Callatya Posted October 16, 2007 Report Share Posted October 16, 2007 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? I'm not even sure I could do anything about it short of chopping them off, and that doesn't seem wise as they look very gilly and necessary. Link to comment Share on other sites More sharing options...
Figure_8 Posted October 16, 2007 Report Share Posted October 16, 2007 Oh dear that does look like a big oops doesn't it? having no idea what on earth you could possibly do I'd be inclined to leave it and hope it sorts itself out in the next moult Link to comment Share on other sites More sharing options...
splendidbetta Posted October 16, 2007 Report Share Posted October 16, 2007 Can you get a closer photo of the filamentous extrusions? Do they appear to act as gills? Do they look regular and uniform? I see that they're only on one side. Link to comment Share on other sites More sharing options...
Callatya Posted October 16, 2007 Author Report Share Posted October 16, 2007 I'm pretty sure they are gills. According to the shell casing, he has them on both sides and they seem to moult just like the rest of him (which is odd, how could something in a shell be used to breathe?) They are graduated in size, but yes, very regular and uniform. Link to comment Share on other sites More sharing options...
splendidbetta Posted October 16, 2007 Report Share Posted October 16, 2007 How strange. Can you see where the gills would be on the analogous segment of the molted exoskeleton? Are there any ridges or grooves etc on the inside of the shell that look like they may have covered the gills? Do the 'gills' beat? No idea if they are supposed to; water is circulated over them by other appendages I think. Presumably they would still work, I think they are exposed to the water inside the carapace. Hopefully it's just a developmental mishap and he'll be normal in a couple molts. I found these dissection photos. They show the "gills", which resemble your Marron's extrusions: http://www.biology.ualberta.ca/courses.hp/...diss-dorsal.GIF http://www.biology.ualberta.ca/courses.hp/...iss-lateral.GIF Also this description and associated diagrams: http://www.science.mcmaster.ca/Biology/Har...HTM#Respiratory http://www.science.mcmaster.ca/Biology/Har...YFISH/FIG1B.JPG http://www.science.mcmaster.ca/Biology/Har...FISH/XFIG1A.JPG __________ Well thanks Abbey, it was quite interesting to learn a bit about these aquatic invertebrates ^_^ Link to comment Share on other sites More sharing options...
Callatya Posted October 16, 2007 Author Report Share Posted October 16, 2007 The shell has come away in 3 separate segments; tail, carapace, and everything else (legs/eyes/guts/etc). I can see what looks like fine gill 'covers' on the everything else piece, somewhat like tiny little socks, so I think they just slot in there under the carapace. Given that though, I'm not sure how they'v slipped out, and even less sure that there would be opportunity for them to slip back in at a later point. They aren't currently beating, but given the water circulation on the outside of the carapace would be greater than that on the inside, it probably won't hinder their effectiveness. More pictures coming, the poor chap is exhausted and has slumped down on his belly to rest in the perfect spot for close-ups. ^_^ Link to comment Share on other sites More sharing options...
Bettarazzi Posted October 16, 2007 Report Share Posted October 16, 2007 Do you think they should have been moulted but are still stuck to him? Are those just the old gills and there are perfectly functioning gills on the inside? Link to comment Share on other sites More sharing options...
Chuckie Posted October 16, 2007 Report Share Posted October 16, 2007 Glad his injury didn't wreck the moult. I know you were worried about that. Not sure what to make of the gilly things and I haven't time to read the links Stefan posted (they look interesting) but if they were inside the shell, how would water circulate around them so as to act as gills? Link to comment Share on other sites More sharing options...
splendidbetta Posted October 16, 2007 Report Share Posted October 16, 2007 From what I could see, the shell is not water-tight around the leg area, so water can slip in under the shell where the legs join to the body. Link to comment Share on other sites More sharing options...
Callatya Posted October 17, 2007 Author Report Share Posted October 17, 2007 OK, that is the old exoskeleton, and really, it looks normal. Both sides look the same. The fluffy bits down at the base seem to be the gill shells (I maintain that it is bizarre to have shells on gills) and the two triangluar-ish poking up bits hug close to his body and keep his innards in. They have a clear flap coming off the top of them that appears to form a sort of pocket around the gills, so they are under the carapace, but not in with the rest of the guts. I'm not sure *where* the water comes through to circulate though, perhaps through the bottom and then out the back? A lady on the cray forum has said that this isn't uncommon (!) and tha6t some survive and some don't. I'm a little worried about him as he hasn't started eating his old shell yet, but since it took him over a week to prepare, I'll set aside over a week to recover. He looks so stuffed, he is slothed over on his belly near the filter intake with his little betta 'friend' (something weird going on there, but it is interesting) Link to comment Share on other sites More sharing options...
splendidbetta Posted October 17, 2007 Report Share Posted October 17, 2007 Abbey, are the 'gills' growing out like grass through splits in the side of the carapace, or are they poking out from underneath the carapace like sprigs of elodea, curving upwards to lie over the shell? If so, they probably slipped out during the molt process. Otherwise, I can't see how the shell could have splits to let them through. Link to comment Share on other sites More sharing options...
Callatya Posted October 17, 2007 Author Report Share Posted October 17, 2007 They have popped out at the bottom, almost certainly during the moult as they were nice and neat beforehand, but I am still baffled as to how. It miust have been one serious moult. Unfortunately it has proven too much for him, and I found him laying upside down this afternoon :) Link to comment Share on other sites More sharing options...
Beano Posted October 17, 2007 Report Share Posted October 17, 2007 awwwwww!!!!!!! Sorry. Seems like a real cut throat world in the shellfish life... Link to comment Share on other sites More sharing options...
splendidbetta Posted October 17, 2007 Report Share Posted October 17, 2007 Aww, So sorry Abbey :) Link to comment Share on other sites More sharing options...
brettc777 Posted October 17, 2007 Report Share Posted October 17, 2007 poor poor marron. You going to get another? Link to comment Share on other sites More sharing options...
Bettarazzi Posted October 17, 2007 Report Share Posted October 17, 2007 It seems bizarre that an animal could die from going through a necessary process. Surely they would have evolved so that only the ones that survived the moult would live to pass on their genes. Link to comment Share on other sites More sharing options...
splendidbetta Posted October 17, 2007 Report Share Posted October 17, 2007 Sometimes these things happen as "accidents". It isn't something that is necessarily inherited, but is a developmental issue which doesn't then get passed on to future offspring if the organism survives. If the organism survives, it still gets to pass on its genes, but if it doesn't, bad luck. Therefore natural selection in these situations will possibly kill the mishapped molters, but this selection might not actually influence the frequency of the occurrence of the developmental issue in the next generation. Remember development is as much influenced by the environment as it is by genes. I guess you could think of this bad molt scenario (assuming hereditary factors aren't involved) as analogous to a teenager tripping and falling and breaking a bone. Or a rabbit with an extra set of half-ears behind the normal set. Such occurrences don't necessarily get passed on. The only way you could determine whether the molting thing is hereditary is to see if that yabby's offspring had a higher rate of developing the issue. Also, the invertebrate developmental process is still effective under ideal conditions, and most arthropods mass produce offspring. At least some offspring will live to survive "accidents" in development. Link to comment Share on other sites More sharing options...
Chuckie Posted October 17, 2007 Report Share Posted October 17, 2007 NO!!!! I loved this guy. So sorry, Ab. ;) Link to comment Share on other sites More sharing options...
Figure_8 Posted October 18, 2007 Report Share Posted October 18, 2007 :) ;) Link to comment Share on other sites More sharing options...
shooshoo Posted October 19, 2007 Report Share Posted October 19, 2007 So sorry to hear that you lost him he was a gorgeous little guy! I know it doesn't help now, but in case this happens to anyone else in the future i thought i might add what i know about these critters (following on from comments such as 'i might cut them off....') yes, they were his gills!! and yes they do usually sit under the carapace between the front two 'legs' on either side of the forward body, the allows for them to be both protected by the carapace as well as exposed to water currents, also, being attached to the front legs any movement allows for extra exposure and water flow (being stuck under the carapace sometimes reduces total surface area, thus leg movement increases the total surface area of the gills allowing for more efficient oxygen transference) yes it is possible for this to happen, just as it is possible for the gills to be 'pushed' back under the carapace and into the correct position. i don;t know why this would have caused his death but my thoughts are that this is merely a result of another injury. anyone, please correct me if i'm wrong, its been a while since i've studied marine creature biology! again, sorry to hear you lost him :balloons: Link to comment Share on other sites More sharing options...
Beano Posted October 19, 2007 Report Share Posted October 19, 2007 Maybe he just didn't have enough energy left to eat, and the gills thing was a minor side issue? Anyway, I never posted it, but I was also thinking "maybe you could just cut it off" LOL! Poor Mr Marron. Link to comment Share on other sites More sharing options...
Chuckie Posted October 19, 2007 Report Share Posted October 19, 2007 i thought i might add what i know about these critters (following on from comments such as 'i might cut them off....') Uh, what Abbey actually said was that there didn't seem seem much she could do about it other than cut them off, which she clearly thought was a bad idea as they looked 'gilly and necessary'. Abbey has vet nurse training. she was obviously not seriously contemplating recklessly chopping the creature's bits off! Any details about how the gills might be pushed back under the carapace, or links to details? Link to comment Share on other sites More sharing options...
Callatya Posted October 19, 2007 Author Report Share Posted October 19, 2007 Nah, I wasn't actually going to slice them off, but it did cross my mind before I'd had a chance to look at the discarded shell and see how exactly they slotted in, thinking that they'd actually formed in between the two shells instead of flipping out of place mid-moult. Very fleeting thought, in the way of "And you can't cut them off because they look important, but can you safely leave them there and if so, will it fix itself or should they be taken off so it corrects next moult?" It took about 3 seconds to decide that 1 set of gills was not going to satisfactorily support a critter his size so either way they had to stay. I did consider pushing them back under but, as he was incredibly soft and still quite strong, I was concerned that with only one operator and without proper restraint that one good whip of that tail and I'd risk slicing his gut That, and it is the sort of thing that should be done by someone who knows more about cray anatomy than someone who asks for confirmation on what the fluffy bits are ) I don't think the death was a result of injury so much as deficiency and exhaustion. I hadn't had him all that long, and he was showing signs of calcium deficiency within a fortnight of being here. I was building him up, but he didn't have much time between when I cottoned on to that problem and when he stopped eating to prepare. He took over 2 weeks before he eventually moulted, which seemed like way too long, even at his size. Given that his last meal was about 16 days beforehand (I tried every day just in case, but he was just not interested ), and that his calcium levels seemed a bit low, and that he had two fairly substantial fight injuries that may have caused him to spend more time and energy extricating himself, I think the resultant gill issue was the least of his problems :P Link to comment Share on other sites More sharing options...
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