Temperature, photoperiod, and water–electrolyte balance in rainbow trout, Salmo gairdneri

Abstract

1977. Temperature, photoperiod, and water-electrolyte balance in rainbow trout, Sulmo gairdneri. Can. J. Zool. 55: 1377-1388. The influence of temperature and photoperiod upon water-electrolyte balance was considered in animals acclimated to four combinations of two temperature (2, 18°C) and photoperiod (18 h light4 h dark, 6 h light-18 h dark) regimes through evaluation of Na, K, Ca, Mg, and C1 levels in plasma, skeletal, and cardiac muscle and liver. Water content and distribution and approximate cellular ion levels were estimated for skeletal muscle and liver. Evidence of significant influence upon water balance was obtained in one-half of the analyses performed, with effects being particularly pronounced in cold-acclimated, 'winter'-photoperiod specimens. Temperature effects were observed in two-thirds of the comparisons made with respect to electrolyte levels. These were not biased in relation to photoperiod. Most significant photoperiod-correlated variations in electrolyte levels (over one-half of the total considered) were observed at low ternperature. These observations are discussed in relation to compensation of rainbow trout for ternperature perturbation of the osmoregulatory and ionoregulatory systems, and the possible basis of photoperiodic influence upon these responses. MURPHY, P., et A. H. HOUSTON. 1977. Temperature, photoperiod, and water-electrolyte balance in rainbow trout, Salmo gairdneri. Can. J . Zool. 55: 1377-1388. On a analyse I'influence de la temperature et de la photoperiode sur I'equilibre hydrique et ionique chez des animaux acclimates a quatre combinaisons de temperature (2, 18°C) et de photoperiode (I8 h lumiere4 h obscurite, 6 h lumiere-18 h obscurite); les concentrations de Na, K , Ca, Mg et CI dans le plasma, dans les muscles squelettiques et cardiaque et dans le foie ont ete evaluees. On a estime le contenu et la repartition de I'eau, de mime que les concentrations approximatives d'ions dans les cellules, dans les muscles squelettiques et dans le foie.L'influence de la temperature et de la photoperiode s'est rnanifestee dans la moitie des experiences, particulierement chez les poissons acclimates au froid, a la photoperiode d'hiver. Les effets de la temperature sur les concentrations d'electrolytes se sont produits dans les deux tiers des cas; la photoperiode ne change rien dans ces cas. C'est a basse temperature que la photoperiode influence le plus les concentrations d'ions (chez plus de la moitie des poissons). On discute de ces resultats en fonction des mecanismes de compensation utilisks par la truite arc-en-ciel lors de perturbations de temperature des systemes osmoregulateur et ionoregulateur; on croit a I'influence possible de la photoperiode sur ces rnecanismes.[Traduit par le journal]

Effect of low sea water temperature on water balance in the Atlantic salmon, (Salmo salar L.)

“…The rate of drinking varies with fish species and water salinity (Evans 1968;Potts et al 1970; Rowdon and Cornish 1973;Hirano 1974;Eddy and Bath 1979), but temperature may also influence osmoregulation of fish in both sea and freshwater (Byrne et al 1972;Murphy and Houston 1977). The effects of temperature on water balance and drinking rate of fish in seawater have, however, been investigated on very few occasions (Maetz and Evans 1972; Motais and Isaia 1972).…”

A literature review of the blood chemistry of rainbow trout, Salmo gairdneri Rich.

“…Only one group of trout had low chloride levels in this temperature range. Furthermore, one author observed a slight decrease with rising temperature (Hickman et al, 1964;Houston et al, 1968;Houston & McCarthy, 1978;Houston & Smeda, 1979;Toews & Hickman, 1969;Rao, 1969;McCarty & Houston, 1977;Murphy & Houston, 1977). The potassium content increased at high temperature in most investigations, but remained constant in two trout populations Houston & McCarthy, 1978, Houston & Smeda 1979McCarty & Houston, 1977;Hickman et al, 1964;Murphy & Houston, 1977).…”

“…The chloride content, however, is enhanced by a short light period (Meisner & Hickman, 1962;Murphy & Houston, 1977).…”

“…Hence, the environmental temperature distinctly affects osmoregulation (Murphy & Houston, 1977). Fluctuations of electrolyte concentration may play an important part in the temperature compensation of enzymatic regulation.…”

“…Fluctuations of electrolyte concentration may play an important part in the temperature compensation of enzymatic regulation. The effect of water temperature on osmoregulatory ability depends on season and photoperiod (Houston & Smeda, 1979;Murphy & Houston, 1977). Though this is considered, the reports of different authors on temperature-dependent electrolyte changes are contradictory.…”