Most of the 182 species in the spider family Desidae (saltwater spiders) are found in Australia and the South Pacific (Platnick 2013). In North America north of Mexico, there is one native species and one species originally from Australia. The small and inconspicuous spiders of the native species, Paratheuma insulana, are intertidal and found in coral rubble in southern Florida (Florida Keys) and the Caribbean; they have also been reported from oyster beds at low tide along the Gulf coast of northern Florida. These spiders remain in their silken retreats during high tide and emerge at night during low tide to hunt (no web is built). The introduced species, Badumna longinqua (formerly known as Ixeuticus martius), is a large dark spider that in North America is found in and around buildings in coastal California and Oregon (Ubick 2005; Simó et al. 2011). It spins conspicuous, messy webs (including a silken retreat) and is capable of delivering a painful, if not medically serious, bite (Isbister and Gray 2004) (Bradley 2013). The only other Nearctic representative of this family is the nocturnal Paratheuma interaesta, from around the Sea of Cortez (Gulf of California) in Sonora, Mexico, which lives along rocky shores and builds retreats in empty barnacle shells (Roth and Brown 1975; Ubick 2005). Ubick briefly reviewed the confusing taxonomic history of some of the spiders now placed in the Desidae (Ubick 2005 and references therein).
Desidae is a family of spiders, some of which are known as intertidal spiders. The family is named for the genus Desis, members of which live in a very unusual location — between the tides. The family has been reevaluated in recent years and now includes inland genera and species as well, such as Badumna and Phryganoporus. In 2017, the family Amphinectidae was merged into Desidae. The family Toxopidae has been separated off. Those intertidal spiders that are truly marine commonly live in barnacle shells, which they seal up with silk; this allows them to maintain an air bubble during high tide. They emerge at night to feed on various small arthropods that live in the intertidal zone.
As now circumscribed, the family Desidae is mainly found in South America and Australasia, with some species reaching north to Malaysia.[1]
Metaltella simoni has been introduced in a large part of the Southern United States (records exist from California, Louisiana, Mississippi, and Florida) and is considered an invasive species in Florida. It is feared that it could extirpate the native titanoecid species Titanoeca brunnea.
As of April 2019, the World Spider Catalog accepts the following genera:[1]
Desidae is a family of spiders, some of which are known as intertidal spiders. The family is named for the genus Desis, members of which live in a very unusual location — between the tides. The family has been reevaluated in recent years and now includes inland genera and species as well, such as Badumna and Phryganoporus. In 2017, the family Amphinectidae was merged into Desidae. The family Toxopidae has been separated off. Those intertidal spiders that are truly marine commonly live in barnacle shells, which they seal up with silk; this allows them to maintain an air bubble during high tide. They emerge at night to feed on various small arthropods that live in the intertidal zone.
