well, the way i could tell curviceps apart was that the males were clearly more slender and had pointier fins. with thayeri and dorsiger, if the criteria is the same, then i'm very confused. my 2 thayeri both have very pointy fins, so they could be both males, although when i bought them one didn't have such elongated fins. the 2 dorsiger have also pointy fins ,not rounded, but they are also heavy and round, not slender, so i'm confused. they tend to spar a lot and show bright colors. my 2 P. altispinosa on teh other hand are easier to sex: the male has much more elongated, red fins. tsuh yang chen, nyc ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@listbox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@listbox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!