Sabbea gen. nov., a new diatom genus (Bacillariophyta) from continental Antarctica

Phytotaxa ◽  
2019 ◽  
Vol 418 (1) ◽  
pp. 42-56 ◽  
Author(s):  
JORDAN BISHOP ◽  
KATEŘINA KOPALOVÁ ◽  
JOSHUA P. DARLING ◽  
NICHOLAS O. SCHULTE ◽  
TYLER J. KOHLER ◽  
...  

The non-marine diatom flora of the Antarctic Continent includes several endemic taxa recorded over the past 100 years. One of these taxa, Navicula adminensis D.Roberts & McMinn, was described from the Vestfold Hills, East Antarctica. Detailed light and scanning electron microscopy observations have shown that based on its morphological features, the species does not belong to the genus Navicula sensu stricto. To determine the most closely related genera to N. adminensis, the morphological features of Adlafia, Kobayasiella, Envekadea, Stenoneis, Berkeleya, Climaconeis, and Parlibellus were compared with those of N. adminensis. Although each of these genera shows one or more similar features, none of them accommodates the salient morphological characteristics of N. adminensis. Therefore, a new genus, Sabbea gen. nov., is herein described, and Navicula adminensis is formally transferred to the new genus as Sabbea adminensis comb. nov. The genus Sabbea is characterized by uniseriate striae composed of small, rounded areolae occluded externally by individual hymenes, a rather simple raphe structure with straight, short proximal ends and short terminal raphe fissures, open girdle bands with double perforation and a very shallow mantle.

Nematology ◽  
2002 ◽  
Vol 4 (7) ◽  
pp. 875-882 ◽  
Author(s):  
Dieter Sturhan

AbstractBased mainly on an analysis of the host ranges of the species presently placed in Cactodera, sensu lato, and of selected morphological characteristics, an attempt is made to improve the definition of the genus which, after exclusion of C. betulae and C. johanseni, is considered to be monophyletic. The host range of Cactodera, sensu stricto, appears to be restricted to the subclass Caryophyllidae with the ten known species showing an adaptive radiation on host genera in five families of the orders Caryophyllales and Polygonales. This may be a result of co-evolution. Cactodera betulae cannot be assigned to any of the presently recognised genera of cyst-forming nematodes and therefore Betulodera gen. nov. is proposed with B. betulae comb. nov. as the type and only species. The relationship of Betulodera gen. nov. to other genera of Heteroderidae and to some undescribed heteroderid species has still to be evaluated. The new genus is characterised by circumfenestrate cysts with only a slightly protruding vulval cone, three incisures in the lateral field of the second-stage juveniles and presence of phasmids in the males. The hosts are in unrelated plant orders and subclasses. Cactodera aquatica, a species inquirenda, is returned to the genus Heterodera and Heterodera johanseni (Sharma et al. , 2001) comb. nov. is proposed for C. johanseni.


2012 ◽  
Vol 12 (12) ◽  
pp. 32741-32794 ◽  
Author(s):  
E.-M. Kyrö ◽  
V.-M. Kerminen ◽  
A. Virkkula ◽  
M. Dal Maso ◽  
J. Parshintsev ◽  
...  

Abstract. Over Antarctica, aerosol particles originate almost entirely from marine areas, with minor contribution from long-range transported dust or anthropogenic material. The Antarctic continent itself, unlike all other continental areas, has been thought to be practically free of aerosol sources. Here we present evidence of local aerosol production associated with melt-water ponds in the continental Antarctica. We show that in air masses passing such ponds, new aerosol particles are efficiently formed and these particles grow up to sizes where they may act as cloud condensation nuclei (CCN). The precursor vapours responsible for aerosol formation and growth originate very likely from highly abundant cyanobacteria Nostoc commune (Vaucher) communities of local ponds. This is the first time when freshwater vegetation has been identified as an aerosol precursor source. The influence of the new source on clouds and climate may increase in future Antarctica, and possibly elsewhere undergoing accelerating summer melting of semi-permanent snow cover.


2013 ◽  
Vol 13 (7) ◽  
pp. 3527-3546 ◽  
Author(s):  
E.-M. Kyrö ◽  
V.-M. Kerminen ◽  
A. Virkkula ◽  
M. Dal Maso ◽  
J. Parshintsev ◽  
...  

Abstract. Over Antarctica, aerosol particles originate almost entirely from marine areas, with minor contribution from long-range transported dust or anthropogenic material. The Antarctic continent itself, unlike all other continental areas, has been thought to be practically free of aerosol sources. Here we present evidence of local aerosol production associated with melt-water ponds in continental Antarctica. We show that in air masses passing such ponds, new aerosol particles are efficiently formed and these particles grow up to sizes where they may act as cloud condensation nuclei (CCN). The precursor vapours responsible for aerosol formation and growth originate very likely from highly abundant cyanobacteria Nostoc commune (Vaucher) communities of local ponds. This is the first time freshwater vegetation has been identified as an aerosol precursor source. The influence of the new source on clouds and climate may increase in future Antarctica, and possibly elsewhere undergoing accelerating summer melting of semi-permanent snow cover.


2014 ◽  
Vol 46 (6) ◽  
pp. 763-782 ◽  
Author(s):  
Ulrik SØCHTING ◽  
Isaac GARRIDO-BENAVENT ◽  
Rod SEPPELT ◽  
Miris CASTELLO ◽  
Sergio PÉREZ-ORTEGA ◽  
...  

AbstractBased on a combined three locus analysis two new genera,CharcotianaandAmundsenia,are proposed in the lichen familyTeloschistaceae, subfamilyXanthorioideae.Charcotianaincludes the new speciesC. antarctica, which is known only from continental Antarctica. The bipolar genusAmundseniaincludes the new speciesA. austrocontinentalis, which is also known only from continental Antarctica, and the Arctic speciesCaloplaca approximatawhich is here combined into the new genus. The two new genera are phylogenetically distinct, but poor in morphological characters; the new species consist mainly of minute apothecia in cracks of rocks located in the climatically harshest regions of the Antarctic. They are somewhat similar to another continental Antarctic species,Austroplaca frigida,which is described as a new name based on the illegitimate nameCaloplaca frigidaSøchting. The distribution of the four species is mapped.


Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Achim Hiller ◽  
Wolf-Dieter Hermichen ◽  
Ulrich Wand

Radiocarbon dating is an important tool for reconstructing Late Quaternary paleoenvironmental history of the Antarctic continent. Because of the scarcity of datable material, new suitable substances are welcomed. We present here novel paleoenvironmental records—subfossil stomach oil deposits (mumiyo). This waxy organic material is found in petrel breeding colonies, especially in those of snow petrels, Pagodroma nivea. The substance is formed by accumulation and solidification of stomach oil regurgitated for the purpose of defense. We demonstrate and outline the usefulness and limitations of 14C dating mumiyo for determining dates of local ice retreat, moraines and petrel occupation history.


Phytotaxa ◽  
2016 ◽  
Vol 252 (1) ◽  
pp. 31
Author(s):  
ELENA JOVANOVSKA ◽  
ALEKSANDRA CVETKOSKA ◽  
SLAVICA TOFILOVSKA ◽  
NADJA OGNJANOVA-RUMENOVA ◽  
ZLATKO LEVKOV

A new diatom genus, Cribrionella gen. nov., is described from Quaternary sediments of Lake Ohrid. Cribrionella comprises distinct morphological features, such as: i) presence of submarginal alveoli followed by regularly or irregularly arranged areolae, ii) cribra on external areolar openings, iii) absence of silicate layers on internal areolar openings, but presence of thick and inwardly raised circumferential silica trabeculae, iv) rimoportulae positioned on costae, and v) absence of central fultoportulae. Detailed light and scanning electron microscope analyses were undertaken and used for comparison to morphologically related genera. The typus generis Cribrionella ohridana is compared to species from its morphologically closest genus Cyclotella sensu stricto (e.g., C. atomus, C. delicatula, C. bifacialis). Cribrionella ohridana has not been reported from the extant diatom flora of Lake Ohrid, nor in the nearby Lake Prespa. The discovery of a new genus in Lake Ohrid confirms again the importance of the lake, not only in light of species richness and endemicity, but also in evolutionary history of the family Stephanodiscaceae.


Phytotaxa ◽  
2015 ◽  
Vol 208 (2) ◽  
pp. 103 ◽  
Author(s):  
Tyler J Kohler ◽  
KATEŘINA KOPALOVÁ ◽  
BART VAN DE VIJVER ◽  
J. PATRICK KOCIOLEK

A revision of the freshwater diatom genus Luticola from the McMurdo Sound Region, including the McMurdo Dry Valleys and Cape Royds, Antarctica, was made to contribute to a consistent flora for the entire Antarctic Region. Detailed light and scanning electron microscopic observations, review of pertinent literature, and examination of historical and type material lead to the identification of 12 Luticola species. Four new species and one new combination are proposed, including L. bradyi sp. nov., L. spainiae, sp. nov., L. macknightiae, sp. nov., L. transantarctica, sp. nov., and L. elegans, comb. nov. stat. nov. Several of these taxa were previously identified as part of the L. muticopsis (Van Heurck) D.G.Mann complex; Navicula muticopsis f. evoluta W. & G.S. West, L. muticopsis f. reducta (W. & G.S. West) Spaulding, and N. muticopsis f. capitata Carlson, or mistaken for the similar L. mutica (Kützing) D.G.Mann and L. cohnii (Hilse) D.G.Mann. Morphological features of all new species were compared to the closest morphologically similar taxa, and their ecology and biogeography are discussed. All Luticola species considered here show restricted Antarctic distributions, and 8 of the 12 reported species are known only from the Antarctic continent.


2021 ◽  
Vol 97 (1) ◽  
pp. 21-54 ◽  
Author(s):  
Vladislav A. Gorin ◽  
Mark D. Scherz ◽  
Dmitriy V. Korost ◽  
Nikolay A. Poyarkov

The genus Microhyla Tschudi, 1838 includes 52 species and is one of the most diverse genera of the family Microhylidae, being the most species-rich taxon of the Asian subfamily Microhylinae. The recent, rapid description of numerous new species of Microhyla with complex phylogenetic relationships has made the taxonomy of the group especially challenging. Several recent phylogenetic studies suggested paraphyly of Microhyla with respect to Glyphoglossus Günther, 1869, and revealed three major phylogenetic lineages of mid-Eocene origin within this assemblage. However, comprehensive works assessing morphological variation among and within these lineages are absent. In the present study we investigate the generic taxonomy of Microhyla–Glyphoglossus assemblage based on a new phylogeny including 57 species, comparative morphological analysis of skeletons from cleared-and-stained specimens for 23 species, and detailed descriptions of generalized osteology based on volume-rendered micro-CT scans for five species–altogether representing all major lineages within the group. The results confirm three highly divergent and well-supported clades that correspond with external and osteological morphological characteristics, as well as respective geographic distribution. Accordingly, acknowledging ancient divergence between these lineages and their significant morphological differentiation, we propose to consider these three lineages as distinct genera: Microhylasensu stricto, Glyphoglossus, and a newly described genus, Nanohylagen. nov.


Author(s):  
Modest Guţu ◽  
Thomas Iliffe

Leptochelia Vatulelensis(Crustacea: Tanaidacea), A New Species From Anchialine Caves of the South-Western PacificLeptochelia vatulelensisn. sp., discovered on the small islands of Vatulele (Fijian group) and Ouvéa (Loyalty Islands, New Caledonia), is described and illustrated. The new species is distinguished from the others of the"Leptochelia-dubiagroup" (to which it is generally similar) by the following combination of morphological characteristics: (1) the presence of three to four distal setae on the maxilliped basis; (2) merus of pereopods III and IV with only a distosternal seta; (3) endopod of the uropods formed of four (rarely three) articles; (4) males with two (sometimes three) relatively short aesthetascs on the first five articles of the antennular flagellum; (5) male cheliped with a diminished dimorphism; (6) males with a vertical comb-row of setae on the cheliped propodus. Although it inhabits inland, anchialine caves, the new species lacks morphological features that are characteristic of some cave species.


Author(s):  
А. А. Fadeev ◽  
Z. А. Nikonova

The results of study of the 12 year cycle of studies on the only in Russia collection of hops ordinary (Humulus lupulus L.), which contains 250 samples from different regions of Russia and 17 foreign countries. The number of process varieties, composition and origin, it is unique and corresponds to world level. A collection of accessions of hops is a population of female plants with a set of phenological, morphological and economic importance of signs. In the article, the estimation of the collectible varieties of hops at different ripeness groups according to phenological and morphological characteristics according to the method of test for distinctness, uniformity and stability. As the result of the research the Common Hop (Humuluslupulus) sorts were classified in accordance with their maturity time as early maturity (less than 100 days) – 10%, middle-early (101…110 days) – 14, middle duration (111…120 days) – 40, middle-late (121…130 days) – 10% and slow-maturing (more than 130 days) – 26%. Each group has a phenotypic and morphologies features. The early maturity, middle-early and middle duration varieties with vegetative season approximately 120 days are more adaptive to the conditions of the Chuvashia and central part of the Russia and provide obtaining high yield of the hop cones.


Sign in / Sign up

Export Citation Format

Share Document