''Dosima fascicularis'', the buoy barnacle, is "the most specialised

pleuston Neuston, also known as pleuston, are organisms that live at the surface of the ocean or an estuary, or at the surface of a lake, river or pond. Neuston can live on top of the water surface or may be attached to the underside of the water surface. ...

ic goose barnacle"

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 ...

. It hangs downwards from the water surface, held up by a float of its own construction, and is carried along by

ocean current An ocean current is a continuous, directed movement of sea water generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. Depth contours, s ...

Flotation

As an adult, ''D. fascicularis'' lives attached to a float made either of natural flotsam or of a cement it secretes itself, which has a texture like that of

expanded polystyrene foam Polystyrene (PS) is a synthetic polymer made from monomers of the Aromatic hydrocarbon, aromatic hydrocarbon styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin pe ...

. It is the only barnacle to produce its own gas-filled float. The cyprid

larvae A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

are

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 ...

ic, and must attach to a float for metamorphosis into the adult form, but the adults are eventually capable of using their own float, sometimes forming aggregations of many individuals attached to a single float. Among the floats used by adult buoy barnacles are pellets of tar, seaweeds, plastic debris, driftwood, feathers, cranberry, cranberries, Cuttlebone, cuttlefish bone, the "by-the-wind-sailor" ''Velella, Velella velella'', seagrass leaf, leaves, Styrofoam, seeds, and even apples; they have even been known to colonise the backs of turtles and the sea snake ''Pelamis platurus''. It is a r-selection, fugitive species, which can be Competition (biology), out-competed by other barnacle species, and relies on being able to colonise surfaces and reproduce quickly; after settling on a float, ''D. fascicularis'' can reproduce within 45 days. ''D. fascicularis'' appears to be increasing in abundance as a result of anthropogenic marine debris accumulating in the sea; this source of floats was of "minor importance" in 1974.

Related species

Although formerly placed in the genus ''Lepas'', the buoy barnacle is now generally placed in the genus, ''Dosima''. ''Dosima'' is distinguished from ''Lepas'' by the form of the ''carina'', and by the exceptional thinness and brittleness of its exoskeleton.

Distribution

''D. fascicularis'' has a cosmopolitan distribution, with a preference for Temperateness, temperate seas, having been found at latitudes from 71° North off Siberia to 57° South near Cape Horn. Groups have been observed journeying from Japan to the Hawaiian Islands in the Pacific Ocean, and sometimes wash up on westerly and southerly beaches in the British Isles, as well as westerly beaches further south in Europe. It is not normally found in the Mediterranean Sea, but may have begun to colonise there from the Atlantic Ocean.

References

{{Taxonbar, from=Q6569712 Barnacles Taxa named by John Edward Gray