Who Gives A Fish Forums

Hey there,

I'm having a bit of trouble sexing my 2 Julidochromis marlieri, or Marlier's Julie - I'm pretty sure I've got a pair, but I just can't seem to find any pics that show the differences between males and females. All I can find are descriptions about genital papillae, which I'm guessing is something to do with a fin near their, ahem, back end.

I've got Big and Small (yeah, that's what we call them, lol) and they've claimed a rocky cave ornament as their territory. As you'd expect, one is a fair bit bigger than the other. My question is, how can I tell which one's male and which one's female? Does anyone have any pics they could share?

Thanks heaps.

If you've got a noticeable size difference and they're hanging out together, it's a pretty safe bet you've got a pair on your hands.

Thanks for the reply, I really appreciate it. I'd assumed they were a pair, given the size difference, but I'd been getting some conflicting advice from other sites and was a bit worried, to be honest.

I was even told they'd be in danger because of the way they swim - all angles, in and out of the rocky bits, and sometimes hiding vertically next to the pump. But after digging deeper, I found that's just natural behaviour for them.

I also had someone say I should've bought 4-6 and let them pair off, then return the others. But, there were only two at the LFS, so I'll stick with my original assumption - Big and Small are a male and female pair.

Yeah, generally you'd get 6 and let them sort themselves out. If they're a decent size, you can make an educated guess. What's the size difference like now, though?

Big is roughly 2 - 2.5 inches, and Small is around 1 - 1.5 inches, length-wise. Big is also noticeably plumper, as well as being longer.