archaster

[dragonwrasse]

Anthony

A LFS has archaster stars on sale. From reading your book, I'm getting somewhat conflicting feedbacks on these. In one place, it's said that they can completely sterilize a sandbed, but they are also listed in the "Best of Sea Stars" section. Can you clarify? Are they going eat all the worms and good sand guys along with detritus and algae? Thanks.

[Anthony Calfo]

all true... they can be quite voracious and will reduce the biodiversity of the bed... it is that very thing that makes them so good: for some systems (the caveat!). It depends on what you need/value more...

These poor starfish starve to death slowly in most systems. Frankly, if they go into a tank much under 200 gallons and/or with anything less than a mature deep sand bed (1 yr. plus ideally), they will starve in less than 2 years IMO.

Now for a big tank, if you want/need a deep sand bed, and value denitrification most... then you may be willing to have this excellent deposit feeder keep the bed aerated and nicely "clean" (free of diatom growth, etc). At one per 6-8 square feet of DSB, say, minimum. It does not get much cheaper to maintain a sand bed!

But if instead you have a want/need for better infauana to the sand bed (no refugium in the tank, needy fishes like dragonets, tube-snouts, small wrasses, etc)... then perhaps you will not want to give up ground on the bio-diversity. You will then have to compromise and find other (more expensive usually) means of maintaining the sand bed (unless you manually stir it weekly or better).

Like most aspects of marine keeping ("best" lights, "best" flow, etc.), there is no absolue answer... it depends on a sometimes complex evaluation of wants/needs for the tank and species being kept.

Anthony :)