''Haloclava producta'' 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 ...

sea anemone Sea anemones are a group of predation, predatory marine invertebrates of the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemones are classifi ...

in the family

Haloclavidae Haloclavidae is a family of sea anemones. Members of the family are found worldwide and many live largely buried in soft substrates with only their oral disc and tentacles protruding. Characteristics Members of this family mostly have elongated ...

, commonly known as the ghost anemone. This species is native to shallow water in the northwestern Atlantic Ocean, between

Cape Hatteras Cape Hatteras is a cape located at a pronounced bend in Hatteras Island, one of the barrier islands of North Carolina. Long stretches of beach, sand dunes, marshes, and maritime forests create a unique environment where wind and waves shape ...

and the

Bay of Fundy The Bay of Fundy (french: Baie de Fundy) is a bay between the Canadian provinces of New Brunswick and Nova Scotia, with a small portion touching the U.S. state of Maine. It is an arm of the Gulf of Maine. Its extremely high tidal range is the hi ...

, where it makes a temporary burrow in soft sediment. It is found on sand flats, both intertidally and subtidally.

Description

''H. producta'' has an elongated column up to in length and an oral disc surrounded by a whorl of about twenty short, knobbed tentacles. The column has a very thin body wall and is studded with about twenty rows of hollow blisters; it makes up most of this anemone's surface area. At the base of the column, the pedal disc is modified into a "physa", an inflatable digging organ.

Biology

The water in the shallows where ''H. producta'' lives is sometimes low in oxygen. Under these conditions, the sea anemone extends its column and tentacles, perhaps to expose the largest possible area of epidermis to the water to increase oxygen uptake. It also irrigates the burrow in which it lives in the sediment, creating a current through it by a series of peristaltic waves. If exposed to

hypoxia Hypoxia means a lower than normal level of oxygen, and may refer to: Reduced or insufficient oxygen * Hypoxia (environmental), abnormally low oxygen content of the specific environment * Hypoxia (medical), abnormally low level of oxygen in the tis ...

for periods of several days, its interior turns black and it gives off

hydrogen sulphide Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The unde ...

. It can survive in low oxygen conditions for eleven days or more.

Venom

A type of

dermatitis Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved can v ...

with itchy red skin has been recognised in people who are exposed to the sand and mud flats around

Long Island Long Island is a densely populated island in the southeastern region of the U.S. state of New York (state), New York, part of the New York metropolitan area. With over 8 million people, Long Island is the most populous island in the United Sta ...

New York New York most commonly refers to: * New York City, the most populous city in the United States, located in the state of New York * New York (state), a state in the northeastern United States New York may also refer to: Film and television * '' ...

. Although ''H. producta'' had not previously been considered to be

venom Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

ous to humans, exposure to these sea anemones was thought to be responsible for the irritating rash, and this is now accepted as the cause. The condition is known as "clam diggers' itch" or "ghost anemone dermatitis", and usually affects hands and wrists, ankles, knees and inner thighs.

References

{{Taxonbar, from=Q2296885 Haloclavidae Animals described in 1856