Jonah crab

Description

The Jonah crab (Cancer borealis) is a marine brachyuran crab that inhabits waters along the east coast of North America from Newfoundland to Florida. Jonah crabs possess a rounded, rough-edged carapace with small light spots, and robust claws with dark brown-black tips. The maximum reported carapace width for males is 222 mm, while females rarely exceed 150 mm. It is the closest relative to the European brown crab in the Western Atlantic. Jonah crabs have been reported at depths of up to 750 m. Habitat preferences for Cancer borealis range from rocky substrate in Rhode Island and the Gulf of Maine to silt and clay substrate on the continental slope. It is widely accepted that this species moves offshore in the fall and winter, and females have been documented moving inshore in late spring and summer. The Jonah crab is known to move to areas of preferred temperature for behavioral thermoregulation. The preferred temperature of this animal changes depending on the temperature to which it is acclimated. The estimated average preferred temperature is 15.4 °C (59.7 °F). According to stomach content analysis on individuals from the Gulf of Maine, the diet of Cancer borealis consists of mussels, arthropods, snails, and some algal species. Blue mussels (Mytilus edulis) composed more than 50% of analyzed stomach contents. Jonah crabs have long been caught as bycatch in lobster traps. Once, they were considered a nuisance and a pest that stole the bait in the traps and they were thrown back in the sea by many angry fishermen. In the past twenty years, particularly in New England, landings have increased due to increased fishing pressure and market demand. Landings of Cancer borealis in the United States rose from 2-3 million pounds annually in the 1990s to more than 17 million pounds in 2014. In 2014, 70.05% of landings came from Massachusetts, followed by Rhode Island with 24.43%. Jonah crabs are not managed federally in the United States, but instead are managed by individual states with interstate coordination by the Atlantic States Marine Fisheries Commission.