Whoops, sorry I’m late to the party even though I was tagged. I first saw this at work, couldn’t immediately respond…and then forgot about it. Apologies!
I’m certainly no expert on sexing tarantula molts, and have only sexed one to date (and I’m not even totally sure I got that one right). I definitely can’t tell from these pictures alone, but others have posted some good advice and resources. With the molt spread and softened, is there a little flap up between the top pair of book lungs that can be moved back and forth (like with a toothpick)? If there’s a flap, it’s female. If there’s no flap, it’s male. The “flap,” if present, is the spermathecae, where the female receives and stores sperm. No flap means you’ve got a chap!
I can only take partial credit for the rhyme…and it came into existence after a rather embarrassing brain fart. Story time!
So for a little backstory, I have a chinchilla, and when sexing chinchillas, there’s a similar rhyme. Males will have a larger gap between their genital cone and anus than females, so the rhyme is, “If there’s a gap, it’s a chap.”
When I was first trying to sex a molt from my G. pulchripes, I soaked it in water and dish soap, got my toothpicks out, and spread out the molt. I looked between the top book lungs and got in there with my toothpick and found a movable flap…but then I couldn’t remember if the presence of a flap meant it was male or female. I thought, “Isn’t there a cute rhyme about this? Oh yeah, ‘if there’s a flap, it’s a chap’!” So I spent about a day being vaguely disappointed that my tarantula seemed to be male. Then at some point the next day, it hit me that the rhyme about “chaps” was about chinchillas and gaps, not tarantulas and flaps. So my tarantula with a flap was female (hooray!), and I adapted the chinchilla sexing rhyme to be accurate for tarantulas. Hence, “If there isn’t a flap, you’ve got a chap.”
Apologies!
So my tarantula with a flap was female (hooray!), and I adapted the chinchilla sexing rhyme to be accurate for tarantulas. Hence, “If there isn’t a flap, you’ve got a chap.” 