HCA: Hermit Crab Association

This is my lovely hermit crab cheese she was one of my first ever crabs and I am 100% positive she was a female before I don’t have any good photos but she definitely was a she and I was just gender checking my new crabs and decided to gender check with my older ones and cheese appears to be a male cheese molted about two weeks ago



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I don't think hermit crabs can change genders, which set of legs are you looking at? The gonopores will be on the 3rd set of legs (not including claws). The 3rd set of legs is the first set that are shorter and mainly grip the inside of the shell. You could try using a magnifying glass, sometimes gonopores are pretty small. It could also be your hermie was always a male, I thought one of my hermit crabs had gonopores but it was actually some substrate that had gotten stuck to his legs Another way to tell is also the legs, males have hairy legs, females have smooth legs

The males have hairy legs/females have smooth legs thing is actually a myth. In fact, it is believed hermit crabs can change genders! That could just be another widespread myth though.

I would say it's possible your crab could have changed genders!

Anyone feel free to correct me if I'm wrong

gender changing is a very debated topic.. some site are pro, some are very con.. it's really not been researched with creditable support to say for sure.

Not trying to be picky, but would like to correct the wording so that it is accurate. When we are referring to crabs being male or female, we are referring to their sex, not their gender.

*slight bump*

Wait, now I'm confused. The gonopores are on the last set of walking legs or the first set of small shell-gripping legs?
I thought I saw gonopores on Mitchelle (hence the name change from Mitchell), but I was looking on her 2nd walking legs.

See here for gonopore location: viewtopic.php?t=92519






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This comes up fairly often, and I think it's safe to say that the gonopore spots can come and go with molting. It's been noted many times before. Wild crabs also have a fairly high percentage of intersex individuals, and this can mean both having one gonopore, and also have a gonopore status that does not match their reproductive organs.

What we don't know is if they actually fully change sex, both internally and externally. I have my doubts on this as the gonopores are fully molted every time so would be easier to alter, but their internal organs are not. Observation of individuals over time and the randomness of this occuring makes it difficult if not impossible for scientists to investigate, and finding out would also require less than savory methods to the average keeper.

Something you may be able to watch for is the presence of pleopods if s/he were to change shells in front you. These are the structures across their back that females use to hold and incubate eggs. Again, not 100% accurate in terms of sexing, but it would strongly lean towards the crab being female if they are there.

It be interesting to know the chromosomal make-up of our hermits, and sex linked chromosomes/genes. It would play a better descriptor to determine male vs female, and if our crabs are indeed intersex, expression of these genes would paint a far clearer picture. Intersex while common in many animal species, is also rare in itself, and I truely do think that intersex individuals are likely to just not displaying gonopores between between different moulting windows.

aussieJJDude wrote: ↑

Sat Sep 10, 2022 6:50 pm

It be interesting to know the chromosomal make-up of our hermits, and sex linked chromosomes/genes.

It's being looked into! More into food crop species but its setting up a good understanding of how it works across crustacea overall. It's...more complicated than I was expecting. Some of their results does show for intersex being a thing! All it takes is a small disruption in various hormones and sex characteristics are affected.

Sex Determination and Differentiation in Decapod and Cladoceran Crustaceans: An Overview of Endocrine Regulation
Kenji Toyota, Hitoshi Miyakawa, [...], and Taisen Iguchi

https://www.ncbi.nlm.nih.gov/pmc/articl ... po=20.0893