The Sand Sea Star – Archaster angulatus is a common and widespread starfish species found in the Indo-Pacific region. This species is distinguished by its five arms and its preference for sandy habitats.
Description & Characteristics
The Archaster angulatus has a characteristically flat, five-armed body with a central disc. It can reach a maximum size of around 10 centimeters in diameter. The arms are relatively short and thick, tapering to a blunt point. The aboral surface (upper surface) is typically covered in small, granular ossicles (bony plates) that give it a rough texture. The oral surface (underside) is smooth, with a central mouth surrounded by five rows of tube feet. The color of the Archaster angulatus can vary, ranging from pale brown to reddish-brown.
Habitat and Occurrence
The Archaster angulatus is a benthonic species, meaning it lives on the seabed. It is commonly found in sandy and muddy habitats, particularly in shallow coastal waters. The species is typically found at depths ranging from the intertidal zone down to 50 meters, with a strong preference for the littoral and sublittoral zones. This makes the Archaster angulatus a common sight in marine ecosystems throughout the Indo-Pacific region.
Taxonomy
The species Archaster angulatus belongs to the Class: Asteroidea, the group containing all starfish species. It is further classified under the Order: Valvatida, which is known for its diverse group of starfish, and the Family: Archasteridae, a family of starfish known for their often-robust bodies.
Feeding
The Archaster angulatus is a detritivore, meaning it primarily feeds on dead organic matter. It plays an important role in the marine ecosystem by consuming detritus, which helps to keep the seabed clean and prevent the build-up of organic debris. This species uses its tube feet to gather organic matter from the surrounding sand and sediment.
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