''Gonactinia'' is a monotypic
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
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 ...
s, and ''G. prolifera'' is the only species in the genus. It is sometimes called the storey anemone
[ and is found on either side of the northern Atlantic Ocean.
]
Distribution and habitat
''Gonactinia prolifera'' is known from either side of the northern Atlantic Ocean including Maine
Maine () is a state in the New England and Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and north ...
and northwestern Europe, from the Mediterranean Sea, and the southern Pacific Ocean, including the coasts of New Zealand and Chile. Its natural habitat is on rocks, but it is also found on mollusc shells and large fronds of algae, from the fore-shore down to depths of about .
Biology
Like other sea anemones, ''G. prolifera'' is a predator
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...
, catching plankton
Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...
with its tentacle
In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...
s. When a prey item is encountered, a rhythmic succession of reflex actions take place by which the food particle is passed by the tentacles to the mouth and then swallowed. Locomotion is by "walking" or swimming.[ The anemone walks by making a series of short, looping steps, first extending its column parallel with the substrate, then attaching one tentacle to the substrate by means of the cnidocytes, detaching the pedal base, reattaching it close to the single, now contracted, tentacle, releasing this tentacle and straightening up. Each step takes half a minute or more and advances the anemone a few millimetres. Swimming is done by rapid movements of the tentacles beating synchronously; the tentacles are used like oars and a bout of swimming may consist of ten to thirty strokes. Swimming takes place after the anemone is stimulated sharply in some way or is attacked by a ]nudibranch
Nudibranchs () are a group of soft-bodied marine gastropod molluscs which shed their shells after their larval stage. They are noted for their often extraordinary colours and striking forms, and they have been given colourful nicknames to matc ...
.Anthopleura stellula
''Anthopleura stellula'' is a species of sea anemone in the family Actiniidae. It was first described in 1834 by Wilhelm Hemprich and Christian Gottfried Ehrenberg as ''Actinia (Isacmaea) stellula.'' It is found in the Indian Ocean and the Red Se ...
''. A rudimentary band of tentacles begins to grow on the column, after which the upper and lower regions pull themselves apart. The upper part grows a new pedal disc and the lower part a new oral disc with tentacles. Sometimes the first signs of the following transverse fission appear before the previous one is completed and the surfaces healed.
References
{{Taxonbar, from1=Q21445995, from2=Q1869994
Gonactiniidae
Hexacorallia genera
Monotypic cnidarian genera