Spooktober Arachtober!
Harvestman spiders (Opiliones)- Family: Gonyleptoidea-
Although commonly known as harvestman spiders, this arachnid is not actually a spider. The closest relatives of the Opilione order are scorpions and mites (which often parasitize the harvestmen, visible in bottom right photo of a female Sadocus polyacanthus)
Unlike spiders harvestman have a “fused” body. It lacks the distinct segmentation between the cephalothorax and abdomen. Other major differences include the lack of both venom and silk glands, and having one pair of eyes, sometimes none at all. Their second, longest pair of legs act as “antennae”. In defense, they have ozophores that produce a smelly, noxious fluid. Males have simplified penises, a trait absent in all other arachnids (this isn’t a thing I actively look for in animals, it’s purely coincidental). Most species are omnivorous and nocturnal. Though their thorny bodies and gangly legs may look intimidating, they are quite small and harmless to humans.
The tropical Gonyleptoidea family is one of the largest families in the order Opiliones with over 2,500 species. Gonyleptidae are unique in size as well as the appearance and behavior of the males. The large, ventral spikes on the abdomen’s “shield”, used for bumper butts fighting, is only present in males (male and female comparison in last two photos). Male Gonyleptidae are also solely responsible for guarding the eggs.
Photos: (top) (second) (third) (left) (right)