Pentaceraster regulus (Müller & Troschel, 1842)
Pentaceraster regulus, commonly referred to as the Regular Star or the Spotted Sea Star, is typically a five-armed sea star ( abnormal with 4 arms). It belongs to the starfish family Oreasteridae. This intriguing echinoderm is native to the warm, shallow waters of the Indo-Pacific region. The Spotted Sea Star is often found in habitats with soft, sandy, and muddy bottoms, and can also be spotted among sea grasses.
Current Status of Name :
This name is currently accepted taxonomically.
Rank : Species
Environment : Marine
Taxonomy Classification
- Kingdom : Animalia
- Phylum : Echinodermata
- Class : Asteroidea
- Order : Valvatida
- Family : Oreasteridae
- Genus : Pentaceraster
- Species : Pentaceraster regulus
Pentaceraster regulus
Description :
Morphology:
- Body form: Pentaradial symmetry with five cylindrical arms.
- Size: Can reach up to 40 cm (16 inches) in diameter from arm tip to arm tip.
- Arms: Cylindrical, tapering towards the tips, and typically curved upwards.
- Aboral (upper) surface: Covered with numerous small, conical spines and tubercles (knobs).
- Oral (underside) surface: Covered with short, blunt spines and tube feet.
- Color: Highly variable, ranging from yellow, orange, red, or brown, often with darker or lighter markings.
- Madreporite: A small, sieve-like structure on the aboral surface used for filtering water.
Anatomy:
- Water vascular system: Used for locomotion, feeding, and respiration.
- Digestive system: A simple gut with a mouth at the center and radial canals extending into each arm.
- Reproductive system: Gonads located in each arm, with separate sexes.
- Nervous system: Radial nerve ring and radial nerves controlling tube feet and arm movement.
Habitat and Distribution:
- Found in the tropical and subtropical waters of the Indo-Pacific region, including the Red Sea, Indian Ocean, and western Pacific Ocean.
- Inhabits coral reefs, rocky areas, and sandy bottoms, typically at depths of 3-30 meters (10-100 feet).
Ecology and Behavior:
- Omnivorous, feeding on algae, sponges, coral polyps, and small invertebrates.
- Uses its tube feet for locomotion, clinging to surfaces, and capturing prey.
- Exhibits a behavior known as “righting response” when overturned.
- Capable of regenerating lost arms or body parts.
Reproduction and Life Cycle:
- Dioecious (separate male and female individuals).
- Reproduction occurs through external fertilization, with gametes released into the water column.
- Larvae undergo a planktonic stage before settling and metamorphosing into juveniles.
- Lifespan can vary but is generally several years, with some individuals living up to 20 years or more.
Conservation Status:
- The IUCN Red List has not assessed the conservation status of Pentaceraster regulus.
- However, like many coral reef species, it may be threatened by habitat degradation, pollution, and other human-induced impacts.
This description covers the key aspects of the regal sea star, including its taxonomy, morphology, anatomy, habitat, distribution, ecology, behavior, reproduction, and conservation status within the phylum Echinodermata.