Researching this particular star fish brings up a lot of responses. Problems are that they all differ especially with the description of the Red Knobby Sea Star FIsh. Seems that the Red Chocolate Chip Star fish is at times called the Red Knobby. As we all know Chocolate Chip Star Fish are most definitely NOT reef safe as they eat corals.. I did have a red starfish that had bumps all over for many years in my tank that never harmed anything. It died during a tank crash not so long ago.
:google:
Below is just one of many:
http://www.aquacon.com/starfish.html
Red Knobby Star
Echinaster echinophorus
Description: The Red Thorny Starfish (Echinaster echinophorus) is sometimes called a Flame Red Thorny Starfish, a Red Thorn Back Starfish, or a Red Spiny Starfish. It belongs to the family named Asteriidae. Typically reaching a max size of about 8.0 inches in length, the Red Thorny Starfish is passive in nature and hardy in stamina. It's more active during the daytime and less at night, and will hang out across the entire tank. According to FishDB current data, captive breeding success is good and there are no external signs of sexual differences. Echinaster echinophorus in general should have standard (3 watts/gallon) light to thrive. Tank parameters should be maintained with ph level between 8.1 - 8.3, temperature between 77 - 79 degrees fahrenheit, and a salinity between 1.020 - 1.023. Some of the environmental concerns that you should strive to replicate in your home aquaria to promote succesful acclimation include a well established aquarium, high water quality, and porous live rock.
Notes: Starfish are intolerant of sudden changes in oxygen levels, salinity and pH of the water, and cannot tolerate copper-based medications. Extra care and time should be taken whenever acclimating this animal.The drip acclimation method is highly recommended for all Sea Stars due to their intolerability to changes in water chemistry. Starfish must never receive exposure to air during acclimation.
Level of Care: Moderate
Acclimation Time: 3+ hours
Reef Compatibility:Eat Sponges
Approximate Purchase Size: 2 - 3 inches