Hudson River Animal of the Month: Blue Crab

Eli’s “Fish” Facts - Blue Crab

Callinectes sapidus 

Blue crabs are one of the most common invertebrates that we catch at CURB every year. We generally start catching them in mid to late May, and continue seeing them, especially as juveniles, throughout the rest of the summer and fall. Over the winter, blue crabs generally burrow in the sediment at the bottom of the river so catching them after November is very unusual. The name Callinectes sapidus is a combination of Greek and Latin, and actually means beautiful savory (or tasty) swimmer. And they are good swimmers indeed, thanks to their modified back legs which are sometimes known as swimmerets. They are also the same crabs that we eat when we have soft shell crab, so you may know of them as tasty as well. 

One of my favorite blue crab facts is that they are autotomous, which means they can release any of their limbs at will! So if a predator is chomping down on one of their legs, they can simply eject it to swim away as quickly as possible. They are able to do this because they regularly molt, or shed their shells, as they grow. Depending on their size and how often they molt, they can usually grow back their leg to full size after a few molts. 

Blue crabs are a highly aggressive and cannibalistic species. Males and females tend to live very far apart, because females are likely to fight with or be eaten by males if it is not mating season. They have a several-day mating ritual that includes the female shedding her shell so she is in a soft phase, and the male holding onto her and guarding her again until her shell hardens. She can actually store the male’s spermatophores for up to one year until it is safe to fertilize and lay her eggs in the ocean waters, since males will also eat their own babies if given the opportunity! Females also usually don’t live as long as males, so anglers are encouraged to throw females, or “sooks”, back into the water if caught. The male “jimmies” are usually considered fair game to keep for soft shell crabbing. However, if you are eating animals from the Hudson River, please follow the DEC guidelines for fishing: https://www.health.ny.gov/publications/2794.pdf.

Meet the Animals: Blue Crab