Osmotic induction marking with Alizarin Red S on pejerrey, Odontesthes bonariensis juveniles

DANIELA CAMPANELLA; ÁNGELA GÁRRIZ; DARÍO COLAUTTI; GUSTAVO M. SOMOZA; LEANDRO A. MIRANDA

NEOTROPICAL ICHTHYOLOGY

SOC BRASILEIRA ICTIOLOGIA

Lugar: Porto Alegre; Año: 2013 vol. 11 p. 95 - 100

1679-6225

Juveniles of pejerrey, Odontesthes bonariensis, were exposed to 0.1% Alizarin Red S(ARS) alone or with a previous immersion in 2.2% saline solution (Osmotic Induction, OI)to enhance the ARS marking method. Fish were marked in the field and immediatelyreleased in 1 m3 cages in ?La Salada de Monasterio? lagoon, Chascomús, Buenos Aires,Argentina. After 73 days, clear marks were observed in the otoliths, caudal fin rays andscales with both treatments, being the intensity of the signal in the scales of OI+ARStreated fish higher. On the other hand, no marks were observed in the control group on thesame structures. Approximately one year post-treatment (385 days), only marks in caudalfin rays were found clearly in OI+ARS treated fish. After this period, no significantdifferences in total length or weight between marked or control fish were observed and themortality ranged between 30-40 % in all cages. These results provide strong evidence forthe potential applicability of this cost-effective marking technique in differentiation of wildand hatchery-produced pejerrey. The success in the caudal fin rays marking is also important because it is so easy to do it and does not require the sacrifice of fish.