Asterina Outbreak

Discussion in 'Inverts' started by omard, Nov 9, 2007.

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

  1. omard

    omard Gnarly Old Codfish

    Joined:
    Sep 28, 2003
    Messages:
    4,745
    Location:
    Silverdale, Washington
    [​IMG]


    Asterina Wega​





    Has been quite a while since I have had a outbreak of these...(which have been a plague in my tank since onset.)

    This AM (09 Nov 2007) - netted the following off glass. Have only seen one or two for quite a while, which I did not bother to pull out.




    [​IMG]





    Apparently they are back with a vengeance. Have seen them come in "waves" before, and will have to go week or so, pulling them out daily to get population down. If this many on glass...God knows, how many are hanging out in and around LR. -- I can see a number of them, but cannot get to them without siphoning - which I do on water change days.



    Nardoa and Asterina spp Sea Stars


    [​IMG]


    There is some controversy over the Asterina species sea stars, which can multiply to great numbers in reef aquariums. Most aquarists report no problems with them, but some claim that they eat SPS corals and make every effort to remove them. There are more than one species of Asterina and it's speculated that some species may be harmful. It's also speculated that the Asterina sea stars will consume SPS corals once they reach a certain density. I happened to put a Nardoa species sea star into a small reef aquarium that contains a large population of Asterina sea stars. I discovered that the Nardoa sea star regularly consumed the Asterina sea stars. The Nardoa sea star san be a good biological control for those aquarists that want to reduce their population of Asterina sea stars.
    GREG SCHIEMER


    [​IMG]




    Starfish: Considerations for the Common (and Commonly Misunderstood) Varieties




    [​IMG]


    Asterina sea stars have been accused, unfairly at times, for preying on coral tissue. While some individuals appear to eat some desirable reef invertebrates, the problem may be a simple matter of an opportunistic predator adapting to a change in the available, preferred foods (worms, algae).

    Returning to our example of the common, small Asterina species found in some reef tanks, these sea stars in recent years have suffered, unfairly I might add, the reputation of being risky or just plain un-safe in the reef. This is interesting because for many years prior to that, they were not only regarded as harmless, but beneficial! What happened? Did they all change their voter registrations overnight? No, the answer really is quite simple. It also explains why some other "controversial" reef invertebrates have contradictory reputations like Mithrax/Mithraculus crabs. Many such creatures are opportunistic feeders. While they favor one type of prey that is convenient or popular to us, like sand bed worms, brown diatoms or bubble algae, they will adapt to eating other food items following the reduction or absence of a preferred food item. Thus, the reef keeper with a persistent growth of microalgae in a garden reef display will likely have less trouble with misbehaving omnivores than another aquarist with an aggressively skimmed and scrubbed tank that supports little growth of the matter. In a phrase, the hungrier that a so-called "reef-safe" creature gets, the less "reef-safe" that creature becomes. In the case of Asterina, many years ago during the bare-bottomed, nutrient poor Berlin style era of reef keeping, reef husbandry with early protein skimmers and limited nutrient export processes was not as efficient as it is today; diatoms and other nutritious growths grew quickly in our tanks. And Asterina were not considered un-safe by hobbyists.

    Anthony Calfo








    [​IMG]






    [​IMG]
  2. Click Here!

  3. Camilsky

    Camilsky Montipora Capricornis

    Joined:
    Oct 28, 2007
    Messages:
    1,005
    Location:
    Groningen, The Netherlands
    Gosh... I don't have any corals right now... And there are approx. 7 Asterina in my tank already. Shall I start extermination ?!

    Cheerio!
  4. amcarrig

    amcarrig Super Moderator Staff Member

    Joined:
    Aug 4, 2004
    Messages:
    9,175
    Location:
    CT
    So, are you saying that yours have come back as well Omar?
  5. omard

    omard Gnarly Old Codfish

    Joined:
    Sep 28, 2003
    Messages:
    4,745
    Location:
    Silverdale, Washington

    Oh yes...point of post. They are back.

    Even Harley's don't want them. :-/
  6. omard

    omard Gnarly Old Codfish

    Joined:
    Sep 28, 2003
    Messages:
    4,745
    Location:
    Silverdale, Washington

    Would strongly recommend getting them out while you still can.

    If you see 7, you probably have 50. (tiny ones.)

    I think my sixline may eat the little ones and is reason I go long periods without seeing them. - But when they show up, they show up in bunches. :mad:

    Scott
  7. IBMGeek

    IBMGeek Montipora Digitata

    Joined:
    Feb 15, 2007
    Messages:
    1,054
    Location:
    Miami,Fl
    My LFS Has a nice nano with a bunch of corals and he is growing some little stars just like that on the glass.
  8. Click Here!

  9. Nemo 2

    Nemo 2 Bristle Worm

    Joined:
    Sep 27, 2007
    Messages:
    136
    i have one of those in m tank that i have been trying to take a picture of but i havnt been able to.so if there leg breaks off that means they reproduse off the broken off leg correct?
  10. amcarrig

    amcarrig Super Moderator Staff Member

    Joined:
    Aug 4, 2004
    Messages:
    9,175
    Location:
    CT
    Everybody should keep in mind that not all asterinas are coral eaters so no need to start killing them willy nilly. It seems that the white/grey ones are safe but the ones that are brown-ish are not.
  11. Nemo 2

    Nemo 2 Bristle Worm

    Joined:
    Sep 27, 2007
    Messages:
    136
    mine seems to change color.when i first discovered him he was very white now he is turning a tan brown color.he came on the lastbit of live rock i purchased.
  12. omard

    omard Gnarly Old Codfish

    Joined:
    Sep 28, 2003
    Messages:
    4,745
    Location:
    Silverdale, Washington

    Would be surprised if only one...;)