Common name: Knobby Sea Star

General information

The Knobby Sea Star, scientifically known as Pentaceraster mammillatus, is a striking marine invertebrate popular among reef aquarium enthusiasts. It is characterized by its distinctive horn-like spines and chocolate chip-like tubercles covering its dorsal surface, which give it its common names. This sea star can exhibit a range of colors, typically from reddish-brown to orange or yellow hues, adding a vibrant touch to any marine setup.

Care

Caring for the Knobby Sea Star requires a well-established aquarium with a sandy bottom and ample live rock for grazing. They are omnivorous and will feed on detritus, small invertebrates, and sometimes even coral polyps, so they should be monitored in a reef tank to prevent damage to coral populations. Regular feeding with meaty foods like shrimp or squid can help satisfy their dietary needs without harming other tank inhabitants.

Reproduction

Reproduction in Pentaceraster mammillatus typically involves broadcast spawning, where males and females release sperm and eggs into the water column. In the aquarium, however, breeding is less common, and hobbyists rarely observe successful reproduction.

Symbiosis

While not known for any specific symbiotic relationships, the Knobby Sea Star may inadvertently provide microhabitats for small organisms among its spines and tubercles. However, this is not a significant aspect of its biology in the context of aquarium keeping.

Habitat

The natural habitat of the Knobby Sea Star includes coral reefs and rocky substrates in the Indo-Pacific region. They are often found at various depths, from shallow waters to deeper reef slopes, where they roam in search of food.