The taxonomic history of the diatom genus Amphora is one a broad early morphological concept resulting in inclusion diversity taxa, followed by an extended period revision and refinement. introduction molecular systematics has increased pace largely resolved relationships between major lineages, indicating homoplasy evolution amphoroid symmetry. Within two largest monophyletic Halamphora now taxonomically refined , intrageneric ecological have yet to be explored within phylogenetic...

This study seeks to determine the phylogenetic position of diatom genus Rhoicosphenia. Currently, four hypotheses based on morphology siliceous valve and its various ultrastructural components, sexual reproduction, chloroplasts have been proposed. Two previous morphological studies tentatively placed Rhoicosphenia near members Achnanthidiaceae Gomphonemataceae, no molecular completed. The as sister 'monoraphid' diatoms is problematic due apparent non-monophyly that group, so monophyly are...

Diatoms are the most diverse lineage of algae and at base aquatic food webs, but only 11 their mitochondrial genomes have been described. Herein, we present six diatom species, including: Melosira undulata, Nitzschia alba, Surirella sp., Entomoneis Halamphora coffeaeformis, calidilacuna. Comparison these to currently published revealed a novel ubiquitous feature block consisting tatC-orf157-rps11. The presence intronic retrotransposable elements in barcoding region cox1 may explain historic...

The diatom genus Diprora (Bacillariophyceae) was described from a cave on Kauaʻi, Hawaiʻi. Due to its lack of raphe system and bilateral symmetry, the first assigned Fragilariophycidae ('araphid diatoms'), but systematic affinities were undetermined. We present three-gene phylogeny, based nuclear (SSU rDNA) chloroplast (rbcL, psbC) genes, determine phylogenetic relationships in tree life. concatenated multi-gene phylogenies, individual genes trees show nest deep within raphid diatoms,...

Background and aims – With the advent of molecular techniques to analyze relationships among diatom genera came realization that complex canal raphe system has evolved in at least two separate lineages, Bacillariales Rhopalodiales + Surirellales. One genus with a system, Denticula, is small, but morphologically diverse group species whose systematic position been debated since its description. Methods Presented here documentation valve girdle band morphology D . kuetzingii, tenuis, valida,...

Background and aims – We examine the possibility of independent evolution same features multiple times across pennate diatom tree life.
 Methods key results Features we have studied include symmetry, raphe number amphoroid symmetry. Phylogenetic analysis, with both morphological molecular data suggest in each these cases that evolved from 5 to 6 independently. also look at certain having once diagnosing large genera diatoms, suggestive an adaptive radiation such as Mastogloia, Diploneis...

Diatoms are the most diverse lineage of algae, but diversity their chloroplast genomes, particularly within a genus, has not been well documented. Herein, we present three genomes from genus Halamphora (H. americana, H. calidilacuna, and coffeaeformis), first pennate diatom to be represented by more than one species. ranged in size ~120 150 kb, representing 24% difference genus. Differences genome were due changes length inverted repeat region, intergenic regions, variable presence ORFs that...

Amphora Ehrenberg ex Kützing sensu lato incorporates a large and diverse group of diatoms. Although having its greatest taxonomic diversity in marine environments, inland waters the USA appear to hold amount undescribed taxa requiring thorough investigation. Presented here are descriptions illustrations seven new species collected from western USA, based on light scanning electron microscope observations. Species described include A. copulatoides, manifesta waldeniana genus subgenus H....

SUMMARY We describe a new genus and species of the diatom family Stephanodiscaceae with light scanning electron microscopy from Libo Small Hole, County, Guizhou Province, China. Edtheriotia guizhoiana gen. & sp. nov. has striae across valve face varying lengths, are composed fine towards margin onto mantle. Many round to stellate siliceous nodules cover exterior valve. External fultoportulae opening short tubes; rimportula lacks tube. Internally hyaline rim is positioned near margin....

The raphid diatom genus Amphora has been subject to considerable revision over the previous 30 years, with many species transferred newly created or existing genera. Despite these efforts, recent work demonstrated that taxa presently assigned continue be non-monophyletic and further is required. This investigation re-examines Mereschkowsky's Tetramphora, which he described as including all four chloroplasts, arranged in pairs linked by large pyrenoids. Although largely ignored last 100 shown...

Summary Cymbellonitzschia is a small genus of canal raphid diatoms within the B acillariales reported from both freshwater and coastal marine environments. The characterized by its distinct dorsiventral or ‘cymbelloid’ valve outline with raphe either on dorsal or, more commonly, along ventral margin. Of six currently described species only two representatives, type name C . minima widely diluviana , have received detailed morphological treatments. This lack understanding diversity group...

We describe a new diatom species of the genus Eunotia from karst pond in Maolan Town, area Moalan Nature Reserve, Guizhou Province, China, using light and scanning electron microscopy. The is similar to sudetica, differing size shape valves. Externally, has striae contained shallow, irregularly-shaped channels individual areolae have narrow openings due presence rimmed occlusions. A large external opening rimportula occurs at one end each valve. Internally, alveoli covering areolae, are...

The prairie pothole region of North America is characterized by a large number lakes and wetlands created during the last glacial retreat. These waterbodies are their generally small sizes (70% less than 0.4 ha), high densities (as many as 40 km −2) elevated but variable conductivities, ranging between 230–70,000 µS cm−1. Although this boasts great diversity habitats, few studies have investigated diatom present. Presented here descriptions illustrations three new species from genus...

The potential for algal-derived lipid products has been well documented and, therefore, garnered considerable research attention over the last 30 years. Although promising, many hurdles remain in strain selection, optimization and enhancement commercial production of these products. As this field moves away from coarse screening efforts that characterized early into focused investigations evolution, comparative genetics genetic engineering, measures accumulation are directly comparable...

:The genus Amphora is a large and widely distributed group of raphid diatoms, frequently found in fresh, brackish, salt water environments from around the world. Presented here description phylogenetic position aliformis, new species collected Banzu Flats, Tokyo Bay, Japan. This has unique morphology, with features seldom or never before observed within Amphora, such as dorsal marginal wing ventral apical pores, well an early diverging lineage genus. As many diverse groups evidence called...

AbstractSince its description the amphoroid diatom Amphora thumensis has confounded simple taxonomic classification having been assigned to Amphora, Cymbella, and now Halamphora. Taxonomic ambiguity around this taxon stems from small size reduced, often contradictory, morphological features. In investigation, we confirm position of A. by presenting a four-marker molecular phylogeny for population collected spring-fed lake in Rocky Mountains Colorado, USA. Our phylogenetic hypothesis places...