Osmoregulatory Plasticity of Juvenile Greater Amberjack (<i>Seriola dumerili</i>) to Environmental Salinity
Andre Barany,
Neda Gilannejad,
María Alameda-López,
Liliana Rodríguez-Velásquez,
Antonio Astola,
Gonzalo Martínez-Rodríguez,
Javier Roo,
Jose Luis Muñoz,
Juan Miguel Mancera
Affiliations
Andre Barany
Department of Biology, Faculty of Marine and Environmental Sciences, Instituto Universitario de Investigación Marina (INMAR), Campus de Excelencia Internacional del Mar (CEI·MAR), University of Cádiz, Puerto Real, E11510 Cádiz, Spain
Neda Gilannejad
Instituto de Ciencias Marinas de Andalucía, Consejo Superior de Investigaciones Científicas (ICMAN-CSIC), Puerto Real, E11519 Cádiz, Spain
María Alameda-López
Department of Biology, Faculty of Marine and Environmental Sciences, Instituto Universitario de Investigación Marina (INMAR), Campus de Excelencia Internacional del Mar (CEI·MAR), University of Cádiz, Puerto Real, E11510 Cádiz, Spain
Liliana Rodríguez-Velásquez
Department of Biology, Faculty of Marine and Environmental Sciences, Instituto Universitario de Investigación Marina (INMAR), Campus de Excelencia Internacional del Mar (CEI·MAR), University of Cádiz, Puerto Real, E11510 Cádiz, Spain
Antonio Astola
Department of Biomedicine, Biotechnology, and Public Health, Faculty of Sciences, Campus de Excelencia Internacional del Mar (CEI-MAR), University of Cadiz, Puerto Real, E11510 Cádiz, Spain
Gonzalo Martínez-Rodríguez
Instituto de Ciencias Marinas de Andalucía, Consejo Superior de Investigaciones Científicas (ICMAN-CSIC), Puerto Real, E11519 Cádiz, Spain
Javier Roo
Grupo de Investigación en Acuicultura (GIA), Instituto Universitario Ecoaqua, Universidad de Las Palmas de Gran Canaria, Crta. Taliarte s/n, E35214 Gran Canaria, Spain
Jose Luis Muñoz
Department of Production, IFAPA Centro “El Toruño”, Junta de Andalucía, El Puerto de Santa María, E11500 Cádiz, Spain
Juan Miguel Mancera
Department of Biology, Faculty of Marine and Environmental Sciences, Instituto Universitario de Investigación Marina (INMAR), Campus de Excelencia Internacional del Mar (CEI·MAR), University of Cádiz, Puerto Real, E11510 Cádiz, Spain
Osmotic costs in teleosts are highly variable, reaching up to 50% of energy expenditure in some. In several species, environmental salinities close to the isosmotic point (~15 psu) minimize energy demand for osmoregulation while enhancing growth. The present study aimed to characterize the physiological status related to osmoregulation in early juveniles of the greater amberjack, Seriola dumerili, acclimated to three salinities (15, 22, and 36 psu). Our results indicate that plasma metabolic substrates were enhanced at the lower salinities, whereas hepatic carbohydrate and energetic lipid substrates decreased. Moreover, osmoregulatory parameters, such as osmolality, muscle water content, gill and intestine Na+-K+-ATPase activities, suggested a great osmoregulatory capacity in this species. Remarkably, electrophysiological parameters, such as short-circuit current (Isc) and transepithelial electric resistance (TER), were enhanced significantly at the posterior intestine. Concomitantly, Isc and TER anterior-to-posterior intestine differences were intensified with increasing environmental salinity. Furthermore, the expression of several adeno-hypophyseal genes was assessed. Expression of prl showed an inverse linear relationship with increasing environmental salinity, while gh mRNA enhanced significantly in the 22 psu-acclimated groups. Overall, these results could explain the better growth observed in S. dumerili juveniles kept at salinities close to isosmotic rather than in seawater.
