—We made estimates of annual production of stream trout in two Lake Superior tributaries in northeastern Minnesota in 1977-1978. The Caribou River (total alkalinity, 34 mg/L as CaCO3) drains pan of the north shore of Lake Superior in an igneous rock geology. The Blackhoof River (total alkalinity, 83 mg/L) drains glacial drift and lake clay at the western end of Lake Superior. Annual production ...

ALLEN, D. M., W. N. MCFARLAND, F. W. MUNZ, and H. A. Pos-roN. 1973. Changes in the visual pigments of trout. Can. J. Zool. 51: 901-914. The proportions of two visual pigments (rhodopsin and porphyropsin) were examined in four species of trout under experimental and natural conditions. Brook trout (Salvelinus fontinalis), rainbow trout (Santo gairdneri), and brown trout (Salmo truita) have diffe...

The trout heart is 10-fold more sensitive to Ca(2+) than the mammalian heart. This difference is due, in part, to cardiac troponin C (cTnC) from trout having a greater Ca(2+) affinity than human cTnC. To determine what other proteins are involved, we cloned cardiac troponin I (cTnI) from the trout heart and determined how it alters the Ca(2+) affinity of a cTn complex containing all mammalian c...

The aims of this study were to determine hatching performance, body and yolk weight at hatching, the growth rate during the yolk absorption and yolk conversion efficiency of Black Sea trout, brook trout and their hybrid larvae, and to compare the relationships between length, total wet weight, dry yolk body weights of alevins and degree-days. The Black Sea trout egg has shorter incubation durat...

—We tested larval Pacific giant salamanders (Dicamptodon tenebrosus) for chemical and behavioral defenses against cutthroat trout (Oncorhynchus clarki). Youngof-year Dicamptodon were fully palatable to trout during single and repeated offerings. However, larvae increased refuge use in response to chemical cues from trout, although they did not select different microhabitats (shallow or deep) be...

  Six different diets including two rainbow trout starters, Gammarus dry powder, shrimp dry powder, egg yolk dry powder and newly hatched Artemia were used in feeding of Caspian Kutum larvae. During a 4-week trial, larvae with a mean weight of 17.5 ± 4.7 mg were fed with three replicates and growth parameters were measured at the end of the experiment. Thirty fish in each experimental unit with...

The aim of this study was to investigate the interaction between fish cage culture and sediment bacterial contamination in the area southern of Caspian Sea. For this purpose, sampling of sediment was collected in Mazandaran province (Nowshahr region) during the rainbow trout farming period at different distances (shadow, 200 and 1000 m from the cage) in 2017-2018. The results showed that in the...

1 The introduction of farmed trout (stocking) to support anglers’ catches is a well-established and widespread practice. Many fisheries rely upon it to remain viable for example reservoir trout fisheries that lack natural trout production. However, in waters with a natural population of trout, stocking of farmed fish can present risks to the wild population through inter-breeding and competition.

Blood acid-base regulation following exhaustive exercise was investigated in freshwater(FW) and seawater(SW) adapted rainbow trout (Salmo gairdneri) of the same genetic stock. Following exhaustive exercise at 10°C, both FW and SW trout displayed a mixed respiratory and metabolic blood acidosis. However, in FW trout the acidosis was about double that of SW trout and arterial blood pH took twice ...

The anti-predator behaviours of a New Zealand freshwater crayfish (Paranephrops zealandicus) to the native long-finned eel (Anguilla dieffenbachii) and the introduced brown trout (Salmo trutta) were investigated. Crayfish modified their behaviour in the presence of both trout and eels. However, a significantly greater number of defensive chela displays and swimming responses were made to eels t...