Small grey starfish - harmful?

Discussion in 'ID This!' started by SirReefsAlot, May 23, 2011.

to remove this notice and enjoy 3reef content with less ads. 3reef membership is free.

  1. SirReefsAlot

    SirReefsAlot Plankton

    Joined:
    May 17, 2011
    Messages:
    8
    Just wondering what these starfish are and if they are harmful. They each have five points and there are about 5-10 in my 35 gallon and 10g sump that I know of. Asterina?? The one pictured is the largest I have found, about 1cm across, others are smaller. They are all a spotted light grey color.

    [​IMG]
     
  2. Click Here!

  3. JJL

    JJL Purple Tang

    Joined:
    Jan 5, 2011
    Messages:
    1,818
    Welcome to 3reef
    Yup, asterina starfish
    Some people say in large numbers certain asterinas can be harmful to coral, but I would just keep them in there ;)
    JJL
     
  4. grinder37

    grinder37 Whip-Lash Squid

    Joined:
    Sep 17, 2009
    Messages:
    2,984
    yes asterinas

    ps-welcome to 3reef!
     
  5. Corailline

    Corailline Super Moderator

    Joined:
    Sep 8, 2010
    Messages:
    19,652
    Location:
    It is a dry heat, yeah right !
    Those are Asterina starfish. I would bet those eat coralline. Most a are harmless. As long as you do not find them under hard coral frags or missing zoanthids they are probably safe. I myself like them and do not remove them.
     
  6. 2in10

    2in10 Super Moderator

    Joined:
    Aug 6, 2009
    Messages:
    19,258
    Location:
    Sparks, NV
    Welcome to 3reef

    Asterinas and they look safe
     
  7. SirReefsAlot

    SirReefsAlot Plankton

    Joined:
    May 17, 2011
    Messages:
    8
    I have pulled 60 of these out of my tank just because they leave white bleach spots where they eat the coralline alge. They seem to breed like crazy. I did see one large one munching on an SPS so I immediately ripped him out. I haven't seen any on corals since.
     
  8. Click Here!

  9. Pastey

    Pastey Ritteri Anemone

    Joined:
    Jun 7, 2011
    Messages:
    638
    Yep they'll eat coralline. I've seen trails of white in my coralline from them eating as they move. Pain if you're trying to get a nice coralline coverage on new rock but I imagine it'd be OK if you have gotten to the point when coralline is more of a "problem".
     
  10. Ashevillian

    Ashevillian Pajama Cardinal

    Joined:
    Jun 27, 2011
    Messages:
    1,437
    Location:
    Asheville, NC
    watch them leave white spots on your coralline algae as they munch down on your purple. thats why i dont like them i usually grab them and throw them in the sump, i've seen some tanks get over run with them but i dont know how it gets that bad