Inter-population thermal variability and physiological response in the intertidal fish Scartichthys viridis (Blenniidae)
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Fecha
2007
Profesor/a Guía
Facultad/escuela
Idioma
es
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Sociedad de Biología de Chile
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Licencia CC
Licencia CC
Resumen
La determinación de las condiciones del hábitat que generan variabilidad fisiológica individual representa conocimientos básicos clave para entender el sentido de las respuestas de los animales a cambio de hábitat. Los peces costeros Scartichthys viridis habita bajo pozas intermareales a lo largo de la costa chilena. Debido a que el agua de mar en el intermareal bajo se renueva en cada ciclo de marea, esta zona se caracteriza por una variación térmica baja y abundante comida dentro y entre localidades. Se evaluó si las condiciones térmicas del agua del mar y de la disponibilidad de alimentos de bajo pozas intermareales registradas en tres localidades de la costa chilena son suficientes para generar diferencias fisiológicas y energéticas en individuos de S. viridis capturados en tres poblaciones geográficas separadas que abarcan unos 1.200 km. Peces del sur aclimatados a 25 ° C mostraron mayores tasas metabólicas que los de otras localidades y tratamientos térmicos. Por otra parte, los peces del sur en condiciones naturales mostraron mayor factor de condición que los peces del norte. Esta evidencia es suficiente para indicar que las pequeñas diferencias latitudinales en la temperatura del agua de mar intermaeral asociado a la disponibilidad de alimentos diferencial inducida por una restricción energética en esta especie. Además, la población meridional de S. viridis podrían sufrir importantes efectos sobre la asignación energética si la temperatura del agua aumenta ligeramente, con repercusiones en su distribución geográfica en el sur del Océano Pacífico.
Determining habitat conditions that generate individual physiological variability represents key basic knowledge to understand the direction of animal’s responses to habitat change. The coastal fish Scartichthys viridis inhabits low intertidal pools along the Chilean coast. Because seawater in the low intertidal is renewed during every tidal cycle, this zone is characterized by a low thermal variation and abundant food within and between localities. We evaluated whether seawater thermal conditions and food availability of low intertidal pools registered in three localities of Chilean coast are sufficient to generate physiological and energetic differences in individuals of S. viridis captured from three geographic separate populations spanning approximately 1,200 km. Southern fishes acclimatized to 25 ºC showed higher metabolic rates than those from other localities and thermal treatments. On the other hand, southern fishes in natural conditions showed higher condition factor than northern fishes. This evidence is sufficient to indicate that slight latitudinal differences in tidepool seawater temperature associated to differential food availability induced an energetic constraint in this species. Moreover, southern population of S. viridis may suffer important effects on energetic allocation if seawater temperature increases slightly, with repercussions on its geographic distribution in southern Pacific Ocean.
Determining habitat conditions that generate individual physiological variability represents key basic knowledge to understand the direction of animal’s responses to habitat change. The coastal fish Scartichthys viridis inhabits low intertidal pools along the Chilean coast. Because seawater in the low intertidal is renewed during every tidal cycle, this zone is characterized by a low thermal variation and abundant food within and between localities. We evaluated whether seawater thermal conditions and food availability of low intertidal pools registered in three localities of Chilean coast are sufficient to generate physiological and energetic differences in individuals of S. viridis captured from three geographic separate populations spanning approximately 1,200 km. Southern fishes acclimatized to 25 ºC showed higher metabolic rates than those from other localities and thermal treatments. On the other hand, southern fishes in natural conditions showed higher condition factor than northern fishes. This evidence is sufficient to indicate that slight latitudinal differences in tidepool seawater temperature associated to differential food availability induced an energetic constraint in this species. Moreover, southern population of S. viridis may suffer important effects on energetic allocation if seawater temperature increases slightly, with repercussions on its geographic distribution in southern Pacific Ocean.
Notas
Indexación: Scielo
Palabras clave
Peces intermareales, Compensación fisiológica, Pozas intermareales, Intertidal fish, Physiological compensation, Tidepool, Scartichthys viridis
Citación
Revista chilena de historia natural, Vol. 80, N° 4, 439-446, 2007.