Species Similarity and Magnitude

2021 ◽  
pp. 169-223
Keyword(s):  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Rachel Pool ◽  
Clara Romero-Rubira ◽  
Juan Antonio Raga ◽  
Mercedes Fernández ◽  
Francisco Javier Aznar

Abstract Background Current data about Pseudaliidae show contrasting patterns of host specificity between congeneric species. We investigated how both contact and compatibility between hosts and parasites contributed to the patterns of lungworm infection observed in a community of five species of cetaceans in the western Mediterranean. Methods The lungs of 119 striped dolphins Stenella coeruleoalba, 18 bottlenose dolphins Tursiops truncatus, 7 Risso’s dolphins Grampus griseus, 7 long-finned pilot whales Globicephala melas, and 6 common dolphins Delphinus delphis were analysed for lungworms. Parasites were identified by morphology and analysis of ITS2 sequences using both maximum likelihood and Bayesian inference methods. Body length was used as a proxy for lungworm species fitness in different hosts and compared with Kruskal-Wallis tests. Infection parameters were compared between cetacean species using Fisher’s exact tests and Kruskal-Wallis tests. Phylogenetic specificity was explored by collating the overall lungworm species prevalence values in hosts from previous surveys in various localities. To explore the relative importance of vertical and horizontal transmission, Spearman’s rank correlation was used to look for an association between host size and lungworm burden. A Mantel test was used to explore the association between lungworm species similarity and prey overlap using dietary data. Results Halocercus delphini had higher infection levels in striped dolphins and common dolphins; Stenurus ovatus had higher infection levels in bottlenose dolphins; and Stenurus globicephalae had higher infection levels in long-finned pilot whales. These results are congruent with findings on a global scale. Morphometric comparison showed that the larger nematodes were found in the same host species that had the highest parasite burden. Lungworms were found in neonatal striped dolphins and a Risso’s dolphin, and there was a weak but significant correlation between host size and parasite burden in striped dolphins and bottlenose dolphins. There was also a weak but significant association between prey overlap and lungworm species similarity. Conclusions Data indicate that phylogenetic specificity has an important role in governing host–parasite associations, as indicated by the higher infection levels and larger nematode size in certain hosts. However, diet can also influence infection patterns in these preferred hosts and contribute to less severe infections in other hosts.


2018 ◽  
Vol 120 (5) ◽  
pp. 2453-2465 ◽  
Author(s):  
Mintao Zhao

Studies of human and rodent navigation often reveal a remarkable cross-species similarity between the cognitive and neural mechanisms of navigation. Such cross-species resemblance often overshadows some critical differences between how humans and nonhuman animals navigate. In this review, I propose that a navigation system requires both a storage system (i.e., representing spatial information) and a positioning system (i.e., sensing spatial information) to operate. I then argue that the way humans represent spatial information is different from that inferred from the cellular activity observed during rodent navigation. Such difference spans the whole hierarchy of spatial representation, from representing the structure of an environment to the representation of subregions of an environment, routes and paths, and the distance and direction relative to a goal location. These cross-species inconsistencies suggest that what we learn from rodent navigation does not always transfer to human navigation. Finally, I argue for closing the loop for the dominant, unidirectional animal-to-human approach in navigation research so that insights from behavioral studies of human navigation may also flow back to shed light on the cellular mechanisms of navigation for both humans and other mammals (i.e., a human-to-animal approach).


2019 ◽  
Author(s):  
María F. Checa ◽  
David Donoso ◽  
Elisa Levy ◽  
Sebastián Mena ◽  
Jaqueline Rodriguez ◽  
...  

AbstractOur goal was to test the hypothesis that assembly processes that limit species similarity (i.e., competition) predominantly occur in more ‘stable’ abiotic environments, whereas habitat filtering (i.e., habitat characteristics) is a major driver of community composition within more variable environments at regional (e.g., aseasonal vs seasonal forests) and local scales (e.g., understory vs. canopy). A combined approach of phylogenetic- and functional trait-based analyses using forewing length and aspect ratio as traits, were used to this hypothesis.A 3-year survey was carried out at three sites (i.e., wet, transition and dry forests) across a climatic gradient in western Ecuador. Transition and dry forests were considered as seasonal, whereas wet forest were considered aseasonal. Butterflies were sampled using traps baited with rotting banana and prawn every two months from Nov 2010 to Sep 2013. Traps were set up at two heights, in the understory and canopy. DNA was extracted to sequence the barcode’ section of the mitochondrial gene cytochrome oxidase 1 (COI) for phylogenetic analyses. Measurements of morphological traits, forewing length and aspect ratio were done using digital photographs of specimens.A total of 6466 specimens representing 142 species of Nymphalidae were recorded. Based on phylogenetic- and trait-based analyses, we rejected the hypothesis that assembly processes that limit species similarity (i.e., competition) are likely to predominantly occur in more ‘stable’ abiotic environments, whereas habitat filtering can be a major driver of community composition within more variable environments at regional (i.e., aseasonal forest vs seasonal forests) and local scales (i.e., understory vs. canopy). My study of assembly mechanisms revealed the opposite pattern, with stronger evidence for the action of ecological filters in the assembly of butterfly communities from the wet aseasonal forests, and competition likely to be a major assembly process within dry seasonal forests. The present study therefore provided new insights into community assembly mechanisms in one of the richest butterfly faunas worldwide.


2017 ◽  
Vol 32 (1) ◽  
pp. 11
Author(s):  
IVONNE LUNA ORTEGA ◽  
VICENCIO DE LA CRUZ FRANCISCO

Las macroalgas son abundantes en el arrecife Oro Verde, Veracruz pero, hasta ahora, se desconocía su riqueza taxonómica, y se presume que presentan asentamientos en los corales escleractinios hermatípicos. Por ello el presente trabajo investigó qué especies de corales presentaron colonizaciones algales; además, se determinó la composición taxonómica y la similitud de los ensambles de macroalgas entre las especies de corales escleractinios. Se establecieron diez puntos de muestreo de manera sistemática en el arrecife; en cada lugar de estudio se colocó un transecto de banda de 50 x 2 m para localizar y recolectar macroalgas en superficies muertas de corales escleractinios. La frecuencia de aparición de las algas se estimó con base en el total de corales estudiados, así como para cada especie coral. Para explicar similitudes y diferencias significativas de la composición de ensamblajes macroalgales entre especies de corales se aplicaron análisis de similitud y ordenación. Los corales escleractinios con ensambles de algas fueron Siderastrea siderea, Montastraea cavernosa, Pseudodiploria strigosa, Colpophylia natans, Stephanocoenia intersepta, Porites astreoides, Orbicella annularis, Orbicella faveolata. De un total de 100 colonias coralinas revisadas se determinaron 32 especies de macroalgas, las cuales están representadas en tres divisiones, 10 órdenes y 15 familias. Las macroalgas corticadas, foliosas corticadas y filamentosas fueron las más representadas en especies. Las algas de mayor frecuencia sobre los corales masivos fueron Laurencia obtusa, Amphiroa rigida y Caulerpa chemnitzia. Los corales masivos con mayor número de registros de algas fueron S. siderea (9 especies), M. cavernosa (19) y P. strigosa (17). Los ensambles algales en los corales masivos presentaron baja similitud, sin embargo no se detectaron grupos significativamente disimiles. Solamente S. siderea y M. cavernosa son ligeramente parecidos en la composición ficológica. Los resultados sugieren que los corales masivos del arrecife Oro Verde son vulnerables a la colonización de algas, pero es necesario indagar qué condiciones preceden al asentamiento algal.Macroalgal assemblages on dead surfaces of scleractinian corals (Anthozoa: Scleractinia) in the Oro Verde reef, Veracruz, MexicoBenthic macroalgae are abundant in the Oro Verde reef but their taxonomic richness was hitherto unknown and it is presumed to present settlements on the massive corals. For this reason, the present work investigated which species of massive corals show algal colonization. Also, their taxonomic composition was determined, and the similarity of the algal assemblages between species of scleractinian corals was measured. Ten sampling points were systematically established in the reef, where a transect band of 50 x 2 m at each site was placed to locate and collect algae fron the dead surfaces of scleractinian corals. The frequency of occurrence of algae species was estimated based on the total number of coral species studied, as well as on each coral species. Similarity and ordination analysis were applied in order to explain similarities and significant differences of the phycological composition among the coral species. Scleractinian corals with algal assemblages were: Siderastrea siderea, Montastraea cavernosa, Pseudodiploria strigosa, Colpophylia natans, Stephanocoenia intersepta, Porites astreoides, Orbicella annularis, Orbicella faveolata. Thirty-two species of algae were identified from a total of 100 revised coral colonies which are represented in 3 divisions, 10 orders and 15 families. The corticated, foliose corticated and filamentous macroalgae were the most represented species. The most frequent algae on massive corals were Laurencia obtusa, Amphiroa rigida and Caulerpa chemnitzia. Massive corals with higher algal records were S. siderea (9 species), M. cavernosa (19 species) and P. strigosa (17 species). The algal assemblages on the massive corals presented low similarity. However, no significant dissimilar groups were detected. Only S. siderea and M. cavernosa are relatively similar in phycological composition. The results suggest that the massive corals of the Oro Verde reef are vulnerable to the colonization of algae, but it is necessary to investigate the conditions preceding algal settlement.


2011 ◽  
Vol 79 (2) ◽  
pp. 157-166 ◽  
Author(s):  
Maciej Wódkiewicz ◽  
Anna Justyna Kwiatkowska-Falińska

Forest seed banks mostly studied in managed forests proved to be small, species poor and not reflecting aboveground species composition. Yet studies conducted in undisturbed communities indicate a different seed bank characteristic. Therefore we aimed at describing soil seed bank in an undisturbed forest in a remnant of European lowland temperate forests, the Białowieża Forest. We compared similarity between the herb layer and seed bank, similarity of seed bank between different patches, and dominance structure of species in the herb layer and in the seed bank of two related oak-hornbeam communities. We report relatively high values of Sorensen species similarity index between herb layer and seed bank of both patches. This suggests higher species similarity of the herb layer and soil seed bank in natural, unmanaged forests represented by both plots than in fragmented communities influenced by man. Although there was a set of core seed bank species present at both plots, yielding high Sorensen species similarity index values, considerable differences between plots in seed bank size and dominance structure of species were found, indicating spatial variability of studied seed bank generated by edaphic conditions. Dominance structure of species in the herb layer was not reflected in the underlying seed bank. This stresses, that natural forest regeneration cannot rely only on the seed bank, although some forest species are capable of forming soil seed banks. While forest seed banks may not reflect vegetation composition of past successional stages, they may inform on history and land use of a specific plot.


2013 ◽  
Vol 280 (1768) ◽  
pp. 20131201 ◽  
Author(s):  
Matthew C. Fitzpatrick ◽  
Nathan J. Sanders ◽  
Signe Normand ◽  
Jens-Christian Svenning ◽  
Simon Ferrier ◽  
...  

A common approach for analysing geographical variation in biodiversity involves using linear models to determine the rate at which species similarity declines with geographical or environmental distance and comparing this rate among regions, taxa or communities. Implicit in this approach are weakly justified assumptions that the rate of species turnover remains constant along gradients and that this rate can therefore serve as a means to compare ecological systems. We use generalized dissimilarity modelling, a novel method that accommodates variation in rates of species turnover along gradients and between different gradients, to compare environmental and spatial controls on the floras of two regions with contrasting evolutionary and climatic histories: southwest Australia and northern Europe. We find stronger signals of climate history in the northern European flora and demonstrate that variation in rates of species turnover is persistent across regions, taxa and different gradients. Such variation may represent an important but often overlooked component of biodiversity that complicates comparisons of distance–decay relationships and underscores the importance of using methods that accommodate the curvilinear relationships expected when modelling beta diversity. Determining how rates of species turnover vary along and between gradients is relevant to understanding the sensitivity of ecological systems to environmental change.


2012 ◽  
Vol 11 (2) ◽  
pp. 76
Author(s):  
Riche - Hariyati ◽  
Erry - Wiryani ◽  
Yunita Kus Astuti

Rawa Pening is a natural lake that has 17 inlet (rivers thats lead water into lake) and one outlet Tuntang RiverInlet and outlet of Rawa Pening Lake have differences in physico-chemistry factor and covering of plant water.Plankton is one of organism that influenced by this condition.The aim of this research is to establish structure community of plankton in inlet and outlet Rawa PeningLake. Sample was taken from 7 inlet (the downstream of Segalok, Torong, Panjang, Galeh, Rengas, Kedungringisand intercourse of Parat, Legi and Muncul downstream). Sample of outlet taken from upstream of Rawa PeningLake, around of port and before bridge. Sample then analyzed by diversity index, similarity index, equaliy index,and total individu per liter. Seventy seven plankton were found in inlet and outlet Rawa Pening Lake. Sixty fivespecies are phytoplankton and contains of 22 species Chlorophyceae, 38 species Bacillaryophyceae, 2 speciesCyanophyceae, 2 species Euglenophyceae and one species of Chrysophyceae. 12 species are zooplankton andcontains of 10 species Rotifera also one species Sarcomastigophora and one species of Copepoda. Based on diversityindex, equality index, and total individu the community structure of plankton in inlet is relatively stabil than in outletRawa Pening Lake.The similarity index showed that the level of species similarity is low. This is indicated thatstructure community of plankton in inlet and outlet is different.


Ecology ◽  
2015 ◽  
Vol 96 (1) ◽  
pp. 143-153 ◽  
Author(s):  
L. Chalmandrier ◽  
T. Münkemüller ◽  
S. Lavergne ◽  
W. Thuiller

Author(s):  
E. V. Maramokhin

This paper provides an overview of the biology and species diversity of xylotrophic basidiomycetes, as well as the biotopic relationships of xylotroph mycobiota with phytocenoses. Ecological groups of these organisms are considered in connection with substrate specialization and their species similarity in birch and aspen small-leaved forests of different pharmacy. A brief assessment of the influence of the anthropogenic factor on the biological diversity of the represented group of organisms is given. For the first time, the Kostroma region is divided into southern, central, and northern parts to assess species diversity depending on weather, climate, and phytocenotic factors. The data on the study of changes in the degree of integration of mycocenoses of birch and aspen forests within the studied areas of the region are presented. In total, over 60 species of xylotrophic basidiomycetes were found in the small-leaved forests in the region, among which 38 species primarily affected birch forests and 40 species of pathogenic xylotrophic basidiomycetes have tropism for P. tremula. It was established that species belonging to the Coriolaseae family predominate in the species composition of wood-destroying mycobiota; they comprise about 27% of the total species composition in birch forests and about 24% of the species composition in aspen forests.


2020 ◽  
Vol 7 (1) ◽  
pp. 71-80
Author(s):  
Suryana Suryana ◽  
Betty Mayawatie ◽  
Joko Kusmoro ◽  
Budi Irawan

The diversity of ferns (Pteridophyta) in the five mountainous in West Java (Mt. of Patuha, Papandayan, Tangkuban Perahu, Pangrango, and Guntur) has not been widely reported. The aim of this research was to obtain data on diversity and similarity of fern species in the five mountains in West Java. This research was conducted by exploring and descriptive analysis method. Comparison of species diversity among all reseach field were calculated by the index of species similarity according to Sorenson. The diversity of ferns in Mt. Patuha, Papandayan, Tangkuban Perahu, Pangrango, and Guntur were 27, 14, 26, 40 and 5 species, respectively. The total number of ferns species in five locations are 83 species from 25 families. Comparison of species diversity among fileds based on the Sorenson similarity index is low (<50%), except between the Mt. Patuha and Mt. Papandayan areas is high (> 50%).


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