Pagurus Usually, a few new species are discovered each year. The following list is current : The following are all "nomina nuda". They have never been validly described as new species, but only mentioned under these names: Pagurus Pagurus is a genus of hermit crabs in the family Paguridae. Like other hermit crabs, their abdomen is not calcified and they use snail shells as portable homes. These marine decapod crustaceans are omnivorous, but mostly prey on small animals and scavenge carrion. "Trigonocheirus" and "Pagurixus" used to be considered subgenera of "Pagurus", but the former is nowadays included in "Orthopagurus", while the
Social spider but this is a rare event and has not been studied sufficiently to quantify for any social spider species. Females can also out-number males as much as 10:1 in many species; this too acts as a genetic bottleneck and further decreases the genetic variation of the species. Species include: Social spider A social spider is a spider species whose individuals form relatively long-lasting aggregations. Whereas most spiders are solitary and even aggressive toward other members of their own species, some hundreds of species in several families show a tendency to live in groups, often referred to as colonies. Most species