Grain mites; crabs molting I think - what to do?

[mom2kcs]

Hi,

I recently moved most of my PPs to a larger tank, but left behind five that have been under for weeks, presumably molting. I was going to move them when they emerged. I have had them for about a month, so it could also be PPS. However, there is no evidence that they are coming up at night, and also no evidence of death - tank smells fine. Last night I noticed there were what appeared to be floating grains of sand in both the dechlor. fresh and salt water dishes - only they were wriggling! I have access to a decent microscope, and from comparing these critters to pictures on the web, these definitely look like grain mites. Every hermie got a bath right after purchase and there was no evidence of these in their bath water, but maybe I missed them since they are so tiny... I have Eco Earth and reptile sand in the tank (a 20g long), and have read about ways to clean the tank to get rid of the mites - but any advice on how to wait out the possibly molting crabs? I guess I am not sure which is worse - to disturb the crabs to clean everything (and risk them dying in the process) or to wait it out and have the mites in the meantime cause problems for the crabs - and spread to my other bigger crabitat which is nearby... Any advice much appreciated - have learned a lot from you all already!

One other thing - I just added a heating pad to the side of the tank a few days ago - before these appeared - since the temperature has dropped in our house a bit at night and didn't want the subsurface crew to get chilly - am wondering if the humidity + temperature could have contributed?

[Carrie]

Just wanted to let you know that an answer will be forthcoming. This question is a big one and fortunately there's time to do a little research. I've seen some websites that say mites are a pest (like fleas, biting the soft abdomen... and possibly, therefore, a soft post-molt crab) and some OTHER websites that say they're harmless pests that don't irritate the crab. I'm also wondering if mites dig far down enough to annoy a crab who's dug under to molt. If mites are just a "surface" problem then they came along after the crabs dug under, by the sound of it.

You have the exact situation I was going thru early this summer. Difference being that I wasn't moving between tanks, just changing from Calci-Sand (which kept the tank way too dry, tho nicely warm) to an earth/sand mxture. My tank is the same size, too. And at the time I discovered the mites nobody was dug under for a molt so this didn't play into my decision to "sterlize" everything. Quite a dilemma...

I'm also dealing w/ the hotter days/cooler nights issue. I had a heater on the side of the tank but I put it underneath eventually. Right now there are 3 UTH and a heat lamp going (it's a "moonglow" bulb and I don't think it heats much!). There's one big UTH and one really old one that doesn't heat too well, but it helps... and one small one. All of this but the smallest UTH is on the right side of the tank, so that crabs can choose which temp variant they're in depending on what side of the tank they go to. The ones who dig are choosing the hotter side. I also have a tray of earth/sand w/ some natural sea sponges in it called the Swamp. I pour water into that to increase humidy and the earth/sand by it gets all nice and damp and the crabs who want to dig are picking that "packable" substrate to dig in. It's located in the "hot" side of the tank, to increase evaporation/humidity.
The "jungle earth" mixed with the sand keeps a certain consistency--it doesn't harden up like sand would and it's very easy to dig in, yet it's also "packable" for a crab to make a "molting den" under, say, the food dish or even the Swamp itself. This mixture also seems to hold moisture w/o molding and helps w/ maintaining humidity.

The catch: mites can come w/ earth substrate! I've only had one case myself and since 2004 I've been using all earth until recently, when it became half sand. (Some Calci-Sand is still in the mix.)

Anyway... does anyone know exactly where mites come from and if they are in fact an irritant to hermit crabs enough to warrant digging up possible molters (briefly!) to sanitize the environment?

Wai and I spent a fair amount of time discussing this tonight... and I've sent an e-mail to Carol of Crabworks (who has Jon and Kate the 33-yr-"old" hermit crabs) b/c she's given me so much wonderful info before. She's done a lot of research (her crabs are only a year "younger" than I am!) and she might've come across something reliably scientific. As we all know, "reliable" and "scientific" aren't always the same thing when one is researching hermit crab care online.

If it turns out that the mites don't get under the surface to a crab who's underground to molt... when each crab comes safely up again after the molt, presumably you can follow the mite removal methods (namely, bathing the crab in lukewarm water) at that point to keep the new tank mite-free.

Sounds like you've set up a wonderful home... or homes. Besides the tiny non-paying "guests," of course... mites'll happen.

P.S. I looked up the number for FMR (Florida Marine Research). It's in my signature below now. Ask for Kathy--hopefully she's still there. They've talked me thru several crises over the years! I know everyone's looking for some "live" help in a desperate situation...

-- Ohio? hit by a tropical storm? whaaat? --

[mom2kcs]

Kira,

Thank you SO much for your reply - and by the way - loved your molting story - what a wonderful experience that must have been!

Here's what I did:

The mites were crawling up the sides of the glass last night and I could see them on the glass lid as well, which is not a 100% tight fit. There were a substantial number of them. Since these are grain mites, I was worried that they could possibly infest our food in the house as well, or us (they reportedly cause rashes on people that work with contaminated grain) and decided to chance getting the hermies out. Mind you, I was sweating through the delicate procedure of unearthing these poor creatures while simultaneously trying NOT to get mites on me!

As it turns out, four were not molting at all - they were perfectly fine (well, as perfectly fine as PPS gets) and there was no evidence that they had molted - dark coloration and dull tips of the legs. I have read they get very pointed tips after molting and have seen this on a small hermie that recently did successfully molt. However, one of the small (dimesize) PPs, "Twitchie" looked like he had molted. He looked to be a light pinkish-purplish color - a pastel - and looked pretty soft. He was fully withdrawn into his shell, but I could see his BP moving so I know he was alive. I only touched his shell. I moved him to a 5 gallon tank that I set us as an iso tank with EcoEarth (new!) moistened with dechlor. salt water, and gently buried him in a slightly widened hole. They all received baths, even Twitchie. I did not realize he had molted until the EE was washed out from his shell opening. He has a bit of an oversized shell that allows him to back WAY into the spirals. No evidence of any mites on the crabs at all or in the bath water - and I looked closely!

The four non-molters were active after their baths but immediately buried themselves in the iso tank. I put a hermie hut on the opposite side of the tank from where Twitchie is buried and that worked well - they all went in and promptly dug down in that position. Someone was out for food and water last night though - they left a mess in the dishes. And there were no wriggly creatures in the iso tank water dishes this morning or this evening.

So as much as I fretted over this decision, I am glad I did it to have gotten rid of the uninvited houseguests and potential threat to the crabs. Now it will be a wait and see for Twitchie. I did look for any sign of uneaten exoskeletons to move but saw no signs. I hope Twitchie has already indulged.

I agree about the mites being surface pests - and probably did come along after the crabs went down. I looked at the substrate I had moved about and there was no sign of any mites beneath the surface. I am surprised that they seemed to accumulate in the water dishes though. It was like they had formed little mite 'rafts' in the dishes that were composed of maybe 50-100 or so mites each, all joined together in a floating mass. This was in both the salt and fresh water dishes - and the mite rafts grew over the course of the day and/or night. I suppose it makes sense for them to join together to increase the surface tension so they won't sink/drown? But I don't understand why they would accumulate in the water dishes. Seems like that is the last place they would want to be. I was under the impression that they could not tolerate the salt water but these were perfectly happy wriggling about in the salt water just as in the fresh water.

I had read about the EE possibly bringing pests with it but was hoping it wouldn't happen to my crabitat... how naive! If I were a hermie I think I would like to bury in it too - seems soft and cozy. Interesting - when I set up the bigger tank (a 37g tall so they can do more climbing), I used half EE and half play sand (moistened the sand with salt water, the EE with fresh, all dechlor.). I have PPs and Es. The Es especially LOVE the sand and do not seem to want to sit on the EE. I should say they love even more so to be on top of the Mopani wood and grapevine, but when they are on the substrate they pick the sand. I haven't seen anyone comment on this preference. Maybe it has to do with the salt water I used to prepare it?

Thanks again. I sure hope this doesn't happen again but seems the chances are decent that it might. I hope we can get some sage advice from Carol - I have read about her Jon and Kate and very much enjoyed that - I believe that her story may have been one of the first sparks that fueled my now raging addiction... these were supposed to be my daughter's pets that I was only going to help set up correctly. Hmmm.

[Carrie]

Wow!!

My first instinct was to say "dig up the possible molters" and do exactly what you did. Wai is sort of the voice of caution at times like this. I am newly concerned about mites b/c my jumbo, Aleta, molted and was just fine at the time I thought there might be mites... and by the time I realized there were she died. I don't know if she left her shell twice b/c of some stress (like simply having a hard time w/ her molt--she never took to eating afterwards much) or b/c she was being attacked by mites inside her shell.

I think those mites are all over everything and they're hard to see but in and around the water dish is where we can see them best. That's how I noticed mine, too. If not for taking the water dish out for Claude the Clawless to use it from time to time I might not have noticed them at all. I, too, was worried about them getting all over the house. I always let the crabs wander around my bed! (I washed everything!) And of course I kept feeling little tickly things walking on me like you do if you have a dog and it gets fleas. Or the time I took this really huge spider out of the house. Kept imagining there were OTHERS. Fortunately I don't think they spread beyond the substrate. I was worried b/c you can't use pesticides all over your house and then safely let any crabs wander.

Twitchie sure sounds like a recent molt!

My two pre=molt crabs (they hadn't dug under yet but they had the signs) seemed to enjoy the extra baths. They got about 4 by the end. Here and there someone would actually stay underwater and soak' that's when I'd just put the crab on my hand in the water so that its eyes were showing above water and it knew it was safe--then these guys started rubbing water into their uncomfortable old exos. (These two crabs have started digging in the moist earth/sand by the Swamp.) Arwen's just now started acting pre-molt, but she's golf-ball size, way bigger than the others. She's developed a recent interest in digging, too.

When I had Calci-Sand and "Jungle Earth" the crabs wouldn't go on the CalciSand 2/3 of the tank. I did have it divided up like that. I think the Calci-Sand was too hot and too well-packed. Eventually there was a little bridge of earth that lead to the water dish; the food dish was next to it. They all stayed by the Swamp in the earth/cool corner. Now they have genuine beach sand (as picked up on a trip to Myrtle Beach by me!) and the earth, all mixed together. They're loving it. It's moist by the Swamp but not "wet" and it doesn't get too hot--the sand/earth retain moisture and regulate the temp some, too.

What I try to ask with everything in regards to my hermies: what would ___ be like in nature? They like to climb trees and they like oak leaves and other greens, therefore they have to live not directly on the beach but near the treeline, which would then be an earth/sand mixture. (My other trademark question: "I wonder if the crabs would eat that...")

I had my first hermit crabs when I was 9, way back in 1984. My parents helped me to create the most scientific environment possible, considering the lack of info available on them. They even bought me the one book available back then and made sure I read it. I didn't find much info over the years until I went online searching in 2000. Since then I've been changing things around and trying out what I've read--some of which has been helpful, and some harmful. Most has been helpful! After 2000 the lifespans doubled from months into years. Still trying for perfection... if I can find it. Perfection = my own crabs who are with me for 33+ years. Over the years my engineer dad and his scientist friends have offered me advice, too.

Carol and her crabs are inspiring. I'm always in awe that these crabs lived thru the era of NO information.

I'm going on a cruise in the Caribbean w/ my mom and I'm heading out into hermit crab territory. I will be able to experience something of their natural environment. When I went to Mexico in 2003 near the beach there were land crabs living in the treeline area up to about half a mile from the beach. These weren't fiddler crabs--these looked more like our crabs crossed w/ them. They werenn't coconut crabs, either--way too small and w/o the abdomen that's a little like our crabs', only w/ exo on it. And boy was it hot and humid there!

Given how your mites proliferated... all over the place... I'm glad I got rid of mine when I did! They didn't get around to "proliferating." They were numerous enough to be "scary," tho. B/c of Aleta I decided to "sanitize" everything immediately, in case they were in fact inside the shells biting the crabs' abdomens. I did note that there were no mites that were washed out of their shells when I bathed them several times.

Thanks for the new info on them, too! I still put in the earth but I got a new bag of it and threw the old earth out. And watched carefully. No signs of any new mites after I "sanitized" everything.

It's an adventure... that's for sure!! Molters: in case they have to be disturbed you can quckly replicate their cave where you want to put them. Match up heat/humidity... If there's an emergency...

Hermit crabs can live for years and years... that's what I'm working on. Sounds like you're off to a VERY wonderful start!

[Wai]

I've generally argued against digging up moulters due to my past experiences. Back then I was still crabbing, the only successful moult I had was also the one which I did not interfere with in any way. The others perished, either before I found them or after I tried picking them up to move them to ISO. That's just me though; I'm not arguing that all hermit crabs will die if you fiddle with them as they are hardening up.

[krabby_katie]

Yeah, I've dug a lot of mine up (not on purpose, they weren't anywhere near where they were supposed to be) and I've never had a death from a molt. Even still, I would try to avoid this as much as possible!

[mom2kcs]

Just an update -

Twitchy survived! Twitchy emerged from the substrate yesterday, looking all spiffy with his hardened exo. I have also been monitoring the iso for mites - absolutely no evidence of any - so the 'probation' gang moved in to the 37g to join the others. Twitchy has been exploring the new environment and seems to be doing fine.

Thanks to all for advice - and especially to Kira. I will be anxious to read about your cruise and any crabs you see!