Genetic diversity and structure of the commercially important native fish pacu (Piaractus mesopotamicus) from cultured and wild fish populations: relevance for broodstock management

Phenotypic and genetic diversity of motile aeromonads isolated from diseased fish and fish farms

Samples from the kidney of 100 diseased fish with signs of haemorrhagic septicemia and 50 samples from outlet water of fish farms were taken aseptically and cultured. In the laboratory, 75 colonies of gram-negative bacteria were biochemically diagnosed as motile aeromonads in our Bacteriology Laboratory Unit using API 20E rapid identification system. The genotype identification using specific p...

Population genetic structuring in pacu (Piaractus mesopotamicus) across the Paraná-Paraguay basin: evidence from microsatellites

The Paraná-Paraguay basin encompasses central western Brazil, northeastern Paraguay, eastern Bolivia and northern Argentina. The Pantanal is a flooded plain with marked dry and rainy seasons that, due to its soil characteristics and low declivity, has a great water holding capacity supporting abundant fish fauna. Piaractus mesopotamicus, or pacu, endemic of the ParanáParaguay basin, is a migrat...

The basis of vagal efferent control of heart rate in a neotropical fish, the pacu, Piaractus mesopotamicus.

The role of the parasympathetic nervous system, operating via the vagus nerve, in determining heart rate (f(H)) and cardiorespiratory interactions was investigated in the neotropical fish Piaractus mesopotamicus. Motor nuclei of branches of cranial nerves VII, IX and X, supplying respiratory muscles and the heart, have an overlapping distribution in the brainstem, while the Vth motor nucleus is...

Commercially Important Catadromous Fish

Biological indicators of stress in pacu (Piaractus mesopotamicus) after capture.

The effects of capture (chasing, netting and air exposure) on cortisol, glucose, chloride, sodium, potassium and calcium concentrations, osmolality, hematocrit, hemoglobin concentration, red blood cells count (RBC) and mean corpuscular volume (MCV) were investigated in pacu (Piaractus mesopotamicus). A total of 132 fish (49.7 +/- 11.7 g) were subjected to capture and 3 minutes air exposure and ...