Serpent Starfish - Ophioderma sp.
These elusive starfish will spend most of it's time resting under your rocks. Some will come out when they smell fish food added to the tank. Most often you will see their legs hanging out from under the rocks hoping to grab some fish food floating nearby. They are great tank cleaners because they will eat any uneaten fish food that would normally get stuck & decay under our rocks. Can sometimes be seen roaming the tank at night after the lights are off.
NEVER take this starfish (or any other for that matter) out of the water!!
Special Acclimation is needed! With tank lights off, do not open their bag & float for 15 minutes to equalize any temperature difference. After 15 minutes, open the bag, check the bag salinity with a refractometer & if your tank is more than 2 degrees different than their bag DOUBLE the acclimation time! Continue to float & gently start adding some of your tank water to the bag. On average the bags I use for them will need 1/2 cup every 15 minutes - do this for an hour then submerse the entire bag under your tank water and gently jiggle the bag to release.
My water is reef water & is totally safe to add to your tank. If they end up upside down when released, gently flip them over as it takes energy for them to right themselves.
Average size is approx 4-6 inch
Pictures are examples only. Expect some variations.