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Rightio.

Thoughts? Suggestions?

I am thinking that those frilly bits are supposed to be well and truly under the shell, and not flapping about looking yummy. How do you think he could have managed this??

I was worried about his moult as he had a claw injury that looked like it might stick, and his shell was very variable in density, so I'm chuffed that he got out OK, but this result was very unexpected.

I'm concerned that it might not rectify at the next moult, I can't see how it would get back under there... though I can't see how it would have come out either. Do you think it will fix itself next moult?

For animals, the entire universe has been neatly divided into things to (a) mate with, (b) eat, (c) run away from, and (d) rocks. - Terry Pratchett

You're right, Calla, in that those tasty-looking frilly bits (which are actually gills, part of biramous appendages in decapods) should not be exposed. Frankly, I have no idea how that happened.

What's your calcium level at? Low levels of calcium would make exoskeleton development more difficult.

As far as fixing itself on the next moult...no idea. Truthfully, I'm not sure there's much you can do to ensure that other than make sure your water is nice and hard and give him lots of good, protein-rich food. He'll need both to make his chitin shell nice and tough.

If he's in a tank with other inhabitants, make sure that you keep a close eye that he's not getting picked on. Gills are blood-rich and soft, so they'd be easy targets.

bugger. They looked very gill-like to me but I had my fingers crossed they'd turn out to be the cray equivalent of an appendix.

Calcuim levels were low (though I haven't got a kit for that), however I've been bumping it up and am continuing to do so. It wouldn't surprise me if that played a part, I'm fairly certain he wasn't fed from the time he was shipped to the wholesaler to the time I got him, so I was on the back foot and have been working him up, just not quickly enough it seems.
I was actually worried he wasn't softening enough in some places to kick it loose as he seemed rather solid in comparison to the other species, but I've never had this species moult or a cray at this size, so it was a bit hard to judge. He was definitely very soft around the edges of the carapace, they went a rather dark translucent green last night. Really, the thing that bothered me was that it was so uneven.

I'm really puzzled. I have the old shell, I can see the gill area there, are they meant to moult too? I can see what looks like casings for them. They've almost had to have been growing in between the two shells, but that doesn't seem right, though neither does having them kick out from under the new shell during a moult. If they don't moult too, will the increased water circulation cause them to increase in size now that they have the space to do so? If they become damaged, will they grow back between moults?

I'm watching the fish, so far they seem uninterested. He's way too tolerant of them and I have a feeling they'll need to come out at some point.

*sigh* he looks like a big blue hotrod with fake fur exhausts. Poor little man.

For animals, the entire universe has been neatly divided into things to (a) mate with, (b) eat, (c) run away from, and (d) rocks. - Terry Pratchett

Hi Callatya,

What a fascinating occurence. Is it both sides or just the one pictured?

Any chance you could post some specific water parameters and maybe some more pics... different angles, the moulted shell if that's possible?

G_T



Never be afraid to try something new. Remember that a lone amateur built the Ark. A large group of professionals built the Titanic.

I'll go and get some more pics. Water paramters will have to wait a day or so as I only have basic ammonia/nitrite/nitrate kits and I think there are other things that would be more interesting in this case.

It is just the one side (you can see the other side reflected a bit, thats nice and normal)

Once he hardens up a bit I'll try and get him into a position so I can get a picture of his underside.

For animals, the entire universe has been neatly divided into things to (a) mate with, (b) eat, (c) run away from, and (d) rocks. - Terry Pratchett

Close up and a few others







Attached Image:


For animals, the entire universe has been neatly divided into things to (a) mate with, (b) eat, (c) run away from, and (d) rocks. - Terry Pratchett

I learn more than I want to sometimes!

You poor thing Calla! But talk about a post that is different as well as interesting! You take the cake there!

Hope it all turns out ok! Or turns in ok?

It looks like the new shell just didn't develop over the gills while it was still under the old one. Kinda weird. I would bet that it won't fix itself, though. Once it is outside the exoskeleton, there's no way for it to go back in (short of trying to physically force it under the old shell, which is just a stupid idea) because you're never going to have a new shell growing on top of the old one. I don't think it would affect his health all that much. Just keep an eye on the fish with him.

Edit: Sigh. I need to read other people's posts better. You already covered a lot of what I asked, Calla.

I have the old shell, I can see the gill area there, are they meant to moult too? I can see what looks like casings for them.

I guess I don't quite understand what you're asking here. Are what meant to moult?

If they don't moult too, will the increased water circulation cause them to increase in size now that they have the space to do so? If they become damaged, will they grow back between moults?

I'm not sure if the gills would increase in size or not, but I would guess they wouldn't. Additionally, I suspect that the gills very well could grow back should they get damaged. Decapods are pretty good with regeneration.

Are the gills meant to moult? Looking at the shell structure, it seems that they are sandwiched in between the body and the carapace, so technically on the outside. There appears to be 'gill shells' for lack of a better term.



Bad news I'm afraid, I had my fingers and toes crossed that he'd bounce back a bit, but I think the whole ordeal was just too stressful for him. I have just found the poor bugger laying upside down.
I'm still trying to find a cause as this seems like something that should have a cause.

Poor little man

For animals, the entire universe has been neatly divided into things to (a) mate with, (b) eat, (c) run away from, and (d) rocks. - Terry Pratchett

AAAAHHHH! Sooooo sorry Calla!

He was such a beautiful specimen!

If I remember right, blue is not the usual color of these cray's? When nature start's doing things out of the norm it seems the result is a creature that is usually not quite up to par. Not knowing anything about cray's, this would still be my uneducated guess as to why he had this unusual thing happen to him. Nature just does freaky things sometimes, especially when you mess with it to much.

I appreciate you sharing him with us though. I will never forget the beautiful blue cray that Calla shared with us on FP! I'm so sorry for the unusual loss of your beloved pet. This is definitely a case for the science books.

Well, I apparently don't really know about health problems in crays.

Sorry for your loss, Calla.

Just found this after being alerted to it by Fish Patty.

If you're thinking that increased Calcium would help in future instances, then there's an interesting way in which you can boost Calcium supplies to crustaceans such as this.

Get some cuttlefish bone (as sold in pet shops for budgies to nibble at) and powder some of it into a hollow in a cube of freeze dried Tubifex. Then feed that to your crustacean. Cuttlefish bone has been used as a Calcium supplement for terrapins for some time, so I see no reason why it can't be used as a supplement for freshwater (or for that matter) marine crustaceans too.

The only problem with cuttlefish bone is that it is very bouyant. It's about the same density as balsa wood, and consequently is pretty near unsinkable in its raw form unless you attach it to a huge weight. However, the ease with which it can be powdered makes it usable in power filters (provided you can sandwich it between layers of filter wool) and at a push even in a box filter driven by an air pump. Cuttlefish bone is a mix of Calcium Carbonate, Calcium Phosphate and some useful trace elements that will probably prove beneficial to supply to any freshwater crustacean, whether as a filter medium supplement to boost dissolved Calcium levels or as a feed supplement if you can integrate it into the crustacean's food. Of course, before embarking upon this, I'd be careful about other occupants in the aquarium - if the crustacean is sharing its quarters with fishes that are intolerant of high Calcium levels, it might be worth rehousing the crustacean in a purpose constructed home of its own with a suitable supply of Calcium and mineralising its water.

For example, one fish species I would avoid putting in hard water even though it's a fairly hardy fish (travel shock issues notwithstanding) is the Rummy Nosed Tetra, as this is a species that becomes sterile if it is exposed to high dissolved Calcium levels. Likewise, I'd avoid numerous other Amazonian fishes as companions for a crustacean with a high Calcium demand.

If you're looking for a crustacean that has a lower Calcium demand, see if you can find one that's adapted to live in low mineral content waters such as the Amazon. Several Macrobrachium shrimps fit this bill (the juveniles are recorded as a natural food item for Discus, for example), or some of the softer water Asian species from the same Genus. However, some of these grow to quite a size - Macrobrachium rosenbergii grows big enough for the human dinner table!

Incidentally, even with decent Calcium supplementation and a well rounded diet, some crustaceans can fail to moult properly for other reasons - inheritance of a mutation, inability to find an appropriate hiding place away from disturbances (such as other members of the same species, or certain fishes) all of these can contribute to disaster for the occasional specimen.

Sorry you lost old Bluey Callatya, he was a nice one.


Panda Catfish fan and keeper/breeder since Christmas 2002