Diadematidae

Common Names

Diadematidae are commonly referred to as diadems or diadema sea urchins. Some species also have specific names, such as the long-spined sea urchin (Diadema setosum) and the black sea urchin (Diadema antillarum).

Characteristics

Diadematidae are characterized by their long, sharp spines, which can be up to 10 cm long in some species. The spines are often brightly colored and can be poisonous, serving as a defense mechanism against predators. The test is typically smooth and covered in small, secondary spines. Diadematidae also possess a distinctive arrangement of tube feet, which are used for locomotion and feeding.

Environments

Diadematidae are found in a variety of marine habitats, including coral reefs, rocky shores, and seagrass beds. They are commonly found in tropical and subtropical waters, but some species can tolerate cooler temperatures.

Diet

Diadematidae are herbivores, feeding primarily on algae. They use their tube feet to scrape algae off rocks and other surfaces. Some species have been observed grazing on seagrass and even consuming small invertebrates.

Reproduction

Diadematidae reproduce sexually, with external fertilization. The females release eggs into the water column, where they are fertilized by sperm from the males. The fertilized eggs develop into larvae that float in the water until they settle on the seabed and transform into juveniles.

Ecological Importance

Diadematidae play an important role in marine ecosystems. Their grazing activities help to control the growth of algae, maintaining the balance of the reef community. They are also an important food source for a variety of fish and other invertebrates.

References

Wikipedia: Diadematidae
World Register of Marine Species: Diadematidae
Encyclopedia of Life: Diadematidae