Crayfish Sexing: How to Determine the Gender of Your Crayfish

male vs female crayfish

This site does not constitute pet medical advice, please consult a licensed veterinarian in your area for pet medical advice.

To tell you frankly, I spent hours trying to figure out how to identify crayfish gender. Most of the resources are very complicated and for animal experts. It is quite hard for us, crayfish keepers to understand those scientific resources. So, in this article, I’ll show you the differences in laymen terms so that even a beginner crayfish keeper can identify the crayfish gender.

Male CrayfishFemale Crayfish
Male crayfish is larger in size when sexually maturedNot as large as the male
The claw is larger in male crayfishThe claw remains comparatively shorter in female crayfishes
Male crayfish has a narrow abdomenFemale crayfishes tend to have a wider abdomen for storing eggs
Strong and fully developed GonopodGonopod is not as developed as the males
The fourth set of pereopods (walking legs) has a nodule at the base. These are called Claspers.No nodule at the base of the fourth set of pereopods. The third set of pereopods will have two holes at each side of the pereopod’s base. Eggs come out from these holes.
The pleopods (swimmerets) are less developed in the male crayfish.The pleopods (swimmerets) are well-developed in the female crayfish.

I know seeing only the table above can make you more confused. I know it will make me. So, let me explain all these differences as easily as possible in the rest of the article.

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A Little Bit Of Crayfish Anatomy

Before we can identify the crayfish gender properly, we need to know a little bit about the crayfish anatomy. Please fear not, it will not be a biology class. I’ll just introduce you to the organs that are needed for differentiating male and female crayfishes.

The image is taken as a screen shot from Kim Owen’s Crayfish Anatomy Video [very good resource for understanding crayfish anatomy]

First, look at the claws. These claws are known as Cheliped or 1st walking leg set.

After the Claw, there are additional 4 pairs of walking legs. These walking legs are called Pereopods.

After the walking legs, on the abdomen of the crayfish, you’ll see very small sized legs like walking legs. These are called swimmerets of Pleopods. The first set of Pleopods is called Gonopod.

That’s all the anatomy you need to know for identifying crayfish gender. It was easy, right?

Crayfish Male Female Differences

Before we dive into each of the differences, please know that adult crayfishes are much easier to sex than the juvenile ones. The juvenile crayfishes don’t have properly developed organs yet, so it can be much trickier to sex them.

All the images illustrated below are taken from

Inspect The Gonopod

identifying crayfish gender gonopod

I think, inspecting the Gonopod is by far the easiest way to identify crayfish gender. In males, the Gonopod is very developed and large. In the females, you’ll be barely able to see the Gonopod.

In the above image, the gonopod is marked inside the red circle. You can’t see such a developed gonopod in the female.

Males Have Claspers, Females Have Holes

It is very hard to see the claspers and holes in an image. You can definitely see these in real life by holding a crayfish closely.

In the male crayfish, the fourth set of pereopods (walking legs) has a nodule at the base. These are called Claspers. The females don’t have these claspers.

In the female crayfishes, the third set of pereopods will have two holes at each side of the pereopod’s base. Eggs come out from these holes. These holes are absent in the males.

Males Are Larger

identifying crayfish gender size

When sexually matured, males are typically larger than the females. The above image will give you a good idea about the size difference between male and female crayfish.

Claws Are More Prominent In Males

identifying crayfish gender claw

As you can see, the claws are larger and more prominent in the male crayfish.

Final Words

So, I hope all these graphical illustrations will help you out to differentiate between male vs female crayfish. I know it can be hard at the first time. However, after couple of practices, you can easily identify the gender of your crayfish.

About Muntaseer Rahman

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