Biogeographic patterns of fish species richness in Ontario lakes in relation to historical and environmental factors

1995 ◽  
Vol 52 (7) ◽  
pp. 1462-1474 ◽  
Author(s):  
Nicholas E. Mandrak

Fish species richness in Ontario lakes was summarized for 80 equal-area quadrats and ranged from 59 species per quadrat in southwestern Ontario to 17 species per quadrat in northern Ontario. Correlograms based on Moran's I coefficient indicated the spatial structure of lake species richness was anisotropic and exhibited a strong south–north gradient of decreasing richness. Relationships among Euclidean distance matrices based on richness, postglacial dispersal, climate, elevation, lake chemistry, and lake morphometry were identified with the aid of the Mantel test and principal coordinates analysis. The presence of spatial autocorrelation may bias matrix correlations; therefore, spatial autocorrelation was removed using the partial Mantel test. The results of the partial Mantel test indicated regional lake species richness was significantly correlated with postglacial dispersal and climate. In particular, the results of principal coordinates analysis identified length of time since deglaciation, length of time covered by glacial lakes, distance from dispersal corridor, and mean annual air temperature as the dominant variables in these data sets.

2015 ◽  
Vol 105 (3) ◽  
pp. 325-332 ◽  
Author(s):  
Juliane A. C. Soares ◽  
Valéria F. Batista-Silva ◽  
Daiane D. Boneto ◽  
Dayani Bailly ◽  
Milza C. F. Abelha ◽  
...  

ABSTRACT This study investigated the assemblages attributes (composition, abundance, richness, diversity and evenness) and the most representative genera of Odonata, Anisoptera at Água Boa and Perobão Streams, Iguatemi River basin, Brazil. Both are first order streams with similar length that are impacted by riparian forest removal and silting. Quarterly samplings were conducted from March to December 2008 in the upper, intermediate and lower stretch of each stream. The Mantel test was used to check the influence of spatial autocorrelation on the Odonata composition. Spatial variations in the composition were summarized by the Principal Coordinates Analysis (PCoA) using Mantel test residuals. The effects of spatial correlation on richness and abundance were investigated by the spatial correlogram of Moranʼs I coefficients. The most representative genera in each stream were identified by the Indicator Value Method. The spatial variations in the attributes of the assemblages were assessed using analysis of variance of null models. We collected 500 immature individuals of 23 genera and three families. Among the attributes analyzed only the composition and abundance showed significant spatial differences, with the highest mean abundance found in the Perobão Stream. Miathyria and Zenithoptera were the indicator genera of the Água Boa Stream and Erythrodiplax, Libellula, Macrothemis, Progomphus and Tramea were the indicator genera of the Perobão Stream.


2021 ◽  
Vol 80 (2) ◽  
Author(s):  
Mostafa Ebadi ◽  
Rosa Eftekharian

Senecio vulgaris L., an annual herb belonging to the Asteraceae, is widely distributed in different regions of the world. There is no information on the intraspecific variations of the morphological and molecular features of this species. In the present investigation, we studied the morphological and genetic diversity of 81 accessions of S. vulgaris collected from 10 geographical populations. Eleven inter simple sequence repeat (ISSR) primers were used for the examination of genetic variations among the populations. Analysis of molecular variance (AMOVA) and GST analyses revealed significant differences among the investigated populations. A significant correlation between genetic distance and geographical distance was revealed by the Mantel test. However, reticulation analysis indicated the occurrence of gene flow among most of the populations studied. Principal component analysis (PCA) plot showed that the number of capitula, length of the cauline leaf and plant height were the most variable morphological characters. Principal coordinates analysis (PCoA) plot revealed two groups of populations, according to molecular and morphological data. The results suggested the existence of possible intraspecific taxonomic ranks within this species.


2020 ◽  
Vol 8 (1) ◽  
pp. 80 ◽  
Author(s):  
Parichat Into ◽  
Ana Pontes ◽  
José Paulo Sampaio ◽  
Savitree Limtong

The ecology and diversity of phylloplane yeasts is less well understood in tropical regions than in temperate ones. Therefore, we investigated the yeast diversity associated with the phylloplane of corn, an economically important crop in Thailand, by a culture-dependent method. Thirty-six leaf samples were collected and 217 yeast strains were isolated by plating leaf-washings. The strains were grouped by PCR-fingerprinting and representative strains were identified by analysis of the D1/D2 domain of the large subunit rRNA gene. In total, 212 strains were identified within 10 species in the Ascomycota and 32 species in the Basidiomycota. Five strains represented potential new species in the Basidiomycota, one strain was recently described as Papiliotrema plantarum, and four strains belonged to the genera Vishniacozyma and Rhodotorula. A higher number of strains in the Basidiomycota (81.6%) was obtained. Hannaella sinensis was the species with the highest occurrence. Principal coordinates analysis ordinations of yeast communities revealed that there were no differences in the similarity of the sampling sites. The estimation of the expected species richness showed that the observed species richness was lower than expected. This work indicated that a majority of yeast associated with the phylloplane of corn plant belongs to the phylum Basidiomycota.


2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
Jukka Salmela

Species richness of terrestrial and freshwater biota generally decreases with increasing latitude. Some taxa, however, show an anomalous species richness pattern in a regional or global scale. The aim of this study was to examine (i) regional variation in species richness, (ii) faunistic composition, (iii) occupancy, and (iv) proportions of different distribution types of Finnish crane flies. Analyses were based on incidence data pooled into 20 biogeographical provinces. Finnish crane fly fauna consists of 335 species; the provincial richness varies from 91 to 237. The species richness of all species and saproxylic/fungivorous species decreased with increasing latitude; mire-dwelling crane flies displayed a reversed pattern (Spearman's correlations). Thirty-one species occupied a single province and 11 species were present in all provinces. Provincial assemblages showed a strong latitudinal gradient (NMS ordination) and faunistic distance increased with increasing geographical distance (Mantel test). Nearly half (48%) of the Finnish crane flies are Trans-Palaearctic, roughly one-third (34%) are West Palaearctic, and only 16 and 2% are Holarctic and Fennoscandian, respectively. Endemic Fennoscandian species are discussed in detail; most likely there are no true endemic crane flies in this region.


Nutrients ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3400
Author(s):  
Patrícia M. Oba ◽  
Hannah D. Holscher ◽  
Rose Ann Mathai ◽  
Juhee Kim ◽  
Kelly S. Swanson

Background: Oral microorganisms contribute to oral health and disease, but few have studied how infant feeding methods affect their establishment. Methods: Infant (n = 12) feeding records and tongue and cheek swabs were collected within 48 h of birth, and after 2, 4, and 6 mo. DNA was extracted from samples, bacterial and fungal amplicons were generated and sequenced using Illumina MiSeq, and sequences were analyzed using Quantitative Insights Into Microbial Ecology (QIIME) and Statistical Analysis System (SAS) to evaluate differences over time and among breast-fed, formula-fed, mixed-fed, and solid food-fed infants. Results: Considering all time points, breast milk- and mixed-fed infants had lower oral species richness than solid food-fed infants (p = 0.006). Regardless of feeding mode, species richness was lower at birth than at other time points (p = 0.006). Principal coordinates analysis (PCoA) of unique fraction metric (UniFrac) distances indicated that bacterial communities were impacted by feeding method (p < 0.005). Considering all time points, breast-fed infants had higher Streptococcus, while formula-fed infants had higher Actinomyces and Prevotella. Regardless of feeding mode, Propionibacterium, Porphyromonas, Prevotella, Gemella, Granulicatella, Veillonella, Fusobacterium, Leptotrichia, Neisseria, and Haemophilus increased with age, while Cloacibacterium and Dechloromonas decreased with age. Oral fungi were detected in infants but were not impacted by diet. Conclusions: These findings demonstrate that the establishment of oral bacteria depends on dietary composition and age. More research is necessary to determine whether this affects risk of oral caries and other health outcomes later in life.


Author(s):  
M. A. Gondal ◽  
S. Iqbal ◽  
U. Atique ◽  
N. U. Saher ◽  
N. A. Qureshi ◽  
...  

Abstract The primary objective of this study was to investigate the seasonal fish and crustacean variations concerning taxonomic composition, species richness, and diversity in sandy beach habitat. For this purpose, we investigated the Sonmiani Hor lagoon area during four distinct seasons, i.e., northeast (NE) monsoon, pre-monsoon, south-west (SW) monsoon, and post-monsoon for one year. During each haul, the net was pulled about 100m along the beach in 0.5m depth. The results showed a strong linear correlation between the diversity index and equitability in fishes (r = 0.978). The diversity index was strong negatively correlated with the abundance and biomass (r = -0.978, -0.972, respectively). The physical attributes like sea surface water temperature and salinity showed a strong negative effect on species assemblages (r = -0.981 and -0.943, respectively). The mean air and water temperature illustrated approximately 3°C difference during NE and pre-monsoon seasons. However, salinity, pH, and electrical conductivity did not show any significant seasonal variabilities. Under the ecological indices, the fish species displayed higher diversity (H’ = 3.19) during SW monsoon, whereas the lowest diversity was observed during pre-monsoon (H’ = 1.58). The equitability and species richness, however, remained more noticeable during SW monsoon (J’ = 0.81). The total number of individuals of fish and crustaceans reached 4799 with 3813 fish individuals and 986 individuals of crustaceans. A total of 27 families of fish while five crustacean families comprising of 30 genera and 38 fish species while ten genera and 17 species of crustaceans were recorded. Liza subviridis displayed the highest abundance among the sampled fish species. In conclusion, fish species constituted a significant part of the coastal fauna in the study area. The seasonal variations displayed distinct variations in fish species composition and diversity.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1803
Author(s):  
Valentino Palombo ◽  
Elena De Zio ◽  
Giovanna Salvatore ◽  
Stefano Esposito ◽  
Nicolaia Iaffaldano ◽  
...  

Mediterranean trout is a freshwater fish of particular interest with economic significance for fishery management, aquaculture and conservation biology. Unfortunately, native trout populations’ abundance is significantly threatened by anthropogenic disturbance. The introduction of commercial hatchery strains for recreation activities has compromised the genetic integrity status of native populations. This work assessed the fine-scale genetic structure of Mediterranean trout in the two main rivers of Molise region (Italy) to support conservation actions. In total, 288 specimens were caught in 28 different sites (14 per basins) and genotyped using the Affymetrix 57 K rainbow-trout-derived SNP array. Population differentiation was analyzed using pairwise weighted FST and overall F-statistic estimated by locus-by-locus analysis of molecular variance. Furthermore, an SNP data set was processed through principal coordinates analysis, discriminant analysis of principal components and admixture Bayesian clustering analysis. Firstly, our results demonstrated that rainbow trout SNP array can be successfully used for Mediterranean trout genotyping. In fact, despite an overwhelming number of loci that resulted as monomorphic in our populations, it must be emphasized that the resulted number of polymorphic loci (i.e., ~900 SNPs) has been sufficient to reveal a fine-scale genetic structure in the investigated populations, which is useful in supporting conservation and management actions. In particular, our findings allowed us to select candidate sites for the collection of adults, needed for the production of genetically pure juvenile trout, and sites to carry out the eradication of alien trout and successive re-introduction of native trout.


Hydrobiologia ◽  
1993 ◽  
Vol 259 (3) ◽  
pp. 157-167 ◽  
Author(s):  
Thierry Oberdorff ◽  
Eric Guilbert ◽  
Jean-Claude Lucchetta

2006 ◽  
Vol 34 (1) ◽  
pp. 52-61 ◽  
Author(s):  
Atahualpa Sosa-López ◽  
David Mouillot ◽  
Julia Ramos-Miranda ◽  
Domingo Flores-Hernandez ◽  
Thang Do Chi

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Francisco M. P. Gonçalves ◽  
Rasmus Revermann ◽  
Amândio L. Gomes ◽  
Marcos P. M. Aidar ◽  
Manfred Finckh ◽  
...  

The study was carried out in the Cusseque area of the Municipality of Chitembo in south-central Angola. Our objectives were to assess the floristic diversity, the species composition, and stand structure of Miombo woodlands during regeneration after shifting cultivation. A total of 40 plots of 1000 m2were surveyed and analyzed, corresponding to mature forests/woodlands and three fallow types of different age. The analyses were based on plot inventories of all trees with DBH ≥ 5 cm. A total of 51 woody species, 38 genera, and 19 families were recorded. The dominant family was Fabaceae, with subfamily Caesalpinioideae being very abundant. Shannon Diversity and Evenness were highest in mature forests and young fallows, while the mature forest stands showed the highest species richness. A Principal Coordinates Analysis (PCoA) showed many species shared between the intermediate fallow types, but only few species were shared with young fallows. Mature forests formed a clearly distinct group. This study shows potential pathways of forest recovery in terms of faster regeneration after agricultural abandonment and, thus, the results presented here can be used in future conservation and management plans in order to reduce the pressure on mature forests.


Sign in / Sign up

Export Citation Format

Share Document