T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Flatworms 1

Domain: Eukarya 
Kingdom: Animalia 
Subkingdom: Eumetazoa 
Superphylum: Platyzoa 
Class : Turbellaria
Order: Seriata
Family: Platyhelminthes
Genus: Turbellaria 


Most are undescibed

Flatworms are found throughout New Zealand, but their diversity, fauna, and distribution are still poorly known. More than 100 different species of terrestrial flatworms are expected to exist in New Zealand, but most species are undescribed, and little is known about their distribution, ecology, or impact on other invertebrates.

Terrestrial flatworms are free-living soil animals, 0.5-10 cm in length, with flattened and unsegmented bodies. The size of a flatworm is not constant, as these animals can stretch out or contract considerably, changing shape as they move. Typically, the body is elongated, with narrower anterior and posterior ends. Eye spots may be present, but often are absent or very small, so that the head and tail ends of a flatworm are not easily identified if it is not moving. The movement is by a gliding motion, and a thin mucous trail is left behind the worm as it moves. The New Zealand flatworms are often colourful, with spots and stripes or in solid colours, in many shades of reddish-brown, purple, whitish, and black.

One New Zealand flatworm Arthurdendyus triangulatus (Artioposthia triangulata), an earthworm-feeding species, has become a dreaded invasive species in Europe. This voracious carnivorous flatworm was accidentally introduced into parts of Northern Ireland, Scotland, and a few other places in the 1970s, and now causes serious
problems in the soil by wiping out local earthworm populations. Arthurdendyus triangulatus has no preferred prey, but will eat any species of earthworm that it can find, at a rate of approximately one earthworm a week.

Undescribed NZ native terrestrial flatworm body contracted.




Undescribed NZ native terrestrial flatworm body extended




Undescribed NZ native terrestrial flatworm egg cocoon  found Te Henui Walkway


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