Monometridae

Monometridae is a family of sea anemones belonging to the order Actiniaria. These anemones are characterized by their distinctive tentacle arrangement. Unlike many other sea anemones which have numerous tentacles arranged in radial symmetry, Monometridae typically possess a reduced number of tentacles, often only two or four, that are exceptionally long and slender. These tentacles are highly contractile and are used to capture prey that drifts within their reach.

The body column of Monometridae can vary in size and shape, but it is generally cylindrical. The oral disc, where the mouth and tentacles are located, is prominent. They are typically benthic, attaching themselves to hard substrates such as rocks, shells, or other invertebrates in marine environments. Their habitat can range from shallow coastal waters to deeper ocean zones.

Reproduction in Monometridae is thought to occur both asexually, through budding or pedal laceration, and sexually, with the release of gametes into the water column. The larval stage is planktonic before settling to the seafloor to develop into a new anemone. While specific details about their diet and ecological role are still being researched for all species, they are generally considered carnivorous, feeding on small invertebrates and planktonic organisms. The family currently comprises a relatively small number of described species.