Spatial patterns of meiofauna and diversity of nematode species assemblages in the Uvea lagoon (Loyalty Islands, South Pacific)

2008 ◽  
Vol 88 (5) ◽  
pp. 931-940 ◽  
Author(s):  
Y. Guo ◽  
M.-N. Helleouet ◽  
G. Boucher
Keyword(s):  
Species Richness ◽  
Spatial Patterns ◽  
Environmental Parameters ◽  
Nematode Species ◽  
Abundant Species ◽  
Diversity Indices ◽  
Species Assemblages ◽  
Leeward Side ◽  
Local Composition ◽  
Total Species Richness

Meiofauna assemblages were investigated at 15 stations on triplicated samples in the Uvea Atoll (Loyalty Islands) in relation to 9 selected environmental parameters. Spatial patterns and variability of meiofauna density were quantified according to location, macrofauna and nematode species assemblages. Meiofauna was dominated by ciliates and nematodes. Densities of total meiofauna and of most of the meiofauna taxa were significantly higher in the back reef North Pléiades stations than the leeward side of the Island. The highest correlation between biotic patterns and environmental parameters that best explains the pattern was with sediment thickness and to a lesser extent organic matter, C/N ratio and depth. One hundred and thirty-four nematode species were identified with four dominant species Chromadora macrolaimoides, an undescribed species of Bolbonema, Daptonema svalbardense and Prochromadorella septempapillata. Three significantly different nematode species assemblages were detected in two of the previously described macrofauna assemblages by cluster analysis and multidimensional scaling methods suggesting that nematodes are more sensible ecological indicators than macrofauna. Diversity indices based on dominance were not significantly different among the three nematode species assemblages but indices based on species richness and rarefaction were significantly higher leeward of Uvea Island. Estimates of total species richness showed no sign of stabilizing with sample size. However, rare species stabilized very quickly, whereas abundant species were added with increasing sampling coverage, indicating a high spatial variability of the local composition of nematodes.

scholarly journals Sheep nemabiome diversity and its response to anthelmintic treatment in Swedish sheep herds

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Peter Halvarsson ◽  
Johan Höglund
Keyword(s):  
Species Richness ◽  
Diversity Index ◽  
Nematode Species ◽  
Abundant Species ◽  
Anthelmintic Treatment ◽  
Host Age ◽  
Larval Culture ◽  
Nematode Parasites ◽  
South Central ◽  
Nematode Diversity

Abstract Background A novel way to study the species composition and diversity of nematode parasites in livestock is to perform deep sequencing on composite samples containing a mixture of different species. Herein we describe for the first time the nematode community structures (nemabiomes) inhabiting Swedish sheep and how these are/were affected by host age and recent anthelmintic treatments. Methods A total of 158 fecal samples were collected (n = 35 in 2007 and n = 123 in 2013–2016) and cultured from groups of sheep on 61 commercial farms in the south-central part of the country where most animals are grazed. Among the samples, 2 × 44 (56%) were paired collections from the same groups pre- and post-treatment with anthelmintics such as macrocyclic lactones, benzimidazoles or levamisole. Samples were analyzed for their nemabiome using the PacBio platform followed by bioinformatic sequence analysis with SCATA. Species richness and diversity were calculated and analyzed in R. Results Nematode ITS2 sequences were found in all larval culture samples except two, even though the fecal egg counts were below the McMaster threshold in 20 samples. Sequencing yielded, on average, 1008 sequences per sample. In total, 16 operational taxonomical units (OTU), all with ≥ 98 % identity to sequences in the NCBI database, were recognized. The OTUs found represented nematode species of which ten are commonly associated with sheep. Multiple species were identified in all pre-anthelmintic treatment larval culture samples. No effects on nematode diversity were found in relation to host age. On the other hand, recent anthelmintic treatment lowered species richness, especially after use of ivermectin and albendazole. Interestingly, despite zero egg counts after use of levamisole, these samples still contained nematode DNA and especially H. contortus. Conclusions Our findings provide evidence that nemabiome analysis combined with diversity index analysis provides an objective methodology in the study of the efficacy of anthelmintic treatment as both high and low abundant species were detected.

scholarly journals Ichthyofauna of the Mata de Itamacaoca, an urban protected area from the upper Munim River basin, Northern Brazilian Cerrado

2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Elioenai da Silva Oliveira ◽  
Erick Cristofore Guimarães ◽  
Pâmella Silva de Brito ◽  
Lucas de Oliveira Vieira ◽  
Rafael Ferreira de Oliveira ◽  
...  
Keyword(s):  
Species Richness ◽  
River Basin ◽  
Fish Species ◽  
Fish Community ◽  
Linear Models ◽  
Anthropogenic Impacts ◽  
Sampling Site ◽  
Abundant Species ◽  
Diversity Indices ◽  
Alien Invasive Species

Abstract: The Munim River basin is one of the main river drainages of the Hydrological unit Maranhão, but there are few published studies which focus on ichthyological surveys and taxonomic work within this basin. The present study aims to provide a fish species inventory of the Mata da Itamacaoca, one of the few urban protected areas from the upper Munim River basin, comparing the ichthyofauna with other lists by conducted at the upper Munim River basin. A total of 42 collection expeditions were conducted, the sampling was conducted at five collecting sites distributed within the boundaries of Mata de Itamacaoca, upper Munim River basin. Diversity indices were calculated and generalised linear models (GLMs) were employed to assess differences in species richness, diversity and evenness depending on season and location in relation to the reservoir dam wall. In order to visualize fish community differences, non-metric multidimensional scaling (nMDS) and a one-way PERMANOVA was used to understand whether factors of site, season and location to the dam wall had an effect on fish community compositions. A total of six orders, 13 families, and 23 fish species were found, and the order with the highest species richness, considering all reaches, was Characiformes followed by Cichliformes. The most abundant species was Nannostomus beckfordi, while Pimelodella parnahybae and Hoplerythrinus unitaeniatus were the rarer species sampled. There were no alien invasive species collected within the study area. Species richness was significantly higher below the dam wall, but there were no other significant differences in diversity indices with regards to season or location. Fish community composition was significantly different above and below the dam wall and was significantly affected by sampling site. Season did not have an effect on fish community. This study corroborates other studies conducted in the Unidade Hidrológica Maranhão sensu Hubbert and Renno (2006), that the ichthyofaunal composition and taxonomy of species within this region face major data deficits, anthropogenic impacts, this study may be a baseline for comparing similar environments throughout the region.

scholarly journals Sheep nemabiome diversity and its response to anthelmintic treatment in Swedish sheep herds

2021 ◽  
Author(s):  
Peter Halvarsson ◽  
Johan Höglund
Keyword(s):  
Species Richness ◽  
Diversity Index ◽  
Nematode Species ◽  
Abundant Species ◽  
Anthelmintic Treatment ◽  
Host Age ◽  
Larval Culture ◽  
Nematode Parasites ◽  
South Central ◽  
Nematode Diversity

Abstract BackgroundA novel way to study the species composition and diversity of nematode parasites in livestock is to perform deep sequencing on composite samples containing a mixture of different species. Herein we describe for the first-time the nematode community structures (nemabiomes) inhabiting Swedish sheep and how these are/were affected by host age and recent anthelmintic treatments.MethodsA total of 158 fecal samples were collected (n=35 in 2007 and n=123 in 2013-2016) and cultured from groups of sheep on 61 commercial farms in the south-central part of the country where most animals are grazed. Among the samples, 2 x 44 (56%) were paired collections from the same groups pre- and post-treatment with anthelmintics such as macrocyclic lactones, benzimidazoles or levamisole. Samples were analyzed for their nemabiome using the PacBio platform followed by bioinformatic sequence analysis with SCATA. Species richness and diversity were calculated and analyzed in R.ResultsNematode ITS2 sequences were found in all larval culture samples except two, even though the fecal egg counts were below the McMaster threshold in 20 samples. Sequencing yielded, on average, 1,008 sequences per sample. In total 16 operational taxonomical units (OTU), all had ≥98 % identity to sequences in the NCBI database, were recognized. The OTUs found represented nematode species of which 10 are commonly associated with sheep. Multiple species were identified in all pre anthelmintic treatment larval culture samples. No effects on nematode diversity were found in relation to host age. On the other hand, recent anthelmintic treatment lowered species richness, especially after use of ivermectin and albendazole. Interestingly, despite zero egg counts after use of levamisole, these samples still contained nematode DNA and especially H. contortus.ConclusionsOur findings provide evidence that nemabiome analysis combined with diversity index analysis provide an objective methodology in the study of the efficacy of anthelmintic treatment, as both high and low abundant species were detected.

Diversity of nematodes in the yellow-necked field mouseApodemus flavicollisfrom the Peripannonic region of Serbia

2014 ◽  
Vol 90 (1) ◽  
pp. 14-20 ◽  
Author(s):  
B. Čabrilo ◽  
V.M. Jovanović ◽  
O. Bjelić-Čabrilo ◽  
I. Budinski ◽  
J. Blagojević ◽  
...  
Keyword(s):  
Species Richness ◽  
Generalized Linear Models ◽  
Linear Models ◽  
Alpha Diversity ◽  
Nematode Species ◽  
Diversity Indices ◽  
Taxonomic Distinctness ◽  
Field Mouse ◽  
Apodemus Flavicollis ◽  
Longitudinal Gradient

AbstractUp to six nematode species were identified from 86 specimens of the yellow-necked field mouseApodemus flavicollisfrom three mountainous localities known as Avala, Cer and Liškovac in Serbia. The highest prevalence of infection of 97% was recorded from Mt. Avala. Only one nematode species,Syphacia frederici, occurred in all three localities. There was complete overlap in nematode species from Mts. Avala and Liškovac, whereas the taxonomic distinctness of Mt. Cer was seen in the presence of the insect-transmitted speciesRictularia proni. Locality was a statistically significant factor in all the best-fitted generalized linear models of variation in abundances. The highest level of both species richness and parasite alpha diversity (Shannon'sH= 1.47) was found in the easternmost Mt. Liškovac, whereas the diversity indices were lowest for the westernmost Mt. Cer (Shannon'sH= 0.48). In view of this geographical difference, the beta diversity indices were calculated along a west to east longitudinal gradient.

scholarly journals Historical Zooplankton Composition Indicates Eutrophication Stages in a Neotropical Aquatic System: The Case of Lake Amatitlán, Central America

Diversity ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 432
Author(s):  
Sarahi Jaime ◽  
Adrián Cervantes-Martínez ◽  
Martha A. Gutiérrez-Aguirre ◽  
Eduardo Suárez-Morales ◽  
Julio R. Juárez-Pernillo ◽  
...  
Keyword(s):  
Central America ◽  
Focal Point ◽  
Zooplankton Community ◽  
Environmental Parameters ◽  
Water Source ◽  
Abundant Species ◽  
Biological Data ◽  
Local Composition ◽  
Species Richness And Abundance ◽  
Tropical System

This paper presents a study of freshwater zooplankton biodiversity, deemed as a reliable indicator of water quality. The Guatemalan Lake Amatitlán, currently used as a water source, has shown signs of progressive eutrophication, with perceptible variations of the local zooplankton diversity. Biotic and abiotic parameters were determined at four sites of Lake Amatitlán (Este Centro, Oeste Centro, Bahía Playa de Oro, and Michatoya) in 2016 and 2017. The local composition, the species richness and abundance of zooplankton, and the system environmental parameters were analyzed during both years surveyed. Biological data suggesting eutrophication of this tropical system were obtained, including a high rotifer abundance (11 species: the rotifers Brachionushavanaensis (109 ind L−1) and Keratellaamericana (304 ind L−1) were the most abundant species in this lake). The presumably endemic diaptomid copepod species, Mastigodiaptomusamatitlanensis, was absent in our samples, but we report the unprecedented occurrence of two Asian cyclopoid copepods (i.e., Thermocyclopscrassus and Mesocyclops thermocyclopoides) for Lake Amatitlán and Guatemala. The presence of larger zooplankters like adults and immature copepods (i.e., Arctodiaptomusdorsalis) and cladocerans (Ceriodaphnia sp.) at site “Este Centro” indicates a relatively healthy zooplankton community and represents a focal point for managing the conservation of this lake.

scholarly journals Aphids and ladybird beetle’s abundance and diversity in alfalfa fields of Yasouj, southwestern of Iran

2017 ◽  
Vol 49 (3) ◽  
Author(s):  
S. Mirfakhraie ◽  
K. Saeidi
Keyword(s):  
Species Richness ◽  
Coccinella Septempunctata ◽  
Abundant Species ◽  
Diversity Indices ◽  
Aphid Species ◽  
Aphis Fabae ◽  
Forage Legume ◽  
Species List ◽  
Medicago Sativa L ◽  
Abundance And Diversity

Alfalfa (Medicago sativa L.) is the oldest and the most important forage legume. It has been cultivated for forage longer than any other crop. Diversity indices provide information about community composition. Diversity indices are measured by species richness and species evenness therefore, it could give us more ecological information rather than a simple species list in the fields. During 2015-2016, aphids and ladybird beetle’s abundance and diversity were monitored in alfalfa fields of Yasouj. Samplings were conducted with 150 plants in the alfalfa fields from mid-May to mid-November. Species richness was measured using Shannon and Simpson indices. In this study, six aphids and five coccinellid species were collected and identified. Among the collected aphid species, Aphis fabae (Scopoli, 1763) and Therioaphis maculata (Buckton, 1899) were most abundant in the fields. For coccinellids, Coccinella septempunctata L. was the most abundant species. Highest aphid species diversity was observed on 17 May 2016.

scholarly journals SPATIAL VARIATIONS IN RARITY IN THE AEGEAN TENEBRIONID BEETLES (Coleoptera, Tenebrionidae)

2006 ◽  
Vol 38 (2) ◽  
pp. 227 ◽  
Author(s):  
S. Fattorini
Keyword(s):  
Species Richness ◽  
Population Density ◽  
Spatial Patterns ◽  
Rare Species ◽  
Abundant Species ◽  
Faunal Assemblages ◽  
Aegean Islands ◽  
Remote Islands ◽  
Species Rarity ◽  
Coleoptera Tenebrionidae

Three measures of species rarity were calculated to investigate possible spatial patterns of variation in tenebrionid community rarity on the Aegean islands. For each species rarity was evaluated as geographic distribution (mean incidence of species on islands in the archipelago), ecological tolerance (total area of the islands occupied) and population density (number of decades of species’ records from 1870 to 2000). In addition, Kattan’s index of vulnerability was computed. These rarity and vulnerability measures were used to construct analogous indexes at community level. Plotting species richness on island coordinates, produced a map where richness decreased in the centre of the archipelago, reaching highest values on peripheral islands. Geographic rarity increased from the centre of the archipelago to periphery. By contrast, ecological tolerance and population density show the following pattern: islands located very close to the Anatolian mainland, as well as those that are clumped, host the most eurytopic and abundant species, while remote southern islands have ecologically specialized faunas with low population density. Vulnerability (i.e. the reverse of Kattan’s index applied to communities) decreased in remote islands, which are usually also the smallest. As a whole the tenebrionid beetles on the Aegean Islands constitute threatened faunal assemblages of great ‘rarity’ under several dimensions, and some islands are especially rich in rare species, deserving special attention in conservation efforts.

scholarly journals Effects of reindeer density on vascular plant diversity on North Scandinavian mountains

Rangifer ◽  
2005 ◽  
Vol 25 (1) ◽  
pp. 5 ◽  
Author(s):  
Johan Olofsson ◽  
Lauri Oksanen
Keyword(s):  
Species Richness ◽  
Vascular Plants ◽  
Vascular Plant ◽  
Detrended Correspondence Analysis ◽  
Diversity Indices ◽  
Rare Plants ◽  
Strong Impact ◽  
Total Species Richness ◽  
Species Lists ◽  
Mountain Chain

We studied the effects of reindeer grazing on species richness and diversity of vascular plants on dolomite influenced low alpine sites in the species rich northern part of the Scandes using 8 sites with different reindeer densities. Two sites were situated inside Malla Strict Nature Reserve, where reindeer grazing have been totally prohibited since 1981, and strongly restricted since 1950s. The six other sites were located in other species rich hotspot sites standardized to be as similar to the dolomite-influenced sites in Malla Strict Reserve as possible but varying in reindeer densities commonly found in the Fennoscandian mountain chain. Each site with a habitat complex especially rich in rare vascular plants (the Dryas heath – low herb meadow complex) was systematically sampled in four plots of 2 m x 10 m. The plots were divided to 20 squares of 1 m x 1 m, and complete species lists of vascular plants were compiled for each of the squares. The first DCA (detrended correspondence analysis) axis was strongly related to an index of reindeer grazing, indicating that grazing has a strong impact on the composition of the vegetation. None of the characteristics indices of biodiversity (species richness, evenness or Shannon-Wiener H’) was correlated with reindeer density. The local abundances of categories consisting of relatively rare plants (Ca favored plants and red listed plants of Finland) showed significant, positive correlation with the intensity of reindeer grazing. We conclude that even though the density of reindeer has no influence on the total species richness or diversity of vascular plants, reindeer may still be important for regional biodiversity as it seems to favour rare and threatened plants. Moreover, our results imply that standard diversity indices may have limited value in the context of conservation biology, as these indices are equally influenced by rarities and by trivial species.Abstract in Swedish / Sammandrag: Vi studerade hur renbete påverkar kärlväxtflorans artrikedom och diversitet på dolomitpåverkade lågalpina lokaler i de artrikaste delarna av norra Fennoskandien. Vi inventerade 8 lokaler med olika rentätheter. Två lokaler ligger inom Malla Nationalpark, där renar har varit förbjudna sedan 1981 och starkt begränsade sedan 1950-talet. De sex andra lokalerna ligger i andra artrika områden med samma dolomitdominerade berggrund, men är betade av renar. Rentätheterna vid de studerade lokalerna varierar från helt obefintligt till bland de högsta rentätheter man kan finna i Fennoskandien. Inventeringen utfördes genom att systematiskt undersöka fyra 2 m x 10 m stora ytor i varje lokal i en habitattyp som är speciellt rik i ovanliga kärlväxter (fjällsippehed-lågörtsäng komplex). Varje yta delades upp i 20 småytor (1 m x 1 m), och en total artlista upprättades för var och en av dessa småytor. Den första axeln i DCA (detrended correspondence analyses) analysen korrelerade med rentätheten. Det visar att renar påverkar sammansättningen av växtsamhället. Ingen av de vanliga måtten på biodiversitet (artrikedom eller Shannon-Wiener diversitetsindex) var korrelerade med rentätheten. Trots detta, var tätheterna av Ca-gynnade växter och arter rödlistade i Finland positivt korrelerade med rentätheten. Trots att renarna inte påverkade totala artrikedommen, kan de vara betydelsefulla för regionala biodiversiteten eftersom de gynnar ovanliga och hotade arter. De vanliga måtten på biodiversitet har begränsat värde för bevarandebiologiska frågeställningar, eftersom de är lika känsliga för ovanliga och vanliga arter.

scholarly journals BEETLE DIVERSITY ASSOCIATED WITH FOREST STRUCTURE INCLUDING DEADWOOD IN SOFTWOOD AND HARDWOOD STANDS IN NOVA SCOTIA

2004 ◽  
Vol 42 (2) ◽  
Author(s):  
Daniel Kehler ◽  
Soren Bondrup-Nielsen ◽  
Cristine Corkum
Keyword(s):  
Species Richness ◽  
Nova Scotia ◽  
Forest Structure ◽  
Forest Stand ◽  
Stand Age ◽  
Species Assemblages ◽  
Total Species Richness ◽  
Total Species ◽  
Bois Mort ◽  
Stand Characteristics

Associations between beetles and forest stand characteristics, as well as beetle diversity, were investigated for 41 forest stands in Nova Scotia, Canada. Over 200 morphospecies from 45 Families of beetles were caught using window flight-intercept traps. In both years, correspondence analysis revealed distinct groupings of softwood and hardwood stands based on species assemblages. Multiple regression analysis was used to determine associations between forest variables and total species richness. Analyses were conducted for all stands combined and for hardwood and softwood stands separately. Hardwood stands had greater beetle richness than softwood stands. Within hardwood stands, volume of intermediate-sized deadwood was the best predictor of total species richness. Within softwood stands, volume of well-decayed deadwood was the best predictor of total beetle richness. Deadwood volume was associated with stand age in softwoods, and it appears that over 140 years is required for deadwood volume to reach pre-disturbance levels.On a étudié des associations entre les coléoptères et les caractéristiques des peuplements ainsi que la diversité des coléoptères pour 41 peuplements de la Nouvelle-Écosse, au Canada. Plus de 200 morpho-espèces appartenant à 45 familles de coléoptères ont été capturées à l’aide de pièges-fenêtres. Pour les deux années, des analyses de correspondance ont révélé des regroupements distincts dans les peuplements de résineux et de feuillus, d’après les assemblages d’espèces. On s’est servi d’une analyse de régression multiple pour établir des associations entre des variables des forêts et la richesse totale en espèces. Des analyses ont été effectuées pour l’ensemble des1 peuplements et séparément pour les peuplements de feuillus et pour les peuplements de résineux. La richesse en coléoptères était plus grande dans les peuplements de feuillus, pour lesquels le volume de bois mort de taille moyenne constituait le meilleur indicateur de la richesse totale en espèces. En ce qui concerne les peuplements de résineux, c’était le volume de bois mort bien décomposé qui était le meilleur indicateur de la richesse totale en coléoptères. Dans le cas des résineux, le volume de bois mort était associé à l’âge du peuplement, et il semble qu’il faille plus de 140 ans pour retrouver les niveaux pré-perturbation.

scholarly journals Fungal diversity in selected coastal mangrove ecosystems in East Berbice Corentyne, Guyana, South America

2021 ◽  
Vol 17 (1) ◽  
pp. 138-146
Author(s):  
Wazim R Sharif ◽  
Phillip NB Da Silva
Keyword(s):  
Species Richness ◽  
Fungal Diversity ◽  
Species Abundance ◽  
Environmental Parameters ◽  
Diversity Indices ◽  
Mangrove Ecosystem ◽  
Fungal Species ◽  
Fruiting Bodies ◽  
Mangrove Ecosystems ◽  
Study Sites

There is limited data on the fungal diversity in mangrove ecosystems in Guyana. This study investigated fungal diversity during the dry season in three selected coastal mangrove ecosystems along the Corentyne Coast of East Berbice, Guyana. Sampling was conducted within randomly established 50 m x 50 m plots containing 20 mini transects of length 12.5 m x 10 m in the overwash mangrove ecosystem at each of six study sites within the three study locations. Samples retrieved from the study plots included leaf, bark, soil and fruiting bodies. These were placed into separate bags and labelled appropriately. Environmental parameters were recorded at each study plot. Fruiting bodies were used to identify macrofungal species, and the leaf, bark and soil were used to prepare cultures from which microfungal samples were identified. The species that were identified were used to compile a checklist of fungal species, and diversity indices were calculated. A total of thirty (30) species were recorded, nine (9) of which were microfungi identified from the cultured samples and twenty-one (21) species were identified from macrofungal fruiting bodies retrieved at the study sites. The results further revealed that an increase in pH and salinity and a decrease in temperature resulted in an increase in species richness. Tidal activity also appeared to reduce species richness. Aspergillus, Rhizopus and Trichoderma were the dominant species at the three study sites with high relative species abundance. There also appeared to be some instances of substrate specificity.

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