What is a Japanese spider crab? They may look like something from a 1950s sci-fi film, but Japanese spider crabs are gentle giants. And giants they are. Of the 60,000 species of crustaceans on ...

Despite their common name, horseshoe crabs are more closely related to spiders and scorpions than to “true crabs,” which are crustaceans. They’re in the class Merostomata, which means “leg ...