New Zealand flatworm
Encyclopedia
The New Zealand flatworm (Arthurdendyus triangulatus) is a large flatworm
native to New Zealand
. It can vary from 5 mm in length when hatched to approximately 17 centimetres (6.7 in) in mature adults. The ventral surface of the flatworm is a pale buff colour while the dorsal surface is dark brown. Young flatworms vary in colour from white to pale orange and develop their adult colouration as they grow.
During the day, flatworms can be found resting on the surface of soil underneath objects in close contact with the ground. They may also be found beneath the soil surface hunting for earthworms.
Reproduction involves the production of egg capsules of about 8 mm in length. The capsules are shiny, flexible and cherry red in colour at first and later darken to black after several days. After an unknown incubation period, several pale, tiny flatworms hatch out of the brittle capsule. One egg capsule is produced at a time with the bulge clearly visible in the dorsum of the adult worm.
in Europe
, feeding there almost exclusively on earthworms. This degrades soil
quality. European earthworm predators are reluctant to eat it although cases of frogs and beetle larvae consuming flatworms have been recorded. It has been seen in England
, Scotland
, Northern Ireland
and the Faroe Islands
. It might have arrived in the early 1960s, being first recorded in Belfast
in 1963. The New Zealand flatworm is easily transported accidentally in plant pots in adult or egg form. They tend to be common in garden centres and may have arrived in the UK with exotic plants. It is suggested that they may thrive in parts of western Norway, southern Sweden, Denmark, Germany and northern parts of Poland, if they invade these regions.
As movement continues, circular, diagonal and longitudinal muscles in the rest of the body contract. Friction between the ventral surface and the substratum is reduced by mucus produced by the ciliated epidermal cells. A. triangulatus can achieve speeds of up to 17m per hour.
Flatworm
The flatworms, known in scientific literature as Platyhelminthes or Plathelminthes are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrate animals...
native to 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...
. It can vary from 5 mm in length when hatched to approximately 17 centimetres (6.7 in) in mature adults. The ventral surface of the flatworm is a pale buff colour while the dorsal surface is dark brown. Young flatworms vary in colour from white to pale orange and develop their adult colouration as they grow.
During the day, flatworms can be found resting on the surface of soil underneath objects in close contact with the ground. They may also be found beneath the soil surface hunting for earthworms.
Reproduction involves the production of egg capsules of about 8 mm in length. The capsules are shiny, flexible and cherry red in colour at first and later darken to black after several days. After an unknown incubation period, several pale, tiny flatworms hatch out of the brittle capsule. One egg capsule is produced at a time with the bulge clearly visible in the dorsum of the adult worm.
Invasive species
It is an invasive speciesInvasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
in 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...
, feeding there almost exclusively on earthworms. This degrades soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
quality. European earthworm predators are reluctant to eat it although cases of frogs and beetle larvae consuming flatworms have been recorded. It has been seen in England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
, Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
, Northern Ireland
Northern Ireland
Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west...
and the Faroe Islands
Faroe Islands
The Faroe Islands are an island group situated between the Norwegian Sea and the North Atlantic Ocean, approximately halfway between Scotland and Iceland. The Faroe Islands are a self-governing territory within the Kingdom of Denmark, along with Denmark proper and Greenland...
. It might have arrived in the early 1960s, being first recorded in Belfast
Belfast
Belfast is the capital of and largest city in Northern Ireland. By population, it is the 14th biggest city in the United Kingdom and second biggest on the island of Ireland . It is the seat of the devolved government and legislative Northern Ireland Assembly...
in 1963. The New Zealand flatworm is easily transported accidentally in plant pots in adult or egg form. They tend to be common in garden centres and may have arrived in the UK with exotic plants. It is suggested that they may thrive in parts of western Norway, southern Sweden, Denmark, Germany and northern parts of Poland, if they invade these regions.
Locomotion
When at rest, A. triangulatus rolls itself up and can appear like a very tiny Swiss roll. When it starts to move, it uncurls, at the same time as the circular muscles beneath the epidermal cells at the anterior end contract. The paler head-end extends forward, becoming as thin as the lead in a pencil. During movement it is repeatedly raised a couple of millimetres from the substratum before being lowered again.As movement continues, circular, diagonal and longitudinal muscles in the rest of the body contract. Friction between the ventral surface and the substratum is reduced by mucus produced by the ciliated epidermal cells. A. triangulatus can achieve speeds of up to 17m per hour.
External links
- Central Science Laboratory (CSL), United Kingdom - information dedicated to the flatworm
- Factsheet