Janitorial Crab Opinions

[NaH2O]

It seems there are varying opinions on whether or not crabs should be a part of a janitorial crew. What is your opinion? Please indicate:

* Size of your system
* Number of crabs (not hitchhikers - crabs you have added for janitorial reasons)
* Types of crabs
* Do you offer empty shells for hermits?
* Would you recommend them as part of a clean-up crew?

[Craig Manoukian]

In my 80 gallon reef I keep Scarlet and Blue Leg Hermits, about 15 and 15. In my 29 gallon I keep exclusively Scarlet Hermits about 4.

They are marvelous maintenance workers. Snails who perish provide them with a sufficient supply of replacement shells. When they get too big, IMHO, I take then to the LFS and echange then for smaller ones.

[BoomerD]

Same scenario here too. In my 90, I have about 2 dozen hermits, mixed scarlets & blue legs, and a couple of emerald mithrax crabs too. In my 40, maybe a doxen of mixed hermits, and 1 emerald mithrax. I also get rid of them either to the LFS or the sump when they get too big, or in the case of the emeralds, too agressive.

[strat]

when i had my 50 gal fowlr i had lots of red legged(pacific) hermits. i did offer them shells, it was cool to see a shell that we put in the night before crawling around the aquascape.... i voted that they do an ok job.. they were useful in cleaning up scraps of food, but not too good with the algae... thats about it.
strat

[Witfull]

gee....what to vote for...hmmm...this is a hard desision!!!

[jimeluiz]

Wit - you strike a hard bargain!

I probably have 25 or so blue and scarlet legged crabs doing their thing in our 58 gal tank. There are DEFINITELY combative situations going on. But overall it does not seem to be a problem.

The crab that worries me is our GIANT MONSTER hitchiker growing on steroids, eclipsing all other growth in the tank.

I appreciate the cleanup nature of the hermits.

[NaH2O]

Thanks for the replies, everyone! Karma!

[tankgirl]

Hi Nikki,
Well, in addition to the hermits I transferred from my 50, I bought another 120 for the 260Gal. I'm not actually sure how much they help the tank - I don't have sand and get the detritus out pretty regularly - but the hermits can get into places in the LR that snails can't and sift thru the detritus in the LR. I do buy empty shells for them pretty often. Two of my open brains have eaten a hermit!

I have some commensal crabs in my acros, too. Like them a Lot! They keep the acros clean and don't seem to ever leave the acros.

[sharks]

I go one-way or the other.
In the 120 are all snails and in the 72 are all hermits.
A mix of turbos, trochus, nerite, nassarius, and cerith snails
I have all small blue leg and scarlets in the 72
I got to say though I love watching the crabs more then the snails
S

[fidojoe]

I started off with about 10 zebra hermits, some died off, got some blue leg, some died off, got some reef hermits. I never had more than about 10 total in my 50, but then I started getting snails, and I had the one remaining zebra go evil! first he went after the snails, then he started lunging at my clownfish, yikes, he was outta there, along with the other remaining crabs, except for one reef hermit that managed to avoid my crab eradication attempts, but he's been behaving. The crabs that I took out are now in mwrager's agressive FO tank, probably trigger/puffer food

Now, I've discovered a new problem tonight, I found a white crab molt on my sand, it was about 1/4" wide, it looked like the tips of the claws were brownish to black, they were kinda small, so it was hard to tell if the claws were curved tips, or pointed tho. I've never added a non-hermit crab to my tank, so it had to have come in on my new LR. Fun, fun

[reefshadow]

I go one way or the other like Sharks, too. I haven't had any luck mixing them because the hermits kill the snails.

In the 125 sps I keep a large assortment of snails- nassarious, stomatella, turbos, astreas and cerith. The only crabs are acro crabs and my anemone crabs.

In my 125 prop I keep blue red and zebra leg hermits, and an emerald. I keep quite a few emptey shells in there for them.

I think the snails do a better job than the hermits, but that might just be because my prop system is relatively young and also system differences. I'm seeing a little hair algae crop up in there lately

Seeya! -Becca

[Craig Manoukian]

Here is a list of other reef hermits from Gresham Hendee. He is a moderator at 3Reef.com and works for the San Fransico bay area wholesalr Cortez Marine:

From Mexico:

the Staghorn Hermit - Manucomplanus varians - A left clawed white hermit with red eyes and a fire coral shell that filter feeds- best if no other shells are around (so he won't jump his fire coral shell (janaria mirabilis) for the normal ones) and theres plenty of un-obstucted sand bed for him to move around. Don't worry about his shell attacking other corals, its extremelly unpotent.

Mexican Red Hermit - Calcinus Californiensis - Another left clawed hermit (larger left claw) that is dark red with some lighter red/black outlines - a VERY good algea feeder - attacks caulerpa with a gusto if you've got a problem with it and loves hair algae as well.

the Red Tipped Hermit or Dwarf Mexican Hermit - Clibanarius sp - loves cyanobacteria!!!


From the Caribbean:

the Blue Leg hermit - Clibanarius tricolor - An equal clawed hermit - An average hermit when it comes to grazing algae - known to attack other hermits and snails for their shells (more so then others)

the Scarlet Hermit - Paguristes cadenati - An excellent aglae grazer and very mellow to other hermits and snails

the Red Hermit - Calcinus tibicen - not to be confused with the bright red Scarlet Hermit, this one is a deep dark red and a Left clawed hermit

the Little big Claw Hermit aka Polka-dotted Hermit - Phimochirus operculatus - a very aggressive feeder and not to common in the trade - Great looking hermit!!

From Hawaii:

the Zebra Hermit - Calcinus seurati - mentioned above

the Electric Orange Hermit - Calcinus spp. (probably a color morph of the seurati but I'm not sure)- mentioned above

From the South Pacific:

More Blue leg TYPE hermits (dfferent colors) - several differnet Clibanarius spp. - Same as mentioned above - not to common in the trade

More Calcinus spp. hermits, including but not limitted to:

the Electic Blue Neon Hermit - Calcinus elegans - Marshal Islands/Australia/PNG
the Left Clawed Hermit - Calcinus laevimanus - Indo Pacific
Calcinus gaimardii - Indo Pacific
Calcinus latens - From Australia

It's good information, thanks Gresh!

[NaH2O]

Wow, Craig, I think you may give Wit nightmares - with all of those crabs!!

Awesome information! Thank you, karma your way!!

[Craig Manoukian]

Does anybody have any experience with these species?

Rogue Corps brought some Hawaiian Zebra Hermits back from his trip to the islands and didn't voice any complaints about their behavior.

[fidojoe]

I do NOT like zebras, they are ok when they're small, but when they get big, they attack anything and everything, and they don't contribute too much with the cleanup once they develop the taste for meat either.