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I was wondering is there any other factors to molting besides the animal getting bigger?

I mean like weather, water changes so on anything really..


Any help in my question would be great!!!
Angel Eel

Some have speculated that molting might, in some instances, represent a toxicological reaction to untenable internal accumulation of environmental pollutants.

might also be worth looking at what prevents/delays moulting too.

you don't want to go to jelly while mating is on, or when things are drying out, or when food is scarce or when predators abound etc...

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

By all means feel free to explain both , I was watching my cray wiggle out of her shell and started to wonder...

As there is not alot of info on these fellas on the computer, which leads me to ask you wonderfull people


If anyone knows anything at all on molting please help me!


Also I would even like to know what the old shell is composed of. As they eat it after they molt, I know it has vitamins but is it alot or just a pinch? I am very curious when it comes to this

Well thanks alot,
Angel Eel

It has calcium in it which helps harden their new shells.


Kim

yuppers

A) its easy food hen they are soft and B) its still got a good deal of calcium in it

They do suck most of the calcium into their little gastrolith, but they can't get all of it.


I think Veneer might be the best person to nab to try to explain things in more detail I've not done much in depth study on them.



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

might also be worth looking at what prevents/delays moulting too.

"In M. rosenbergii and most other species of decapod crustacea including crabs and lobsters, the physiological processes of molting and reproduction are inextricably linked and under the control of various hormones. Crustaceans, which are arthropods, bear much endocrinological similarity to insects, and differ greatly from vertebrate species. However, compared with insects, which have been studied more widely, little is known about endocrinological mechanisms in Crustacea.

It is well-established that ecdysteroids such as 20-hydroxyecdysone serve as “molting hormone* in Crustacea and are excreted from a tissue known as the Y-organ. On the other hand, peptides (molt-inhibiting hormone: MIH) originating in the sinus gland complex of the eyestalks exert negative influence on molting. In M. rosenbergii, molting occurs approximately once per month accompanied by growth of the animal. In females, reproduction occurs in synchronization with the molt cycle during which vitellogenin (yolk protein) is produced and ovaries develop and mature. This process is also under the inhibition of an eyestalk hormone: vitellogenesis-inhibiting hormone (VIH). In hatcheries and on prawn farms, the technique of eyestalk ablation has long been employed to induce female maturation; the basis of this is the removal of the eyestalks and thus the removal of the source of these inhibitory hormones.

While much progress has been made regarding negative control of molting and reproduction, it is unclear whether positive control mechanisms exist. Regarding molting, it is still not known what causes ecdysteroid titers in the hemolymph (crustacean blood) to surge just before a molt. It is also not known how the negative effects of VIH are lifted, enabling the animal to produce vitellogenin for uptake into the ovaries. In insects, juvenile hormone (JH), which is a larval developmental hormone, also appears in the adult female to stimulate yolk protein production and uptake. At JIRCAS, we are interested in the functioning of juvenoid substances in M. rosenbergii and are attepting to determine whether such hormones exert similar influences in crustacean species. At present, we have detected a JH-precursor molecule, methyl farnesoate (MF) (Figures 2a,b), in the hemolymph of M. rosenbergii. It was expected that MF would be present in only females undergoing ovarian maturation, but it was detectable in both females and males without connection to reproductive events. MF was also seen to fluctuate during the molting cycle, suggesting involvement together with ecdysteroids in regulating molting."

From http://ss.jircas.affrc.go.jp/engpage/annualreport/1996/overview/fisdivision2-2.html.

you don't want to go to jelly while mating is on, or when things are drying out, or when food is scarce or when predators abound etc...

Actually, many freshwater shrimp can viably mate only while the female's exoskeleton is still soft (immediately after a molt).

"

I'm not sure if anyone has observed this phenomenon.... usually after purchasing some cherry shrimps, they will either molt in the bags or the next day after introducing to the tank... It happened to me a couple of times and some of my friends had the same experience...

The difference in water temp and makeup usually acts as a catalyst for moulting for crustaceans. There were enough incidents for me to come up with this. I had on several times, encountered mass moulting of up to 10 individual crayfishes after a change in water."

From http://www.shrimpnow.com/forums/showthread.php?t=203&page=2&pp=10.



Last edited by Veneer at 03-May-2005 20:31

I was of the understanding that Shrimp, like insects, moult as they grow larger. My shrimp has moulted 6 times, and every time he moults he is larger than before.


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Yes, but they dont moult because they get larger, they get larger just after they moult. They cannot grow inside the hard shell, they have to toss it off first and then they have several hours of rapid growth before the new shell hardens up.



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