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  1. Arrow Crab, a data point and a question (M)
    by mcconnel/ (Guy McConnell) (Tue, 3 Mar 1992)
  2. Arrow Crab, a data point and a question (M)
    by mcconnel/ (Guy McConnell) (24 Mar 92)

Arrow Crab, a data point and a question (M)

by mcconnel/ (Guy McConnell)
Date: Tue, 3 Mar 1992
Newsgroup: alt.aquaria,sci.aquaria,rec.aquaria

    I'm sorry that I don't have the attributions but that's life.  Anyway,
recently someone asked about Arrow Crabs eating bristleworms.  Someone else
answered that they were reputed to do do just that.  I bought one last week
and I'm happy to report that it does indeed eat bristle(fire?)worms.  I saw
the crab pluck one out of a rock and shred him into bite-sized pieces.  It 
then proceeded to eat each piece at its leisure.  I was happy to see that as I
bought the crab specifically to fight my bristleworm population.

    Now for the question.  What type of additives are needed to keep this
little fellow alive?  For some reason, I seem to recall that iodine is a good 
idea if you have crustaceans in the tank.  Thanks for any input.

Guy McConnell

Arrow Crab, a data point and a question (M)

by mcconnel/ (Guy McConnell)
Date: 24 Mar 92
Newsgroup: alt.aquaria,sci.aquaria,rec.aquaria

In article <34791-at-uflorida.cis.ufl.EDU> (Philip Duvalsaint) writes:
>In article <> (Kevin Sullivan) writes:
>>One more question for arrow crab keepers: (OK more than one)
>>Are there any animals that shouldn't be kept with arrow crabs?
>>(Animals I might want in my 20 gallon microreef.)
>I would not advise putting an arrow crab in a reef tank. Since it will nibble
>on the soft corals, live rock, mushrooms etc... In addition, arrow crabs and
>banded coral shrimp are mortal enemies.  I would either get a fish only tank
>and add the arrow crab - or add shrimp to the existing set up. 

    Since I started this thread, I'd be interested to know where the
information about the Arrow Crab "nibbling" on things came from. 
While my tank is not, at the present, a full-blown mini-reef, it is
heading in that direction.  One of the reasons I bought the Arrow
Crab was the assurance that I got from several sources (pet stores,
people who have them, etc.) that they would *not* harm sessile
inverts.  I have some base rock in my tank which is covered with
featherdusters, an Atlantic condylactis anemone, a tank-raised
clownfish, a brittle star, some "Florida false coral" (flesh
colored), and the Arrow Crab.  Until the addition of the crab, I
also had literally hundreds of small bristleworms as well.  For all
appearances, they are gone now.  While there still may be a few
left, they have been cut to a fraction of their previous population,
if no wiped out entirely, by the Arrow Crab.  It has not bothered
the featherdusters, the false coral, or the anemone.  I have even
seen it pick up a small featherduster off of the bottom of the tank
and then release it as soon as it "realized" what it was.  The crab
has done what I bought it for; eliminate the bristleworms in
anticipation of building up my reef tank.  I intend to keep it
unless someone can convince me that it would be harmful to other
reef inhabitants (other than the shrimp - I'll accept that one).
>Banded coral shrimp pairs are interesting to watch, as the clean each other
>religiously, often mate and generally stay in contact with each other with
>their long tentacles. I'd also lose the bristle worms because they can also
>destroy live rock (as well as stinging the ^%$-at-^%#! out of your hand.)

    "Losing" the bristleworms is precisely the reason for buying the
Arrow Crab (in my case anyway).  As I mentioned in a previous post,
I have not seen any worms in my tank that were over about 1.5" long
so the crab might not be effective against the giant ones that some
people have.  Even if I have to get rid of the crab ino order to
keep reef inhabitants safe, it still fit into my overall approach to
aquarium keeping:  Plan, take it slow, and think over thoroughly any
purchase - be it specimen, equipment, or whatever.  It got rid of
the worms so I'm happy with it.  It looks quite interesting too.

Guy McConnell

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