Crab "eating" plastic OK?

[crabocado]

Busy (around 9 yrs. old) has a plastic shelter from PetSmart in her 20 gal tank that looks like a half-pipe of bark. She's had it for a few months. In recent weeks I noticed white spots, which I thought might be mold, or just wear & tear exposing the uncolored base material. Recently I realized she's actually broken through to an interior "space", and sure enough, the "bark" is actually whitish once you get through the colored outer surface. She spends time sitting there plucking more bits of plastic off.

On walks in the house, in the past she's shown a fondness for soft plastic (earbuds lying around; occasionally electric cords). But she's never seemed to pluck hard plastic before. (For years she's had a hard plastic "dead branch" in the tank but that has never shown any damage). She only emerged from her latest molt a couple weeks ago, so maybe she's got a newfound ability to crack into the hard stuff.

I took the "bark" shelter out in case this is harmful, but I'm wondering what you think? I don't know if she is eating it. I worry about bits of undigestable stuff blocking her digestive tract.

FYI, first time adding photos to this site! I started an "imgur" account just for this purpose.

[JTKermie]

She's putting her own custom touches on it! Like you say, I'd take it out for the reasons you suggest.

I've got some of that type of decor in my fish tanks. It holds up OK in that environment without any big pinchy things. LOL

[myllkti]

Yeah they don’t tend to eat plastic, but if your crab seems to be I would just take it out rather than risking it

[wodesorel]

Does she have any cork bark? Mine sit and munch away on it, and it's a good source of tannins. It might not even be the plastic attracting her so much as it's an activity for her to keep busy with.

[crabocado]

She doesn't have any cork bark. I'll drop by the pet stores and see what's available. Or I could maybe find a piece of pine bark on a hike here. I guess I felt the plastic furnishings were less likely to start some kind of infestation. I wouldn't want some colony of insects to develop that might eat a molting crab. Currently I actually have some tiny black flies in/around the tank. I never realized this rather heavy, very hard plastic bark is so easy for a crab to demolish. Regarding tannins, my understanding is those are a plant defense against predation by animals, so I would tend to think it is potentially harmful, although that's just a broad brush way of thinking.

[crabocado]

Arg, today I noticed a bunch of white dots in the tank. First thoughts: Mold? Ectoparasites? Nope! It turns out those are new bits of hard plastic - starting just in past day or so, she has unleashed her fury on the plastic "dead branch" that has been in her tank for quite a few years. No doubt out of frustration because her plastic "bark" toy was removed from the tank. Apparently she has grown to a size now that "nothing" is safe in the tank. Well, nothing made of plastic that has realistic texture, which allows her to get a grip with her big claw.

[Hermiecrab]

Oh dear...

[CrabbyLover77]

Maybe grab some moss too if she doesn't have any? My guys like to shred it up when it dries out.
Do you have any of Motörcrab's curiosity cubes? I put popcorn in mine and my crabs seem to enjoy playing with them. Keeps them busy.

Sent from my Moto G (5) Plus using Tapatalk

[crabocado]

Thanks CrabbyLover77, for those suggestions. So, does the moss recover after the crab shreds it? Moss does sound like a great idea, in fact I'd been toying with adding some kind of real vegetation to the tank, just wasn't sure where to start, but since they sell in moss in the pet stores that seems like an easy one.

As far as the "curiosity cubes", nope, have never heard of 'em, and I'd love to know more. Is it something that Motörcrab sells? Or is it a make-it-yourself item? Any tips appreciated...

[CrabbyLover77]

Thanks CrabbyLover77, for those suggestions. So, does the moss recover after the crab shreds it? Moss does sound like a great idea, in fact I'd been toying with adding some kind of real vegetation to the tank, just wasn't sure where to start, but since they sell in moss in the pet stores that seems like an easy one.

As far as the "curiosity cubes", nope, have never heard of 'em, and I'd love to know more. Is it something that Motörcrab sells? Or is it a make-it-yourself item? Any tips appreciated...

You're welcome!

The moss is pretty much a goner once they shred it, but they seem to enjoy the activity lol. I just put in little bits at a time for them to play with.

Motör and Xeno make the cubes and sell them in their Etsy shop. It looks like they're on a break right now though. Here's the link anyway:

https://www.etsy.com/shop/CoenobitaCuri ... _purchases

I tried making one myself first, but it didn't come out great. So then I just bought 2 from Motör/Xeno and they are much nicer lol.

Sent from my Moto G (5) Plus using Tapatalk

[Motörcrab]

I'm with wodesorel on this. Crabs tend to get bored if there are not enough things to entertain them. Having an exercise wheel along with areas to climb will give them more places to roam. Our crabs actually spend a lot of their time climbing up high off the substrate.

[KyMart]

Busy (around 9 yrs. old) has a plastic shelter from PetSmart in her 20 gal tank that looks like a half-pipe of bark. She's had it for a few months. In recent weeks I noticed white spots, which I thought might be mold, or just wear & tear exposing the uncolored base material. Recently I realized she's actually broken through to an interior "space", and sure enough, the "bark" is actually whitish once you get through the colored outer surface. She spends time sitting there plucking more bits of plastic off.

On walks in the house, in the past she's shown a fondness for soft plastic (earbuds lying around; occasionally electric cords). But she's never seemed to pluck hard plastic before. (For years she's had a hard plastic "dead branch" in the tank but that has never shown any damage). She only emerged from her latest molt a couple weeks ago, so maybe she's got a newfound ability to crack into the hard stuff.

I took the "bark" shelter out in case this is harmful, but I'm wondering what you think? I don't know if she is eating it. I worry about bits of undigestable stuff blocking her digestive tract.

FYI, first time adding photos to this site! I started an "imgur" account just for this purpose.

She is such a pretty girl! Aww!

[crabocado]

Thanks!

Update (since my last post on this thread) - I've had a 3/4-cylinder of cork bark in there for the last year and a half I guess, as a replacement for that plastic thing she was eating/destroying. I think the cork bark has worked well, she probably has made some holes in it but hasn't really done any significant damage.

[KyMart]

Thanks!

Update (since my last post on this thread) - I've had a 3/4-cylinder of cork bark in there for the last year and a half I guess, as a replacement for that plastic thing she was eating/destroying. I think the cork bark has worked well, she probably has made some holes in it but hasn't really done any significant damage.

Yay! Glad to hear that she is doing well and having fun with her new cork bark!