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 . , at least 45,700 spider species , and 113 families have been recorded by taxonomists . Most detect prey mainly by sensing vibrations , but the active hunters have acute vision , and hunters of the genus Portia show signs of intelligence in their choice of tactics and ability to develop new ones .