Odontaster
Odontaster is a genus of sea stars, commonly referred to as “spiny starfish” or “spiny sea stars,” belonging to the family Odontasteridae. These starfish are characterized by their distinctive, spiny bodies, which serve as a defense mechanism against predators. They are found in a variety of marine environments, from shallow intertidal zones to deep-sea habitats, and are widely distributed across the Southern Hemisphere.
Characteristics
Members of the genus Odontaster typically have five arms that are covered in sharp, conical spines. These spines can vary in size and density depending on the species. The color of Odontaster starfish can range from reddish-brown to purplish-black, with some species exhibiting a more colorful pattern. They also have a distinctive madreporite, a small, sieve-like structure on the aboral surface that regulates water flow into the water vascular system.
Environments
Odontaster species inhabit a range of marine environments, including:
- Intertidal zones
- Subtidal zones
- Deep-sea habitats
They are commonly found on rocky shores, kelp forests, and soft-bottom sediments. Their geographical distribution is primarily confined to the Southern Hemisphere, including the coasts of Australia, New Zealand, Chile, and Antarctica.
Feeding
Odontaster starfish are primarily carnivorous and feed on a variety of invertebrates, including barnacles, mussels, snails, and other sea stars. They use their tube feet to pry open their prey and then extend their stomach into the shell or body of their victim, digesting the flesh externally. Some species are known to be opportunistic scavengers and will also consume dead animals.
Reproduction
Odontaster starfish reproduce sexually, with individuals releasing sperm and eggs into the water column. The fertilized eggs develop into free-swimming larvae, which eventually settle to the bottom and metamorphose into juvenile starfish. Some species exhibit brood care, with the female carrying the eggs on her aboral surface until they hatch.
References
For further information on Odontaster, consult the following reliable sources: