PHYLOGENY, MORPHOGENESIS, EVOLUTIONARY developmental biology, ORGANISMS, MICROBIAL ecology, and TAXONOMY
Abstract
Robust phylogenetic hypotheses have become key for studies addressing the evolutionary biology and ecology of various groups of organisms. In the species-rich heteropteran superfamily Pentatomoidea, phylogenies at lower taxonomic levels are still scarce and mostly employ exclusively morphological data. In this study, we conducted a total evidence phylogeny focusing on the tribe Carpocorini (Pentatomidae), using morphological data and four DNA markers ( COI, Cytb, 16S and 28S rDNA; ∼2330 bp; 32 taxa) in order to investigate the relationships within Euschistus Dallas, one of the most speciose pentatomid genera, and between Euschistus and related genera. Our hypotheses generated by maximum likelihood and Bayesian inference show that the current taxonomic composition and classification of Euschistus and allied genera are in need of revision. Euschistus was recovered as nonmonophyletic, with the subgenera forming four independent lineages: Euschistus ( Euschistus) and Euschistus ( Lycipta) Stål are sister groups; Euschistus ( Euschistomorphus) Jensen-Haarup is more closely related to Dichelops Spinola and Agroecus Dallas; and Mitripus Rolston is divided into two clades closely related to Sibaria Stål and Ladeaschistus Rolston. We chose not to change the classification of E. ( Euschistomorphus) until further data become available, and propose to split Euschistus into three genera with the exclusion of Euschistus ( Mitripus) and all of its species. Here we elevate Mitripus to genus rank to include M. acutus comb.n., M. convergens comb.n. and M. legionarius comb.n., and propose Adustonotus Bianchi gen.n. to include A. anticus comb.n., A. latus comb.n., A. tauricornis comb.n., A. grandis comb.n., A. hansi comb.n., A. paranticus comb.n., A. irroratus comb.n. and A. saramagoi comb.n. We also provide identification keys to the genera Adustonotus gen.n., Ladeaschistus, Mitripus n. rank and Sibaria, here defined as the Mitripus genus group, and to the species of Mitripus and Adustonotus gen.n. Our results provide insights into the current status of the classification of the Pentatomidae, suggesting the need for phylogenetic analyses at different taxonomic levels within stink bugs. This published work has been registered in ZooBank, . [ABSTRACT FROM AUTHOR]
The diazotrophic community in microbial mats growing along the shore of the North Sea barrier island Schiermonnikoog (The Netherlands) was studied using microscopy, lipid biomarkers, stable carbon (δC) and nitrogen (δN) isotopes as well as by constructing and analyzing 16S rRNA gene libraries. Depending on their position on the littoral gradient, two types of mats were identified, which showed distinct differences regarding the structure, development and composition of the microbial community. Intertidal microbial mats showed a low species diversity with filamentous non-heterocystous Cyanobacteria providing the main mat structure. In contrast, supratidal microbial mats showed a distinct vertical zonation and a high degree of species diversity. Morphotypes of non-heterocystous Cyanobacteria were recognized as the main structural component in these mats. In addition, unicellular Cyanobacteria were frequently observed, whereas filamentous heterocystous Cyanobacteria occurred only in low numbers. Besides the apparent visual dominance of cyanobacterial morphotpyes, 16S rRNA gene libraries indicated that both microbial mat types also included members of the Proteobacteria and the Cytophaga-Flavobacterium-Bacteroides group as well as diatoms. Bulk δN isotopes of the microbial mats ranged from +6.1‰ in the lower intertidal to −1.2‰ in the supratidal zone, indicating a shift from predominantly nitrate utilization to nitrogen fixation along the littoral gradient. This conclusion was supported by the presence of heterocyst glycolipids, representing lipid biomarkers for nitrogen-fixing heterocystous Cyanobacteria, in supratidal but not in intertidal microbial mats. The availability of combined nitrogen species might thus be a key factor in controlling and regulating the distribution of the diazotrophic microbial community of Schiermonnikoog. [ABSTRACT FROM AUTHOR]
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