Fociformes

Fociformes is a small order of sessile, filter-feeding marine invertebrates with a distinctive cup- or funnel-shaped body. The name combines a reference to a central pore system, thought to coordinate feeding currents, with the standard -formes ending used for taxonomic groups. The order is currently represented by several genera within the family Fociformidae and is distributed in temperate and tropical seas around the world.

Morphology and anatomy emphasize a flexible, often disc- or cup-shaped body that adheres to hard substrates. A ring of tentacle-like lobes surrounds an anterior opening, functioning in conjunction with ciliary currents to capture particulate food. A central pore network connects to internal canals responsible for circulating water and distributing nutrients. Bodies are typically small to medium in size, and many species possess a durable outer wall of protein-rich material.

Habitat and ecology encompass a range of coastal to offshore environments. Fociformes attach to rocks, shells, or other hard substrates, sometimes forming monospecific mats. They are suspension feeders, drawing in plankton and detritus from the surrounding water. Some species host mutualistic microorganisms that aid in nutrient acquisition, while others rely primarily on their own filtering apparatus. Predation is limited by their sessile lifestyle, but they may be affected by sedimentation and changes in water quality.

Reproduction and development are diverse but commonly involve separate sexes with external fertilization and free-swimming larval stages that settle to form new individuals. Some genera can reproduce asexually through budding under favorable conditions. The fossil record for Fociformes is sparse but indicates a long-standing presence in marine ecosystems, with morphological features that show both lineage continuity and occasional convergence across unrelated groups.