As lobster researchers we often get called with lobster-related questions or special lobster finds. This week we received a really cool looking hermaphroditic lobster from a local fisherman. This lobster is half male and half female, split right down the middle.
One way male and female lobsters are different are in the structure of the first pair of swimmerets (just past the walking legs on the tail). Here’s a picture of the underside of the lobster where you can see that difference. You can also see the sperm duct highlighted on the male side which is absent on the female side.
Let’s flip the lobster over. Females have significantly wider tails than males (this is because females store their eggs underneath their tails so it pays to have a bigger and more protective tail). Here you can see the wide tail on the left side (female) and the straighter, narrower tail on the right (male).
And there you have it, a hermaphroditic lobster.