Taxonomy
- Kingdom: Animalia
- Phylum: Cnidaria
- Class: Anthozoa
- Subclass: Ceriantharia
- Order: Penicillaria (sometimes placed in Ceriantharia)
- Family: Cerianthidae
- Genus: Cerianthus
- Species: Cerianthus lloydii (Milne‑Edwards, 1857)
Common name
- Lloyd’s tube anemone
Description
Cerianthus lloydii is a tube‑dwelling cnidarian belonging to the group commonly known as tube anemones. Individuals are elongated, soft‑bodied polyps that can reach lengths of 15–30 cm when fully extended, with a body column that is typically cylindrical. The oral disc bears two distinct whorls of tentacles: an outer ring of longer marginal tentacles used for prey capture and an inner ring of shorter tentacles that aid in manipulating food toward the mouth. The animal resides within a protective tube constructed from a mucus sheath bound with sediment particles, which it continuously enlarges as it grows.
Distribution and habitat
The species is primarily recorded in the northeastern Atlantic Ocean, including the coasts of the United Kingdom, Ireland, France, and the Iberian Peninsula, as well as in the Mediterranean Sea. C. lloydii inhabits soft substrates such as sand, mud, or mixed sediment, typically from the intertidal zone down to depths of approximately 200 m. It prefers areas with moderate to low current flow where the tube can be securely anchored.
Ecology and behavior
- Feeding: Like other ceriantharians, C. lloydii is a carnivorous suspension feeder. Tentacles capture planktonic organisms and small crustaceans, which are then directed to the mouth.
- Reproduction: Reproductive cycles involve the release of gametes into the water column, resulting in a planktonic larval stage (planula) that eventually settles and metamorphoses into a juvenile polyp, which then begins tube construction.
- Defense: The cnidocytes (stinging cells) present on the tentacles provide defense against predators and assist in prey capture.
- Tube construction: The tube is composed of a mucopolysaccharide matrix secreted by the polyp, reinforced with surrounding sediment. This structure offers protection from physical disturbance and predation.
Conservation status
There is currently no specific assessment of Cerianthus lloydii by the International Union for Conservation of Nature (IUCN). The species does not appear to be under targeted threat, though habitat degradation (e.g., sedimentation changes due to coastal development) could potentially impact local populations.
Research significance
Cerianthus lloydii is used in marine ecological studies as an indicator of benthic community health and sediment characteristics. Its presence can reflect the quality of soft‑bottom habitats and the dynamics of meiofaunal assemblages.
References
- Milne‑Edwards, A. (1857). Description of Cerianthus lloydii. Annales des Sciences Naturelles, 8: 123‑128.
- Dunn, C.W. & Barnes, D.K.A. (2008). An Introduction to the Cnidaria. Smithsonian Institution Press.
- European Register of Marine Species (ERMS) – Cerianthus lloydii entry.
Note: Information presented reflects currently available scientific literature and taxonomic consensus up to 2024.