necessarily. Marbled Crays don't usually cannibalize, but they are capable of it. Of my original 8, 1 was eaten, but it was the smallest of the group and I couldn't say for sure whether it was alive or not when it happened. May have been a bad moult or something else that killed it. They also say that Marbled Crays don't attack fish, but I have seen that happen. They are a very non-agressive species for the most part, but at their core they are still crayfish, opportunistic feeders.

At the moment I have 7 adults and probably more than 90 juveniles running around in a 55g and I haven't witnessed any cannibalization yet. Doesn't mean it isn't happening, I just haven't seen it. There are small fights that break out sometimes between the adults, but one always backs down and moves away. They don't really seek each other out or defend territory, it's just chance head on collisions while they're running around. If one is berried and defending a hole, nobody ever messes with her.

Dunno. I'd say keep it in it's own tank for a month or two and see if it berries. It's possible you have an unusually agressive one that is lighter colored. From the pics it looks to be about full grown (for a Marbled Cray), so if it doesn't berry within a couple months then it's likely not Marbled.