Rediscovery of an unusual chytridiaceous fungus new to the order Rhizophydiales

The newest order in Chytridiomycota, Rhizophydiales, shows remarkable genetic divergence and zoospore ultrastructural diversity. From submersed mud from a marsh near an oligotrophic lake in the Patagonia region of Argentina, we isolated a previously undescribed chytrid in Rhizophydiales with unique 28S rRNA and ITS1-5.8S-ITS2 sequences and a distinctive zoospore and thallus. In a combined LSU + 5.8S phylogeny of representative taxa in the order, the nearest relative to this new species is Rhizophlyctis harderi, and their zoospores share several similar character states. A new genus is erected for this chytrid, the first to be brought into pure culture from this region.     

Ultrastructural and molecular phylogenetic delineation of a new order,the Rhizophydiales (Chytridiomycota)

In the order Chytridiales, Rhizophydium is a morphologically defined genus based upon the production of a monocentric, inoperculate, epibiotic sporangium, an endobiotic rhizoidal axis which branches, and an epibiotic resting spore. Despite its simple morphology, over 220 species of Rhizophydium have been described. Recent phylogenetic analyses using nuLSU rRNA (28 S rRNA) gene sequences of a geographically diverse sampling of Rhizophydium cultures revealed that the classical genus Rhizophydium is genetically more variable than previously understood and actually represents multiple genera. In the present study, we use zoospore ultrastructural characters and 28 S rRNA and 5.8 S ribosomal gene sequences of 96 isolates in culture to circumscribe the monophyletic Rhizophydium clade as a new order, Rhizophydiales. Correspondingly, zoospores of members of the Rhizophydiales exhibit a unique suite of ultrastructural character states that further define the order and distinguish it from the order Chytridiales. Molecular analyses reveal several strongly supported clades within the Rhizophydiales. Three of those clades encompass a broad range of isolates and are defined as new families Rhizophydiaceae, Terramycetaceae, and Kappamycetaceae. To resolve close relationships within Terramycetaceae, combined 28 S rRNA and ITS1–5.8 S–ITS2 sequences were analysed and details of zoospore ultrastructural character states determined, with two new genera, Terramyces and Boothiomyces, described. Two species formerly classified in Rhizophydium are transferred to the new genera. This work provides a framework for additional taxonomic revisions within the new order Rhizophydiales and compares genetic variation useful in defining genera, species, and populations within this lineage of chytrids. A broader sampling of representatives is needed before taxonomic decisions can be made for remaining clades within the Rhizophydiales.     

The anamorphic genus Calcarisporiella is a new member of the Mucoromycotina

The phylogenetic position of the anamorphic genus Calcarisporiella was investigated. Three isolates of Calcarisporiella, including an authentic strain and a newly obtained isolate, were analyzed phylogenetically using rDNA sequences. The result indicated that Calcarisporiella, which was classified as an ascomycetous anamorph, is a member of Mucoromycotina. It formed an independent clade separated from the other known orders of this subphylum.     

Smeagolida,a new order of gymnomorph mollusc from New Zealand based on a new genus and species

Abstract

Smeagol manneringi n.gen. & sp. is erected as the only known representative of a new order, Smeagolida, and is compared with existing gymnomorph orders. The relative ranking of Gymnomorpha, Opisthobranchia, and Pulmonata is discussed, and use of the name Systellommatophora is abandoned. The gymnomorph slugs are interpreted as a polyphyletic assemblage of stem euthyneurans, but subclass Gymnomorpha is retained as a convenient grouping.     

Halteromyces,a new genus in the Mucorales

Halteromyces radiatus is described as a new genus and species in the order Mucorales. The genus is referred to the family Mucoraceae and has close affinities to the genusAbsidia. The fungus grows readily in pure culture. The asexual structures are described; no sexual structures have been found despite extensive contrasts with members of the genusAbsidia andGongronella.     

Colipila, a new genus in the Helotiales

Colipila, a new member of the Helotiales, is erected for two previously undescribed lignicolous species resembling Dasyscyphella and Lachnum by macroscopy. Species of Colipila are characterized by their long, entirely smooth, hyaline, thin-walled, multiseptate, subulate to basally fusoid hairs that tend to be curved on the stipe and lower flanks, and dimorphic, partly strongly protruding paraphyses which closely resemble the hairs. The type species, C. masduguana, is recorded repeatedly in southern France on rotten decorticated branches and trunks of Castanea sativa on the moist forest floor in sub-Mediterranean regions with siliceous soils, but also once on Quercus robur in a temperate forest with calcareous soil. The second species, C. pilatensis, was found on wood of an unidentified member of Rosaceae in a calcareous region of the Northern Alps and is known only from the holotype. The phylogenetic position of C. masduguana within the Helotiales was not resolved based on the analysis of nuclear LSU ribosomal DNA sequences. A key to the species of Colipila is provided.     

Herbstia,a new genus in the Amaranthaceae

Herbstia, a new monotypic, Brazilian genus of Amaranthaceae is proposed for the taxon heretofore known asChamissoa brasiliana (Moquin) Fries. It differs fromChamissoa in its exarillate seeds and structurally indehiscent fruit, and from the South IndianIndobanalia, in which genus Moquin originally placed it, in habit and in the strictly axillary cymules of flowers.     

Heterorepetobasidium, a new genus in the Auriculariales

A new genus, Heterorepetobasidium, is proposed to accommodate two new species, H. subglobosum and H. ellipsoideum, recently collected in Taiwan. These species have apically, partially septate basidia, strongly swollen sterigmata, and repetobasidia. The systematics of the new taxa and related ones, inclusive of Ceratobasidium and the Ceratobasidiaceae, are reinterpreted.     

Siepmannia, a new genus in the Mucoraceae

A new genus Siepmannia of the Mucoraceae family is described. Siepmannia pineti sp. nov. and S. lariceti sp. nov. were isolated from forest soils in Poland. The species were differentiated on the basis of morphology and ITS1/2 rDNA sequencing. Siepmannia pineti and S. lariceti are identical in some aspects. Both show distinct morphological dimorphism in culture depending on conditions of growth and exhibit distinct mycotrophism manifested by sporulation in the presence of other fungi. Their morphological elements are minute. The phylogenetic grouping of Siepmannia with Absidia parricia and A. zychae leads to the creation of two new combinations, S. parricida and S. zychae.     

Paraulopidae and Paraulopus, a new family and genus of aulopiform fishes with revised relationships within the order

A species group hitherto concealed within Chlorophthalmus (Chlorophthalmidae) is described as a new family and genus of Aulopiformes, Paraulopidae and Paraulopus, respectively. Paraulopus clearly belongs in Aulopiformes owing to an enlarged uncinate process on the second epibranchial, the absence of a swimbladder, and fusion of the medial processes of the pelvic girdle, but characterized by having the following combination of characters: the fourth basibranchial with a long tail but no gap separating fourth basibranchial and fifth ceratobranchial, epipleural bones distributed from posterior portion of abdominal vertebra to anterior portion of caudal vertebra, and flesh specimens of most species with paired olive spots dorsally on body. The phylogenetic position of Paraulopus is defined by a cladistic analysis of 101 morphological characters, in 21 genera of Aulopiformes. In a single most parsimonious tree, Paraulopus and Chlorophthalmus are in two different major clades, there being four major clades in all, roughly corresponding to the four suborders of Aulopiformes. Paraulopidae is included in the suborder Synodontoidei. In addition, Bathysauroides is transferred to Chlorophthalmoidei from Giganturoidei, and Bathysauroides and Bathysauropsis are elevated to familial status. Received: January 13, 2001 / Revised: September 27, 2001 / Accepted: October 15, 2001     

Zopfochytrium is a new genus in the Chytridiales with distinct zoospore ultrastructure

While surveying chytrid diversity in lakes and streams, we found on cellulosic bait a chytrid that had both monocentric and polycentric thallus forms. We brought this chytrid into axenic culture from three sites in eastern North America, studied its thallus development and zoospore ultrastructure, and compared its 28S rDNA sequence with those of other members of the Chytridiomycota. Thallus morphology matched that described for the rare chytrid, Cladochytrium polystomum Zopf. Sporangia were spherical and produced numerous long discharge tubes. After discharge, zoospores remained in spherical clusters at the tips of the inoperculate openings of discharge tubes. After 10–30 min zoospores either swam away or encysted in place. Zoospore ultrastructural features included a cell coat, flagellar plug, and paracrystalline inclusion, features typical of members of the Chytridiales. However, the flagellar apparatus structure and organellar organization differed from that of zoospores previously described. Based on its molecular phylogeny and its zoospore ultrastructural features, we classify C. polystomum as a member of the Chytridiaceae in the Chytridiales. Because its thallus development and its ribosomal DNA sequences diverged decidedly from those of Cladochytrium tenue Nowak, the type species of Cladochytrium, we erected Zopfochytrium as a new genus for this chytrid.     

Utriascus, a new ascomycetous genus in the Sordariales

The new monotypic genus Utriascus is described from wood of Ulmus glabra in the ?umava Mts. National Park, Czech Republic. It is characterized by superficial, setose ascomata, unitunicate, saccate, and long-pedunculate asci that lack any discharge mechanism in the apex and one-celled, dark pigmented ascospores enclosed in a hyaline ornamented sheath. Utriascus is classified in the Sordariales.     

Endomelanconiopsis, a new anamorph genus in the Botryosphaeriaceae

A new lineage is discovered within the Botryosphaeriaceae (Ascomycetes, Dothideomycetes, incertae sedis). Consistent with current practice of providing generic names for independent lineages, this lineage is described as Endomelanconiopsis gen. nov., with the anamorphic species E. endophytica sp. nov. and E. microspora comb. nov. (= Endomelanconium microsporum). Endomelanconiopsis is characterized by eustromatic conidiomata and holoblastically produced, brown, nonapiculate, unicellular conidia, each with a longitudinal germ slit. Phylogenetic analysis of partial sequences of LSU, ITS and translation elongation factor 1 alpha (tef1) indicate that E. endophytica is sister of E. microspora and that they are nested within the Botryosphaeriaceae. However because there is no support for the "backbone" of the Botryosphaeriacae we are not able to see the interrelationships among the many genera in the family. Neither species is known to have a teleomorph. Endomelanconiopsis differs from Endomelanconium because conidia of the type species of Endomelanconium, E. pini, are papillate at the base, conidiogenous cells proliferate sympodially and the pycnidial wall is thinner; we postulate that the teleomorph of E. pini as yet unknown is an inoperculate discomycete. Endomelanconiopsis endophytica was isolated as an endophyte from healthy leaves of Theobroma cacao (cacao, Malvaceae) and Heisteria concinna (Erythroplaceae) in Panama. Endomelanconiopsis microspora was isolated from soil in Europe.     

Punctelia, a new lichen genus in the Parmeliaceae

The genus Punctelia Krog gen. nov., comprising subgen. Punctelia (the Parmelia borreri group) and subgen. Flavopunctelia Krog subgen. nov. (the Parmelia flaventior group), is here segregated from Parmelia s. str. The main differences between the two genera lie in the development of the pseudocyphellae, the chemical properties of the medulla, and the centres of distribution. Parmelia s. str. has its highest number of species in East Asia and the Australian region, Punctelia in the Americas and Africa.