scholarly journals ANDROGENETIC DEVELOPMENT OF BROOK TROUT (SALVELINUS FONTINALIS MITCHILL), ARCTIC CHAR (SALVELINUS ALPINUS L.) AND THEIR HYBRIDS

2011 ◽  
Vol 4 (is1) ◽  
pp. 232-233
Author(s):  
Ocalewicz K
2015 ◽  
Vol 84 (2) ◽  
pp. 159-166
Author(s):  
Karel Halačka ◽  
Radovan Kopp ◽  
Ondřej Klíma ◽  
Jan Mareš

Brook trout (Salvelinus fontinalis) is a species of fish native to North-East America. Brook trout are also commercially raised in large numbers for food production. Skin infection and/or parasite outbreaks can have a serious economics effect on aquaculture businesses. For this reason, it has been hybridized with the more resistant Arctic char (Salvelinus alpinus). The aim of this study was an examination of the epidermal structure and dynamic in brook trout and its Arctic char hybrid which is less sensitive to skin infection. The samples of fish (72 brook trout, 72 brook trout × Arctic char hybrid) from fish farm in Pravíkov (49°19’10”N, 15°5’40”E) were collected five times during the year 2011. Absolute and relative epidermal thickness (in relation to body size) and relative proportion of secretory cells in a given volume of epidermis were measured. The epidermis structure of brook trout and brook trout × Arctic char hybrid both display similar seasonal dynamics, with a decrease in absolute and relative epidermal thickness and a reduction in the relative percentage of mucous secretory cells over the summer. On the other hand, the lower absolute (mean 103 µm (range 84–146 µm) in brook trout; 88 µm (range 68–115 µm) in hybrids) and relative epidermal thickness (mean 4.8 (range 3.6–6.8) in brook trout; 4.4 (range 2.9–6.4) in hybrids) and lower volume of secretory cells was observed to the hybrid (mean 28% (range 19–33%) in brook trout; 23% (range 10–30%) in hybrids). It can interrelate with their higher resistance to infection and/or parasite outbreaks.


1995 ◽  
Vol 52 (1) ◽  
pp. 179-185 ◽  
Author(s):  
Louis Bernatchez ◽  
Hélène Glémet ◽  
Chris C. Wilson ◽  
Roy G. Danzmann

Although mitochondrial introgression between taxa has been increasingly documented, interspecific replacement of mtDNA is rare, particularly when the donor species is absent. We document evidence for a population of brook trout (Salvelinus fontinalis) in which all individuals possess the mitochondrial genome of Arctic char (S. alpinus) despite the present-day absence of the latter species in the watershed where the population is located. The mitochondrial genotype of 48 brook trout from Lake Alain (Québec) was characterized by RFLP analysis performed over the entire mtDNA molecule and/or a 2.5-kb PCR-amplified segment of the ND-5/6 region. Although the fish examined were morphologically indistinguishable from typical brook trout and homozygous for the diagnostic alleles characteristic of brook trout, the mtDNA of all individuals was identical to the Québec Arctic char haplotype. Together, these results indicate that the mtDNA haplotype observed in Lake Alain brook trout has resulted from ancient introgression with Arctic char rather than ancestral polymorphism or convergent evolution. They also demonstrate that introgressive hybridization between those two species can have significant and long-term effects on their genetic composition.


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.


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).


2013 ◽  
Vol 22 (1) ◽  
pp. 281-288 ◽  
Author(s):  
Konrad Ocalewicz ◽  
Piotr Hliwa ◽  
Konrad Pomianowski ◽  
Rodrigo Lisboa ◽  
Malgorzata Jankun

Author(s):  
Konrad Pomianowski ◽  
Konrad Ocalewicz

Abstract Arctic char (Salvelinus alpinus) and brook trout (Salvelinus fontinalis) hybridize and their offspring is viable and fertile. This may be a real treat for the native European stocks of Arctic char which gene pools might be unintendedly contaminated with the genetic elements of brook trout. On the other hand, hybrids of these two species are appreciated by customers and have some potential for the aquaculture. Moreover, Salvelinus hybrids and backcross individuals are interesting models in the research focused on influence of hybridization on the genomic organization and chromosome rearrangements. Thus, the main goal of the present study was to examine chromosomes of Arctic char × brook trout F1, F2 hybrids and backcross individuals and compare with genomic information concerning parental species to recognize karyotypic changes provoked by the hybridization events. Application of conventional and molecular (FISH) techniques allow to identify characteristic chromosomes for both parental species in the hybrid progeny and show multiplicity of cytotypes among different types of crosses with variability in structure and number of chromosome (81–85) and chromosome arm (99–101). Chromosome fragment was detected in the karyotype of one F1 and one backcross individual and the presence of one triploid (3n) fish was documented. Occurrence of chromosomes containing internally located telomeric sequences (ITS) inherited after brook trout or both parental species was shown in F1 and backcross progeny. Moreover, additional CMA3-positive signal on chromosome from Arctic char pair no. 2 in F1 fish and interstitially located active NOR visible on subtelo-acrocentric (F2 hybrid) and acrocentric (Sf × H individual) chromosomes were detected. Described polymorphic chromosomes together with specific, interstitial location of CMA3-positive found in F2 and Sf × H hybrids and DAPI-positive regions observed in H × Sa fish at different uniarmed chromosomes pair presumably are remnants of chromosomal rearrangements. Provided results strongly indicate that the hybridization process influenced the genome organization in the Salvelinus hybrid progeny.


1991 ◽  
Vol 48 (8) ◽  
pp. 1437-1445 ◽  
Author(s):  
Johan Hammar ◽  
J. Brian Dempson ◽  
Eric Verspoor

Electrophoretic analysis of successive samples of Salvelinus collected in the Fraser River watershed of northern Labrador in 1984 and 1986 revealed the existence of natural hybrids between Arctic char (Salvelinus alpinus) and brook trout (S. fontinalis). We examined 11 electrophoretic loci in liver tissue; 10 loci were informative and six were diagnostic of the two species and their hybrids. The electrophoretic phenotypes of some hybrid specimens sugested that they were second-generation hybrids and/or backcrosses to the parental species. Hybrids were represented by six different year classes, indicating that crossing between the species in the system is a regular occurrence. The hybrids, although visually difficult to distinguish from brook trout, were meristicaîly intermediate or more closely resembled Arctic char. The observations raise a number of questions regarding the ecological circumstances promoting hybridization in the evolution of Arctic char and brook trout populations. The results stress the need for restrictions on introducing brook trout into systems with original populations of Arctic char. Further, Arctic char from the Fraser River are commonly used for aquaculture research and development; therefore, there is a clear need to screen fish carefully to determine whether or not they represent introgressed gene pools.


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