Hermits breeding?!

[Fishkeeper]

So I have a cousin who has a nano saltwater tank, and she has a redleg and a blueleg hermit crab. We saw her recently, and she told me that there were now eight little ones as well as the big ones:ssuprised: . Fortunately she has lots of extra shells in the tank, so they all have homes. She says 2 of them look like bluelegs and 6 look like redlegs. She had the live rock in the tank for six months before she got the hermits, so she probably would've seen them if they were hitchhikers. Has anyone else heard of hermits breeding in aquaria?

[Fishkeeper]

Anyone gonna imput?

[kaybee]

It's very challenging to successfully breed the kind of hermit crabs that are kept in salt water aquariums due to the planktonic larval stage that they start life as and the type of daily care that these larvae require.

Very challenging to intentionally rear these larvae (in a tank set up for just that purpose where the ultimate focus/goal is to grow them): http://www.marinebreeder.org/forums/viewtopic.php?f=196&t=5976&sid=c834a8e59996014b98c79af2f59bccd6

http://www.int-res.com/articles/meps/141/m141p027.pdf

Extremely difficult/near impossible in a conventional nano tank with no specialized care for the larvae, that is to say that they just suddenly appear with not specialized rearing by the owner. Nearly all hermit crab larvae would be eaten by fish, inverts, corals or removed by filtration system, protein skimmers, water changes, etc in an ordinary tank.

The fact that red leg and blue leg hermits are different species and both types have apparently generated progeny in the nano tank leads me to believe the two new blue leg and six new red leg hermits were either already in the tank or subsequently introduced. For this to even be feasible, both the initial red and blue leg hermits would have had to have been females already carrying fertilized eggs or something like that to begin with.

Do you have a time line on when the initial hermits were acquired and when the new one's appeared, and how large were the new one's when they were discovered?

[Fishkeeper]

The tank was up for about 6 months before the hermits were added, and the live rock was very thoroughly searched before putting it in. The babies were discovered just before Christmas. As to size, the shells they chose to live in were smaller than half a pea, so very small. The tank did have a slight floating algae problem, so that might have fed the larva. The tank only had one fish and no corals, and the filtration system has a pad in the first chamber, so if any larvae went in the filter they would end up on the pad.