There is one species of spider.
Latrodectus is a genus of spiders in the family Theridiidae , most of which are commonly known as widow spiders . Spider . A minority of species are social , building communal webs that may house anywhere from a few to 50,000 individuals . Although most spiders live for at most two years , tarantulas and other mygalomorph spiders can live up to 25 years in captivity .