Dwarf Hermit Crab

[JennyPenny]

I thought I would start a new thread for my questions. Has anyone put dwarf hermit crabs in their setup, success or failure? I starting reading about them last night and thought one or two very small ones would be OK for my little 2.2 gallon. But I couldn't find much info about what species are definitely safe for brackish. Most stores listed them as requiring full saltwater. Other sites say any can be in brackish. Some sites say you must add iodine to the tank so they can molt successfully. And do they require acclimation, or can I just put them in? Most importantly, will they eat baby shrimp or larvae? And assuming I provide a lot of shells, will they still eat my thorned nerites or Malaysian trumpet snails?

[KenCotigirl]

I tried them. One problem is for our setup you can have one or two. They seem to be out of view often. I do not believe it is worth the time.

Ken

[shrimpy4]

I have one I purchased advertised as a Hawaiian left-handed Dwarf that exists with Opae in the wild in Brackish water.

He's about the size of a kidney-bean with the shell included, had no problem just plopping him into the water. But the species I got must not be listed correctly, since the Dwarf Hermits are supposed to have one claw larger than the other and be bluish, he's reddish and both of his are the same size and pointed. I like having him in there, he's interesting to watch as he walks, climbs, and roots around. When I feed the bowl, I'm really just feeding him a pinhead-sized pellet of food twice a week, he monopolizes it as soon as he realizes it's in there, running over from wherever he is and lightly batting away the Opae if they try to eat some too. He's molted once since I started doing that, but changes shells every couple of months.

At one point I read they like company, so I ordered another one. That one was definitely the right species, bluish with one claw larger, but he was TINY. Smaller than a lentil, and maybe 1/4 the size of the bigger guy. The bigger guy ate him at some point, which I feel pretty bad about. That's when I started to feed him twice a week instead of just once every week or two weeks, but I still don't know if I would risk getting another hermit in my 1-gallon bowl.

[minishrimps]

I'm intrigued by these hermit crabs, I might get a couple, i'm not sure I'll add them in my Opae tank yet, if at all, but I already have another 5.5 gallon tank on the way. Can ask you to PM me details about what purveyor you used to acquire them? Thanks!

[Jackal148]

I have 2 Fluval 6 Aquariums set up Sg 1.010 and the other 1.019Both have been breeding and both contain Blue Leg Hermits -- 3 in each tank. For a long time, the hermits in the 1.019 tank bred about every ten days. The larva floated about for a few days but after about 3 there were none to be seen. Probably starved to death. Never noticed the Opae bothering them. When they were breeding, I must admit, I was feeding the tank a bit more than I currently due which might explain why they are not spawning while the opae do. The reason for the higher salinity in the one tank was because I wanted to try to raise dwarf seahorses. The crab larva would have been a good food source in addition to baby brine and copepods. That experiment ended when I got a huge population of colonial hydras which shattered the progress I had made with the copepod population and the speed with which they pulled the BB out of the water column. The Blue Legs are pretty active and really scurry about when food is added. They can be comical to watch when they change shells. Some times switching form a current home to a new one and then back again often a few times before settling. Occasionally, I have seen 2 get into the same shell for a while. (mating?)

I never notice any spawning of the Blue Legs in the lower salinity tank. Could have been the salinity level or there just wasn't the right sexual mix. I did acclimate them slowly to the lower levels of salinity from that in which they arrived and they have been doing well no for over 2 years. Also doing very well is a Marimo Ball in the 1.010 Salinity tank. It was one of several marble size pieces from others in my fresh water tank that I acclimated to higher salinity levels. Took pieces from various freshwater ones and put them in an aquarium by themselves to which I slowly added salt water. When I reached 1.010 I put a few into the 1.010 tank where over time most began to unwind and fall apart but one continued strong, retained its shape and color and has been slowly growing. It is now about a little bigger than a ping pong ball. The ones I got acclimated to 1.019 lasted a few weeks but began to deteriorate and were removed. May try Mustafa's moss balls once the weather improves and postal costs come down.

[minishrimps]

I have one I purchased advertised as a Hawaiian left-handed Dwarf that exists with Opae in the wild in Brackish water.

He's about the size of a kidney-bean with the shell included, had no problem just plopping him into the water. But the species I got must not be listed correctly, since the Dwarf Hermits are supposed to have one claw larger than the other and be bluish, he's reddish and both of his are the same size and pointed. I like having him in there, he's interesting to watch as he walks, climbs, and roots around. When I feed the bowl, I'm really just feeding him a pinhead-sized pellet of food twice a week, he monopolizes it as soon as he realizes it's in there, running over from wherever he is and lightly batting away the Opae if they try to eat some too. He's molted once since I started doing that, but changes shells every couple of months.

At one point I read they like company, so I ordered another one. That one was definitely the right species, bluish with one claw larger, but he was TINY. Smaller than a lentil, and maybe 1/4 the size of the bigger guy. The bigger guy ate him at some point, which I feel pretty bad about. That's when I started to feed him twice a week instead of just once every week or two weeks, but I still don't know if I would risk getting another hermit in my 1-gallon bowl.

Are these Hawaiian Left Handed Dwarf hermits entirely aquatic or do they need some occasional of dry land respite?

[Varanus]

Are these Hawaiian Left Handed Dwarf hermits entirely aquatic or do they need some occasional of dry land respite?

Most hermit crabs are by nature completely aquatic and will rarely come on land unless forced out of the water, the well-known land-dwelling ones are actually in the vast minority when it comes to their behavior and habitat. As far as I know the many marine species have no problems with being underwater all the time, even though they can survive for a while on land if they have to.

[minishrimps]

Great, thanks. My understanding is that this species is a tide pool dweller sometimes dealing with moments of dry land exposure during tidal shifts. I wasn't sure if it was a necessary element that they may need.

[mcdaney]

Great, thanks. My understanding is that this species is a tide pool dweller sometimes dealing with moments of dry land exposure during tidal shifts. I wasn't sure if it was a necessary element that they may need.

Yup you're right. Successful breeding of these hermit crabs might have something to do with it. Interesting creatures indeed

[JennyPenny]

Thank you for the info everyone! I think I will hold off on adding the crabs as this point. I did add two horn/thorn nerite snails and they have cleaned the glass so well that I might have to put them in my freshwater tank.
I like not having to feed the tank and it sounds like with the hermit crabs it would be mandatory a few times a week or so. I might set up a separate tank and try them by themselves. If I did want them with my shrimp I would only get one due to my small setup.
Jackal148 I'm surprised your marimo is thriving! I have not heard of success adapting these to brackish water. That's great that you managed to do it. If I end up purchasing more shrimp I will get one of Mustafa's moss balls, but I'm on a budget right now.

[bcoll197]

I got 10 crabs in 2014 and distributed them among several set-ups. The only ones that survived are the two in my 2.5g filtered tank, with airflow I control to keep low. All the ones I had in unfiltered tanks died. I remember to feed them once a week, or two...or longer . I have had good results with crab cuisine and spirulina; I just have to put in some extra of the crab diet, as the snails and shrimp go nuts for it, too. Mine are active and peaceful. I often find them perched on the sea fan or the sponge filter picking off particles.

[minishrimps]

I got 10 crabs in 2014 and distributed them among several set-ups. The only ones that survived are the two in my 2.5g filtered tank, with airflow I control to keep low. All the ones I had in unfiltered tanks died. I remember to feed them once a week, or two...or longer . I have had good results with crab cuisine and spirulina; I just have to put in some extra of the crab diet, as the snails and shrimp go nuts for it, too. Mine are active and peaceful. I often find them perched on the sea fan or the sponge filter picking off particles.

I recently spoke with a purveyor of dwarf hermit crabs and they told me that despite the fact that they can survive in the wild in some pretty stagnant pools, they need either a filtered tank, or, at minimum some sort of aeration in the tank...

[Corucia]

I've had dwarf hermits in all three of my tanks, which have bee up and running for roughly 2.5 years (3 gallons), 2 years (3 gallons) and 9 months (7 gallons), respectively. None of the tanks are filtered or aerated. The water is completely stagnant. I feed them (and the shrimp) a small portion of crushed pellets once a week.

In terms of mortality, I originally introduced six crabs into each tank. In the three gallon tanks, I've have two of the crabs survive in the oldest tank and three in the other. Interestingly, the two survivors in the oldest tank have grown quite large. They are fairly active and in shells just a bit smaller than a dime in diameter.

The three survivors in the other three gallon tank haven't grown much since I got them and just switch from one (small) shell to another. Of note, at least one of the crabs in this tanks appears to have eaten one (or more) of my pipipi snails and is now housed in one of their shells. I saw him eyeing up another snail this weekend (he was mounted on top of one trying to pry in) but relented when I dropped some food in. This particular fellow also seems to be a somewhat different strain than the others and is much faster (sometimes does a mini sprint).

Finally, in the 7 gallon tank, I think I still have four or five still going, but because of the numerous hiding spaces it's hard to find them all at once. These fellows haven't grown much either, and I've had at least one if them canabalize a snail in this tanks as well and is using a pipipi snail shell.

[minishrimps]

I've had dwarf hermits in all three of my tanks, which have bee up and running for roughly 2.5 years (3 gallons), 2 years (3 gallons) and 9 months (7 gallons), respectively. None of the tanks are filtered or aerated. The water is completely stagnant. I feed them (and the shrimp) a small portion of crushed pellets once a week.

In terms of mortality, I originally introduced six crabs into each tank. In the three gallon tanks, I've have two of the crabs survive in the oldest tank and three in the other. Interestingly, the two survivors in the oldest tank have grown quite large. They are fairly active and in shells just a bit smaller than a dime in diameter.

The three survivors in the other three gallon tank haven't grown much since I got them and just switch from one (small) shell to another. Of note, at least one of the crabs in this tanks appears to have eaten one (or more) of my pipipi snails and is now housed in one of their shells. I saw him eyeing up another snail this weekend (he was mounted on top of one trying to pry in) but relented when I dropped some food in. This particular fellow also seems to be a somewhat different strain than the others and is much faster (sometimes does a mini sprint).

Finally, in the 7 gallon tank, I think I still have four or five still going, but because of the numerous hiding spaces it's hard to find them all at once. These fellows haven't grown much either, and I've had at least one if them canabalize a snail in this tanks as well and is using a pipipi snail shell.

This is great information to know. I think I misquoted the gentleman that I communicated with. He said he thinks they "prefer" to have some sort of aeration... I'm glad to hear that they can survive well without. I was planning on adding one to my 2.5 gallon. I am setting up another tank for crabs that will hopefully have about five total hermits and five pipipis. I've already littered that tank with about 50 various sized pipipi nerite and moonshells hopefully that's enough to chose from the crabs won't eat the snails!

[Mustafa]

The question though is if there is any Supershrimp reproduction in tanks with hermit crabs that get fed once or twice a week. I would guess no, but let's hear about some experiences here.