Diana Wrigley de Basanta

The biodiversity of myxomycetes in central Chile

The results obtained from two expeditions to survey the biodiversity of myxomycetes in Central Chile are reported in this paper. The surveys were carried out as part of Global Biodiversity of Eumycetozoans project funded by the National Science Foundation (USA) and the Myxotropic project funded by the Spanish Government. The expeditions were made to the temperate zone of the central part of the country between 23° and 39° South latitudes, which is characterized by Mediterranean vegetation, as well as to the transition areas between the arid and semi-arid regions of northern Chile, and the humid, cold Valdivian and Andean-Patagonian forests of the far South. Eight of the fifteen regions of the country, from Antofagasta to Araucanía, in selected areas where the native vegetation is well preserved, were included in these surveys. Over 600 collections were obtained, and a total of 110 species of myxomycetes representing 29 genera have been identified. Two of these (Dianema succulenticola, Didymium chilense) are species new to science and are described in this paper, 12 species (Collaria nigricapillitia, Comatricha alta, Cribraria oregana, Dianema depressum, Didymium eximium, D. nivicolum, Enerthenema melanospermum, Lepidoderma chailletii, Macbrideola ovoidea, Physarum clavisporum, Ph. newtonii and Trichia alpina) were previously unknown for either the Neotropics or South America, and 49 additional species are new records for Chile. Comments are provided on the morphology, distribution and ecology of selected species and light and SEM micrographs of the most significant species are included. An evaluation of the biodiversity of myxomycetes in Chile, with special emphasis on the endemic plants that provided the substrates with which they were associated, and a comparative analysis of our results with those from other countries of South America is presented.

Biodiversity of myxomycetes in subantarctic forests of Patagonia and Tierra del Fuego, Argentina

A biodiversity survey for myxomycetes was carried out in Patagonia and Tierra del Fuego (Argentina) in late January and early February 2005. Specimens were collected from six National Parks, located in five different provinces between 39° and 55°S latitude. Nothofagus forests represented the primary vegetation type investigated, but Valdivian temperate rainforests also were included in the survey, as were coniferous forests dominated by species of Araucaria, Astrocedrus and Fitzroya. More than four hundred (442) specimens of myxomycetes representing 67 different species in 23 genera were collected either in the field, or from moist chamber cultures prepared with samples of bark and litter obtained from the same collecting sites. The total species list generated from both the field and laboratory components of the survey includes six new records for South America and 13 new records for Argentina. Two species of the genus Diderma, D. gracile and D. robustum, described originally from Tierra del Fuego 35 years ago and not reported since, were among the more interesting collections. A third species of the genus, D. antarcticum, found only once since its description in 1887, was found for the third time in the world during the survey. These collections were compared to the type material deposited in La Plata, Argentina (LPS) and the first photographs of these species by LM and SEM are included. Ecological comments are made on how macroenvironmental factors as well as microhabitats, influence patterns of myxomycete distribution.

Biodiversity studies of myxomycetes in Madagascar

The results of the first comprehensive study of myxomycetes from the island of Madagascar, a world biodiversity hotspot, are reported in this paper. The island is of continental origin, the fourth largest in the world, and has been geographically isolated for more than 160 million years, since its separation from Gondwanaland. The isolation, size and topography of Madagascar have triggered the development of a great variety of different habitats and favoured multiple evolutionary pathways, resulting in many animals and plants that exist nowhere else on earth. Fieldwork for the biodiversity survey of the central and southern parts of the island took place in May 2009, to coincide with the end of the rainy season. Tropical moist forest, sclerophyll forest and dry forest were selected for sampling in Ranomafana, Andringitra, Andohahela and L’Isalo National Parks. Some unique vegetation was sampled in the spiny dry forest and succulent scrub with plants from the genera Alluaudia, Euphorbia, Kalanchoe and Pachypodium. The survey produced 124 species from 22 different genera in more than 750 myxomycete collections. In this paper one species, Perichaena madagascariensis, is described as new to science, 21 species are new records for Africa, and 106 are reported for the first time from Madagascar. Some unusual collections included Physarum lakhanpalii that appeared on Ravenala madagascariensis, Fuligo intermedia and Licea nannengae found on Adansonia grandidieri, Perichaena pulcherrima, Physarum dictyosporum, and P. echinosporum on Euphorbia and Licea rufocuprea on bark. The scope, methods and results of this survey are included in this paper, and comments are made on the ecology, distribution and substrate association of the myxomycetes of these areas of Madagascar. Macrographs, micrographs and SEM images of interesting species are included. The results indicate that the island of Madagascar has a unique assemblage of species of myxomycetes, different from neighbouring islands and from similar but distant environments.

Biogeographic patterns of the myxomycete biota of the Americas using a parsimony analysis of endemicity

Myxomycetes are microorganisms frequently considered to be of cosmopolitan distribution, however as studies in unexplored areas have intensified, more information has become available on the patterns of distribution of these organisms, but no historical or cladistic biogeographic approaches have been applied to understand such patterns. In this study a parsimony analysis of endemicity (PAE) was used in order to generate a preliminary hypothesis on the biogeographic relationships of 13 American areas in which a well-known myxomycete biota exists. In general terms the hypotheses of the relationship between the myxomycete assemblages of areas used in this study agree with those reported for other groups of organisms. They appear to show that a historical-geographic pattern influences the distribution of myxomycetes as much as environmental factors. Three main clades were found in the analysis, with the first one including the two subantarctic localities, the second one representing the South American transition zone and the last one including all the Neotropical and Nearctic areas, but arranged into two subclades, one with the arid areas and the other with the tropical and temperate humid areas. Each clade or subclade in the cladogram is supported by the presence of several morphospecies, some of which appear to represent endemic species restricted to specific geographic areas. The results of this analysis are proposed as a working hypothesis that can perhaps be supported in the future with new data from other complementary regions of America or with more intense surveys in the areas already explored. They are inconsistent with the hypothesis of cosmopolitan distribution for these microorganisms, as they appear to indicate groups of species that are restricted to certain geographic areas, some of which may be endemic, such as those from the subantarctic forests of South America, those found exclusively in the South American arid areas or those that have been recently described from arid areas of North America.

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. They differ from one another mainly in spore size and ornamentation, the form of the capillitium and the stalk length and ratio of the stalk length to the total height of the sporocarp. The morphology of the new species was examined with light microscopy and scanning electron microscopy (SEM), and micrographs of relevant details are included. Lamproderma argenteobrunneum also was obtained in moist chamber culture, and the mature sporocarps displayed all features typical of field-collected samples. The known geographical distribution of L. argenteobrunneum includes the main ranges of the European alpine system (Alps, Carpathians, Pyrenees) as well as those of North America, while L. kowalskii has been recorded so far from several sites in California in the United States.

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. It can be distinguished by the persistent funnel-shaped invagination of the peridium, the top of which appears as a deep umbilicus in closed sporothecae, and the calcareous hypothallus shared among several sporocarps. This combination of characters, with a circumscissile dehiscence of the sporotheca and a cream stalk packed with rhombic lime crystals, is unknown in other described species. Morphology was examined with scanning electron microscopy and light microscopy, and micrographs of relevant details are included here. Phylogenetic analysis with 18S rDNA sequences of different species of Didymium supports the distinct identity of this new species. Some collections of this myxomycete were made at up to 4600 m, an altitude almost unknown for this group of microorganisms.

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. Twenty-two collections were found in the field during two consecutive years at 10 localities in Mendoza province Argentina, including one collection isolated from a moist chamber culture of ground litter. The new species was examined under stereomicroscope, light microscope and scanning electron microscope and micrographs of relevant details are included.

Licea metallica, a new myxomycete from Laos

A new sessile species of myxomycete in the genus Licea is described and illustrated. This new species (Licea metallica) appeared in moist chamber cultures on samples of bark collected from two different unidentified trees in Laos. It differs from all other species in the genus in having subglobose iridescent sporocarps with both a pale apical disc of refuse material and a cylindrical mound of refuse material at the base. The spores are reddish brown, totally smooth and characterized by a spore wall with a thinner area that takes up almost half the spore diameter. Micrographs of these and other relevant features of the new species are presented.

Myxomycetes in Education: The Use of These Organisms in Promoting Active and Engaged Learning

Abstract The potential for using myxomycetes in education is enormous. They are safe, nontoxic, hypoallergenic living microorganisms that can serve as excellent model organisms in a variety of educational settings. Their indisputable importance in the correct functioning of any terrestrial ecosystems underlines the importance of including them whenever possible. The fact that they are an inexpensive, locally available resource, irrespective of location, means that myxomycetes are a group with unique didactic advantages. Some of the educational opportunities afforded by these visible protists, principally those examples used by the coauthors, are described in this chapter. Some simple techniques for classroom use, examples of literature relating to the educational uses of myxomycetes, and information on how to photograph these organisms are also included.

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

ABSTRACT 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. The species developed on dead leaves of cushion plants growing in the extremely harsh environments of the central Andean puna at almost 5000 m elevation and the Andino-Patagonian steppe. Morphology was examined with scanning electron microscopy and light microscopy, and micrographs of relevant details are included here. In order to confirm the identity of the new species described in this paper, a molecular study was conducted based on partial sequences of both the 18S rRNA and the elongation factor 1-alpha gene. Phylogenetic analysis including two specimens from different countries of the newly described species, Didymium azorellae, strongly supports the grouping of these specimens as a separate clade from the rest of the analyzed species.