Osmoregulatory changes in wedge sole (Dicologoglossa cuneataMoreau, 1881) after acclimation to different environmental salinities

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.

Anesthesia and transport of fat snook Centropomus parallelus with the essential oil of Nectandra megapotamica(Spreng.) Mez

“…Euryhaline fish maintain plasma glucose and lactate levels constant within their optimum salinity range, and alterations are observed when these fish are exposed to extreme salinities (Arjona et al, 2007;Herrera et al, 2009). No significant changes were observed in these parameters in fat snooks, indicating that the acclimation to FW and SW did not require higher energy demand.…”

Effect of salinity on survival, growth and biochemical parameters in juvenile Lebranch mullet Mugil liza (Perciformes: Mugilidae)

“…Fish held in hypo or hyperosmotic environments would show additional energy requirements for osmoregulation that could hamper growth when compared to those kept at an isosmotic environment (Boeuf & Payan, 2001;Tsuzuki et al, 2007;Herrera et al, 2009;Pérez-Robles et al, 2012). Energy cost associated with osmoregulation may vary at the different ontogenetic developmental stages.…”

“…Considering the osmoregulatory cost as being proportional to the osmotic gradient existing between the fish body fluids and the external medium (Handeland et al, 1998), it is reasonable to expect that growth would be maximized when fish is reared in water of salinity near the isosmotic condition. In teleosts, the plasma isosmotic point generally corresponds to the water salinity of 12‰ (Boeuf & Payan, 2001;Tsuzuki et al, 2007;Herrera et al, 2009;Nordlie, 2009). However, the significance and fate of the energy spared under isosmotic conditions remain controversial (Boeuf & Payan, 2001;Kidder III et al, 2006).…”

Yearly growth and metabolic changes in earthen pond-cultured meagre <em>Argyrosomus regius</em>

“…salinity, temperature) or biotic (i.e. reproduction, growth) factors have been reported in teleost species , Arjona et al 2009, Herrera et al 2009, Arjona et al 2010.…”