Increased Survival in Salmonid Hybrids by Induced Triploidy

1983 ◽  
Vol 40 (11) ◽  
pp. 2040-2044 ◽  
Author(s):  
Paul D. Scheerer ◽  
Gary H. Thorgaard
Keyword(s):  
Salmo Trutta ◽  
Salvelinus Fontinalis ◽  
Salmo Gairdneri ◽  
Fish Hybrids ◽  
Tiger Trout ◽  
General Method

All possible hybrid crosses between brook (Salvelinus fontinalis), brown (Salmo trutta), and rainbow (Salmo gairdneri) trout were made and a portion of the fertilized eggs from each mating were heat shocked to induce triploidy. Within a species, triploids generally showed poorer survival to the initiation of feeding than diploids. In most crosses, however, triploid hybrids showed much better survival than diploid hybrids. The triploid tiger trout (brown × brook) hybrid showed the most potential of the hybrids tested. Induced triploidy could be a useful general method for increasing survival in interspecific fish hybrids.

Biochemical and Serological Characteristics of Ontario Isolates of Yersinia ruckeri

1982 ◽  
Vol 39 (6) ◽  
pp. 870-876 ◽  
Author(s):  
R. M. W. Stevenson ◽  
J. G. Daly
Keyword(s):  
Brook Trout ◽  
Salmo Trutta ◽  
Salvelinus Fontinalis ◽  
Geographic Range ◽  
Salmo Gairdneri ◽  
Bacterial Disease ◽  
Yersinia Ruckeri ◽  
Fish Health ◽  
Brown Trout Salmo Trutta ◽  
Coregonus Artedii

During testing hatchery and wild fish from Ontario sources, we isolated bacteria that had sufficient characteristics in common with Yersinia ruckeri to suggest they were strains of this organism. Three isolates from brook trout (Salvelinus fontinalis), rainbow trout (Salmo gairdneri), and cisco (Coregonus artedii) biochemically resembled the sorbitol-fermenting Serovar II strain of Y. ruckeri, but gave cross reactions with antiserum to the Hagerman strain, Serovar I. A fourth isolate from brown trout (Salmo trutta) appeared to be different from the three previously described serovars. A fifth isolate previously obtained from muskrat (Ondatra zibethica) intestine biochemically and serologically corresponded to the Hagerman serovar. We suggest that the geographic range of Y. ruckeri and variations in its biochemical and serological properties are greater than previously believed. These findings are of significance in diagnosis and regulation of enteric redmouth disease of salmonids.Key words: Yersinia ruckeri, enteric redmouth, ERM, bacterial disease, fish health protection

Parasites of Freshwater Fishes (Salmonidae and Coregonidae) of Insular Newfoundland

1967 ◽  
Vol 24 (9) ◽  
pp. 1911-1943 ◽  
Author(s):  
I. M. Sandeman ◽  
J. H. C. Pippy
Keyword(s):  
New Species ◽  
Host Specificity ◽  
Salmo Salar ◽  
Salmo Trutta ◽  
Salvelinus Fontinalis ◽  
Salmo Gairdneri ◽  
Coregonus Clupeaformis ◽  
Two New Species ◽  
Host Parasite ◽  
Lake Fish

A survey was made of the parasites of freshwater game fishes in Insular Newfoundland. A total of 304 fish from five species (Salvelinus fontinalis, Salmo salar (grilse, landlocked, parr, smolt), Salmo gairdneri, Salmo trutta, and Coregonus clupeaformis) was examined from 43 sampling stations covering the main watersheds of the island. Twenty-six parasitic species are recorded. Two new species, Phyllodistomum limnosa and Salmincola exsanguinata, are described. Descriptions are given and the systematic positions of the following discussed: Trichophrya piscium, Crepidostomum farionis, Apophallus brevis (metacercariae), Dibothriocephalus sp., Echinorhynchus lateralis, Metabronema salvelini, Philonema agubernaculum, Salmincola salmonea, and Argulus canadensis. A host–parasite list with percentage infections is given for all species of fish and a table showing the distribution between river and lake fish over the island as a whole is given for the commoner parasites of S. fontinalis. Distribution and host specificity are discussed.

Seasonal change in the amount of visual pigment in the retinae of fish

1982 ◽  
Vol 60 (3) ◽  
pp. 281-287 ◽  
Author(s):  
Donald M. Allen ◽  
Ellis R. Loew ◽  
William N. McFarland
Keyword(s):  
Seasonal Change ◽  
Constant Temperature ◽  
Visual Pigment ◽  
Salmo Trutta ◽  
Salvelinus Fontinalis ◽  
Visual Pigments ◽  
Salmo Gairdneri ◽  
Concomitant Increase ◽  
Retinal Photoreceptors ◽  
The Way

The total amount of two visual pigments, rhodopsin and porphyropsin, extracted from retinal photoreceptors of three trouts and a cyprinid, changes seasonally. In Salmo gairdneri, Salmo trutta, and Salvelinus fontinalis maintained in an outdoor raceway at constant temperature (8 °C) the total amount of visual pigment increased about twofold during the winter, though the proportions of rhodopsin and porphyropsin were relatively unchanged. In eastern common shiners, Notropis cornutis, sampled from a stream, visual pigment increased by about fourfold in winter as compared with summer, and porphyropsin rose from about 17 to 68% of the total amount. A later sample of summer and winter shiners revealed no difference in the density of visual pigment within individual rods.An increased amount of visual pigment will broaden the overall pigment absorptance spectrum and a concomitant increase in porphyropsin will further broaden and shift absorptance toward longer wavelengths. Thus, change in total amount of visual pigment represents a new dimension in the way that visual pigment absorptance can be dynamically altered in certain fishes.

Growth and mortality of diploid and triploid tiger trout (Salmo trutta × Salvelinus fontinalis)

Aquaculture ◽  
1992 ◽  
Vol 106 (3-4) ◽  
pp. 239-251 ◽  
Author(s):  
L.R. McKay ◽  
P.E. Ihssen ◽  
I. McMillan
Keyword(s):  
Salmo Trutta ◽  
Salvelinus Fontinalis ◽  
Tiger Trout

Elementos traza en peces de los lagos patagónicos

2009 ◽  
Author(s):  
◽  
Débora Fabiana Bubach
Keyword(s):  
Oncorhynchus Mykiss ◽  
Salmo Trutta ◽  
Salvelinus Fontinalis

El objetivo de este trabajo fue estudiar algunos elementos traza y mayoritarios en músculo e hígado de peces de lagos de la Patagonia Norte Cordillerana para brindar información sobre los niveles de base en relación a la distribución global de elementos, y efectos locales relacionados con la variabilidad interespecifica en un mismo ambiente y espacial en una misma especie entre las distintas cuencas. Para lo cual, en el primer caso, se compararon las concentraciones elementales en los peces cordilleranos patagónicos que incluyeron salmónidos: Salmo trutta (trucha marrón), Oncorhynchus mykiss (trucha arco iris), Salvelinus fontinalis (trucha de arroyo), un percíctido: Percichthys trucha (perca de boca chica) y un silúrido: Diplomistes viedmensis (bagre aterciopelado) con grupos taxonómicos similares de áreas remotas y con impacto antrópico de distintas regiones del mundo. En el segundo caso, se evaluó la variabilidad interespecífica de la concentración de los elementos en los lagos Nahuel Huapi y Moreno por estar próximos y conectados, y fundamentalmente por la variedad y abundancia de especies de peces. La variabilidad espacial de la composición elemental de los peces en las distintas cuencas relacionadas con diversos factores ambientales como el basamento geológico y el impacto antrópico, se evaluó en la trucha arcoíris que está ampliamente distribuida en los distintos lagos, de vertiente atlántica como el Traful, Espejo Chico, Nahuel Huapi y Moreno, y de pendiente pacífica como Guillelmo, Rivadavia y Futalaufquen.

Food Specialization By Individual Trout

1972 ◽  
Vol 29 (11) ◽  
pp. 1615-1624 ◽  
Author(s):  
James E. Bryan ◽  
P. A. Larkin
Keyword(s):  
Rainbow Trout ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Stomach Contents ◽  
Cutthroat Trout ◽  
Salmo Gairdneri ◽  
Potential Prey ◽  
Repeated Observation ◽  
Size Growth ◽  
Salmo Clarki

Analyses of stomach contents showed that the kinds of prey eaten by brook trout (Salvelinus fontinalis), cutthroat trout (Salmo clarki), and rainbow trout (Salmo gairdneri) were seldom distributed at random among the individuals. Repeated observation of food eaten by individuals in a stream and ponds showed that prey types were eaten in proportions which were characteristic for an individual.Specialization occurred on several different kinds of prey. Although the degree of specialization was higher during shorter intervals, the data suggested that some specialization persisted for half a year. There were no striking correlations between degree of specialization and other individual properties such as size, growth rate, weight of food, number of food items, previous specialization, or area of recapture.In addition to the observations on trout in relatively undisturbed habitats, a field experiment was conducted using laboratory-reared rainbow trout held in small ponds. The food of each trout in the experiment was sampled repeatedly. In analysis of variance, interaction among the individuals and kinds of prey eaten showed that food specialization occurred. Both the absolute and relative abundance of potential prey were constant during the experiment.

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