edgun88
I don't mean to be excessively argumentative but the difference between males and females of the 'free spawning' Ctenopoma species (which include Ctenopoma acutirostre) has nothing to do with spines on their back. Both genders have a patch of spines right behind and below the eye and another at the base of the tail (caudal peduncle) but in males the spines are generally longer and more strongly developed. Having kept MANY of these fish over the years, of many different species, I can tell you that it takes a close examination of the fish out of the aquarium with a high-quality magnifying lens to have any hope of telling the difference between the two sexes. These gender-specific patches of spined scales are not to be confused with the typical comb-like ctenoid scales that these fish possess...all of which have 'toothed' trailing edges. Also, the spines that project from the back of the operculum (gill cover plate) do not appear to be gender-specific either.
-Joe