The ontogeny of Na+ balance during rapid smoltification in pink salmon (Oncorhynchus gorbuscha).
J Comp Physiol B
; 191(1): 17-28, 2021 01.
Article
en En
| MEDLINE
| ID: mdl-32970173
ABSTRACT
Pink salmon hatch in fresh water, but their highly anadromous life history requires them to migrate into the ocean immediately after gravel-emergence, at a very small size. During their down-river migration these larvae undergo rapid smoltification that completely remodels their osmoregulatory physiology. At this time, the larvae reportedly have high whole-body Na+ contents and we hypothesised that the active accumulation of internal Na+ occurs in preparation for ocean entry. Using a comparative approach, the present study characterised the ontogeny of Na+ regulation in larvae of the anadromous pink salmon and the fresh-water rainbow trout. Our results indicate that larvae from both species actively accumulated Na+; however, whole-body Na+ content was higher in rainbow trout larvae compared to pink salmon. The time-course of this response was similar in the two species, with highest Na+-uptake rates ([Formula see text]) shortly after yolk sac absorption, but the mechanism of Na+ accumulation differed between the species. Rainbow trout larvae greatly increased [Formula see text] to overcompensate for a large simultaneous increase in Na+-efflux rate ([Formula see text]), whereas pink salmon mounted a smaller increase in [Formula see text] while maintaining tight control over [Formula see text], which is supported by a significantly lower paracellular permeability. Our results indicate that the transient accumulation of internal Na+ is not a unique feature of the highly anadromous life history in pink salmon and may be a common ontogenetic pattern during larval development in salmonids; and perhaps it is associated with the development of the cardiovascular system during the larvae's transition to a more active lifestyle.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Salmón
/
Oncorhynchus mykiss
Límite:
Animals
Idioma:
En
Revista:
J Comp Physiol B
Asunto de la revista:
BIOQUIMICA
/
FISIOLOGIA
/
METABOLISMO
Año:
2021
Tipo del documento:
Article
País de afiliación:
Canadá