Nematomorpha

Japanese: Nematomorpha

…The number of chromosomes in the horse roundworm is 2n = 2, the fewest among animals. Nematodes are a type of nematode in the class Nematomorpha, which are related to the wireworms and live freely in rivers, but their larvae grow to almost adulthood inside the bodies of praying mantises, grasshoppers, diving beetles, etc., and then leave these hosts. Their bodies are long and slender, as hard as wire, and are 10 to 40 cm long, but some can be over 1 meter long. …

From [Wireworm]

…A general term for invertebrates belonging to the phylum Nematomorpha. The name comes from the fact that their bodies are long and thin like wires, and that the cuticle on their body surface is quite hard.

*Some of the terminology that mentions "Nematomorpha" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…ウマカイチュウの染色体数は2n＝2で動物中もっとも少ない。センチュウ　線形虫綱Nematomorphaはハリガネムシの仲間で，川の中で自由生活するが，幼虫はカマキリ，キリギリス，ゲンゴロウなどの体内でほぼ成体に成長し，これらの宿主から外にでる。体は細長くて針金のように堅く，体長は10～40cmであるが，なかには1m以上のものもある。…