We all know how difficult it is to identify the sex of these fish, so please post a picture in here and we'll try to help you (or at least give an educated guess!).
I would guess the middle one a female too, the rest i confirm according to plastic mac's opinion.
Plastic could you point out why you think the middle one would be male?
Greetings,
John
[img]http://i185.photobucket.com/albums/x276/hypancistrus-zebra/half.gif[/img]
I believe I agree with Plastic, all four are the same fish in each pic, correct?
I was looking at Foto 2, from the first post, and the one on the top left (in Foto 2) appears to be the same as the one Plastic picked as female. It looks to have a shorter snout than the others (for size).
She looks to be No 2 in the pic with the numbers (which appears to be Foto 1 in first post), looks wider in the body near the ventral fins than the others as well. As well as the ventral fins being not as developed (males use them to fan eggs/fry)
Ok, females, tend to have shorter snouts. As having been explained to me and checking mine, maybe I'm not explaining it well to you. Harder to do in typing, but the eyes are further back from the tip of the snout on a male, and this is probably due to males battling for territory - to protect themselves. My thought was that '2' snout seemed shorter - not a whole lot, and I like side pics better. Look at the Home/Species info (scroll down that page) of this web site and check those pics. The female's nose rounds down faster than the male's. My female's look that way.
I would not be able to detemine why she is raised above the glass, or if it means anything. Just giving my opinion with what I can see. Hope that helps.