The Banded Sea Urchin, Double Spined Urchin – Echinothrix calamaris is a striking echinoderm species known for its distinctive appearance and widespread distribution.
Description & Characteristics
The Echinothrix calamaris is a robust sea urchin with a spherical test, or shell, that can reach a maximum size of 10 cm in diameter. Its most prominent feature is the presence of two types of spines: long, slender, and banded spines, which give the urchin its common name, and shorter, stouter, and more numerous spines. The banded spines are typically black and white, while the shorter spines can be various shades of brown, black, or white. These spines are not only for protection but also for locomotion, allowing the urchin to move across the seafloor. The mouth of the urchin, located on the underside, is surrounded by five teeth and a complex chewing apparatus known as Aristotle’s Lantern. The anus is located on the upper surface of the test.
Habitat and Occurrence
The Banded Sea Urchin, Double Spined Urchin – Echinothrix calamaris is a common inhabitant of the subtidal, sublittoral, infralittoral, and deep zones of the oceans. This means it is found from the lower limit of the intertidal zone (intertidal) to the shelf edge at about 200 m water depth. The species is often found in areas with a rocky or coral substrate, and can also be found on sandy or muddy bottoms. It is considered a neritic species, meaning it is found in coastal waters and on the continental shelf. These zones provide the necessary conditions for the species to thrive, from the relatively shallow, sunlit waters of the intertidal to the deeper, darker, and colder environments of the shelf edge.
Taxonomy
The species Echinothrix calamaris belongs to the Class: Echinoidea, Order: Diadematoida, and Family: Diadematidae. This classification reflects its evolutionary relationships with other echinoderms, such as starfish and sea cucumbers.
Feeding
The Echinothrix calamaris is an herbivore that primarily feeds on algae. It uses its Aristotle’s Lantern to scrape algae off rocks and other surfaces. The urchin’s powerful jaws are capable of crushing and grinding tough plant material, allowing it to efficiently extract nutrients from its food.
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