Hi Raymond I have found Bolivian Rams really hard to sex. Even Linke & Staeck admit that "their appearance....make determination of sex a matter of guessing..." However, I have sometimes had success identifying males by their dorsal fin, which tends to trail and become longer as they mature (a method suggested by L & S). Rich ------------------------------------------------------------------------- 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"!