Migration and brackish environment use of Prochilodus lineatus (Valenciennes, 1837) inferred by Sr:Ca ratio transects of otolith

AVIGLIANO, ESTEBAN; PISONERO CASTRO, JORGE; DOMÁNICO, ALEJANDRO; SÁNCHEZ, SEBASTIÁN; VOLPEDO, ALEJANDRA

NEOTROPICAL ICHTHYOLOGY

SOC BRASILEIRA ICTIOLOGIA

Lugar: MARINGÁ; Año: 2017 vol. 15

1679-6225

The streaked prochilod, Prochilodus lineatus represents the most important fishery in the Plata Basin being a recognized economic resource for 5 countries in South America. Some ecological and migratory aspects of this species are known, but the use of the estuary was not studied until now. Our objective was to analyze the use of the estuarine environment, evaluating the proportion of specimens using the estuary, frequency and ages in which incursions occur. To this end, transects of Sr:Ca of lapilli otoliths of fish caught in the Paraná and Uruguay rivers were analyzed; in the latter, downstream and upstream of a hydroelectric dam (Salto Grande). Our results show that the percentage of specimens using the estuary (classified as freshwater stragglers) varies between sites, being higher in the Paraná River (36%) and lower in the Uruguay River (5-33%). The Change-point analysis showed significant differences (Kruskal-Wallis, p=0.02), revealing a larger number of displacements in the Paraná River (22.5 ± 5.63), compared to the other sites (17.3 ± 4.63-18.5 ± 5.29, up and below the dam, respectively) . Species makes estuarine incursions between 1 and 3 times throughout life at different ages (0+-15 years) involving displacement of up to 1,000 km. These incursions have no periodicity or common patterns. This information should be integrated into future management actions, which should also be specific to each area since migration patterns differ between the major rivers of the basin.