Trout salinity

NORDRUM S, BAKKE-MCKELLEP A M, KROGDAHL A, BUDDINGTON R K (2000) Effects of Soybean meal and salinity on intestinal transport of nutrients in Atlantic salmon (Salmo salar L.) and rainbow trout Oncorhynchus mykiss). Comp Biochem Physiol B Biochem Mol Biol. 125 317-35. 

Hansen, H.J.M., A.G. Olsen, and R Rosenkilde. 1993. The effect of Cu2+ on osmoregulation in rainbow trout (Oncorhynchus mykiss) assayed by changes in plasma salinity and gill lipid metabolism. Sci. Total Environ., Suppl. 1993, Part 2 899-905. 

Ferguson, E.A. and C. Hogstrand. 1998. Acute silver toxicity to seawater-acclimated rainbow trout influence of salinity on toxicity and silver speciation. Environ. Toxicol. Chem. 17 589-593. 

Rainbow trout (100-250 g) were purchased from Roaring River fish hatchery, Scio, Oregon and held under conditions previously described (11). Chlorobenzene (MCB) and carbon tetrachloride (CCI4) were obtained from commercial sources and used without further purification. Chlorobenzene was dissolved in an equal volume of com oil and administered as a single intra-peritoneal (i.p.) injection (either 0.5 or 1.0 ml/kg). Control animals received a similar volume of corn oil. Carbon tetrachloride was given undiluted by i.p. injection (0.2, 1.0, or 2.0 ml/kg) and control animals received a similar volume of physiological saline. 

The consequences of these phenomena are extensive. Rainbow trout grow better in brackish water compared with those in fresh water this suggests a useful modification to culture practice (Teskeredzic et al., 1989). The salinity which permits optimum growth rate in this species was identified as 18%o by Tsintsadze (1991). Brown trout are more resistant to the toxic effects of acid water and aluminium when the water is slightly saline (Dietrich et al., 1989). 

The alevins of rainbow trout thrive best in fresh water. Raising the salinity just to 5%o causes a rise in lactate under fully aerobic conditions and markedly decreases the concentration of blood glucose (Krumschnabel and Lackner, 1993), so the advantage of using isotonic saline varies according to developmental stage. 

Pituitary activity is absolutely central to osmoregulation, and hypophy-sectomy destroys the ability of fish to adapt to a change in salinity. The prolactin is synthesized in, and is secreted by, the pituitary, which also secretes adrenocorticotrophic hormone (ACTH), which, in turn, stimulates the adrenals to produce cortisol. The level of ACTH in the plasma is therefore raised when fish are in sea water (Nichols and Fleming, 1990). The pituitary also secretes growth hormone into the blood plasma in sea water (Yada and Hirano, 1992 rainbow trout) but its role is not clear in the present context. 

Rao, G.M.M. (1969). Effect of activity, salinity and temperature on plasma concentrations of rainbow trout. Canadian Journal of Zoology 47,131-134. 

Tsintsadze, Z.A. (1991). Adaptational capabilities of various size-age groups of rainbow trout in relation to gradual changes of salinity. Journal of Ichthyology 31,31-38. 

Milk leucocytes have been shown to adhere to the MFGM (Peters and Trout, 1945a,b). The enzymatic generation of active oxygen species by phagocytic activity is another possible source of pro-oxidants (Salin and McCord, 1977 Kanner and Kinsella, 1983). 

Larsen, B.K. and D. Schlenk. Effect of salinity on flavin-containing monooxygenase expression and activity in rainbow trout (Oncorhynchus mykiss). J. Comp. Physiol. B 171 421-429, 2001. 

Wang, J., S. Grisle and D. Schlenk. Effects of salinity on aldicarb toxicity in juvenile rainbow trout (Oncorhynchus mykiss) and striped bass (Morone saxatilis X chrysops). Toxicol. Sci. 64 200-207, 2001. 

Wang et al. (2001) investigated the effect of salinity of water on the toxicity of aldicarb in fishes. Their stndies indicated that salinity-mediated enhancement of aldicarb toxicity was species-dependent. In rainbow tront, salinity increased the toxicity of aldicarb, the effect attribnted to greater sulfoxidation to aldicarb snlfoxide cansed by increased flavin-containing monooxygenase and the catalytic activities in microsomes of liver, gill and kidney of rainbow trout. 

We have found that perfusion of the trout heart with oxygenated saline or aerated blood significantly improves performance and it is under these conditions that the effects of various power outputs on fractional rates of protein synthesis of the whole ventricle and its fractions were determined (Fig. 14). The whole ventricle shows a linear increase of fractional rates with power output and the fractions have the same response. Fractional rates of protein synthesis in the trout heart appear to be very sensitive to the work performed over relatively short time periods, 20 to 40 min, and the sensitivity to volume loading is in marked contrast to the results from mammalian hearts where an increase in afterload is the major stimulant (Smith and Sugden 1983 Kira et al. 1984). These results point to the fact that not... 

Relationships between power output of the trout heart and the fractional rates of protein synthesis. The hearts were perfused with oxygenated saline and made to generate differing power outputs by pressure loading. (Data from Houlihan et al. unpubl.)... 

Jungham I, Jurss K (1988) Effect of feeding and salinity on protein synthesis in the white epaxial muscle of the rainbow trout, Salmo gairdneri, Richardson. Comp Biochem Physiol 89B 329-333 Kariya Y, Ochiai Y, Hashimoto K (1986) Protein components and ultrastructure of the arm and mantle of Octopus vulgaris. J Soc Fish Sci 52 131-138... 

Rao GMM (1968) Oxygen consumption of rainbow trout, Salmo gairdneri, in relation to activity and salinity. Can J Zool 46 781 -786... 

LABBfi c and MAISSE G (2001), Characteristics and freezing tolerance of brown trout spermatozoa according to rearing water salinity. Aquaculture, 201,287-299. 

---