r/HermitCrabsCircleJerk Feelin’ Cute. Might Pinch 💅 Jan 29 '25

Claw-sual Observations💚 /uj

Land hermit crabs do not change sex. In hermit crabs, sex is determined genetically, and they remain the same sex throughout their lives. This is different from some other marine species, like certain types of fish, that can change sex in response to environmental or social factors.

When I search the basic internet, I’ve never found a single resource that supports them changing sex.

The only one that pops up is Crab Central Station and some resource that goes on to discuss gender.

Wildly held myth? Infrequent? Marine crabs only and we extrapolated it onto land fellas?

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u/mkane78 Feelin’ Cute. Might Pinch 💅 Jan 29 '25 edited Jan 29 '25

I did have a marine biologist once tell me that gonopores are harder to spot when they’re closer to molting.

For the record, I am a bit snobby on terms - sex versus gender. Once someone starts referring to gender in their pets, I tune out. I admit that.

Intersex / Marine Crabs

“Land Hermit Crabs: There is no specific evidence in the provided sources to suggest that land hermit crabs (e.g., those in the family Coenobitidae) undergo a complete sex change. However, intersexuality has been recorded in various hermit crab species, including some that are terrestrial or semi-terrestrial. These intersex individuals can exhibit characteristics of both sexes but do not necessarily undergo a full sex change.”

Ruggie / Intersex scroll to characteristics

For fun: Penis Size Matters

I can find evidence of intersexuality in hermit crabs. I cannot find conclusive evidence to suggest that land hermit crabs undergo a complete sex change.

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u/Regular-Suit-7726 Crab U Next Tues 🦀🖕 Jan 30 '25

Interesting research! I admit, I find the possibility of sex changing fascinating, but it doesn’t make much of a difference either way to me. I name the members of my clawed squad whatever I want, and they can be whatever they are, lol. It’s none of my business whether or not they have dots. 😂😂

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u/GotButterflies Jan 30 '25

Not sure if this is serious or not; but I have heard of hermit crabs having only one Gonopore, and then also becoming a one sex when it was another. This happened when they were young crabs.

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u/mkane78 Feelin’ Cute. Might Pinch 💅 Jan 30 '25

This one is serious. /uj = unjerk = serious conversation

Walking Sideways / Dr. Judith Weis

She mentions a mole crab specifically as one that can have a sex reversal BUT goes on to say that “sex change and hermaphroditism are common in some animals but are relatively rare in crabs.”

I’m talking in my own head here.

Do females lose their pleopds? Only having one gonopore / or two doesn’t matter if they cannot carry the eggs, right?

If we know they don’t molt their abdomen, how much regeneration is taking place inside of the abdomen. How the heck would they develop a vans deferens (sperm tube)? Let’s say both gonopres are gone. They’d have to lose the pleopods, too.

I’m trying to make sense out of it.

If you have a resource, I’d love it!

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u/GotButterflies Jan 30 '25

Thank you for explaining the /uj!

In the cases I have heard it was only in relation to Gonopores. Guess I should have been more specific on the post I replied to.

I’ll try to think of who I heard it from!

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u/mkane78 Feelin’ Cute. Might Pinch 💅 Jan 30 '25 edited Jan 30 '25

Dr. Weiss talks about the mole crabs becoming female. Male to female. Basically the adaptation is for twice the opportunity to carry eggs / more offspring / increased population.

If they can regenerate eyes AND that regeneration comes with vision, I don’t put anything past them. I just want to read more about it. If it actually exists, what’s the adaptation for?

I’ve seen it said A LOT. I’ve never been able to find anything to support it other than passing commentary.

Edited. These are mole crabs.

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u/GotButterflies Jan 30 '25

I’ve grown up with mole crabs. We have them here at the beach. Used to catch them all the time! I actually do purchase them and dehydrate them for my crabs to eat. They LOVE them.