Aspergillus sibiricus (Aspergillaceae, Eurotiales), a novel acid-tolerant species in Aspergillus section Fumigati

A novel species in Aspergillus section Fumigati is described as Aspergillus sibiricus. The new species was isolated from an open coal mine in Altai, Siberia, Russia and is represented by ex-type strain CBS 143307. We used a polyphasic taxonomic approach to characterise the species. A description based on morphological features is provided and shows that the new species differs morphologically from closely related species (A. assulatus, A. nishimurae and A. waksmanii). Partial sequences of the loci encoding β-tubulin (BenA), calmodulin (CaM), ribosomal polymerase II second largest subunit (RPB2) and internal transcribed spacer rDNA region (ITS1-5.8S-ITS2) were analyzed as well. Sequences data, macro- and micromorphological and physiological characteristics distinguish A. sibiricus from all known species in section Fumigati, series Unilaterales. A. sibiricus, isolated from an acidic habitat (pH 3.2–3.4), is able to grow at pH 2 and is considered an acid-resistant species.

Staphylococcus ratti sp. nov. Isolated from a Lab Rat

Staphylococci from the Staphylococcus intermedius-Staphylococcus hyicus species group include numerous animal pathogens and are an important reservoir of virulence and antimicrobial resistance determinants. Due to their pathogenic potential, they are possible causative agents of zoonoses in humans; therefore, it is important to address the properties of these strains. Here we used a polyphasic taxonomic approach to characterize the coagulase-negative staphylococcal strain NRL/St 03/464T, isolated from the nostrils of a healthy laboratory rat during a microbiological screening of laboratory animals. The 16S rRNA sequence, MALDI-TOF mass spectrometry and positive urea hydrolysis and beta-glucuronidase tests clearly distinguished it from closely related Staphylococcus spp. All analyses have consistently shown that the closest relative is Staphylococcus chromogenes; however, values of digital DNA-DNA hybridization <35.3% and an average nucleotide identity <81.4% confirmed that the analyzed strain is a distinct Staphylococcus species. Whole-genome sequencing and expert annotation of the genome revealed the presence of novel variable genetic elements, including two plasmids named pSR9025A and pSR9025B, prophages, genomic islands and a composite transposon that may confer selective advantages to other bacteria and enhance their survival. Based on phenotypic, phylogenetic and genomic data obtained in this study, the strain NRL/St 03/464T (= CCM 9025T = LMG 31873T = DSM 111348T) represents a novel species with the suggested name Staphylococcus ratti sp. nov.

THE IMPORTANCE OF TAXONOMY ON BASE SCIENCE

Although species identification is a central component on Biological Sciences, misidentifications are quite common generating error cascade effects on other environmental studies, resulting on erroneous population estimates, status, trends, and distribution data. One of the main causes of these errors occurs when dealing with damaged material, immature specimens, sexual dimorphism, intraspecific variation, and species with poor or outdated descriptions. Furthermore, usually there is no material retained as voucher of the specimens studied in scientific collections, hindering confirmation the identified species, in morphoanatomical and genetic scope. Even with this reliance on species identification taxonomy has been in decline for many years. In this study, we present the case study of the crustaceans identified for the Minho River estuary (NW Iberian Peninsula), using a taxonomic approach comparing these results with the biological surveys obtained through various ecology studies performed for 4 decades. A total of 64 species of crustaceans were identified within this study, in which 44 were new records for the Minho River estuary, compared to the 25 species identified on the biological surveys analyzed. Being one of the first studies of this nature in the Minho River, the main objective will be to provide taxonomic support in future projects in this area, contributing to the knowledge of the fauna of Portugal and the Iberian Peninsula.

Postulating the Modality of Integrative Taxonomy in Describing the Cryptic Congener Pampus griseus (Cuvier) and Systematics of the Genus Pampus (Perciformes: Stromateidae)

Pomfrets (genus Pampus), a highly commercial fishery resource distributed in the Indo-Western Pacific that includes Lessepsian migrants, have witnessed a series of systematic reforms. In this study, based on comprehensive sampling spanning type localities and coevals in the Northern Indian Ocean, the cryptic and valid species Stromateus griseus is resurrected from the synonymy and re-described as Pampus griseus (New Combination) based on 35 specimens from the Bay of Bengal, corroborated by a molecular analysis, which indicated a confined distribution of the species. The Bayesian phylogeny of the genus was reconstructed, incorporating redressed barcodes (582 nucleotides) and concatenated mitochondrial gene sequence data (1,822 nucleotides) generated from the recorded species P. candidus, P. chinensis and the neophyte along with sequences from GenBank entrusting the latest literature. The phylograms differed in topology as for seven valid species, and the one predicated on the concatenated data erected a highly supported polytomous clade for the P. cinereus complex (P. griseus, P. cinereus, and P. candidus) which shares synapomorphies. Pampus argenteus and P. minor, together, formed a sister clade to the rest. Climate-driven vicariant events during glacial epochs and the Indo-Pacific Barrier effect can be the drivers behind the Indian and Pacific Ocean sister lineages in P. chinensis. A multivariate analysis isolated the cryptic species from its congeners. This article portrays the systematics revision of genus Pampus with an integrative taxonomic approach compiling distinctive molecular, morphological, and anatomical features, revised key for species identification, taxonomic archives of Indian stromateids, and winds up with specific remarks.

The Economic Performance of Central Europe Metropolises. A Comparative Approach

Since the fall of communism, the big cities of Central Europe have been included in the international metropolitan network, and their economic performance has improved significantly. Based on that, it can be asserted that the whole region is undergoing a process of metropolisation, which may be manifested by a focus of development in the limited areas of metropolises. Therefore this paper aims to present the results of a closer examination of this process in Central Europe. It is based on a comparative analysis of the metropolises in relation to their countries in terms of economic performance. A taxonomic approach based on Hellwig’s development pattern is adopted. The available Eurostat data (NUTS 3 level) on a range of socio‑economic characteristics is used. The study results show that the economic performance of Central European metropolises is relatively closer to Western Europe’s cities than the countries’ non‑metropolitan parts. Highlighting development issues in Central Europe from the spatial‑metropolitan point of view is the paper’s added value.

Parasitism, seasonality, and diversity of trombiculid mites (Trombidiformes: Parasitengona, Trombiculidae) infesting bats (Chiroptera) in Poland

The study aims to ascertain the diversity of trombiculid species associated with Chiroptera in Poland, and for the first time in the case of research on Central European Trombiculidae, we use both DNA and morphology in an integrative taxonomic approach to determine species identities of trombiculids. The research was carried out from 2015 to 2019. In total, 2725 larvae were collected from 300 specimens of bats belonging to 11 species. Deutonymphs were obtained through laboratory rearing of larvae; few larvae and deutonymphs were collected also from bats' daily roosts. The presence of trombiculid larvae on hosts was observed between July and April of the following year, with the highest numbers recorded in autumn, during bat swarming. Male bats were infested more often than females (16.4 vs. 6.6%). The highest infestation rate was recorded for Barbastella barbastellus, Myotis nattereri and Plecotus auritus, and the highest prevalence of chiggers (> 30%) for Myotis bechsteinii and P. auritus. The larvae found on bats occupied the areas with free access to the host’s skin: auricles, tragus, and snout. Morphological identification of specimens to the species level was hindered by the mosaic distribution of diagnostic traits. Morphological analyses indicated the presence of Leptotrombidium russicum and Leptotrombidium spp. in the examined material, whereas molecular analyses additionally suggested three other potential species assigned to the same genus based on the assessed scope of intrageneric variation (ASAP method). We argue that the identification of the parasitic larvae (chiggers) using morphological characters does not address the question of actual species boundaries, which, in turn, affects the inferences about host specificity and host range.

Morphological and Molecular Characterization of Trichuris sp. (Nematoda: Trichuridae) in Crested Porcupines (Hystrix cristata; Rodentia: Hystricidae) from Italy

Adult specimens of Trichuris sp. collected from crested porcupines (Hystrix cristata) from Italy were characterized using an integrative taxonomic approach involving morphological and molecular tools. The morphological features of this Trichuris sp. were compared to data already available for Trichuris spp. from Hystrix sp., revealing diagnostic traits, such as spicule length in males or vulva shape in females, which distinguish this Trichuris sp. from the other species. Evidence from sequences analysis of the partial mitochondrial COX1 region indicated that the taxon under study is a distinct lineage. Biometrical and genetic data suggested this Trichuris sp. to be a valid and separated taxon. However, since molecular data from other Trichuris spp. infecting Hystrix, such as T. infundibulus, T. hystricis, T. javanica, T.landak and T. lenkorani, are missing in public repositories, the number and identity of distinct lineages able to infect porcupines remain only partially defined.

Applications of Multi-Agent Deep Reinforcement Learning: Models and Algorithms

Recent advancements in deep reinforcement learning (DRL) have led to its application in multi-agent scenarios to solve complex real-world problems, such as network resource allocation and sharing, network routing, and traffic signal controls. Multi-agent DRL (MADRL) enables multiple agents to interact with each other and with their operating environment, and learn without the need for external critics (or teachers), thereby solving complex problems. Significant performance enhancements brought about by the use of MADRL have been reported in multi-agent domains; for instance, it has been shown to provide higher quality of service (QoS) in network resource allocation and sharing. This paper presents a survey of MADRL models that have been proposed for various kinds of multi-agent domains, in a taxonomic approach that highlights various aspects of MADRL models and applications, including objectives, characteristics, challenges, applications, and performance measures. Furthermore, we present open issues and future directions of MADRL.

Sphingobacterium micropteri sp. nov. and Sphingobacterium litopenaei sp. nov., isolated from aquaculture water

Two novel bacterial strains, designated as DN00404T and DN04309T, were isolated from aquaculture water and characterized by using a polyphasic taxonomic approach. Cells of strains DN00404T and DN04309T were Gram-stain-negative, aerobic, non-motile, oxidase-positive and catalase-positive. Cells of DN00404T were short rod-shaped and those of DN04309T were long rod-shaped. Strain DN00404T was found to grow at 15–37 °C (optimum, 25–30 °C), at pH 6.0–11.0 (optimum, pH 7.5) and in 0–2.0 % (w/v) NaCl (optimum, 1.0 %). Strain DN04309T was found to grow at 15–45 °C (optimum, 20–37 °C), at pH 5.5–11.0 (optimum, 7.5) and in 0–4.0 % (w/v) NaCl (optimum, 0.5 %). Phylogenetic analyses based on 16S rRNA gene and genome sequences revealed that the two strains belonged to the genus Sphingobacterium and were distinct from all known species of this genus. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between the two strains and between each of the two strains and related type strains of this genus were well below the recognized thresholds of 95.0–96.0 % ANI and 70.0 % dDDH for species delineation. The genomic DNA G+C contents of strains DN00404T and DN04309T were 41.6 and 36.0 mol%, respectively. The respiratory quinone in both strains was identified as MK-7, and their major fatty acids were iso-C15 : 0 and summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c), which were similar to those of other species of this genus. The two major fatty acids C16 : 0 and iso-C17 : 0 3-OH were also found in strain DN00404T. Based on genotypic and phenotypic characteristics, two novel species of the genus Sphingobacterium are proposed: Sphingobacterium micropteri sp. nov. with DN00404T (=GDMCC 1.1865T=KACC 21924T) as the type strain and Sphingobacterium litopenaei sp. nov. with DN04309T (=GDMCC 1.1984T=KCTC 82348T) as the type strain.

Rediscovery and redescription of Niphargus enslini Karaman, 1932 (Amphipoda, Niphargidae) in southern Germany

Niphargus enslini Karaman, 1932 was collected only once in 1905 from the Falkensteiner Höhle (Baden-Württemberg, Germany). Two years after its description, the species was synonymized with Niphargus virei and not studied any more. During recent surveys on German niphargids, further samples collected in this cave did not yield N. enslini specimens, but this species was collected in the Blätterteighöhle and in the Schwarzer Brunnen, two caves located in Baden-Württemberg and intercepting the same karstic aquifer feeding Falkensteiner Höhle. In an integrative taxonomic approach, we carefully studied the morphology of the newly collected specimens and sequenced two molecular markers (fragments of the cytochrome c oxidase subunit I (COI) and of the nuclear 28S rRNA gene) to test for possible conspecificity of N. enslini with N. virei. Morphological analysis confirmed that N. enslini is distinct from the N. virei species complex. We provide a redescription of newly collected material, together with new drawings of a more than 100 years old topotypic female. We briefly discuss the putative origin of N. enslini and the age of its split from the N. virei species complex.