ophiurans

Ophiurans, also known as brittle stars, are a class of echinoderms characterized by their five-part radial symmetry, with a central disc and five elongated arms. They are marine invertebrates found in various habitats, including shallow waters and the deep sea. Ophiurans are distinct from other echinoderms like starfish and sea urchins due to their unique method of locomotion. Instead of walking on tube feet, ophiurans use a combination of water currents and their own movements to glide along the seafloor.

The body of an ophiuran consists of a central disc with a mouth at the center and a water vascular system that extends into the arms. This system is used for feeding, respiration, and locomotion. Ophiurans are filter feeders, using their arms to capture plankton and other small particles from the water. They have a simple digestive system and a water vascular system that is more complex than that of other echinoderms.

Reproduction in ophiurans is typically asexual, with new individuals forming from fragments of the parent's body. Sexual reproduction is also possible, involving both male and female gametes. Ophiurans play a role in marine ecosystems as both predators and prey, contributing to the food web through their feeding habits.

Despite their name, ophiurans are not related to snakes or other reptiles, but rather to sea stars and sea urchins. They are found worldwide in both temperate and tropical seas. The study of ophiurans is important for understanding echinoderm evolution and the diversity of marine life.