Wildscreen Arkive indicates that the typical horseshoe crab lives between 20 and 40 years, though it is difficult for scientists to assess their ages. Males and females reach sexual maturity around age 10, and their slow growth process makes it hard to determine their age.
Wildscreen Arkive indicates that a horseshoe crab is more similar to an arachnid than an actual crab. Horseshoe crabs rely on their nine eyes, many legs and hard shell to defend themselves from predators and hunt for food. Horseshoe crabs need deep coastal waters to live and access to sandy beaches to lay their eggs.