Japanese Spider Crab (Macrocheira kaempferi)
Before you get upset that I posted a shot of an animal with a human, I asked if I could do this before posting. I wanted to share the deep water species with the group and this is the image I have. One of the largest crabs on Earth – this is the Japanese Spider Crab (Macrocheira kaempferi). Myth and lore surround this species as old stories tell of giant crabs dragging fishermen to their deaths, consuming them in the depths. The crabs are actually scavengers, they can not swim as adults, they are easy going, and are slow moving; however, one source pointed out that it isn’t impossible that they’d eat a corpse that made its way to the sea floor. This species appears to have a relative small range off of the Pacific side of the Japanese islands at a latitude between 30 and 40 degrees North. Adults inhabit water from 100 to 400 meters depths, juveniles appear to inhabit shallower areas with a mean of 50m depth. From the edge of the carapace to the tip of the claw can span some 4 meters length in this species. The individual depicted here isn't a particularly large individual. Adults have a mass between 16 and 20kg. The Japanese Spider Crab has two zoea stages and one megalops stage which, combined, last several months. The species enacts parental care in that females carry their eggs on their backs and the underside of the carapace to keep water moving around them in order to provide oxygen. Some biologists have hypothesized that these crabs can live for 100 years. The only commentary I could find on conservation status was that “catch has declined considerably across the past 40 years.” There is an active fishery for the species and there appears to be the means and methods to rear this crab from a juvenile stage by way of aquaculture facility. I would like to thank Masato Todate and Yuki Tsukamoto, both with the Takeshima Aquarium, Gamagori City, Aichi Prefecture, Japan, for the opportunity to see and photograph these amazing animals!
The note on captive rearing: https://www.researchgate.net/publication/319592456_CULTURE_OF_THE_GIANT_SPIDER_CRAB_MACROCHEIRA_KAEMPFERI_DE_HAAN_FROM_EGG_TO_JUVENILE_STAGE
The Japanese spider crab , ''Macrocheira kaempferi'', is a species of marine crab that lives in the waters around Japan. It has the largest leg span of any arthropod, reaching up to 3.8 metres and weighing up to 19 kilograms . It is the subject of small-scale fishery which has led to some conservation measures.