Osmoregulatory changes in wedge sole (Dicologoglossa cuneata Moreau, 1881) after acclimation to different environmental salinities |
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Authors: | Marcelino Herrera Luis Vargas-Chacoff Ismael Hachero Ignacio Ruíz-Jarabo Ana Rodiles José I Navas & Juan M Mancera |
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Institution: | IFAPA Centro 'Agua del Pino', Ctra. Cartaya –Punta Umbría, Huelva, Spain; Departamento de Biología, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Puerto Real, Cádiz, Spain |
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Abstract: | The osmoregulatory responses of 20 days of acclimation to environmental salinities of 5‰, 15‰, 25‰, 35‰ and 55‰ were assessed in juveniles of wedge sole ( Dicologoglossa cuneata Moreau, 1881). This sole shows a good capacity to adapt to this range of environmental salinities. A direct linear relationship between environmental salinity and plasma osmolality was observed, with a calculated isosmotic point of 10.4‰ (284 mOsm kg?1). Na+, K+-ATPase activity in the gills followed a 'U-shaped' relationship with environmental salinity, and a direct linear relationship in kidney tissue. Plasma cortisol levels were elevated in fish held in extreme salinities, and glucose levels were higher only in the group maintained at the highest environmental salinity. In the liver, a decrease in glycogen, lactate and amino acid contents was observed in specimens acclimated to extreme salinities (5‰ and 55‰), suggesting mobilization of liver metabolites. Metabolite levels in white muscle showed a pattern similar to the liver, with lower values in specimens acclimated to extreme salinities. We conclude that wedge sole is strongly euryhaline, but acclimation to extreme salinities comes with an energetic cost. |
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Keywords: | wedge sole Dicologoglossa cuneata salinity osmoregulation |
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