i have an oppertunity to buy a "pair" of 2 inch salvini from the lfs for 7 bucks, however i couldnt tell any difference between the two. What is the best way to make sure it is a male and a female?
males have lots of blue dots all along the body of the fish. also males fin extentions are longer. here is a pic from www.aquamojo.com of a pair. the male is on the left. i am not sure at what size they can be sexed at though.
They can be sexed from approximately 1-1.5 inches and up. Females have a large black blotch on the dorsal fin (spiny part) and on teh lower operculum (gill plate). Depending on locality, some may not show the spot on the operculum, but all females ahve the dorsal blotch.