starfish question

[1stMarDiv]

We have 1 fairly large 8" orange starfish in our tank. We recently noticed about 15 very small white starfish traversing along the bottom of the glass. These are about 3/16" and some seem to only have 3 or four arms rather than 5. I was told the orange star had babies. Do these usually survive? How long does it take for them to grow to a noticable size? Thanks.

 

[Zooid]

Sounds more like Asterina stars to me. Some people hate them, I personally don't mind them as long as the population is small.