Aussie salt water myth?

sugarselections · Post by **sugarselections** » Mon May 10, 2010 5:49 pm

My Aussie is pretty active during the day. She's not very nocturnal.

Post by **JediMasterThrash** » Mon May 10, 2010 9:53 pm

Wow very informative and interesting thread.

For a couple pages I thought it might get out of hand, but I applaud everyone for getting it back on track. Constructive arguments are always welcome.

One worthless interjection I have. The cases where animals overindulge are when provided with a quantity in excess of what they would have in the wild. Humans were meant to eat meat, veggies and limited fruit. Copious supply of artificial additives, processed carbs, and the creation of transfats is making us all unhealthy. A cat in the wild might catch a bird or rodent every other day. But at home, given an entire bucket of food will devour the entire thing, instinctively gorging, no guarantee when the next meal will be. But taking a crab that has 24/7 access to saltwater in the wild, and giving them 24/7 access to saltwater in a tank, that's not quite the same thing as alcohol, processed cards, and cat food. Not saying I'm taking a side on this issue, just making my worthless interjection.

Food might be a different issue. I've brought home some crabs from mall kiosks where they were starving, and provided them with a nice big meal full of treats and calcium and watched them devour the whole thing and leave a trail of giant blue crab noodles. Also heard of crabs overeating themselves to death after an extended kiosk stay. One of the reasons we recommend a limited amount of staple foods only in ISO for new crabs. Though it's unknown if these deaths were just PPS or more.

FYI, the blue noodles were because I was using a blue calci-sand for a calcium supplement at one point a long time ago.

Dehydration in humans is caused by insufficient transport mechanisms to remove excess salt, and limited kidney capabilities for processing excess salt. The actual cell water makeup of most animals is almost identical to seawater otherwise. I haven't been able to find info on crabs yet, I'll have to pick up that crab biology book. But it seems most sea-faring animals have the proper salt transport chemicals and high-salinity urine capabilities to prevent dehydration. Given what we know of osmoregulation in hermit crabs, I'd think they would be able to handle it. But Greenaway doesn't mention variabilis.

But we should remember that variabilis is a variation of Coenobita spinosus. Hmm, I thought it was still Coenobita spinosus var. variabilis, but I just found a source that says variabilis was promoted to full species status in 1909 by McCulloch. Spinosus is the inland Australian variety, and variabilis is the beach dwelling Australian variety. It's worth looking into whether info on spinosus would be applicable to variabilis.

And wow, someone really needs to just shut down yahoo answers. It's just amazing the amount of confident answers written by people who have absolutely no idea what they are talking about.

[Journal of Crustacean Biology 1992, pg 196, "Abbreviated Larval Development in the Australian Land Hermit Crab Coenobita Variabilis McCulloch"]

kgbenson · Post by **kgbenson** » Tue May 11, 2010 7:23 am

JediMasterThrash wrote:
One worthless interjection I have. The cases where animals overindulge are when provided with a quantity in excess of what they would have in the wild.

This is not worthless at all - it is an excellent point. Animals have evolved specific appetites such that they will search out what they require. If something is needed or helpful because it is normally in limited supply, there is a relatively strong appetite for that material.

The overall appetite suit of a species generally works quite well in a scenario where things are available in the proportions that the species has been exposed to throughout it's evolution. And these appetites don't disappear overnight so.

It is this phenomenon that allows fast food to survive and such to thrive. Simple sugars, salts and proteins were hard to come by a few thousand years ago. Now, we can have them to excess at any drive through . . .

But we should remember that variabilis is a variation of Coenobita spinosus.

What was this based on? It sounds old enough that there was no DNA eval involved. I wish someone would compare the DNA for all of the species we think exist because I think there might be some interesting cryptic speciation as well as some relationships that folks didn't know exist. Anyone ahve a geneticist and a big pile of cash we can borrow?

And wow, someone really needs to just shut down yahoo answers. It's just amazing the amount of confident answers written by people who have absolutely no idea what they are talking about.

Ahhh - the internet, the disinformation superhighway. Any nitwit with a modem can appear to be an authority.

[Journal of Crustacean Biology 1992, pg 196, "Abbreviated Larval Development in the Australian Land Hermit Crab Coenobita Variabilis McCulloch"]

Do you have this as an e-file? I am having a tough time accessing the JCB

Keith

Post by **JediMasterThrash** » Tue May 11, 2010 9:27 pm

Luckily the relevant information is on the "free" first page:
http://www.jstor.org/pss/1549075

But you might be able to get the full text at your local university library.

There's also a "Zoological catalogue of Australia" but I think they probably all reference the same McCulloch paper, hard to find originals of things written pre-interweb-age.

You can see it referred to regularly as C. spinosus var. variabilis in here:
http://www.repository.naturalis.nl/document/148837

One of the main ancient species works is the "Reappraisal of Hermit Crab Species"
http://www.nhm-wien.ac.at/Content.Node/ ... /PM_PD.pdf
See pages 139-140.

FYI, anyone seen this site before?
http://coenobitaresearch.blogspot.com/
It doesn't look like Sues site, looks like something from UK.

kgbenson · Post by **kgbenson** » Tue May 11, 2010 10:29 pm

JediMasterThrash wrote:Luckily the relevant information is on the "free" first page:
http://www.jstor.org/pss/1549075

But you might be able to get the full text at your local university library.

I was trying to avoid making the trip. I have adjunct status and can usually get electronic versions of the things I want but sometimes I have to get off my duff and head over there. I have been spoiled with all this downloading one can do nowadays if you have the right password.

Keith

scyllarus · Post by **scyllarus** » Thu May 13, 2010 10:03 pm

slightly pointless reply:

i think there may be some variation from animal to animal, as well. when my dog was alive, we fed him at definite times, once in the morning, once at night, to keep him from gorging on the food. on the other hand, my friend's dog has her food dish full all the time, and she only ever eats when she's hungry. so it would stand to reason that, if we have hermit crabs that have distinct personalities, we can also have hermit crabs that will be prone to either gorging themselves or else moderating their food/salt intake.

a random sidenote: i have never seen my pps go near the salt water. they ignore it entirely, as far as i can tell, but they drink almost daily from the fresh water. also, i bathed a new crab in salt water and then, retardedly, forgot to rinse him in fresh. he made a beeline to the freshwater pool, crawled in, and drank a lot.

Post by **JediMasterThrash** » Fri May 14, 2010 9:52 pm

See my post in the middle of this thread:
http://www.hermitcrabassociation.com/ph ... &highlight

Some theories from this thread could of course change what I had previously wrote.

sugarselections · Post by **sugarselections** » Mon Aug 30, 2010 3:47 pm

I wanted to update this thread with new info on my Aussie crab. She has now been living in my community tank on coco fiber substrate with 24/7 access to salt water for 8 months. She just completed another perfect molt and is very healthy and active.

Nat_addicted to HC's · Post by **Nat_addicted to HC's** » Mon Oct 04, 2010 5:14 pm

Hi all,
I have 7 C. Variabilis (Crazy Crabs) I live in South Australia. Not exactly sure if that's what you call Aussies.
All of the pet shops I have been to have told me so many conflicting care methods, even other crabbers here.
I have fresh water and salt water available at all times, HC's will drink & collect fresh when they need it and bath in salt when its required (regulate shell salinity), most places say to put a sea sponge or small river stones in their fresh and salt water bowls so little ones do not drown, they pretty much walk in and wash.
[URL=http://img338.imageshack.us
Scallop shell fresh water
[URL=http://img813.imageshack.us
Salt water
I tend to keep a sponge in the fresh and stones in the salt (easy for me to remember what to top up with)

Guest · Post by **Guest** » Tue Oct 12, 2010 9:25 pm

Hi,

I can see this thread has basically been resolved but as I am from Western Australia and have been to the place where the Aussie crabs are harvested I thought I would just confirm a couple of things. First, they are definitely harvested from the beach. Up in Darwin there are so many on some nights that it is very difficult to walk on the beach without squashing some of them.

I also give mine 24hour access to salt water. They usually visit the salt water bath fairly regularly and dip their front legs in. I have had mine only for 7 months but the lady at City Farmers who has been helping me set up my tank and given me great information has been doing this for years. She has even managed to get hers to have eggs which hatched in the salt water dish. Apparently she kept adding fresh sea water but everyday there were less until after three weeks there were no hatchlings left.

I hope this helps!
cheers Jennie

Nat_addicted to HC's · Post by **Nat_addicted to HC's** » Tue Oct 12, 2010 9:49 pm

Jennie you are so right! its such a pity, no wonder so many crabs die needlessly....how can people care for them properly, when they are buying them they get very little info or incorrect info, The CC's site is really so saddening (I couldnt believe what I was seeing, seemed like a joke). The people from our local pet shop were not really even interested in answering any of my queries as they didnt even know (when I first got interested), nearly everything they told me was wrong. I went in to talk with them, to explain very simply some of the basics that I had learned at the time and they said most people dont really care about that stuff and they just want something easy for parents to buy their kids (its all money isnt it), they dont keep a lid on the tank (no humidity) so people can see them, when I said they love to climb (she didnt believe me) they need salt water........the list goes on, my words fell on deaf ears. I have been slowly rescuing them, sadly they have gotten more in

Guest · Post by **Guest** » Tue Oct 12, 2010 10:43 pm

it is very sad. If you read the harvesters application to export (somebody has a link to it on this thread) he even says that customer feedback they have received indicated that the survival rate after sale is very high. This may be true for a couple of months as they are tough little things but after that most die. I have seen too many die as I grew up and at other peoples houses. When I first brought them for my sons I told them they didn't live for long as I thought that was normal, I didn't know it was ignorance which killed them. Very luckily for my crabs I visited Cityfarmers the next day and got educated. For such a common pet there is appalling amount of ignorance to what level of care the require.

suebee · Post by **suebee** » Tue Dec 07, 2010 8:40 pm

I hope when people read this thread they consider that a person whos crabs did well for a year or even up to 10 years does not compare to the same research of captive crabs on substrate and given daily salt water v/ once weekly for over 35 years.. I met a girl who has had a hermit in a cage living on cherios living on fish rocks for 3 years.. never molted.. that does not prove it healthy or ok.. i see what is going to be the new species spec sheet says its ok to give salt water at all times but i would not agree. i also know of at least one head researcher in Austrailia who would not agree. Both ELHC and Hermit Crab Patch will agree on the Salt water weekly. a few hobiest say other wise. Same with the subatrate The researchers ive mentioned will tell you that they should not be kept on coir aka EE or Eco Earth.
Maybe just my opinion but i felt strong enough on the crabs behalf to bring it up again because of the new species caresheets being made.

feel free to email me any questions if you would like..

samurai_crab · Post by **samurai_crab** » Tue Dec 07, 2010 10:37 pm

I'm just curious were the idea came from to limit it, considering they have access in the wild to saltwater whenever they want it. Why would their habits change in captivity that they can't handle access all the time? This is going on the assumption that they are in range of the ocean all the time, which it seems a few of the Australian crabbers have said they are. Being a biology major at school this whole idea of limiting something an animal requires and needs just seems odd if you take the assumption stated above. Now I'm definitely not an expert nor have i thoroughly researched Aussies since well I doubt I'll have the money/time/place to get some anytime soon but if/when I do its something I would want to know inside and out before keeping them as pets.

tnt4eva · Post by **tnt4eva** » Tue Dec 07, 2010 11:17 pm

I understand Suebee. I feel strongly about it too. I don't think that their access to salt water should be limited when they have unlimited access to it in the wild.