INVESTIGADORES
PINONI Silvina Andrea
congresos y reuniones científicas
Título:
OSMO-IONIC PHYSIOLOGY OF THE EURYHALINE FRESHWATER SHRIMP Macrobrachium borellii AFTER TRANSFER TO SALINE MEDIA
Autor/es:
PINONI, S.; ASARO, A.; WILLINER, VERÓNICA; ITUARTE, ROMINA B.
Lugar:
Mar del Plata
Reunión:
Congreso; REUNIÓN CONJUNTA SAIC SAB AAFE AACYTAL 2023; 2023
Institución organizadora:
SAIC SAB AAFE AACYTAL
Resumen:
The freshwater shrimp Macrobrachium borellii (Caridea: Palaemonidae)is widely distributed in the La Plata basin (northern Argentina,Paraguay and southern Brazil), inhabiting continental aquatic habitatsin which salinity seldom can reach 7. As a part of ongoingstudies about saline tolerance in freshwater palaemonids, our laboratoryexperiment involved the abrupt transfer of shrimp from acontrol condition (2) to 7, 15, 20 and 25 for short- (24 h)and long- (> 21 days) acclimation periods. We measured osmolalityof hemolymph and external media using a cryoscopic osmometer(Gonotec) and relevant inorganic ions (Na+, K+, Cl−, Ca2+) using anelectrolyte analyzer (Diestro). Osmolality of hemolymph and externalmedia as well as hemolymph and external medium ion concentrationwere tested by Student t tests (n= 3-9). Shrimp showed greatosmo- ionic regulatory plasticity managing to survive for more than21 days between 7 and 20, and up to 10 days in salinity 25.Shrimp hyper-regulated osmolality of hemolymph in ≈393 mOsm/kgH2O at 2 and 7; in 512 mOsm/kgH2O at 15 and osmolalitywas isosmotic in 595 and 684 mOsm/kgH2O at 20 and 25, respectively.Hemolymph ion concentration (mM) of shrimp kept in thecontrol condition were: [Na+] 270±13; [K+] 10±2; [Cl-] 201±12; [Ca++]5±0.75. Hemolymph sodium and chloride were hyper-regulated at2 and 7. Whilst hemolymph sodium was hyper-iso regulated at15, 20 and 25, hemolymph chloride was iso ionic in thosesalinities. Hemolymph potassium was hyper- regulated between2 and 25, while calcium was hyper-regulated between 2 and15S but iso ionic in salinity 20 and 25. Our results showedthat the freshwater shrimp M. borelli still retain a high degree of euryhalinity,being able to survive between 2 and up to 25 . Thisspecies is a hyper osmo iono regulator between 2 and 15. Althoughshrimp osmoconform in salinity 20 and 25, status of ionoregulation is ion depend.
