Histochemical localization of phospholipids in the olfactory epithelium of fish

1977 ◽  
Vol 55 (5) ◽  
pp. 776-781 ◽  
Author(s):  
Robert E. Evans ◽  
Toshiaki J. Hara

Histochemical localization of phospholipids in the olfactory epithelium of rainbow trout (Salmo gairdneri), whitefish (Coregonus clupeaformis), Arctic char (Salvelinus alpinus), brook trout (Salvelinus fontinalis), lake trout (Salvelinus namaycush), and black bullhead (Ictalurus melas) was examined. The present results indicate that phospholipids are highly localized in the receptor neurons of all species examined, present not only in the membranes, but also in the cytoplasm. Although the phospholipids of membranes and cytoplasm may not be of the same kind, their localization suggests a role in olfactory function. The Baker acid hematein method shows clear morphological features of the olfactory neurons beyond those obtainable by routine histological methods. The technique may be useful in determining morphological changes and (or) phospholipid alterations caused by a deleterious environment.

1982 ◽  
Vol 39 (12) ◽  
pp. 1580-1584 ◽  
Author(s):  
A. Silim ◽  
M. A. S. Y. Elazhary ◽  
A. Lagacé

We investigated the susceptibility of trouts of different species and origins to infectious pancreatic necrosis virus (IPNV) and the pathogenicity of three strains of IPNV for brook trout (Salvelinus fontinalis) of various origins and lake trout (Salvelinus namaycush) of a single origin. Fish were inoculated by immersion in water containing 105 PFU of virus/mL for 6 h. Susceptibility to IPNV infection was assessed by counting dead fish over a period of 21 d after infection and on histological lesions in the pancreas, kidney, and intestine of the infected fish. Different species of trouts had different susceptibility to IPNV strain 3865. Brook trout had the highest mortality followed by rainbow trout (Salmo gairdneri), whereas the least mortality occurred in lake trout. Brook trout from Crowford, Nebraska, were more than twice as susceptible as the same species from Baldwin Mills, Quebec. Rainbow trout also varied in susceptibility as a result of origin. Virus isolate 3B, originally isolated from chain pickerel (Esox niger), was less virulent than isolates 4495 or 3865 (both from trout). Hatcheries that use water from sources containing pickerel may increase their chances of IPN infection.Key words: trout species, infectious pancreatic necrosis virus, resistance


1998 ◽  
Vol 76 (7) ◽  
pp. 1300-1318 ◽  
Author(s):  
Roy G Danzmann ◽  
Raymond P Morgan II ◽  
Matthew W Jones ◽  
Louis Bernatchez ◽  
Peter E Ihssen

Mitochondrial DNA (mtDNA) restriction fragment length polymorphisms (RFLPs) of 2422 brook trout (Salvelinus fontinalis) from 60 units (major drainages, small stream catchments, and isolated lakes) representing 155 populations in eastern North America were examined to test hypotheses regarding postglacial dispersal and recolonization. An analysis of molecular variance (AMOVA) indicated that 38.8% of the variation was partitioned among the units, while approximately 60% was distributed among populations (phiST = 59.3) compared with 40.7% within populations. This distribution of variation suggests a large degree of heterogeneity in population founding events and phylogeographic structuring in this species. Comparisons of mtDNA diversity between fish from putative refugial and recolonization zones for this species indicate that more than one refugial region contributed to northern recolonization. Haplotypic diversities in recolonized regions are greatest in south-central populations (i.e., southern Great Lakes region), while only one haplotype (haplotype 1) predominates in northern, western, and eastern postglacial zones. Large phylogenetic differences were found between northern and southern populations. Populations outside the zone of glaciation were the most genetically heterogeneous and were represented by fish from all six (A-F) of the major evolutionary clades identified. Only fish from the A, B, and C clades were found in glaciated regions, with C lineage fish restricted to south-central glaciation zones. Fish from the C clade are putatively the most ancestral lineage within the species based upon composite shared RFLPs with lake trout (Salvelinus namaycush) and Arctic char (Salvelinus alpinus).


1972 ◽  
Vol 29 (2) ◽  
pp. 129-142 ◽  
Author(s):  
J. M. Fraser

Recoveries of hatchery-reared brook trout (Salvelinus fontinalis), splake (Salvelinus namaycush × S. fontinalis), and rainbow trout (Salmo gairdneri), planted in lakes having different resident fishes, were highest (9–30%) in a lake in which minnows and the brook stickleback were the only other fishes. Recoveries, by angling and gillnetting, were considerably lower (2–15%) in two lakes containing the white sucker and minnows, and still lower (0.5–5%,) in two lakes containing spiny-rayed species as well. Recoveries were lowest (< 0.5%) in a lake having a complex fish community that included native brook and lake trout. Planted splake and rainbow trout generally yielded higher returns, in weight, than brook trout in comparable situations.The low survival of planted fish was apparently due to the low fertility of the waters and to competition with, or predation by, resident fish species. Predation by fish-eating birds and mammals may also have had an effect.The weight of the catch of salmonids exceeded the weight planted in only one lake. Here, the mean yield of planted salmonids was 8.4 kg/ha per year in comparison with 2.6 to < 0.5 kg/ha per year in the five other study lakes.


1988 ◽  
Vol 45 (S1) ◽  
pp. s127-s135 ◽  
Author(s):  
W. Kwain ◽  
J. R. M. Kelso

Batchawana Lake, the headwater lake in the Turkey Lakes Watershed, was devoid offish. Although a number of factors could cause this fishless state, we conducted in situ studies to partially address conditions related to lake acidification. The spring pH depression did not induce significant, consistent mortality to rainbow trout (Salmo gairdneri) or lake trout (Salvelinus namaycush) caged in situ. In 1981, however, considerable mortality occurred to fish caged in Batchawana Lake during or immediately following the maximum spring pH depression. In the remaining lakes, mortality occurred later in the exposure period. Whole-body concentrations of Na+, Ca2+, and Mg2+ in rainbow trout caged (1980) in three lakes of the watershed were similar; however, K+ appeared slightly higher (but not statistically different) in fish held in the headwater lake. Static bioassays indicated that the 96-h pH-LC50 for brook trout (Salvelinus fontinalis) was 3.80–4.09, considerably lower than the lowest pH, 4.66, observed during spring. Brook trout corralled in Batchawana Lake grew slightly faster and accumulated more Pb and Hg than fish held in a downstream lake. Although pH and trace metal levels in Batchawana Lake may at times be inhospitable to fish, other factors likely contributed to the fishless condition of this lake.


Genome ◽  
2012 ◽  
Vol 55 (1) ◽  
pp. 26-32 ◽  
Author(s):  
K. Pomianowski ◽  
M. Jankun ◽  
K. Ocalewicz

Highly polymorphic Arctic charr ( Salvelinus alpinus Linnaeus, 1758) chromosomes were studied using conventional and molecular methods. The diploid chromosome number in the studied individuals was 2n = 81 or 2n = 82, with a fundamental arm number (NF) = 100. These differences are due to Robertsonian fusions. Interindividual variation in the number and size of DAPI and CMA3 positively stained chromatin sites was observed in studied specimens. In the case of two individuals, the subtelomeric region of the long arm (q) of the largest acrocentric chromosome (chromosome number 10) was positively stained by CMA3 fluorochrome. Both primed in situ labelling (PRINS) and fluorescence in situ hybridization (FISH) revealed that this CMA3-positive region was flanked by telomeric sequences. Previously, the subterminal position of interstitial telomeric sequences located in the vicinity of the CMA3-positive guanine-rich chromatin have been described in two other Salvelinus species, brook trout ( Salvelinus fontinalis ) and lake trout ( Salvelinus namaycush ). Moreover, multichromosomal location and variation in size of CMA3 bands have been observed in various Salvelinus taxa, including fishes with internally located telomeric sequences. These results suggest that relocation of CMA3-positive chromatin segments in these species may be facilitated by flanking interstitial telomeric sequences (ITSs).


1986 ◽  
Vol 66 (3) ◽  
pp. 599-606 ◽  
Author(s):  
S. E. SADLER ◽  
G. W. FRIARS ◽  
P. E. IHSSEN

Growth rates of three salmonid species, brook trout (Salvelinus fontinalis), lake trout (S. namaycush), and rainbow trout (Salmo gairdneri) and one hybrid, splake (S. namaycush × S. fontinalis) were compared at 10 and 16 °C. Two strains of each species, and one of the splake hybrid were examined. At 10 °C the ranking of specific growth rate from highest to lowest for species was: rainbow trout, lake trout, splake, brook trout. At 16 °C the order was: brook trout, rainbow trout, splake, and lake trout. Brook trout, rainbow trout and splake had significantly higher specific growth rates at 16 °C but lake trout showed no difference at the two temperatures. Strain differences were significant in lake trout and rainbow trout, but not in brook trout. Rainbow trout showed a significant strain by temperature interaction. The ranking of feed conversion efficiencies from best to poorest was: lake trout, 10 °C; splake, 10 °C; brook trout, 16 °C; splake, 16 °C; rainbow trout, 16 °C; rainbow trout, 10 °C; lake trout, 16 °C; brook trout, 10 °C. Key words: Temperature, genetics, growth, salmonids, aquaculture


2003 ◽  
Vol 77 (3) ◽  
pp. 255-262 ◽  
Author(s):  
T. Scholz ◽  
R. Kuchta ◽  
A.P. Shinn ◽  
V. Šnábel ◽  
V. Hanzelová

AbstractThe host specificity and distribution ofEubothrium crassum(Bloch, 1779) andEubothrium salvelini(Schrank, 1790), morphologically fairly similar pseudophyllidean tapeworms parasitizing salmonid fish, were critically assessed on the basis of morphological and genetic evaluation of extensive material collected from different definitive hosts and geographical regions in Europe.Eubothrium crassumoccurs in fish of the generaSalmo, i.e. salmon (S. salar– both freshwater and marine), sea trout (S. trutta trutta), brown trout (S. truttafario), and lake trout (S. truttalacustris), and also in Danubian salmon (Hucho hucho) and vendace (Coregonus albula).Eubothrium salveliniparasitizes Arctic char (Salvelinus alpinus) and brook trout (Salvelinus fontinalis) in Europe, and also whitefish (Coregonus wartmanni). Rainbow trout (Oncorhynchus mykiss), which is not a native European fish species, was found to be a suitable definitive host for bothEubothriumspecies, which may occur simultaneously in the same fish. Previous records ofE. crassumin Arctic char and brook trout, and those ofE. salveliniin fish of the genusSalmowere most probably misidentifications. Most studies ofEubothriumhave involved salmonids from the northern part of Europe, with few records from southern and south-eastern Europe. This study also confirmed the reliability of the morphology of the apical disc for the discrimination ofE. crassumandE. salvelini.


1972 ◽  
Vol 29 (11) ◽  
pp. 1615-1624 ◽  
Author(s):  
James E. Bryan ◽  
P. A. Larkin

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.


1985 ◽  
Vol 63 (2) ◽  
pp. 396-399 ◽  
Author(s):  
Hilda Lei Ching

As a result of experimental infections in chicks, diplostomula found in the retina of chinook salmon from the Nechako River were identified as Diplostomum (Diplostomum) baeri bucculentum. Eyeflukes in other salmonids were considered to be the same species based on similar measurements and site in the eyes. These eyeflukes varied in prevalence and mean intensity in seven salmonid species surveyed in nine localities in 1979–1981. The following fish were sampled: rainbow trout (Salmo gairdneri), 505; mountain whitefish (Prosopium williamsoni), 334; lake whitefish (Coregonus clupeaformis), 32; Dolly Varden (Salvelinus malma), 66; lake trout (S. namaycush), 13; kokanee or sockeye salmon (Oncorhynchus nerka), 323; and chinook salmon (O. tshawytscha), 164. Eyeflukes had prevalences ranging from 84 to 100% in six lakes, 64% in the river, 53% in one reservoir site, and a prevalence of 15% in the other reservoir site. Mountain and lake whitefishes had high mean intensities while kokanee had low mean intensities. Correlation of increased intensity with increased fish size was significant for 6 of 27 samples. Four samples of lake whitefish, mountain whitefish, rainbow trout, and chinook salmon showed significant asymmetry when numbers of diplostomula were compared between eyes. More of the heavily infected fish showed asymmetry than did the lightly infected fish.


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