Telling lobster genders apart

Joined Mar 3, 2002
In the restaurant in which I work patrons ask for female lobsters or male on occasion. The manner which I have been telling them apart is to flip the lobster over and look for the 2 les pointed toward the body are finer on the female, also the heavy claw is on the left, also the tail shell is slightly wider where it meets the body(these are all female). But now it's been just crack them open and look, we have 2 lobster fests each week and serve between 200-250 lobsters, so they don't go to waste. How can I distinguish the differences between them, are the ways that I am using incorrect? Please help!!!!!!!!!!!!!!!
Thank you.
Joined May 26, 2001
Yup, there is a difference in those little swimmerets. Females' are soft and sort of hairy-looking. Males' are more sturdy, as if there were actually shells on them. Also, the tails of egg-bearing females are notched by the lobstermen if they were previously caught.

Someone (Isa? CChiu?) recently posted a link to a wealth of lobster lore. Have a look for it, it will answer all you questions, and more. :)


Joined Apr 4, 2000
My knowledge of the lobster anatomy is somewhat limited but if you ever need to know how to put a lobster to sleep or how to make it stand on its head I'll be happy to share a few secrets with you.

If I were you I'd go to the fish market and speak to the guys who sell lobster. They'll, most likely, be able to explain how to differanciate female and male. only by looking at them.

When I last bought lobsters, one of the clerck at the fish monger was able to tell male and female appart just by looking at them.
Joined Aug 25, 2001
The easiest way, for me anyway, is to look at the flipperettes (on the underside if the tail) closest to the head. If they are flagged/fluffy/feathered it is a female. If ard and bony it is a male.

The femal uses the feathered swimmerettes to help gather the eggs under her body. Some claim the male's hard bony swimmerette helps grasp him to the female.

Some also claim they can tell by the broadness of the tail near the body. Since this is a relative oserbation, I think the fethered vs hard swimmerettes is easier.
Joined Jan 24, 2003
I'd be interested in knowing the standing on their head trick.

Back in culinary school, an instructor told a story of how a chef she had worked for got someone to send him an Alaskan King Crab. It arrived in a giant styrofoam cooler with grass packing.
The chef (being of immense size), hunched over the cooler and immediately began poking and proding. After all the oohs and aahs, the chef stood back when the crab flipped out of the cooler, and mind you this is all heresy, stood on two legs and snipped his claws towards the chef, who by then was crying for someone to save him. Eventually someone gave it a kung-fu sweep or something, but I can't get the image of an Alaskan scissorhands.

Next week, softshell crab pranks...
Joined Aug 25, 2001
I can't imagine why anyone would prefer a male lobster unless the idea of seeing the red roe is offensive.

My favorite lobster dinner companions are those who dislike tamale. I get theirs too. (Yes, i know about the health warnings. Tamale is worth a slight risk.) If I get a lot, I'll add a couple of tbls of butter, dash of cayenne and paprika, dash of worscestershire and lemon, MIx well and allow to harden in refrigerator. If there's some left, adding some roe and/or chopped meat from the small claws is always a treat. Great as canapes cold - can be enridhed by a dollop of caviar. Or microwave briefly as a warm dip/spread.

Size of the lobster is purely dependent upon its age. The proportion of meat to shell is a function of the time between moults. Hard shell lobsters have not recently moulted, thus their folesh is "jammed" into the shell. Soft shellers have recently moulted and there is plenty pf "growing room." Because the shell is more empty, fluids accumulate making the meat a bit too soft. I will eat them anyway.

The spinnerette test is the easiest and most objective way to determine sex. Check the flipperette near the body - if it's feathery it's a she; hard and bony, a he.

Width of tail is also a way to sex determinate but is VERY subjective. The lobsterman and pound owners can tell, or they say they can. I have "caught" them showing off by telling while the lobster was in the pool ; and they were wrong upon examng the underside.

Left vs. rioght handedness (where t he big claw is) has nothing to do w ith sex.

If you really have NOTHING to do, you can search for "Our Lady of the Lobster." Open the small stomach sack right below the head - it's a greenish capsule. Rinse it out and pry apart gently.
You will see at the base an ivory-looking of cartilage that looks like the head and bust of a madonna including bosom! BE SURE TO DO THIS AWAY FROM THE MEAT! YOU DO NOT WANT THE STOMACH CONTENTS CONTAMINATING THE MEAT< TAMALE AND ROE. It won't kill you, but is bitter.

Do you get the idea I love lobster?


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Staff member
Joined Oct 5, 2001
Very old thread but I post an article on how to tell a male from female lobster with photos.
[article="28325"]How To Tell If A Lobster Is Male Or Female  [/article]
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