Fiddler crab two weeks. Fiddler crabs such as "Uca mjoebergi" have been shown to bluff about their fighting ability. Upon regrowing a lost claw, a crab will occasionally regrow a weaker claw that nevertheless intimidates crabs with smaller but stronger claws. This is an example of dishonest signalling. The dual functionality of the major claw of fiddler crabs has presented an evolutionary conundrum in that the claw mechanics best suited for fighting do not match up with the mechanics best suited for a waving display. The internal classification of the genus "Uca" is unstable, but it contains around 100 species arranged among
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