gender id

Does the small black spot on the fins underneath mean my yasha is a male? I need another pistol shrimp because mine seems to have disapeared, and the LFS store is only willing to sell their current one with its goby friend. The yasha at the LFS is labeled as female so I could pair them up. Their...

All I can find is the same one picture showing a male female specimen.i suspect my brighter colored one is female and the more drab one is male based on head shape. But they both have the red mark on the top fun characteristic of males I think.

Need help determining whether or not this Red Finned Fairy Wrasse (Cirrhilabrus rubripinnis) is a male or female. I got as many pics as I could, but it's a wrasse. It moves. Fast. So several came out blurry even though it looked fine as I snapped the phone. These are the best ones I had. I...