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.

Odontesthes bonariensis is an inland water fish from the Pampas region, valued due to the quality of its flesh and its attractiveness as a game fish. Chasico ´Lake located in the south of the pampean region is appreciated by fishermen due to O. bonariensis abundance. However, in the last year, a reduction in their catches was recorded. In this work, it was analyzed the changes of O. bonariensis biomass in relation to climate change and salinity in Chasico ´Lake from 1997 to 2013. From 2004 to 2013, when a dry period began, a reduction in lake area (68.1-47.4 km 2 ) and an increase in salinity (18.9-41.5 g l -1 ) were observed. O. bonariensis catches showed a significant decrease in the same period as a result of salinity increments. Possibly, at high salinity, O. bonariensis may still develop but with an impaired reproduction and limited embryo and juvenile survival. In conclusion, after 2004, the fishery quality in Chasico ´Lake showed a decreasing trend from the maximum registered in the Pampas lakes. This was in agreement with a marked decrease in the lake area which in turn increased water salinity up to levels close to the O. bonariensis tolerance limit.

Pampean lakes are characterised by the alternation of flood and drought periods, but little is known about its effects on fish assemblage in an extended temporal scale. This study analyses the temporal variability of the fish assemblage in Chascomús Lake, and discusses the role of temperature and precipitation as potential drivers of fish composition shifts. Data acquisition was based on experimental fishing performed from 1999 to 2013 and from historical fishing records. Two alternative fish assemblage configurations were identified by cluster analysis. Odontesthes bonariensis, Parapimelodus valenciennisand Cyphocharax voga were the dominant species, which accounted for 70-80% of the relative abundance. The species O. bonariensis showed temporal fluctuations in its representativeness, changing from dominant to almost absent, whereas C. voga and P. valenciennis changed their abundance following a similar pattern along time. When historical data were considered, Platanichthys platana appeared as the fourth most relevant species. Precipitation, critical temperatures and fish mortalities were identified as the main drivers of species abundance shifts. This study highlights the importance of long-term assessments to understand the influence of climatic factors and the need to maintain or restore natural ecological processes as the basis to support dynamic sustainable fisheries in Pampean shallow lakes.

In South America, the order Atheriniformes includes the monophyletic genus Odontesthes with 20 species that inhabit freshwater, estuarine and coastal environments. Pejerrey Odontesthes argentinensis is widely distributed in coastal and estuarine areas of the Atlantic Ocean and is known to foray into estuaries of river systems, particularly in conditions of elevated salinity. However, to our knowledge, a landlocked self-sustaining population has never been recorded. In this study, we examined the pejerrey population of Salada de Pedro This article is protected by copyright. All rights reserved.Luro Lake (south-east of Buenos Aires Province, Argentina) to clarify its taxonomic identity.An integrative taxonomic analysis based on traditional meristic, landmark-based morphometrics and genetic techniques suggests that the Salada de Pedro Luro pejerrey population represents a novel case of physiological and morphological adaptation of a marine pejerrey species to a landlocked environment and emphasises the environmental plasticity of this group of fishes.

Cochicó belongs to “Encadenadas del Oeste” system of lakes being a typical water body of the Pampas region. The most abundant fish species in this lake is the pejerrey (Odontesthes bonariensis) valued due to the quality of its flesh and as a game fish. The aim of this study was to compare the gonadal stages of pejerrey during two consecutive spawning seasons (August to December) in relation to sexual steroids and temperature in this lake. In general, pejerrey gonadal development, the Gonadosomatic index and the plasma levels of estradiol and testosterone fluctuated in relation with temperature. In 2014 samplings, females started to ovulating in early August, with a peak during September-October and ending in December with many of them with atretic oocytes. However, in 2015, a marked delay in maturation was observed with ovulated fish only in October and December. This fact may be because the minors mean temperatures recorded in this year. For males, it was possible to find spermiating animals during the whole spawning season and only arrested animals in December. Unexpectedly, histological gonadal analysis revealed for the first time pejerrey with testis-ova, probably due to the intensive use of agrochemicals in this region.

Gómez lake (34 ° 39 'S 61 ° 01' W) is a typical shallow lake of Pampas region placed in the upper area of the Salado river. The most abundant fi sh species in this lake is the pejerrey (Odontesthes bonariensis) valued due to the quality of its fl esh and its attractiveness as a game fi sh. The aim of this study was to describe for the fi rst time in this pejerrey wild population the gonadal stages during three consecutive spawning seasons (August to December) in relation with sexual steroids and temperature in this lake. In general, pejerrey gonadal development, the gonadosomatic index and the plasma levels of estradiol and testosterone varied in relation to air t emperature. During the sampling period, pejerrey females started to ovulate in early August (winter), with a peak in October and ending in December with some of them with atretic oocytes. For males, it was possible to fi nd spermiating animals during the whole spawning season and some arrested animals only in December. Our results confi rm the relationship with pejerrey maturation and temperature and can be useful for decision making in the management of this natural resource.

Evaluación de la calidad de ovas del pejerrey Odontesthes bonariensis en ambientes controlados de agua dulce y salobre Quality evaluation of pejerrey eggs Odontesthes bonariensis in controlled environments of fresh and brackish water

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