Phylogeny and evolution of morphological structures in a highly diverse lineage of fruiting-body-forming amoebae, order Trichiales (Myxomycetes, Amoebozoa).

Early phylogenetic studies refuted most previous assumptions concerning the evolution of the morphological traits in the fruiting bodies of the order Trichiales and did not detect discernible evolutionary patterns, yet they were based on a limited number of species. We infer a new Trichiales phylogeny based on three independently inherited genetic regions (nuclear and mitochondrial), with a fair taxonomic sampling encompassing its broad diversity. Besides, we study the evolutionary history of some key morphological characters.

: A new myxomycete species from high elevation forests in the tropical Andes of Peru.

A new species of the genus (order Physarales, Myxomycetes, Amoebozoa) is described from Peru. Relevant details on spore germination, as well as morphological and phylogenetic data, are provided. At first glance, the new species shares some morphological similarities with both , type of the genus, and , but it strikingly differs from all other species of its genus by combining a short dark stalk, with a reticulate columella, and clustered spores.

Spore ultrastructural features and significance of their diverse ornamental elements in the evolutionary history of the order Trichiales (Myxomycetes, Amoebozoa).

Spores are the dispersal and reproductive units in Myxomycetes, and their ornamentation, usually at the light microscopy resolution limit, is taxonomically meaningful. Here, we analyze with scanning and transmission electron microscopy the spore ultrastructural features in Trichiales, one of the most morphologically diverse orders. In Trichiales, the spore wall consists of two layers, an outer one, including the ornamentation, and an inner layer subdivided into two sections.

: A new myxomycete from the austral Andes emerges from broad-scale morphological and molecular analyses of collections.

A new nivicolous myxomycete is described as a result of a comprehensive study of collections from the entire range of its occurrence. Statistical analysis of 12 morphological characters, phylogenetic analyses of nuc 18S rDNA and elongation factor 1-alpha gene (), and a delimitation method (automatic barcode gap diversity) have been applied to corroborate the identity of the new species. A preliminary morphological analysis of revealed high variability of South American populations where four types of spore ornamentation were noted.

New Approach to the Ultrastructure of the Capillitium in the Order Trichiales (Myxomycetes, Amoebozoa) and its Phylogenetic Implications.

Myxomycetes constitute one of the major lineages within the supergroup Amoebozoa. At the end of their life cycles, most myxomycetes produce spore-bearing fruiting bodies, in which additional structures develop, like the capillitium, a system of sterile filaments intermingled with the spores. The capillitium is a relevant structure in the taxonomy of the order Trichiales, the target group in this study.

Range-wide Phylogeography of a Nivicolous Protist Didymium nivicola Meyl. (Myxomycetes, Amoebozoa): Striking Contrasts Between the Northern and the Southern Hemisphere.

Soil protists play a crucial role in terrestrial ecosystems and often show immense taxonomic diversity. However, for many groups, distribution patterns remain largely unknown. We investigated range-wide intraspecific diversity of a specialized airborne protist (Didymium nivicola Meyl.

Nivicolous Trichiales from the austral Andes: unexpected diversity including two new species.

Nivicolous myxomycetes are a group of amoebozoan protists dependent on long-lasting snow cover worldwide. Recent fine-scale analysis of species diversity from the austral Andes revealed high intraspecific variability of most taxa, suggesting independent evolutionary processes and significant differences in species compositions between the Northern (NH) and Southern (SH) Hemispheres. The present study is the second part of this analysis based on representatives of Trichiales.

Diversity patterns, ecological associations and future of research on Costa Rican myxomycetes.

The most active research period on myxomycetes in Costa Rica has taken place in the last three decades. During this time, most of the collections have been carried out and most of the scientific articles have been produced. However, the lack of standard protocols and systematic planning across the country generated a need to conduct an analysis of myxomycete records to define future lines of work.

Didymium azorellae, a new myxomycete from cushion plants of cold arid areas of South America.

A new species of Didymium (Myxomycetes), D. azorellae, isolated from plant debris in a moist chamber, collected during studies of cold arid areas of Argentina and Peru, is described. It can be distinguished by its small size, the tightly packed layer of lime crystals on the peridium, the very scant, or absent, capillitium, and the unique spore ornamentation, especially by scanning electron microscopy.

A New Classification of the Dictyostelids.

Traditional morphology-based taxonomy of dictyostelids is rejected by molecular phylogeny. A new classification is presented based on monophyletic entities with consistent and strong molecular phylogenetic support and that are, as far as possible, morphologically recognizable. All newly named clades are diagnosed with small subunit ribosomal RNA (18S rRNA) sequence signatures plus morphological synapomorphies where possible.

Morphological and molecular characterization of a new succulenticolous Physarum (Myxomycetes, Amoebozoa) with unique polygonal spores linked in chains.

A new plasmodiocarpic and sporocarpic species of myxomycete in the genus Physarum is described and illustrated. This new species appeared on decayed leaves and remains of succulent plants (Agave, Opuntia, Yucca) growing in arid zones. It differs from all other species in the genus in having polyhedral spores linked in chains like a string of beads, a unique feature within all known myxomycetes.

Nivicolous Stemonitales from the Austral Andes: analysis of morphological variability, distribution and phenology as a first step toward testing the large-scale coherence of species and biogeographical properties.

Nivicolous myxomycetes occur at the edge of spring-melting snow in mountainous areas. They are mostly considered cosmopolitan species morphologically and ecologically uniform across their entire distribution ranges. Thus, long-distance dispersal has been suggested to be the main mechanism shaping their ranges and geographical variability patterns.

Didymium xerophilum, a new myxomycete from the tropical Andes.

A new species of Didymium (Myxomycetes), D. xerophilum, is described, and some details of its life cycle are provided. The new species was collected during studies of arid areas of Argentina and Peru.

Using environmental niche models to test the 'everything is everywhere' hypothesis for Badhamia.

It is often discussed whether the biogeography of free-living protists is better explained by the 'everything is everywhere'(EiE) hypothesis, which postulates that only ecology drives their distribution, or by the alternative hypothesis of 'moderate endemicity' in which geographic barriers can limit their dispersal. To formally test this, it would be necessary not only to find organisms restricted to a geographical area but also to check for their presence in any other place with a similar ecology. We propose the use of environmental niche models to generate and test null EiE distributions.

Perichaena megaspora, a new nivicolous species of myxomycete from the Andes.

A new nivicolous species of Perichaena is described from the Andes in Argentina. The most conspicuous characteristics of Perichaena megaspora are the large spores and their ornamentation in the form of flattened warts. The 16-21 μm diam spores make the new species unique in the genus in which all other species have spores rarely reaching 15 μm diam.

Physarum andinum, a new nivicolous species of myxomycete from the Patagonian Andes.

A new nivicolous species of Physarum was discovered during the study of myxomycetes in the Patagonian Andes of South America. It is described herein under the name Physarum andinum. The species is characterized by stalked sporophores or more rarely sessile sporocarps or short plasmodiocarps.

Ecological niche models reveal the importance of climate variability for the biogeography of protosteloid amoebae.

Habitat availability and environmental preferences of species are among the most important factors in determining the success of dispersal processes and therefore in shaping the distribution of protists. We explored the differences in fundamental niches and potential distributions of an ecological guild of slime moulds-protosteloid amoebae-in the Iberian Peninsula. A large set of samples collected in a north-east to south-west transect of approximately 1000 km along the peninsula was used to test the hypothesis that, together with the existence of suitable microhabitats, climate conditions may determine the probability of survival of species.

Microhabitat and climatic preferences of protosteloid amoebae in a region with a Mediterranean climate.

The role of microhabitat and climate variation in structuring protosteloid amoebae communities has been investigated for the first time in the Mediterranean Basin, a biodiversity hotspot for plants and animals and the largest of the world's five areas with a Mediterranean climate. Abundance data were obtained from natural substrates collected in 13 localities from central Spain, and a total of 1,504 colonies and 18 species were recorded. For this new area, it has been carried out an optimization of the culturing effort based on rarefaction analyses, thus making possible to adapt the protocol to the objectives in future research.

Social amoebae: environmental factors influencing their distribution and diversity across south-western Europe.

The social amoebae (dictyostelids) are the only truly multicellular lineage within the superkingdom Amoebozoa, the sister group to Ophistokonts (Metazoa+Fungi). Despite the exceptional phylogenetic and evolutionary value of this taxon, the environmental factors that determine their distribution and diversity are largely unknown. We have applied statistical modeling to a set of data obtained from an extensive and detailed survey in the south-western of Europe (The Iberian Peninsula including Spain and Portugal) in order to estimate some of the main environmental factors influencing the distribution and diversity of dictyostelid in temperate climates.

Two new species of nivicolous Lamproderma (myxomycetes) from the mountains of Europe and America.

As a result of the revision of European and American collections of genus Lamproderma two new nivicolous myxomycete species, Lamproderma argenteobrunneum and L. kowalskii, are described. The new species are characterized by the silvery-brown sporothecae, the areolate peridium and the ferruginous-brown spores in mass.

Protostelids from deciduous forests: first data from southwestern Europe.

The first data of Protostelids from the southwest of Europe are presented in this paper. A total of 21 species were identified from samples collected in Somiedo Biosphere Reserve (Spain). This is the highest species richness recorded to date for Europe or for a latitude this high (>40 degrees ).

Molecular systematics of dictyostelids: 5.8S ribosomal DNA and internal transcribed spacer region analyses.

The variability and adaptability of the amoebae from the class Dictyosteliomycetes greatly complicate their systematics. The nucleotide sequences of the ribosomal internal transcribed spacers and the 5.8S ribosomal DNA gene have been determined for 28 isolates, and their utility to discriminate between different species and genera has been shown.

The myxomycete genus Schenella: morphological and DNA sequence evidence for synonymy with the gasteromycete genus Pyrenogaster.

The genus Schenella has proven difficult to classify since its description as a new genus in 1911. Macbride placed it with the Myxomycetes but it was unclear with which myxomycete, if any, it should be grouped. Recent identification of abundant samples of Schenella has aided a re-evaluation of its classification as a myxomycete.

Ecological characterization of a tropical myxomycete assemblage--Maquipucuna Cloud Forest Reserve, Ecuador.

The assemblage of myxomycetes (plasmodial slime molds) associated with cloud forests of the Maquipucuna Cloud Forest Reserve in the western Andes was investigated. Within three study sites located along a gradient extending from 1200 to 2700 m above sea level, a clear pattern of decreasing myxomycete diversity and productivity with elevation was apparent. As such, these data conform to the pattern of "reverse diversity" for myxomycetes in the neotropics, with higher diversity for less mesic forest types than for more mesic forest types.