Genetic and Morphological Differentiation between Dwarf and Normal Size Forms of Lake Whitefish (Coregonus clupeafotmis) in Como Lake, Ontario

1993 ◽  
Vol 50 (1) ◽  
pp. 210-216 ◽  
Author(s):  
J. A. Vuorinen ◽  
R. A. Bodaly ◽  
J. D. Reist ◽  
L. Bernatchez ◽  
J. J. Dodson

Normal and dwarf size forms of lake whitefish (Coregonus clupeaformis) from Como Lake, Ontario, were sampled at spawning time and examined for differences in electrophoretic, mtDNA, and morphological characteristics to test the hypothesis of reproductive isolation and provide clues regarding evolutionary origin. Of the 36 enzyme loci examined, 33 were fixed for the same alleles in both dwarf and normal lake whitefish. At the three polymorphic loci, allele frequencies were not statistically different between dwarfs and normals. mtDNA analysis revealed five different haplotypes. The same mtDNA haplotype was the most common in both dwarf and normal lake whitefish, but there was a statistically significant difference in haplotype frequencies between the two size forms. Discriminant and principal component analyses demonstrated highly significant morphological differences between dwarfs and normals. Because the two size morphs spawn in the same place at the same time, it is most likely that genetic differences, not different rearing environments, underly the observed morphological differences. mtDNA haplotypes derived from both the Mississippi and Atlantic glacial refugia are present in Como Lake lake whitefish, raising the possibility of an allopatric divergence for the two forms; however, this hypothesis requires testing by genetic comparisons of other sympatric populations in Ontario.

2014 ◽  
Vol 49 (8) ◽  
pp. 604-612 ◽  
Author(s):  
Julcéia Camillo ◽  
Valentine Carpes Braga ◽  
Jean Kleber de Abreu Mattos ◽  
Ricardo Lopes ◽  
Raimundo Nonato Vieira da Cunha ◽  
...  

The objective of this work was to evaluate the morphological diversity of oil palm seeds and to cluster the accessions according to their morphological characteristics. Forty-one accessions from the oil palm germplasm bank of Embrapa Amazônia Ocidental were evaluated - 18 of Elaeis oleifera and 23 of E. guineensis. The groups were formed based on morphological characteristics, by principal component analysis. In E. oleifera, four groups were formed, tied to their region of origin, but with significant morphological differences between accessions from the same population. For tenera-type E. guineensis seeds, three widely divergent groups were formed, especially as to external parameters, which differentiated them from the other ones. The parameter endocarp thickness stood out in intra- and inter-population differentiation. For dura-type E. guineensis, three groups were formed, with larger seeds and thicker endocarps, which differed from all the other ones. The variability observed for seed characteristics in the analyzed accessions allows the establishment of different groups, to define strategies for genetic improvement.


2005 ◽  
Vol 83 (11) ◽  
pp. 1502-1509 ◽  
Author(s):  
B A Fraser ◽  
N E Mandrak ◽  
R L McLaughlin

We tested whether eastern (Rhinichthys atratulus (Herman, 1804)) and western (Rhinichthys obtusus Agassiz, 1854) blacknose dace could be differentiated in Canada. Eastern, western, and southern forms of blacknose dace had been considered subspecies until recently, when separation of eastern and western species was accepted (J.S. Nelson et al. 2004. Am. Fish. Soc. Spec. Publ. No. 29). However, no study has examined morphological differences in purported diagnostic characters between the two species in Canada. Mensural, meristic, and colouration pattern characters purported to distinguish the two species were measured for blacknose dace across their Canadian range, including likely zones of sympatry. Univariate and multivariate analyses of morphological characters could not distinguish between individuals in allopatric populations from eastern and western regions. Variation among individuals within sympatric populations did not differ significantly from the variation among individuals within allopatric populations, providing no evidence of divergence of the species in sympatry. The delineation of eastern and western species using morphology is not supported by this study, given the lack of differentiation in key distinguishing characters within the Canadian range of the species.


1992 ◽  
Vol 49 (4) ◽  
pp. 769-779 ◽  
Author(s):  
R. A. Bodaly ◽  
J. W. Clayton ◽  
C. C. Lindsey ◽  
J. Vuorinen

We use electrophoretic data on dehydrogenase enzymes to examine the relatedness of sympatric populations of lake whitefish (Coregonus clupeaformis) and provide evidence for the existence of a glacial refuge race of lake whitefish in eastern North America. This Acadian race is presently found in New England, the Gaspé peninsula of Québec, and New Brunswick. It probably survived glaciation in a refugium on the exposed coastal plain of northeastern North America. In areas of contact, most glacial races appear to introgress and do not coexist in sympatry. However, sympatric pairs of populations occur (or occurred) within the ranges of all races of lake whitefish. Allele frequencies for at least one enzyme system examined for most sympatric pairs were significantly different, indicating that these sympatric populations are wholly or substantially, isolated reproductively from each other. Both members of the population pairs examined in the Yukon Territory, Ontario, and Labrador were genetically characteristic of the glacial races of their region. This suggests that they are not the result of speciation due to geographic isolation in different glacial refugia. Thus, their origin appears to be postglacial, but may be older if present genetic similarities are due to recent gene flow between sympatric forms.


2020 ◽  
Vol 6 (2) ◽  
pp. 265-282
Author(s):  
Mithun Das ◽  
Md Mahiuddin Zahangir ◽  
Fatema Akhter ◽  
Md Main Uddin Mamun ◽  
Md Moudud Islam

The morphometric characters are effectively used for the better differentiation among the fish population and sustainable management. The appraisal of the natural population stock and morphological variation within and between two hilsha species (Tenualosa ilisha and Tenualosa toli) from three different habitat (Coastal, riverine and marine) of Bangladesh, were investigated by applying the land mark based morphometric and meristic variation measurement methods. All data were adjusted and Univariate ANOVA, where discriminant function analysis (DFA) and principal component analysis (PCA) exhibited the divergences in eight morphometric measurements and eight truss network measurements among the three stocks of T. ilisha. The 1st DFA accounted for 89.8% & 87.4% and the second DFA resolved 10.2% and 12.6%, respectively in morphometric characteristics variation among the group studied. Scattered plotting from PCA and dendogram from cluster analysis (CA) revealed that, the river habitants were morphologically different from the coastal and marine population. Twelve of fifteen morphometric measurements and thirteen of fourteen truss network measurements showed significant differences between T. ilisha and T. toil with significant variation in meristic characters. PCA revealed 89.23% and 88.29% in case of morphometric and truss measurement respectively confirmed high degree of variations in morphological characteristics between two species. Overall, our results based on morphometrics with truss measurements together provide useful information about the morphological differentiation which will be helpful for sustainable exploration and effective management for these two species. Asian J. Med. Biol. Res. June 2020, 6(2): 265-282


1991 ◽  
Vol 48 (11) ◽  
pp. 2140-2151 ◽  
Author(s):  
Thomas A. Edge ◽  
Don E. McAllister ◽  
Sami U. Qadri

Principal component and discriminant function analyses of morphological variation between whitefish populations from the Canadian Maritime Provinces and the State of Maine, USA, clearly distinguished the Acadian whitefish, Coregonus huntsmani, from the lake whitefish species complex, Coregonus clupeaformis. Ten meristic and 44 morphometric characters were examined and the species were best discriminated by number of vertebrae (>97% separation) and mouth shape. Acadian whitefish had a terminal mouth and 64–67 [Formula: see text] vertebrae, while lake whitefish had a subterminal mouth and 58–64 [Formula: see text] vertebrae. Acadian whitefish were also characterized by having more lateral line scales (88–100, [Formula: see text] than lake whitefish (63–95, [Formula: see text], a shorter adipose to caudal fin length, a smaller adipose fin, and a longer pelvic axillary process than lake whitefish. Considerable morphological variation was found between lake whitefish populations examined although there was no morphological basis to recognize any lake whitefish population as taxonomically distinct. The Acadian whitefish has morphological characteristics of both subgenera Leucichthys and Coregonus; it could be important for understanding the evolution of coregonine fishes and its imminent extinction would represent a serious loss of genetic diversity.


Author(s):  
A. Kalvas ◽  
L. Kautsky

Geographical morphological variations in Fucus vesiculosus populations were studied along the coast of Iceland. Principal component analysis (PCA) based on 11 morphological characters clustered the 26 sampling sites into four different morphological types as follows: (1) a morphological type found along the S-SW-W coast; (2) an intermediate form comprising only two populations in the NW; (3) a type found along the N-NE-E-SE coast; and (4) a type found independent of geographical area, in estuaries and at sites influenced by large freshwater outflows. Populations influenced by low salinity had significantly (P ≤ 0·001) shorter thalli, a shorter distance from the holdfast to the oldest dichotomy, smaller fronds, narrower stipes and midrib width compared to the morphology of all other more saline populations. No significant difference in frond width was found between the S-SW-W and the N-NE-E-SE populations. However, significant (P ≤ 0·001) morphological differences between them were observed, the former having shorter thalli, a greater distance from the holdfast to the oldest dichotomy, narrower stipes and smaller midrib width compared to the latter.


1987 ◽  
Vol 44 (12) ◽  
pp. 2155-2163 ◽  
Author(s):  
I. M. Gray

Differences between nearshore and offshore phytoplankton biomass and composition were evident in Lake Ontario in 1982. Phytoplankton biomass was characterized by multiple peaks which ranged over three orders of magnitude. Perhaps as a consequence of the three times higher current velocities at the northshore station, phytoplankton biomass ranged from 0.09 to 9.00 g∙m−3 compared with 0.10 to 2.40 g∙m−3 for the midlake station. Bacillariophyceae was the dominant group at the northshore station until September when Cyanophyta contributed most to the biomass (83%). Although Bacillariophyceae was the principal component of the spring phytoplankton community at the midlake station, phytoflagellates (49%) and Chlorophyceae (25%) were responsible for summer biomass, with the Chlorophyceae expanding to 80% in the fall. The seasonal pattern of epilimnetic chlorophyll a correlated with temperature. While chlorophyll a concentrations were similar to values from 1970 and 1972, algal biomass had declined and a number of eutrophic species (Melosira binderana, Stephanodiscus tenuis, S. hantzschii var. pusilla, and S. alpinus) previously found were absent in 1982.


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 124-125
Author(s):  
Raul Castro-Portuguez ◽  
Samuel Freitas ◽  
George Sutphin

Abstract Hepatocellular carcinoma (HCC) is the most prevalent cancer in the liver. The majority of ingested tryptophan is processed in the liver through the kynurenine pathway, the endpoint of which is de novo NAD+ biosynthesis. Dysregulation of tryptophan-kynurenine metabolism and NAD+ synthesis may promote mitochondrial malfunction, tumor reprogramming, and carcinogenesis. Using a publicly available gene expression dataset from liver hepatocellular carcinoma (LIHC) samples available through The Cancer Genome Atlas (TCGA; n = 371), we employed Principal Component Analysis (PCA), hierarchical clustering, gene-pattern expression profiling, and survival analysis to cluster patients and determine overall survival. Our analysis of genes encoding kynurenine pathway enzymes determined that patients with high QPRT expression had a poor prognosis with decreased median survival, with no effect on the maximum survival. There is a significant difference in the survival between patients with high QPRT expression relative to patients with high HAAO/AFMID expression (HR = 1.2, [95% CI 0.5-1.8] P = 0.0181, Gehan-Breslow-Wilcoxon Test). Patients with high QPRT expression have higher survival rates compared with low QPRT expression (HR = 1.4, [95% CI 0.9-2.2] P = 0.0344, Gehan-Breslow-Wilcoxon Test). To test the consequences of kynurenine-pathway inhibition in mitochondrial function and morphology we use 4-Cl-3HAA, an irreversible HAAO inhibitor, and observed a small increase in mitochondrial fragmentation in HepG2 cells after 24 hours of treatment. We conclude that kynurenine metabolism may be useful as a biomarker to predict patient prognosis among HCC patients. In ongoing work, we are testing QPRT inhibitors in cell culture as a potential adjuvant for chemotherapies.


2021 ◽  
Vol 16 (1) ◽  
pp. 13-20
Author(s):  
Popoola Omoniyi Michael ◽  
Olagunju Oluwatosin Olubunmi

AbstractIntraspecific morphological variation in Clarias gariepinus was studied in three water bodies. Twenty-three morphometric characteristics and seven meristic were used. Principal component (PC) analysis showed that morphometric traits of River Osun and Ogbese were somewhat related while that of Aago showed no relatedness, there were no difference among the meristic counts of the populations. PC1, and PC2 accounted for 93% and 4% of the variation observed in the populations. High positive correlation was observed in Aago (r = 0.872, b = 2.10) and Ogbese population while low correlation and negative allometric growth (r = 0.425 and b= 1.38) was observed in Asejire population. Cluster analysis revealed that three studied populations are separated into two major clusters, with samples from Asejire and Ogbese population found within the same cluster but different sub- clusters, similarly some of samples from Aago were also within the same cluster while samples 10 were found on a separate and major cluster. The study confirms the variability among individual species within each population, indicates the presence of genetic diversity among the populations of C. gariepinus and the Pre-anal distance and dorsal fin ray count could be employed in the identification of populations of catfish. Key words: morphometric traits, meristic characters, populations, allometric


2015 ◽  
Vol 105 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Fábio T. Mise ◽  
Fagner de Souza ◽  
João P. A. Pagotto ◽  
Erivelto Goulart

ABSTRACT Morphological variations, according to the principles of ecomorphology, can be related to different aspects of the organism way of life, such as occupation of habitats and feeding behavior. The present study sought to examine the intraspecific variation in two populations of Poecilia reticulata Peters, 1859, that occur in two types of environments, a lotic (Maringá Stream) and a lentic (Jaboti Lake). Due to a marked sexual dimorphism, males and females were analyzed separately. Thus, the proposed hypotheses were that the populations that occur in distinct environments present morphological differences. The morphological variables were obtained using morphometric measurements and the ecomorphological indexes. The data were summarized in a Principal Component Analysis (PCA). A Multivariate Analysis of Variance (Manova) was made to verify significant differences in morphology between the populations. Males and females showed similar ecomorphological patterns according to the environment they occur. In general the population from Maringá Stream had fins with major areas, and the Jaboti Lake population eyes located more dorsally. Additionally, others morphological differences such as wider mouth of the males from Maringá Stream, wider heads on Jaboti Lake females and more protractible mouths on males from Jaboti Lake suggest a set of environmental variables that can possibly influence the ecomorphological patterns of the populations, as the water current, availability of food resources and predation. In summary, the initial hypotheses could be confirmed, evidencing the occurrence of distinct ecomorphotypes in the same species according to the environment type.


Sign in / Sign up

Export Citation Format

Share Document