| 1. |
- Cavender, J. C., et al.
(författare)
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Distribution and ecology of dictyostelids in Madagascar
- 2021
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Ingår i: Phytotaxa. - : Magnolia Press. - 1179-3155 .- 1179-3163. ; 505:2, s. 176-186
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Tidskriftsartikel (refereegranskat)abstract
- Samples for isolation of dictyostelid cellular slime molds were obtained from 20 collecting sites at 18 localities in south central and southeastern Madagascar during May 2009. At least thirty species of dictyostelids representing seven genera were recovered from 52 samples of soil/humus. This total included 17 species described as new to science, 13 species already known from various localities throughout the world, and four isolates that remain unidentified. Fourteen of the new species isolated from these samples are members of the whorl-branched, light-spored genus Heterostelium (formerly Polysphondylium). The overall level of species richness of dictyostelids in Madagascar is greater than what is known for all of mainland Africa sampled to date. Levels of biodiversity in Madagascar were higher for mesic than for xeric vegetation types, and each of the newly described species of Heterostelium appeared to have a limited distribution among the localities sampled.
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| 2. |
- Cavender, James C., et al.
(författare)
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New small dictyostelids from seasonal rainforests of Central America
- 2013
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Ingår i: Mycologia. - : Informa UK Limited. - 0027-5514 .- 1557-2536. ; 105:3, s. 610-635
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Tidskriftsartikel (refereegranskat)abstract
- Ten small dictyostelids isolated from samples collected from the surface humus layer of seasonal rainforests of Belize and Guatemala were studied morphologically, and nine were found to represent distinct species, all with an average height of < 2 mm (0.5-3.5 mm). Although their fruiting bodies (sorocarps) closely resemble one another, the nine species differ in their patterns of aggregation, stream pattern, branching development, formation of microcysts, spore shape, presence or absence of spore granules and their distribution, as well as in the shapes and behavior of their sorogens and myxamoebae. These stable morphological features were sufficient to recognize nine new species of small dictyostends, one with two varieties. SSU rDNA sequences were generated for all these new isolates, and phylogenetic analyses of these sequences show these new isolates belong to Dictyostelid group 3. As a result of this and other recent studies, the concept of what constitutes a species in the dictyostelids has become much more restricted and well defined, in as much as some of the morphological and behavioral patterns now being observed were overlooked in the past. The extent, flow direction and conformation of streaming within the group varies from simple aggregation mounds with no streams to short streams, to somewhat longer streams and finally to well developed streams. Each of these is characterized by a particular set of distinguishing features.
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| 3. |
- Perrigo, Allison L., et al.
(författare)
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Additional new species suggest high dictyostelid diversity on Madagascar
- 2020
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Ingår i: Mycologia. - : Informa UK Limited. - 0027-5514 .- 1557-2536. ; 112:5, s. 1026-1042
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Tidskriftsartikel (refereegranskat)abstract
- Dictyostelids are a monophyletic group of sorocarp-forming social amoebae in the major eukaryotic division Amoebozoa. Members of this taxon, which is made up of almost 200 described species, are common in terrestrial soils globally. Still, the alpha diversity is not well known in many areas, and new species are frequently recovered. The highest species richness is found in the tropics. Here, five new species are described from soil samples collected in Madagascar. These species-Cavenderia basinodulosa, C. canoespora, Heterostelium radiatum, H. versatile, andRaperostelium stabile-are described based on both morphological characteristics and molecular data, with sequence data from the rDNA small subunit (SSU). The five new species are morphologically disparate, ranging from relatively small, robust taxa such asR. stabileto taxa with variable morphologies such as the largerH. radiatumandH. versatileand the yellow-tinted and irregularly branched speciesC. canoesporaandC. basinulosa. These new species, together with earlier work where 13 other species were described from the island, suggest that there is a range of genetically diverse and highly morphologically variable dictyostelid taxa occurring on Madagascar, suggesting biogeographic patterns even within these very small organisms.
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| 4. |
- Sheikh, Sanea, et al.
(författare)
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A New Classification of the Dictyostelids
- 2018
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Ingår i: Protist. - : Elsevier BV. - 1434-4610 .- 1618-0941. ; 169:1, s. 1-28
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Tidskriftsartikel (refereegranskat)abstract
- 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. The two major molecular clades are given the rank of order, as Acytosteliales ord. nov. and Dictyosteliales. The two major clades within each of these orders are recognized and given the rank of family as, respectively, Acytosteliaceae and Cavenderiaceae fam. nov. in Acytosteliales, and Dictyosteliaceae and Raperosteliaceae fam. nov. in Dictyosteliales. Twelve genera are recognized: Cavenderia gen. nov. in Cavenderiaceae, Acytostelium, Rostrostelium gen. nov. and Heterostelium gen. nov. in Acytosteliaceae, Tieghemostelium gen. nov., Hagiwaraea gen. nov., Raperostelium gen. nov. and Speleostelium gen. nov. in Raperosteliaceae, and Dictyostelium and Polysphondylium in Dictyosteliaceae. The “polycephalum” complex is treated as Coremiostelium gen. nov. (not assigned to family) and the “polycarpum” complex as Synstelium gen. nov. (not assigned to order and family). Coenonia, which may not be a dictyostelid, is treated as a genus incertae sedis. Eighty-eight new combinations are made at species and variety level, and Dictyostelium ammophilum is validated.
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