''Peachia quinquecapitata'', also known as the twelve-tentacled parasitic anemone, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of sea anemone in the family Haloclavidae. It is found in the

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Tho ...

. The larva is parasitic on certain species of

Anthomedusae Anthoathecata, or the athecate hydroids, are an order of hydrozoans belonging to the phylum Cnidaria. A profusion of alternate scientific names exists for this long-known, heavily discussed, and spectacular group. It has also been called Gymnobla ...

Description

''Peachia quinquecapitata'' lives with its elongated column buried in the sand and its twelve tentacles fanned out on the surface. The oral disc is red and the translucent tentacles are banded with buff and brown in a chevron pattern. Like other members of the genus '' Peachia'', it has a "conchula", an enlargement on the lip by its mouth, which in this species is divided into five lobes.

Distribution

''Peachia quinquecapitata'' is found in shallow seas in the

of the United States including

Puget Sound Puget Sound ( ) is a sound of the Pacific Northwest, an inlet of the Pacific Ocean, and part of the Salish Sea. It is located along the northwestern coast of the U.S. state of Washington. It is a complex estuarine system of interconnected ma ...

Life cycle

The life cycle of ''Peachia quinquecapitata'' was investigated in the laboratory. Spawning was induced by manipulating light levels. The eggs had a diameter of 120 µm and, after fertilisation, developed into

planula A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species and also in some species of Ctenophores. Some groups of Nemerteans also produce larvae that are very similar to the planula, which ...

larvae. Some of the larvae were ingested by the

medusa In Greek mythology, Medusa (; Ancient Greek: Μέδουσα "guardian, protectress"), also called Gorgo, was one of the three monstrous Gorgons, generally described as winged human females with living venomous snakes in place of hair. Those ...

, ''Phialidium gregarium'' (now classified as '' Clytia gregaria''), and only they continued to develop in the laboratory setting. At first they fed on food particles in the gastrovascular cavity of the jellyfish but after 11 days they developed parasitic habits and began to feed on their hosts' gonads, moving on later to other tissues. One anemone larva was able to consume a gonad completely in two days. Thirty-one days after becoming parasitic they had developed into juvenile sea anemones with an adult body plan. At this stage they detached themselves from their hosts and dropped to the sea floor where they started to live independently. This parasitism is likely to be harmful to the host but of advantage to the anemone in that its larvae can develop safely in a protective environment and passively disperse to new localities.Parasitic Anemones on Cross Jelly
The Jellies Zone. Retrieved 2011-10-09. The prevalence of infection in the jellyfish ''Clytia gregaria'' at

Friday Harbor, Washington Friday Harbor is a town in San Juan County, Washington, United States. The population was 2,162 at 2010 census. Located on San Juan Island, Friday Harbor is the major commercial center of the San Juan Islands archipelago and is the county sea ...

peaks in the spring at 62%.

References

{{Taxonbar, from=Q1933322 Haloclavidae Animals described in 1913