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 international introductions, which attests to the high quality and market value of its £esh, as well as its attractiveness as a game ¢sh. The desirable characteristics of pejerrey also make it a good candidate for aquaculture, and the ¢rst trials on pejerrey cultivation (atheriniculture) were started more than a century ago in Argentina. In spite of the considerable interest in its development, little progress has been made and atheriniculture is still restricted to propagation 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 aquaculture development thus far. We also suggest possible scenarios of pejerrey aquaculture development compatible 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 international 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 extensive farming of this species.

The presence of microplastics (MPs) in gut contents of coastal freshwater fish of the Rio de la Plata estuary was studied. Samples were taken in six sites where 87 fish belonging to 11 species and four feeding habits were captured. Presence of MPs was verified in the 100% of fish. The fibres represented the 96% of MPs found. The number of MPs in gut contents was significantly higher close to sewage discharge. There was not found relationship between number of MPs and fish length, weight or feeding habit. The spatial differences in mean number of MPs in fish observed in this study, suggest that environmental availability of MPs could be of great importance to explain the differences found among sampling sites analysed. This work represents the first study about the interaction between MPs and aquatic organisms in this important estuarine ecosystem of South America.

Pejerrey is an important zooplanktivorous native ¢sh of the Argentinean inland waters. It has been traditionally propagated for stocking purposes by relatively costly semi-intensive and intensive methods. In this study, we evaluated the implementation of an extensive culture method by using £oating cages in a shallow pampean lake. Four cages were installed in the Lacombe Lake and stocked with juveniles (16.24 AE 1.69 mm length) at 50 ¢sh m À 3 density for growing until the size of 150 mm, which is considered as a suitable size for stocking. Throughout the experiment, the temperature ranged between 10 and 26 1C and the zooplankton biomass ranged between 12 and 3269 mg dw L À 1 . The growth patterns in the length were similar in the four cages and directly related to the lake thermal conditions and zooplankton availability. The average ¢nal length after 315 days was 154.4 AE 8.8 mm. The survival rates ranged between 53.5% and 64.7% during the ¢rst 110 days and 11.1^25.7% at termination. Growth rate for the ¢rst 2 months was the highest documented for pejerrey culture. This simple technique o¡ers the possibility to produce juvenile pejerrey at a low cost and provides the alternative of reinforcing the natural populations with ¢sh already adapted to the natural environmental conditions. Aquaculture Research, 2010, 41, e376^e384 Floating cage culture of pejerrey in pampean lakes D C Colautti et al.