The first and only Australian invertebrate species officially listed is the Tasmanian Lake Pedder Earthworm. Mr. Grasshopper, Mr. Centipede, Ms. Spider, Mr. Earthworm, Mrs. Ladybug, and the Glowworm. Hermaphrodite species include the common earthworm and certain species of snails. In Canada, it is also called the dew worm, or "Grandaddy Earthworm". Fertilization and development of earthworm eggs takes place in the cocoon. High salinity and sandy soils have greater resistance to earthworm spread. They can also exist at higher densities than European earthworm species. Some strains are also found in the cocoons of the earthworm "Eisenia fetida". The common earthworm is a universal bait for fresh water angling. The cycle is completed by the pig eating the earthworm. As with other earthworm species, "E. fetida" is hermaphroditic. Little is known about the giant Palouse earthworm. Robots have been designed that use peristalsis to achieve locomotion, as the earthworm uses it. This causes the writhing movements observed when a human picks up an earthworm. The spermathecae receive and store the spermatozoa of another earthworm during copulation.