Interspecific interaction may lead to species exclusion but there are several ways in which species can coexist. One way is by reducing the overall intensity of competition via aggregated utilisation of fragmented resources. Known as the 'aggregation model of coexistence', this system assumes saturation and an equilibrium number of species per community. In this study we tested the effects of interspecific aggregation on the level of intraspecific aggregation among ectoparasites of marine fishes (36 communities of gill and head ectoparasite species). If parasite species are distributed in a way that interspecific aggregation is reduced relative to intraspecific aggregation then species coexistence is facilitated. We found a positive relationship between parasite species richness and fish body size, controlling for host phylogeny. A positive relationship between infracommunity species richness and total parasite species richness was also found, providing no evidence for saturation. This result supports the view that infracommunities of parasites are not saturated by local parasite residents. The observed lack of saturation implies that we are far from a full exploitation of the fish resource by parasites. Ectoparasites were aggregated at both population and species levels. However, only half of the ectoparasite communities were dominated by negative interspecific aggregation. We found that infracommunity parasite species richness was positively correlated with the level of intraspecific aggregation versus interspecific aggregation. This means that intraspecific aggregation increases compared with interspecific aggregation when total parasite species richness increases, controlling fish size and phylogeny. This supports one assumption of the 'aggregation model of coexistence', which predicts that interspecific interactions are reduced relative to intraspecific interactions, facilitating species coexistence.
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http://dx.doi.org/10.1016/s0020-7519(99)00029-6 | DOI Listing |
Understanding the factors driving species coexistence and competition in the shrub layer of semi-natural forests is crucial for effective forest management and conservation. However, there is limited knowledge about the interspecific associations of the main species in the shrub layer of communities in the semi-natural forest of Sandu Gulf, Ningde, Fujian Province, China. Therefore, this study aimed to investigate the influence of the abiotic environment on plant communities within the semi-natural forest of on the islands of Sandu Gulf.
View Article and Find Full Text PDFZootaxa
July 2024
Departamento de Zoologia; Universidade Federal do Paraná; Curitiba; PR; Brazil.
Ant attendance or trophobiosis is widely distributed in Auchenorrhyncha and can be defined as a disjunctive association, an interspecific relationship between two symbiotic organisms. Aggregation behavior with or without ant mutualism has been documented for nymphs and adults in a few families of Fulgoromorpha whereas ant-attendance is reported for all planthopper families except for Ricaniidae. Based on field observations of Pharsalus repandus Melichar, 1906, the present work aims to record the first mutualistic interaction of ant-attendance in a species of the family Ricaniidae, report its aggregation behavior, its host plant, and expand its known distribution to the states of Paraná and Minas Gerais.
View Article and Find Full Text PDFCurr Issues Mol Biol
October 2024
Embrapa Mandioca e Fruticultura, Rua Embrapa, s/no, Cruz das Almas 44380-000, BA, Brazil.
Chem Rec
November 2024
Laboratório de Semioquímicos, Departamento de Química, Universidade Federal do Paraná, UFPR, 81531-980, Curitiba, PR, Brazil.
Stink bugs (Hemiptera, Pentatomidae) are well known by the strong odor of the defensive compounds they release, which can mediate intra- and/or interspecific interactions. Pentatomidae is one of the largest families of Heteroptera and includes many phytophagous species that are considered pests of various crops, as well as predatory species that provide biological control. Against this background, numerous research papers in Chemical Ecology have focused on communication within this group.
View Article and Find Full Text PDFPlants (Basel)
September 2024
College of Horticulture, Jinling Institute of Technology, Nanjing 210038, China.
Pollen carries extensive genetic information, which may provide clues regarding the kinship of whose genetic relationships are complex. In this study, the phenotypic variation of pollen from 107 taxa was investigated using combined methods of intraspecific/interspecific uniformity testing, cluster analysis, and Pearson correlation analysis. The family aggregation distributions in sections, species, and cultivars were analyzed to infer their pedigree relationships.
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