Re: Thoughts on Vitamin D
Posted: Tue Jul 09, 2013 9:17 pm
So do we have definitive documentation that Es fight more or lead a less harmonious existence with eachother in the wild than PPs or other species?
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But not even that. Maybe it's my history of working with zoologists and reading field studies, but nothing in the article wodes posted made me raise my eyebrows and say, "Wow, C. compressus exhibits more fights than is expected of any wild animal population." Fights are natural, especially in the wild where the stakes are higher. The article didn't focus on the violent tendencies of C. compressus, in fact it was the second to last thing they mentioned (giving it only a few lines in an 8 page paper).kuza wrote:There's an article about it earlier int he thread, yes. It doesn't say they fight "more" than other species, but it talks about compressus in general fighting a lot.
There's also confirmation bias and the fact that no, not all parties have reported in. I know of a few crabbers who saw how to dissenting opinions were attacked on the E thread and chose to stay out of it. Unfortunately, that means our "sample" is not complete.kuza wrote:If you take the time to read through this thread and the "I hate my E's thread" you'll see a trend of E's being the aggressors for most people. Forget the documentation, we are the statistics.
My aggressive E's came that way, which we discussed before. That's th only reason I dont' believe it's only condition related. It might help exasperate the issue, but I dont' think it's the main ingredient.fraksocks wrote:Fine yes there's a trend but it's far from clear if this their natural way of being or something caused by a condition (or multiple conditions) within captivity. If we made a more comprehensive study of the issue with documentation of the factors involved we might discover that we can make some simple changes that mitigate or make the Es natural tendencies more manageable/predictible. Right now most people are just shrugging their shoulders and saying "it's just Es" or "I hate my Es" what if there is a way for us to make their lives better and take some stress off of us. As an example we might discover that a sexully mature male needs X amount of territory at a minimum or can only be kept with females so knowing they sex of your crabs is very important if you intend to keep Es or we might discover that Es are more effected by changes in the barometric pressure or that they have very specific and mostly inflexible social structures than other crabs so adding new members to an established colony is inadvisable or needs to be done with greater care. Those are just a few examples. To be honest those are just guesses based off of what I've seen in the several threads discussing it. Personally, it's frustrating to me to see a community that I'm part of identify a problem and then say "Well there's just nothing we can do about it" or assume that it's unexplainable before taking the time to do a comprehensive survey or collection of the data to really see what they root cause is. Each member has one part of the picture we just need to put them together.
Apologies if I was ambiguous about our point. Our point was that perhaps behavior and other observations of crabs in captivity (such as the shrinking jumbos I've mentioned a few times now) could be explained in part by vitamin D deficiency. Where that deficiency comes from (diet or lack of UVB) we are not sure, and as for how it manifests-- well maybe in part, as aggression.kuza wrote: My aggressive E's came that way, which we discussed before. That's th only reason I dont' believe it's only condition related. It might help exasperate the issue, but I dont' think it's the main ingredient.
Sorry to go off topic here, but I thought from the first sentence in the first post was bringing the discussion here.
My PPs stay aggressive for a few days. Once they've had access to shells and a few days of good food, they're peaches afterwards.Kat wrote:As far as crabs fresh from the wild go, I'm sure that everyone here has noticed a propensity toward aggressiveness in their new crabs regardless of species.
I was down to five crabs in a 55 gallon with a foot of substrate, how is that overcrowding?? And again, I've been supplementing with D powder from the beginning. (I just chose not to talk about it since it's never been a recommended item with hermit crabs since the safety ingredient cannot be confirmed in use with hermit crabs.)Kat wrote: As far as I can tell, there's a trend toward aggressiveness in Es with overcrowding and lack of UVB, but not a definitive correlation, just based on my own readings here at the HCA with the many members who have Es, and the papers definitely support that (although I'll admit I still haven't read them in full and am working through them)
This is not what your opening post stated at all. It only talked about deficiency of Vitamin D causing all the problems with Es.Kat wrote:I'm postulating, based on general feral animal and WC animal rules, that as competition for resources (including vitamin D), decreases, people will see a correlation in decrease of aggressive behavior.
I have found it interesting that no matter how many times I offer the Es crab meat (the real stuff) or Alaskan Hermit's crab exo (any of the species she's carried, as I have a bit of all of them) - my Es will never touch the stuff, no matter how many times I offer it and how long I leave it. The PPs? Good luck with it lasting overnight! You would think with their penchant for eating others that the Es would want more crab material, but they ignore it. It has to be something species-specific that they're after if it is something diet related.kuza wrote: Protein deficiencies are constantly cited as being likely sources for this behavior when it occurs on this forum, but maybe it's not protein (especially since it apparently happens even with keepers feeding a diet high in proteins), but another type of deficiency.
Very true. Captivity is way different then the wild, and only through trial and error can we learn what works and what doesn't in our own tanks. Just because they're a communal species in the wild doesn't mean they'll do okay with multiple others in captivity. It may very well be that the best combination is one male and one female, or a male and a small harem. (Several fish and reptiles are better kept like this in captivity, even though in the wild they're found in large quantities of mixed groups.) As far as care and environment, start with what we know about the are they are found in, and tweak it from there.rockygurly wrote: I feel that something that's done in a lab or on a field can't always be compared to what goes on in the tanks of hobbyists.
No, but the papers out there on clypeatus and shells are about shell chains - where they line up in a rather neat little order and swap out. Not about them going after the shell of another crab one-on-one, and observed with multiple crabs on multiple occations! That to me is telling that there were no shell chains witnesses with the Es. It shows they're a little more violent and "me me me" and little less organized and "all for one" than PPs at least.boxcat wrote:Maybe it's my history of working with zoologists and reading field studies, but nothing in the article wodes posted made me raise my eyebrows and say, "Wow, C. compressus exhibits more fights than is expected of any wild animal population." Fights are natural, especially in the wild where the stakes are higher. The article didn't focus on the violent tendencies of C. compressus, in fact it was the second to last thing they mentioned (giving it only a few lines in an 8 page paper).
I'll be posting before and after of my straws as well; you can definitely tell changes now, but I want to wait until they are undeniable.kuza wrote:And I'm all for helping figure it out, I'll have before and after pics of my crabs once they have been basking in UVB for a couple months, I think it might be too early to tell any major color variance or attitude changes.