Amino acid spectrum of two Gambusia species (Cyprinodontiformes: Poeciliidae)

The amino acid spectrum was studied in two Cuban fish species - Gambusia puncticulata and G. bucheri from Cuba. Of nine essential amino acids (EAA) identified in total, statistically significant differences between the species were found only in the quantitative value of methionine, but nearly significant differences were observed in arginine and isoleucine. Between eight nonessential amino acids (NEAA), very significant differences were found only in alanine. The hierarchy subsequence of the quantitative values of amino acid apectrum is, of course, coincident in both species. In wild populations of G. puncticulata from various types of aquatic ecosystems, coincident values of leucine, lysine, valine, phenile, tyrosine and histidine were found. As to the localities, statistically significant differences were found in isoleucine, arginine, threonine and methionine. In the other AA registered in both fish species, significant differences also occurred. Significant differences in the quantitative values of AA between G. puncticulata wild populations with natural food available and those in G. puncticulata captive population reared for a long time under experimental conditions (and fed on artificial synthetized food) were found in threonine and serine only.