Cirrina — finned deep-sea octopuses

Key physical characteristics

Cirrates display several features adapted to life far below the sunlit surface: a small internal shell or cartilaginous support rather than a large external shell; small hair‑like filaments called cirri along the arm margins near the suckers; and a web of skin connecting the arms that can form an umbrella shape. Many species have reduced or absent ink sacs and large, flexible fins used for gentle swimming.

• Fins: paired, paddle‑shaped structures for slow propulsion.
• Cirri: delicate filaments that may aid in sensing or manipulating prey.
• Internal support: thin cartilaginous elements rather than a rigid shell.

Habitat and behavior

Cirrina are mostly inhabitants of deep‑sea habitats, where water is cold and pressure is high. They tend to be slow swimmers, using their fins and webbing to hover or drift rather than rapid jetting. Many feed on small benthic and pelagic invertebrates by enveloping prey with their webbed arms or picking it up with their suckers.

Reproduction and life history

These octopuses generally lay relatively large eggs; young hatch in a form resembling miniature adults rather than passing through a long planktonic larval stage. Life histories are adapted to the low‑energy deep ocean, and detailed reproductive strategies vary among species.

Taxonomy, examples and significance

Historically grouped as the suborder Cirrina (also spelled "cirrates"), this assemblage includes families and genera often cited in deep‑sea research, such as the dumbo octopuses (genus Grimpoteuthis) and several related forms. Because many species live at great depths they are infrequently seen, making them of interest for studies of deep‑sea adaptation, biodiversity and evolutionary relationships. Ongoing taxonomic work continues to refine how cirrates are classified relative to their shallow‑water relatives, the incirrate octopuses.