RT Journal Article
T1 Effects of Randomly Fired Underwater Currents as an Occupational Enrichment Program in Rainbow Trout (Oncorhynchus mykiss)
A1 Villarroel, Morris
A1 Miranda de la Lama, Genaro C.
A1 Bermejo Poza, Rubén
A1 Pérez, Concepción
A1 González De Chávarri Echániz, Elisabeth
A1 Torrent, Fernando
A1 Fuente Vázquez, Jesús De La
AB Occupational enrichment (OE) is directed at introducing variations in the tank water so that fish can exercise as they do in the wild. Two trials were carried out to test the effects of randomly fired underwater currents (RFC) on rainbow trout (Oncorhynchus mykiss) maintained in tanks in a recirculation system, using 1226 trout distributed in two independent trials. In Trial 1, fingerling trout (n = 6 tanks, n = 40 fish per tank) were classified into two groups based on low (13%) or high (30%) coefficient of variation in live weight (CV), and exposed to RFC or no currents (controls). In Trial 2, adult trout (n = 12 tanks, n = 20 fish per tank) were either exposed to RFC or to a constant current (controls) from two submerged pumps. Both trials lasted four weeks. No significant differences in growth were observed between treatments in either trial. In Trial 1, RFC fish maintained a similar CV throughout the trial, while CV decreased in controls. Also, in Trial 1, plasma cortisol levels were higher and creatine phosphokinase (CPK) levels lower in tanks with a low initial CV. In Trial 2, the CV was lower in RFC trout, where cortisol levels were also significantly lower and triglycerides significantly higher. The results suggest that OE using RFC can have positive effects by helping to reduce stress levels, and provides fish with biologically meaningful environmental enrichment related to the natural history of the species.
PB MPDI
SN 2073-4441
YR 2021
FD 2021-11-01
LK https://hdl.handle.net/20.500.14352/5025
UL https://hdl.handle.net/20.500.14352/5025
LA eng
NO EU ANIHWA ERA-Net
DS Docta Complutense
RD 6 abr 2025