Stock composition analysis and connectivity of Prochilodus lineatus from Plata Basin (South America) using otolith fingerprints: temporal variation of a dominant cohort.

AVIGLIANO, E; PISONERO, J.,; DOMÁNICO, A.; SÁNCHEZ, S.; BORDEL, N.; A.V. VOLPEDO.

Taipei

Congreso; 6th International Otolith Symposium 2018 (IOS2018); 2018

Comite 6th International Otolith Symposium 2018 (IOS2018)

Prochilodus lineatus is the most importantfishery resource of the Plata Basin (South America). We evaluated theconnectivity and contribution of the two main nursery areas to two fishingstocks (Uruguay and Paraná rivers), considering subadult (2 years) and adult (4years) specimens. Estimates were made using two maximum likelihood methods.Chemical  composition of young-of-yearfish caught in nursery areas in 2010 was used as baseline of the models; whilechemical composition of the core of subadult and adult otoliths (same cohort)was used as sample of unknown origin. Discriminant analysis based on thebaseline showed high classification rate (98.9%). Results suggest that thesubadult stock from Paraná was not mixed (contribution~100%), while the stock from Uruguay had a contributionfrom the Paraná nursery (1.5±1.2-17.9±3.96%). For the adults, the degree ofmixing increased where the contribution from both nursery areas to the Paranáand Uruguay stocks varied between 14.8±4.18 and 85.2±4.18%. This paper showsthe potential application of otolith fingerprints for determining the relativeimportance of recruitment sources of fish in the Plata Basin