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. In this study, we examined the pejerrey population of Salada de Pedro 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.

Distribution of wetlands in Argentina estimated from soil charts - DOI: 10.4025/actascibiolsci.v30i4.5870

We generated a map of wetlands in Argentina from the digital edition of the National Soil Inventory made by the National Institute of Agricultural Technology (Instituto Nacional de Tecnología Agropecuaria, INTA). Potential wetland areas were extracted from the map after an exhaustive analysis of the database and reassignment of the soil classes, by taking into account 1) soil taxonomic classes; 2) constraining factors (waterlogging, flooding, drainage impairment); and 3) cartographic categories, including lakes, lagoons, marshes and salt lakes. Estimated wetland area is about 600,000 km2, representing 21.5% of the national territory; it increases to 23% when considering salt lakes and deepwater bodies, but their surface is underestimated in the INTA database. Finally, we analyzed the distribution and abundance of wetland areas from different eco-regions of Argentina, and compared our results with current global wetland databases.