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Growth Rate

Posted: Tue Jan 17, 2012 4:26 am
by applepoh
Hi everyone. Just asking. Does Blueberries grow slower than other species? Because the blueberries I have did not grow in size for the past 2 years..... lol~ while others type grow much faster.

Thanks for your time.

Re: Growth Rate

Posted: Tue Jan 17, 2012 9:05 am
by Zoeythelost
i'm not sure but it really seems to depend on the crab for other species so I imagine it would be the same for blueberries. In the 6 few months i've been crabbing. I have two Es, one who is still little bitty despite molting several times. And one who has well move than doubled his size, possibly tripled.

Re: Growth Rate

Posted: Tue Jan 17, 2012 10:14 am
by Rocky
My blueberries were already huge when I got them, so I don't expect them to get much bigger.
I've heard that crabs in captivity grow slower and not as big as they could potentially grow compared to wild crabs, I think this is for a number of reasons, like not being in a real natural habitat (despite all our fake plants and vines) and not having fresh, still growing food, and not real running water out of the lake/ocean/river whatever they're used to.
I'm trying to combat this a bit by giving them still growing food when I can, I grow little sprouts and plant them in the ground and they always get eaten, my market sells weird looking lettuce that comes still growing in its container with dirt and roots and everything, I give them veggies right out of my garden when I can, and I don't have this but some people do a bubble thing with their water dishes to make them more natural (and less dirty! :P )

Re: Growth Rate

Posted: Tue Jan 17, 2012 10:23 am
by DragonsFly
Zoey, do you know the sex of those E's? I wonder if the sex may affect how fast they grow. I know it does in some other (non-crab) species of animals.

Re: Growth Rate

Posted: Tue Jan 17, 2012 11:38 am
by applepoh
Haha zoey I like ur signature. " 1 human child" .

Re: Growth Rate

Posted: Tue Jan 17, 2012 6:44 pm
by Zoeythelost
DragonsFly wrote:Zoey, do you know the sex of those E's? I wonder if the sex may affect how fast they grow. I know it does in some other (non-crab) species of animals.
I have often wondered the same thing, if sex effects growth rate. i do not know their sex, the big one is currently molting but i'll try to grab the small one tonight. I can tell ya the bigger one appears to be the alpha crab in the tank, though the small one is pretty pushy herself (or himself). That may play a part on way he is growing so fast

Re: Growth Rate

Posted: Tue Jan 17, 2012 7:25 pm
by Zoeythelost
I'm not getting a sex on the small one. I just completely stressed her out trying and she just would not come out far enough.

Re: Growth Rate

Posted: Tue Jan 17, 2012 7:46 pm
by Rocky
I don't think sex has much to do with it, if that crab seems like the alpha then he probably gets first dibs on all the food :P

Re: Growth Rate

Posted: Tue Jan 17, 2012 8:02 pm
by Zoeythelost
they is plenty food in that tank for everybody and i've only seen him chase other crabs off once. I really think its just his desire to grow bigger.

Re: Growth Rate

Posted: Tue Jan 17, 2012 8:12 pm
by Rocky
I geuss. But also the weight of their shell, whether they've had problems, basically anything that uses energy will slow their growth a little

Re: Growth Rate

Posted: Tue Jan 17, 2012 8:23 pm
by DragonsFly
It is also possible that status itself could affect the growth rate. Status (whether being "alpha" or someplace else in the hierarchy) affects hormone levels in social mammals, and growth is mediated by hormones. I don't know invertebrate physiology, but I know they produce some hormones; I would not be surprised if this social species also has some hormones associated with status, and that these affect growth rate.

Re: Growth Rate

Posted: Tue Jan 17, 2012 8:58 pm
by Zoeythelost
exactly! There is no reason to believe hormones do not play a part in their growth rate.
I raised African Cichlids and it was really interesting to watch their social structure. The non-alpha males were smaller and duller colored to resemble females. Whenever the alpha male died, despite their age a new male would step up brighten, and grow larger. When stressed the females take on the male's coloring to disguise themselves or if no male the alpha female will again take on the males appearance. I know there are species of animals out there that can change their sex if one sex is not presence. And I know people on this board have reported crabs being a different sex after a molt. Which leads me to believe we are sexing them wrong or they are changing their sex.

Re: Growth Rate

Posted: Tue Jan 17, 2012 9:30 pm
by Someoneman
I seem to recall reading somewhere (I've entirely forgotten where, but it was a research paper or something of the same flavor) that among PPs smaller crabs are biased towards male while larger crabs are biased towards female, it very well could have been the reverse. You know what, I'll do some digging and confirm one way or another in a moment.

Re: Growth Rate

Posted: Wed Jan 18, 2012 12:00 am
by Rocky
Wow, you guys have some really valid points, that makes so much sense! :) I never thought of those things. But the females being bigger would make more sense because hermit crabs are in the same family as trantulas and scorpions, in both those species the female is much bigger then the male. I'll keep an eye on my crabs and see if anyone changes sex to! :)

Re: Growth Rate

Posted: Wed Jan 18, 2012 7:11 am
by wodesorel
Two similar sized same-gendered crabs can grow at drastically different rates in captivity, and the underlying reasons really can't be known. It could be social structure, it could be age, it could be previous damage, etc.

I have a jumbo that just shrunk 50% in size during a molt and is now a large. No idea why, but if I had purchased her today I wouldn't have known about that.

Sunshine, who had all her legs eaten off during a molt, is currently the size of a small crab even though she was a solid medium before the attack. Aside from the fact that she is in a shell twice her size becuase her abdomen is too large to fit in what should be a "proper" sized shell for her, if I had picked her up today I would have thought she was a baby crab with those tiny skinny legs!



As for blues (which is the original question :) ) I'm not sure. No one has mentioned anything about them growing slower or faster than other species, but they are probably the least kept crab out there. There was always a lot of talk about Es growing slower than other species, but I found that to not be the case in the two years I've had mine, so it probably just comes to individual crabs rather than a species as a whole. :)