Sabellida
Sabellida is an order of marine polychaete worms, commonly known as feather duster worms or tube worms. They are characterized by their distinctive crown of tentacles, called radioles, which they use to filter food from the water. Sabellids are found in a variety of marine environments, from shallow coastal waters to the deep sea.
Characteristics
Sabellids are typically small to medium-sized worms, ranging in length from a few millimeters to several centimeters. They have a segmented body, with each segment bearing a pair of parapodia (fleshy outgrowths) that help them to move. The most distinctive feature of sabellids is their crown of radioles, which are long, feathery tentacles that surround the mouth. The radioles are covered in cilia (hair-like structures) that create currents to draw food particles towards the mouth.
Environments
Sabellids are found in a wide variety of marine habitats, including:
- Rocky shores
- Coral reefs
- Seagrass meadows
- Deep sea vents
- Muddy bottoms
They are often found in areas with strong currents, where their radioles can effectively filter food from the water.
Feeding
Sabellids are filter feeders, using their radioles to capture small food particles such as plankton, bacteria, and detritus from the water. The cilia on the radioles create currents that draw food particles towards the mouth. Once food particles are trapped in the mucus on the radioles, they are transported to the mouth by the cilia.
Tube Building
Many sabellids are tube-dwelling worms, meaning they construct tubes to live in. The tubes are made of various materials, including mucus, sand grains, and shell fragments. The tubes can be simple or elaborate, and they provide protection from predators and a stable environment for the worm.
Reproduction
Sabellids reproduce sexually, releasing sperm and eggs into the water. Fertilization occurs externally, and the resulting larvae develop into adults. Some sabellids are hermaphroditic, meaning they possess both male and female reproductive organs. Others are dioecious, with separate male and female individuals.