Genus

Macrocheira

1 species

The Japanese spider crab (Macrocheira kaempferi) is a species of marine crab and is the biggest one that lives in the waters around Japan. It has the largest known leg-span of any arthropod around 3.7 meters. The Japanese name for this species is taka-ashi-gani, (Japanese: たかあしがに), literally translating to “tall legs crab”. It goes through three main larval stages along with a prezoeal stage to grow to its great size.

The genus Macrocheira contains multiple species. Two fossil species of this genus have been found, M. ginzanensis and M. yabei, both from the Miocene of Japan. Its diverse taxonomic history is an important part of what these creatures are and how they evolved to be what they are today. They are sought by crab fisheries, and are considered a delicacy in Japan. To prevent overexploitation from harming the species, conservation efforts have been put in place to protect these creatures and their population from overfishing.

The Japanese spider crab is similar in appearance to the much smaller European spider crab (Maja squinado), though the latter, while within the same superfamily, belongs to a different family, the Majidae.

Japanese spider crabs are mostly found off the southern coasts of the Japanese island of Honshū, from Tokyo Bay to Kagoshima Prefecture. Outlying populations have been found in Iwate Prefecture and off Su-ao in Taiwan. Adults are found at depths between 50 and 600 m (160 and 1,970 ft). They like to inhabit vents and holes in the deeper parts of the ocean. The temperature preference of adults is unknown, but the species is regular at a depth of 300 metres (980 ft) in Suruga Bay, where the water generally is about 10 °C (50 °F). Based on results from public aquaria, Japanese spider crabs tolerate temperatures between 6 and 16 °C (43 and 61 °F), but are typically maintained at 10–13 °C (50–55 °F).

The Japanese spider crab is an omnivore, consuming both plant-matter and animals. It also sometimes acts as a scavenger, consuming dead animals. Some have been known to scrape the ocean floor for plants and algae, while others pry open the shells of mollusks.

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The Japanese spider crab (Macrocheira kaempferi) is a species of marine crab and is the biggest one that lives in the waters around Japan. It has the largest known leg-span of any arthropod around 3.7 meters. The Japanese name for this species is taka-ashi-gani, (Japanese: たかあしがに), literally translating to “tall legs crab”. It goes through three main larval stages along with a prezoeal stage to grow to its great size.

The genus Macrocheira contains multiple species. Two fossil species of this genus have been found, M. ginzanensis and M. yabei, both from the Miocene of Japan. Its diverse taxonomic history is an important part of what these creatures are and how they evolved to be what they are today. They are sought by crab fisheries, and are considered a delicacy in Japan. To prevent overexploitation from harming the species, conservation efforts have been put in place to protect these creatures and their population from overfishing.

The Japanese spider crab is similar in appearance to the much smaller European spider crab (Maja squinado), though the latter, while within the same superfamily, belongs to a different family, the Majidae.

Japanese spider crabs are mostly found off the southern coasts of the Japanese island of Honshū, from Tokyo Bay to Kagoshima Prefecture. Outlying populations have been found in Iwate Prefecture and off Su-ao in Taiwan. Adults are found at depths between 50 and 600 m (160 and 1,970 ft). They like to inhabit vents and holes in the deeper parts of the ocean. The temperature preference of adults is unknown, but the species is regular at a depth of 300 metres (980 ft) in Suruga Bay, where the water generally is about 10 °C (50 °F). Based on results from public aquaria, Japanese spider crabs tolerate temperatures between 6 and 16 °C (43 and 61 °F), but are typically maintained at 10–13 °C (50–55 °F).

The Japanese spider crab is an omnivore, consuming both plant-matter and animals. It also sometimes acts as a scavenger, consuming dead animals. Some have been known to scrape the ocean floor for plants and algae, while others pry open the shells of mollusks.

show less