They are soft with a head of half moon-like shape. The data centre is funded by the Department of Culture, Heritage and the Gaeltacht, and the Heritage Council. New Zealand Flatworm . Gardeners in the midlands who worry about invasion by the dreaded New Zealand flatworm can relax for now. The ventral surface is cream coloured and the dorsal surface is dark brown with a cream margin, however very young flatworms are pale-coloured and darken as they age. It ranges in length from 5 - 170 mm. Easily recognisable as different from the earthworm, the NZ flatworm is flat, with dark purple-brown markings on top of a creamy pale underneath and sides. Although flatworms prey on … So, it is not easy to discuss each one. New Zealand Flatworm (Arthurdendyus triangulata) The flatworm Arthurdendyus triangulata is a voracious earthworm hunter and adapted to cooler climates. The National Biodiversity Data Centre is an Initiative of the Heritage Council and is operated under a service level agreement by Compass Informatics. They first arrived in the UK in the 60s – probably from imported plant soil. New Zealand Flatworm. Below is a New Zealand flatworm, Arthurdendyus traiangulatus, formerly know as Artioposthia traiangulatus. They clear a garden of earthworms, leading to sour, airless, com pacted soil. Sometimes they look like hammerhead fish called New Zealand worms. The New Zealand flatworm is mainly found in Scotland, Northern Ireland and the north of England while Australian flatworm is most frequent in south west England ACTION: Gardeners who have either species of flatworms should avoid moving soil, compost or rooted plants from their gardens to other areas that are currently free of flatworms. GARDENERS face no greater crisis than New Zealand flatworms. Surprisingly, there are more than 900 species of land planarians. Not all of them have a hammer-like head. The Shape Of Land Flatworms. Most of these worms have pointed heads too. The New Zealand flatworm feeds by wrapping its body around an earthworm and secreting digestive enzymes which dissolve it, so it can then suck up the resulting earthworm soup.If the supply runs short, it can survive without food for over a year by ‘degrowing’, shrinking to as little as 10% of its body mass until it finds another earthworm. Some flatworm species occupy a very wide range of habitats. And they are a threat to our native earthworm. The temnocephalids, which are parasitic on freshwater crustaceans, occur primarily in Central and South America, Madagascar, New Zealand, Australia, and islands of the South Pacific. The New Guinea flatworm (Platydemus manokwari) is a predatory, terrestrial flatworm.This flatworm averages 1.5 to 5 inches in length and has a shiny, dark brown/black body with a pale stripe running down the middle, though the stripe may not be visible in bright light. ‘The New Zealand flatworm is found mainly in the north of England, Scotland, and Northern Ireland.’ ‘It is forty years since the first New Zealand flatworms were first recorded in Ireland.’ ‘The New Zealand flatworm is concentrated in southern Scotland and the Australian flatworm in southwest England.’ New Zealand flatworms are distinctively large and flat. Description.