North American coconut crab (SciiFii)

The North American coconut crab (Birgus latro americanum), also known as the North American robber crab, is a subspecies of coconut crab that originally did not exist, but has since been created by SciiFii and introduced throughout the coastlines across North America to help boost biodiversity. As with other subspecies of coconut crabs, the North American coconut crab is one of the largest native-modern terrestrial arthropods on Earth and among the largest terrestrial crabs, with a weight up to 4.1 kg (9.0 lb). The North American coconut crab can grow to up to 1 meter (3 feet 3 inches) in length from each tip to tip of the leg. It shows a number of adaptations to life on land. Like other hermit crabs, juvenile North American coconut crabs use empty gastropod shells for protection, but the adults develop a tough exoskeleton on their abdomens and stop carrying a shell. North American coconut crabs have organs known as branchiostegal lungs, which are used for breathing, instead of their vestigial gills, and after the juvenile stage they will drown if immersed in water for too long. They have an acute sense of smell which they use to find potential food sources, and which has developed convergently with that of insects. Adult North American coconut crabs feed primarily on fleshy fruits, nuts, seeds, and the pith of fallen trees, but they will eat carrion and other organic matter opportunistically. Anything left unattended on the ground is a potential source of food, which they will investigate and may carry away, thereby getting the alternative name of "robber crab." The North American coconut crab is popularly associated with the coconut palms, which have been introduced throughout the beaches of the mainland North America, yet coconuts are not a significant part of its diet. Although it lives in a burrow, the North American coconut crab has been filmed climbing coconut and pandanus trees. No reports show a North American coconut crab selectively picking coconut fruit, though they might dislodge ripe fruit that otherwise would fall naturally. Climbing is an immediate escape route (if too far from the burrow) to avoid predation (when young) by large sea birds, or cannibalism (at any age) by bigger, older crabs. Mating occurs on dry land, but the females return to the edge of the sea to release their fertilized eggs, and then retreat back up the beach. The larvae that hatch are planktonic for 3–4 weeks, before settling to the sea floor, entering a gastropod shell and returning to dry land. Sexual maturity is reached after about 5 years, and the total lifespan may be over 60 years. In the 3–4 weeks that the larvae remain at sea, their chances of reaching another suitable location is enhanced if a floating life support system avails itself to them. Examples of the systems that provide such opportunities include floating logs and rafts of marine or terrestrial vegetation. Similarly, floating coconuts can be a very significant part of the crab's dispersal options. The conservation status of the North American coconut crab is Least Concern due to successful conservation efforts, the North American coconut crab's wide range and its tolerance to many of the human activities.