Nematodes (Nematoda)
The first free-living nematodes were described from New Zealand by N A Cobb in 1904 and subsequently J M Hoy (1954) described an insect pathogenic nematode.
More intensive taxonomic study of nematodes started in the early 1960s covering, over the next decades, free-living, plant-parasitic and insect-parasitic nematode groups. The first collation of published records from the specialist disciplines of plant nematology, animal helminthology, marine biology, soil zoology, and invertebrate pathology was for the “Species 2000” initiative. Dr G W Yeates’ preliminary, partial assessment was of a known fauna of some 631 species.
The first records of nematodes of economic importance in New Zealand appeared late in the 19th century (Kirk 1899; Thomson 1922), freshwater species were first described in 1904 (Cobb 1904), and marine nematodes described in 1921 (Ditlevsen 1921). However, systematic research has been sporadic, and only about 647 species (those in “Species 2000” plus Wouts’ Criconematina in Fauna of New Zealand 55) are currently known from the region.
Apart from the nematodes of plants and introduced mammals that have been studied for their perceived economic and public health impacts, the New Zealand nematode fauna is as poorly known as that of most Southern Hemisphere countries. There are tantalising biogeographic links but too few data. Given the present limited knowledge, it is not possible to draw the biogeographic relationships of the nematode fauna of the New Zealand region (see “Species 2000”).
The nematode project studies on the family Tripylidae Oerley, 1880, mainly focused on the genera Tripyla Bastian, 1865; Tobrilus Andrássy, 1959 and Trischistoma Cobb, 1913. Also some nematodes in the family of Alaimidae Micoletzky, 1922.
The nematodes in the families Tripylidae and Alaimidae mainly occur in freshwater and soil. There are probably 20 to 40 species in New Zealand (G W Yeates pers. comm. 2007). They are generally relatively large nematodes. Their description would be a significant contribution to the known nematode fauna of New Zealand.