The pejerrey Odontesthes bonariensis (Valenciennes, 1835) is an inland water ¢sh from the Pampas region comprising part of Argentina, Uruguay and the South of Brazil. Pejerrey is a very popular ¢sh in this region and has a long history of domestic and inter- national introductions, which attests to the high quality and market value of its £esh, as well as its at- tractiveness as a game ¢sh. The desirable characteris- tics of pejerrey also make it a good candidate for aquaculture, and the ¢rst trials on pejerrey cultiva- tion (atheriniculture) were started more than a cen- tury ago in Argentina. In spite of the considerable interest in its development, little progress has been made and atheriniculture is still restricted to propa- gation and stocking for sport ¢shing purposes. In this review, we summarize the history of atheriniculture and the biological, technological, scienti¢c, cultural and infrastructural constraints to pejerrey aquacul- ture development thus far. We also suggest possible scenarios of pejerrey aquaculture development com- patible with the socio^economic conditions of South American countries. Our projections also take into consideration recent scienti¢c ¢ndings on the biology of pejerrey and technological advances in seafood processing, storage and transportation, as well as the latest trends of seafood consumption and interna- tional markets. The best production strategy remains to be determined by trial and error but it is likely that, initially, production should focus on a di¡erentiated, high-quality ¢sh for the premium or international markets rather than attempting to compete with the cheap ¢sh from natural sources. An international cooperation project with Japan has successfully demonstrated the feasibility of breeding pejerrey in captivity and mass producing seeds e⁄ciently in Argentina, and has provided the foundation for the development of intensive and ex- tensive farming of this species.

Sex-determining genes have been successively isolated in several teleosts. In Odontesthes hatcheri and O. bonariensis, the amhy gene has been identified as a master sex-determining gene. However, whether this gene is conserved along related species is still unknown. In this study, the presence of amhy and its association with phenotypic sex was analyzed in 10 species of Odontesthes genus. The primer sets from O. hatcheri that amplify both amhs successfully generated fragments that correspond to amha and amhy in all species. The full sequences of amhy and amha isolated for four key species revealed higher identity values among presumptive amhy, including the 0.5 Kbp insertion in the third intron and amhy-specific insertions/deletions. Amha was present in all specimens, regardless of species and sex, whereas amhy was amplified in most but not all phenotypic males. Complete association between amhy-homologue with maleness was found in O. argentinensis, O. incisa, O. mauleanum, O. perugiae, O. piquava, O. regia, and O. smitti, whereas O. humensis, O. mirinensis, and O. nigricans showed varied degrees of phenotypic/genotypic sex mismatch. The conservation of amhy gene in Odontesthes provide an interesting framework to study the evolution and the ecological interactions of genotypic and environmental sex determination in this group.