Rescue Crabs and Molting

[MrRpage]

My wife and I have been keeping land hermit crabs since 2018. We're relatively confident in our setup - proper substrate depth, heat, humidity, water pools, etc. We just rescued 2 hermit crabs from a fairly poor setup - calcium sand, minimal substrate (only about 1" total), no heat or humidity to speak of besides ambient room temperature, and pellet-fed. They're both in rough shape but seem to be adjusting OK. We have them quarantined them separately in smaller containers within our large 75 gallon tank. Apparently, the larger crab had had a history of aggression towards younger crabs, which we assume is likely due to poor diet choices and lack of suitable shells.

The larger of the two has been digging into the 1" substrate we've given it in its isolation container. It just changed shells, which is promising, but seems lethargic and uninterested in anything other than digging. Based on the quality of their previous enclosure they probably did not get a chance to molt for at least a year. Since both crabs were pellet-fed, we are concerned the larger crab may not have the strength or required nutrient reserves to complete its molt, but it seems like it desperately needs to.

For now, we plan on getting both crabs adjusted to a better diet before we let them out to burrow, but the apparent determination of the larger one to molt and its lethargy are prompting us to reconsider our care plan. We would like to hear additional advice or care suggestions from other crabbers who may have done similar rescues in the past.

We are happy to provide more information if needed! Thank you so much!

[CrabbyLover77]

I think it's important to get them into proper conditions right away. I don't quarantine any of my rescues. I get them into the tank asap so they can do whatever they need to do. I've never had a problem so far. If it were me, I'd let the newbies into the tank right away. My crabbies love friends too, so they're always happy to have more buddies to cuddle with.

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[HermieBingo]

I agree with CrabbyLover

[HermitCrabCHICA]

I agree. Let us know how it goes. Good luck!

[curlysister]

Very experienced crabbers with HCA, who have rescued hundreds of crabs, have never had better survival outcomes from using a method like the PPDS one. A crab can not put off a molt indefinitely - eventually they have to molt, and will do so no matter what conditions or substrate (or lack thereof) they have. So while *you* might want them to have better nutrition prior to molting, *they* may not be able to wait. It is safer for a crab to be able to tunnel and molt underground, than it is for them to surface molt.
Long story short, I too would put them into proper depth of substrate. You might consider giving everyone (both old and new crabs) a quick dip in the fresh water, so that the newbies and the oldies all smell the same, and nobody is perceived to be an interloper.

[Xenocrab]

We recently rescued more crabbies. We use a separate tank and encourage eating and molting. They are separate so other crabs don't injure them while they are recovering. Then after they are mostly recovered, it may take months, but we add a small baby or two for friendship and watch the interaction. If all goes well for some time, we will add them to the bigger tanks, but still watching closely. All our tanks have a pecking order and some don't take kindly to a new crab. We have had to move crabs to different tanks until we find that they can all get along. That's just my experience

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[crabs_lex]

We recently rescued more crabbies. We use a separate tank and encourage eating and molting. They are separate so other crabs don't injure them while they are recovering. Then after they are mostly recovered, it may take months, but we add a small baby or two for friendship and watch the interaction. If all goes well for some time, we will add them to the bigger tanks, but still watching closely. All our tanks have a pecking order and some don't take kindly to a new crab. We have had to move crabs to different tanks until we find that they can all get along. That's just my experience

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when introducing new crabs do u dip them in the water like other people suggest? i’ve never tired it myself and never had a problem but i know all crabs are different. i’m just curious because i know you and motor rescue so many crabs! just curious what works with your experience

[crabs_lex]

We recently rescued more crabbies. We use a separate tank and encourage eating and molting. They are separate so other crabs don't injure them while they are recovering. Then after they are mostly recovered, it may take months, but we add a small baby or two for friendship and watch the interaction. If all goes well for some time, we will add them to the bigger tanks, but still watching closely. All our tanks have a pecking order and some don't take kindly to a new crab. We have had to move crabs to different tanks until we find that they can all get along. That's just my experience

Sent from my Pixel 3 using Tapatalk

when introducing new crabs do u dip them in the water like other people suggest? i’ve never tired it myself and never had a problem but i know all crabs are different. i’m just curious because i know you and motor rescue so many crabs! just curious what works with your experience

[DragonsFly]

If you possibly can provide a different crabitat with proper depth of substrate, that is what I would do. Adding crabs to an existing pair or group is problematic for lots of reasons, but crabs can only put off molting so long, and it is dangerous for them to do so. As someone else said, forcing them to surface molt because they can't dig down is a bad idea. If you can give them a designated "molting habitat," that would be my preference. You can quickly set up a 10 g tank (or similar size improvised 'tat from a plastic bin), basically full of substrate, just for molting.

[MrRpage]

Thank you everyone for your responses! We maintain a 10 gallon tank as a "just in case" isolation tank. In the past 24 hours, we've noticed the new rescues eating well and foraging, though the large one continues to dig. Despite bathing being somewhat controversial, we did elect to bathe both new crabs to get rid of all the calcium sand they had caked onto them. During this time, we allowed them to meet the crabs we currently had in our care, and did not note any signs of immediate aggression.
When we return home today, we'll get the larger crab into deeper substrate so it can molt.

Thanks again to everyone for your responses! We have some experience keeping hermits, but haven't dealt with anything like this!

[DragonsFly]

If you suspect the large one that looks like it needs to molt is particularly weak, that is all the more reason to let it molt somewhere not in the presence of other crabs. And if you have any in your main tank already down molting, remember that newly introduced crabs often dig down right away, and the vulnerable molters already down there, should the new ones encounter them, make an excellent, protein-and-chitin-rich meal.