Japanese Spider Crab Facts
- Firstly, the astounding Japanese Spider Crab easily ranks as the largest known living arthropod. However, that specifically applies in reference to its truly prodigious leg span.
- Sadly, this incredible creature inhabits a rather seriously restricted zone of habitation. This limited range therefore renders the crustacean especially vulnerable to numerous threats.
- Further, like most species with such a restricted range of habitation, it remains especially vulnerable to certain factors. These include the effects of both climate change and habitat loss.
- Sadly for it, however, it also faces an additional threat. That extra danger consists of human hunger. Within its native range, this arthropod remains considered a great delicacy.
- Unfortunately, the IUCN has not yet evaluated the status of this particular species.
Japanese Spider Crab Physical Description
Most notably, the shockingly huge Japanese Spider Crab develops a truly mind-boggling leg span. That holds true because this can often reach up to as much as 18 ft (5.5 m) from claw to claw.
Yet, surprisingly enough, the body itself remains rather small in comparison to the legs. The carapace of the remarkable creature typically only attains a relatively tiny diameter of 16 in (40 cm).
But, the species does display a small degree of sexual dimorphism. In this case, the males display slightly longer chelipeds, also known as claws. This trait also occurs in some related species.
In addition, its overall coloring remains primarily a very bright orange. However, multiple white spots generally develop as well, most especially along the out-sized legs. This makes for a striking appearance.
Furthermore, exceptional specimens of the amazing invertebrate sometimes weigh as much as 42 lbs (19 kg). This makes it the second heaviest known arthropod, only exceeded by the American Lobster.
- Kingdom: Animalia
- Phylum: Arthropoda
- Class: Crustacea
- Order: Decapoda
- Family: Inachidae
- Genus: Macrocheira
- Species: M. kaempferi
Japanese Spider Crab Distribution, Habitat, and Ecology
First of all, the amazing Japanese Spider Crab appears to mainly live in a tiny portion of Asia. As its name suggests, it primarily exists in the waters off the southern coasts of the island of Honshu, in Japan.
In addition, rather small and highly isolated populations have also been found in two other locations. These concentrations appear just off the coasts of the Iwate Prefecture, and of Taiwan.
Typically, the truly enormous arthropod inhabits waters at depths ranging from 160 – 1,970 ft (50 – 600 m). Also, individuals most commonly inhabit either holes or vents on the ocean floor.
The Japanese Spider Crab evolved as an omnivore, consuming both plant matter and animals. It also sometimes feeds as a scavenger, seemingly opportunistically. Thus its diet remains highly varied.
Finally, its precise lifespan remains uncertain, yet estimates place it at about 100 years.