Do you enjoy crabbing and want to learn more about the anatomy of crabs? Are you interested in identifying the sex of a crab? You are not alone.
The differences between male and female blue crabs can be difficult to distinguish but this article will help. It is possible to identify the sex of a crab by looking at its features.
Male crabs have one large claw while females usually have two small claws. Another way to tell males from females is by looking at their abdomens; males have an inverted U-shaped curve on their abdomen while females have a less pronounced curve that looks more like a comma shape.
To get a clear break down of the differences between male and female blue crabs read below:
Differences between Male and Female Blue Crabs

Female Blue Crabs
Top of Crab
- The claws: Female crabs tend to have smaller claws with red tips.
- The Shell: Females tend to be smaller than males
Bottom of Crab
- The apron: The underside of the crab, otherwise known as the apron, will be round on a female crab.

Male Blue Crabs
Top of Crab
- The claws: Male’s claws will be larger with bright blue tips.
- The Shell: Males tend to be larger than females.
Bottom of Crab
- The apron: The underside of the crab, otherwise known as the apron, will be much more pointed on the male crab

Eating Male vs Female Crabs
Depending on where you are your local regulations may prevent you from catching and eating female crabs.
As a result, you will only be able to eat male crabs otherwise known as “Jimmies”. Those who do eat female crabs will often note that they taste sweeter and more flavourful than their male counterpart.
Related Articles: Crabbing in Maryland (Blue Crab Country!)
Summary
It is often hard to tell male blue crabs from female blue crabs. The best way to identify the difference between the two sexes of crab is by looking at their undersides.
Female crabs will have a small, white flap near the front of their undersides that can be seen when they are flipped over on their backs.
Male blue crabs won’t have this flap and will have a long, thin abdomen that sticks out in front of them when they are flipped over on their backs.
References
https://en.wikipedia.org/wiki/Callinectes_sapidus