Lemon Tetra

[AJ Tudor]

Does anyone have any idea how to sex lemon tetra? It's the one thiing I couldn't find the answer to when I researched them?

 

[The-Wolf]

look at the black line running along their anal fins.
The female will have a very fine black line, almost ghostly in appearance
while the males will have a very thick black line.
this is only possible in sexually mature adults and is not always 100% guaranteed as some
alpha females with have a bold black line too.
an alpha male may also have a bold line covering the entire analfin, signifying his dominance

HTH