Over 65, see text Megascolecidae is a family of earthworms native to Madagascar, Australia, New Zealand, Asia, and North America.

[6] Earthworms in this family have the ability to decompose lignocellulose, which requires assistance from microorganisms in their digestive system.

Chemical digestion mainly occurs in the intestinal caeca of earthworms, which have higher protease activity than other parts of the gut.

[9] The ideal condition of reproduction for the megascolecidids is 25 °C, where the eggs hatch the quickest and have the highest cocoon production.

[10] The male reproductive organ of the Megascolecidae includes testes, seminal vesicles, spermathecae, prostate glands,[11] and spermathecal pores.

[20] Fifty-three known species of these earthworms can be found in Western Australia; Graliophilus georgei and G. secundus are some examples.

[21] G. zeilensis can be found in the Northern Territory, specifically in Mount Zeil, West MacDonnell Ranges.

G. zeilensis also can be found on the highest point of the mountain where average rainfall of the region is 250 mm annually.

[24] In Indonesia, 9 different genera can be found; Amynthas, Archipheretima, Metaphire, Metapheretima, Pheretima, Pithemera, Planapheretima, Pleinogaster, and Polypheretima.

[10] Megascolecidae species grow and produce more cocoons during the summer than the winter, because their lifecycle is highly correlated to the temperature and humidity of the environment.

[14] Some Megascolecidae species have adapted to colder temperatures and drier areas, though, which enables them to live in higher-altitude regions of the land.

The abundance of earthworms is highly correlated to soil pH, texture, water content, and temperature.