The coconut crab, (Birgus latro), is a species of terrestrial hermit crab (see this post), also known as the robber crab or palm thief. It is the largest land-living arthropod ( an invertebrate animal having an external skeleton, a segmented body, and jointed appendages) in the world, and is probably at the upper size limit of terrestrial animals with exoskeletons in today’s atmosphere at a weight of up to 4.1 kg (9.0 lb). It is found on islands across the Indian Ocean and parts of the Pacific Ocean. It has been extirpated (extinct in certain areas, but not in others) from most areas with a significant human population, including mainland Australia and Madagascar. The coconut crab is the only species of the genus Birgus, and is related to the terrestrial hermit crabs of the genus Coenobita. Like hermit crabs, juvenile coconut crabs use empty gastropod shells for protection, but the adults develop a tough exoskeleton on their abdomen and stop carrying a shell. Coconut crabs have organs known as “branchiostegal lungs”, which are used instead of the vestigial gills for breathing. They cannot swim, and will drown if immersed in water for long. They have developed an acute sense of smell which they use to find potential food sources. Mating occurs on dry land, but the females migrate to the sea to release their fertilized eggs as they hatch. The larvae are planktonic for 3–4 weeks, before settling to the sea floor and entering a gastropod shell. Sexual maturity is reached after about 5 years, and the total lifespan may be over 60 years. Adult coconut crabs feed on fruits, nuts, seeds, and the pith of fallen trees, but will eat carrion and other organic matter opportunistically. The species is popularly associated with the coconut, and has been widely reported to climb trees to pick coconuts, which it then opens to eat the flesh. Coconut crabs are hunted wherever they come into contact with humans, and are subject to legal protection in some areas.
Serpentine, The sensual attractiveness of snakes, which coexists with their threatening, unpredictable and mysterious nature is truly unique. This dichotomy, in which their beauty seems to be heightened by their danger, and vice-versa, is what I find so fascinating. Add to these contradictions the rich symbolism of serpents and you have a wonderfully compelling subject.