Sex reversal of pejerrey (Odontesthes bonariensis), a species with temperature-dependent sex determination, in a seminatural environment.

This study examined the changes in sex ratios and sex reversal rates in pejerrey Odontesthes bonariensis that occur with the progression of the spawning season in a seminatural setting. Four groups of hatchery-produced pejerrey larvae were stocked in floating cages in La Salada de Monasterio lake (Pampas region), a natural habitat of this species, and reared from hatching beyond gonadal sex determination with minimum human interference. Cage 1 was stocked at the beginning of the spring spawning season and the other cages were stocked with monthly delays until cage 4 in early summer.

Gonadal development in pejerrey (Odontesthes bonariensis) during spawning season in relation with sex steroids and temperature variation in Gómez lake (Pampas region, Argentina).

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 fish species in this lake is the pejerrey (Odontesthes bonariensis) valued due to the quality of its flesh and its attractiveness as a game fish. The aim of this study was to describe for the first 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.

Evidence of a landlocked reproducing population of the marine pejerrey Odontesthes argentinensis (Actinopterygii; Atherinopsidae).

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.

The Duplicated Y-specific Gene Is Conserved and Linked to Maleness in Silversides of the Genus .

Sex-determining genes have been successively isolated in several teleosts. In and , the gene has been identified as a master sex-determining gene. However, whether this gene is conserved along related species is still unknown.

Microplastics in gut contents of coastal freshwater fish from Río de la Plata estuary.

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.

A standard weight equation to assess the body condition of pejerrey Odontesthes bonariensis.

We developed a standard weight equation Ws to aid in the analysis of pejerrey Odonthestes bonariensis body condition over time and across populations using the relative weight index Wr. Weight--length data were compiled from 73 populations of pejerrey (N=16.022) from the Argentine pampas region.