Tetractinellida

Tetractinellida is an order of glass sponges belonging to the class Demospongiae. These sponges are characterized by their siliceous skeletons, which are composed of four-rayed spicules called tetractines. This unique spicular structure is a defining feature of the group. Tetractinellida sponges are found in marine environments worldwide, from shallow waters to the deep sea. They exhibit a wide range of morphologies, including massive, lobate, and encrusting forms. Many species are sessile and attach themselves to substrates such as rocks or other organisms. Their feeding strategy involves filtering water to capture small planktonic organisms and organic matter. Reproduction in Tetractinellida can be sexual, with both male and female gametes released into the water column, or asexual, through budding. Fossil evidence suggests that tetractinellids have a long evolutionary history, with early representatives appearing in the Devonian period. Notable families within this order include the Astrophoridae, Geodiidae, and Lithistidae. Despite their relatively simple body plan, glass sponges play important roles in marine ecosystems, providing habitat and influencing water clarity. Research into Tetractinellida continues to shed light on their biology, ecological significance, and evolutionary relationships within the Porifera phylum.