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 purpose of this study was to present LM and SEM observations Nitzschia taxa encountered on the South Shetland Islands James Ross Island.During ongoing taxonomical revision freshwater limno-terrestrial diatom flora Island (Maritime Antarctic Region) eight unknown belonging genus were found.These previously forcefitted into European names such as N. commutata or perminuta, but detailed light scanning electron microscopical allowed their separation from already known resulted in description...

The goal of this study was to compare the ability morphology and molecular-based surveys estimate species richness for two species-rich diatom genera, Chaetoceros Ehrenb. Thalassiosira Cleve, in Bay Fundy. Phytoplankton tows were collected from sites at intervals over years subsampled morphology-based (2010, 2011), a culture-based DNA reference library (DRL; 2010), survey (2011). DRL utilized 3′ end RUBISCO large subunit (rbcL-3P) identify genetic groups (based on 0.1% divergence rbcL-3P),...

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,...

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...

Abstract High‐sulfur, low‐oxygen environments formed by underwater sinkholes and springs create unique habitats populated microbial mat communities. To explore the diversity biogeography of these mats, samples were collected from three sites in Alpena, Michigan, one site Monroe, Palm Coast, Florida. Our study investigated previously undescribed eukaryotic further explored their bacterial Mat water parameters sulfur spring during spring, summer, fall 2022. Cyanobacteria diatoms cultured...

Light microscope (LM) observations of specimens Rhopalodia constricta (W.Smith) Krammer are made from the holotype slide. LM and scanning electron (SEM) Rabenhorst's material this species also presented. The two populations similar in size ornamentation. Many features seen SEM presented here for first time, including documentation valve interior girdle bands. A flap valvocopula extends onto exterior at apices covers raphe end-this is time feature has been documented Rhopalodiales. compared...

ABSTRACT Fifteen stream segments in an acid mine drainage (AMD) impacted basin were sampled for periphyton, measured water chemistry and evaluated physical habitat June, August October order to assess quality. Periphyton index of biotic integrity (PIBI) scores individual varied among sampling dates, with the June being significantly different (p<4.05). The PIBI correlated six variables at least one variable indicative AMD October. However, metrics generally not measures habitat. Non-metric...

Limited molecular data for marine tube-forming diatoms are available currently and this study provides the first survey of these taxa. To conduct survey, we used a molecular-assisted alpha taxonomy (MAAT) approach that utilizes DNA barcode data. We three markers: 3´ end large subunit RUBISCO (rbcL-3P); variable D2/D3 region nuclear ribosomal (LSU D2/D3); internal transcribed spacer 2 (ITS2) to assign from Canada genetic species groups. The rbcL-3P analysis uncovered 29 groups including...

As sentinels of climate change and other anthropogenic forces, freshwater lakes are experiencing ecosystem disruptions at every level the food web, beginning with phytoplankton, a highly responsive group organisms. Most studies regarding effects on phytoplankton focus potential scenario in which temperatures continuously increase droughts intersperse heavy precipitation events. Like much conterminous United States 2019, Muskegon River watershed (Michigan, USA) experienced record-breaking...

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 contest the recently reported findings that suggest presence of female gametangia in North American range invasive macroalga Nitellopsis obtusa (Harrow-Lyle, T.J., Ginn, B.K., Kirkwood, A.E., and Melles, S.J. 2023. First report starry stonewort ( obtusa) America. Botany, 101: 61–64. doi:10.1139/cjb-2022-0096). The claims do not clearly show identifying morphology N. gametangia, are inconsistent with known characeaen developmental biology, provide evidence commensurate such a claim. More...

Denticula costata Hustedt was originally described from fossil material Sumatra and later assigned to the genus Tetralunata. Although Tetralunata thought be endemic Indonesia, D. has been reported wetwalls South Africa. This disparity in locality prompted us investigate Africa further. (now T. costata) specimens species were different size, shape, structure of raphe system. These differences, as well comparisons other species, allowed determine that African have not previously. Valve...

Cyanobacteria are diverse prokaryotic, photosynthetic organisms present in nearly every known ecosystem. Recent investigations around the world have recovered vast amounts of novel biodiversity seldom sampled habitats. One phylogenetically significant character, secondary folding structures 16S-23S ITS rDNA region, has allowed an unprecedented capacity to erect new species. However, two questions arise: Is this feature as informative is proposed, and how do we best employ these features?...

The influences of intensity and repeated exposure to ultraviolet-B radiation (UVB), photoreactivating repair (PRR), temperature on the scuticociliate Parauronema acutum were explored under laboratory conditions. Population growth was negatively affected after equivalent one sunny summer day ambient UVB, especially in absence PRR. Repeated daily UVB severely compromised ciliate survival. UVB-exposed treatments without PRR recovered slower reached lower final abundances than receiving Reducing...