Elminius modestus
Encyclopedia
Elminius modestus is a species
of barnacle
in the family
Balanidae
, native to Australia
, Tasmania
and New Zealand
, but now spread to Britain
and the north west coasts of Europe
. It reaches a maximum size of about 10 millimetre (0.393700787401575 in) in diameter.
, during the Second World War
. It was believed to have arrived on the hulls
of ships, or possibly the larval stages travelled in bilge water. It has become very common in southern England and Wales and is spreading northwards, but the spread may be limited by the temperature of the sea. It is found on the upper middle shore and is tolerant of low salinity levels where fresh water enters the sea. It avoids exposed positions. It had reached the Scottish Borders
by 1960 and Shetland by 1978. It is found on the Atlantic coasts of Europe from Gibraltar to Germany.
and other organic particles into the shell for consumption. Eggs are laid and develop into nauplius larvae which are released into the phytoplankton
. These then develop into cyprid larvae which later settle and cement themselves onto a rocky substrate.
In the British Isles, E. modestus competes with Semibalanus balanoides
, whereas in southern Europe it also competes with Chthamalus
spp. It is particularly successful because it grows fast, tolerates reduced salinity, has a lower temperature tolerance than Chthamalus spp and a higher tolerance than Balanus
spp. It is also a threat to native species because it reaches maturity in its first season and can produce several broods of larvae per year. It has an extended habitat as it grows both high up the shore and in the neritic zone
.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of barnacle
Barnacle
A barnacle is a type of arthropod belonging to infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. They are sessile suspension feeders, and have...
in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Balanidae
Balanidae
Balanidae is a family of barnacles of the order Sessilia.- Genera :* †Alessandriella Carriol, 2001* Amphibalanus Pitombo, 2004* Arossia Newman, 1982* Austromegabalanus Newman, 1979* Balanus Da Costa, 1778* †Concavus Newman, 1982...
, native to Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
and New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, but now spread to Britain
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
and the north west coasts of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
. It reaches a maximum size of about 10 millimetre (0.393700787401575 in) in diameter.
Description
E. modestus is a pearly grey, semi-translucent barnacle. It is composed of four distinct plates and leans a little to one side.Distribution and habitat
E. modestus originated in Australia and was first seen in British waters, in Chichester HarbourChichester Harbour
Chichester Harbour is a large natural harbour to the south west of the city of Chichester on the Solent. It straddles the boundary of West Sussex and Hampshire. Geographically it is a ria. It is one of four natural harbours in that area of the coastline, the others being Portsmouth Harbour,...
, during the Second World War
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. It was believed to have arrived on the hulls
Hull (watercraft)
A hull is the watertight body of a ship or boat. Above the hull is the superstructure and/or deckhouse, where present. The line where the hull meets the water surface is called the waterline.The structure of the hull varies depending on the vessel type...
of ships, or possibly the larval stages travelled in bilge water. It has become very common in southern England and Wales and is spreading northwards, but the spread may be limited by the temperature of the sea. It is found on the upper middle shore and is tolerant of low salinity levels where fresh water enters the sea. It avoids exposed positions. It had reached the Scottish Borders
Scottish Borders
The Scottish Borders is one of 32 local government council areas of Scotland. It is bordered by Dumfries and Galloway in the west, South Lanarkshire and West Lothian in the north west, City of Edinburgh, East Lothian, Midlothian to the north; and the non-metropolitan counties of Northumberland...
by 1960 and Shetland by 1978. It is found on the Atlantic coasts of Europe from Gibraltar to Germany.
EcolFileogy
E. modestus is a suspension feeder. It has feathery appendages which beat rhythmically to draw planktonPlankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
and other organic particles into the shell for consumption. Eggs are laid and develop into nauplius larvae which are released into the phytoplankton
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
. These then develop into cyprid larvae which later settle and cement themselves onto a rocky substrate.
In the British Isles, E. modestus competes with Semibalanus balanoides
Semibalanus balanoides
Semibalanus balanoides is a common and widespread boreo-arctic species of acorn barnacle. It is common on rocks and other substrates in the intertidal zone of north-western Europe and both coasts of North America.-Description:...
, whereas in southern Europe it also competes with Chthamalus
Chthamalus
Chthamalus is a genus of barnacles that is found along almost all coasts of the northern hemisphere, as well as many regions in the southern hemisphere. These small barnacles have been studied in part because of the taxonomic confusion over a group of species that, by and large, are morphologically...
spp. It is particularly successful because it grows fast, tolerates reduced salinity, has a lower temperature tolerance than Chthamalus spp and a higher tolerance than Balanus
Balanus
Balanus is a genus of barnacles in the family Balanidae of the subphylum Crustacea, containing the following species:*Balanus albicostatus*Balanus amaryllis Darwin*Balanus amphitrite Darwin, 1854*Balanus aquila Pilsbry, 1907...
spp. It is also a threat to native species because it reaches maturity in its first season and can produce several broods of larvae per year. It has an extended habitat as it grows both high up the shore and in the neritic zone
Neritic zone
The neritic zone, also called coastal waters, the coastal ocean or the sublittoral zone, is the part of the ocean extending from the low tide mark to the edge of the continental shelf, with a relatively shallow depth extending to about 200 meters...
.
External links
- Elminius modestus, Marine Life Information Network for Britain & Ireland