Review of the genus Phormidesmis (Cyanobacteria) based on environmental, morphological, and molecular data with description of a new genus Leptodesmis

Phytotaxa ◽  
2019 ◽  
Vol 395 (1) ◽  
pp. 1-16 ◽  
Author(s):  
LENKA RAABOVÁ ◽  
LUBOMIR KOVACIK ◽  
JOSEF ELSTER ◽  
OTAKAR STRUNECKÝ

Very thin filamentous cyanobacteria are ubiquitous in a wide range of environments. For many years they were traditionally studied according to their morphological properties only. With the introduction of additional taxonomic methods (cytomorphological analyses, molecular sequencing, exact ecological studies, better data about phytogeographical distribution), traditional genera such as Leptolyngbya and Phormidium were found to be polyphyletic. Phormidesmis belonged to a newly formed genus that was supposed to explain the variability of such very thin simple filamentous cyanobacteria. However, even after definition of Phormidesmis based on distinct cytomorphological and phylogenetic traits, the variability within this genus remained unresolved. Here we analyzed 26 Phormidesmis strains to describe the variability within this genus, classified two new species (P. arctica and P. communis) and transferred Leptolyngbya nigrescens into P. nigrescens. A tabular review of Phormidesmis species is included. The diacritical features of all these species are: width up to 1–4 µm, barrel-shaped cells, which can be shorter or slightly longer than wide, with apparent constrictions at the cross-walls. Our study shows that Phormidesmis is a morphologically and genetically well-defined genus with a global distribution. A newly described genus Leptodesmis has significant morphological similarities both with Phormidesmis and Leptolyngbya, however with intermediate phylogenetic position with significant divergence in 16S rRNA gene. Leptodesmis is cryptic both to Phormidesmis and Leptolyngbya. In the initial part of the life cycle resembles Leptolyngbya, the appearance of older trichomes change to Phormidesmis like morphology.

2021 ◽  
Vol 95 ◽  
Author(s):  
M.M. Montes ◽  
J. Barneche ◽  
Y. Croci ◽  
D. Balcazar ◽  
A. Almirón ◽  
...  

Abstract During a parasitological survey of fishes at Iguazu National Park, Argentina, specimens belonging to the allocreadiid genus Auriculostoma were collected from the intestine of Characidium heirmostigmata. The erection of the new species is based on a unique combination of morphological traits as well as on phylogenetic analysis. Auriculostoma guacurarii n. sp. resembles four congeneric species – Auriculostoma diagonale, Auriculostoma platense, Auriculostoma tica and Auriculostoma totonacapanensis – in having smooth and oblique testes, but can be distinguished by a combination of several morphological features, hosts association and geographic distribution. Morphologically, the new species can be distinguished from both A. diagonale and A. platense by the egg size (bigger in the first and smaller in the last); from A. tica by a shorter body length, the genital pore position and the extension of the caeca; and from A. totonacapanensis by the size of the oral and ventral sucker and the post-testicular space. Additionally, one specimen of Auriculostoma cf. stenopteri from the characid Charax stenopterus (Characiformes) from La Plata River, Argentina, was sampled and the partial 28S rRNA gene was sequenced. The phylogenetic analysis revealed that A. guacurarii n. sp. clustered with A. tica and these two as sister taxa to A. cf. stenopteri. The new species described herein is the tenth species in the genus and the first one parasitizing a member of the family Crenuchidae.


Zootaxa ◽  
2021 ◽  
Vol 4995 (2) ◽  
pp. 334-344
Author(s):  
QIAN ZHOU ◽  
FAHUI TANG ◽  
YUANJUN ZHAO

During a survey of parasitic ciliates in Chongqing, China, Trichodina matsu Basson & Van As, 1994 was isolated from gills of Tachysurus fulvidraco. Furthermore, the 18S rRNA gene and ITS-5.8S rRNA region of T. matsu were sequenced for the first time and applied for the species identification and comparison with similar species in the present study. Based on the morphological and molecular comparisons, the results indicate that T. matsu is an ectoparasite specific for the Siluriformes catfish. Based on the analyses of genetic distance, multiple sequence alignments, and phylogenetic analyses, no obvious differentiation within populations of T. matsu was found. In addition, the ‘Trichodina hyperparasitis’ (KX904933) in GenBank is a misidentification and appears to be conspecific with T. matsu according to the comparison of morphological and molecular data.  


2020 ◽  
Vol 86 (4) ◽  
pp. 401-421 ◽  
Author(s):  
Giulia Fassio ◽  
Valeria Russini ◽  
Barbara Buge ◽  
Stefano Schiaparelli ◽  
Maria Vittoria Modica ◽  
...  

ABSTRACT Species in the family Capulidae (Littorinimorpha: Capuloidea) display a wide range of shell morphologies. Several species are known to live in association with other benthic invertebrates—mostly bivalves and sabellid worms, but also other gastropods—and are believed to be kleptoparasitic filter feeders that take advantage of the water current produced by the host. This peculiar trophic ecology, implying a sedentary lifestyle, has resulted in highly convergent shell forms. This is particularly true for the genus Hyalorisia Dall, 1889, which occurs in deep water in the Caribbean and Indo-West Pacific provinces, with two nominal species recognized so far. Combining morphological, ecological and molecular data, we assessed the diversity of the genus, its phylogenetic position inside the family and its association with its bivalve host, the genus Propeamussium de Gregorio, 1884 (Pectinoidea), resulting in the description of nine new cryptic species. When sympatric, species of Hyalorisia are associated with different host species, but the same species of Propeamussium may be the host of several allopatric species of Hyalorisia.


Zootaxa ◽  
2009 ◽  
Vol 2005 (1) ◽  
pp. 57-66 ◽  
Author(s):  
WEIWEI LIU ◽  
JIQIU LI ◽  
SHAN GAO ◽  
CHEN SHAO ◽  
JUN GONG ◽  
...  

The morphology of a new marine urostylid ciliate, Apokeronopsis sinica n. sp., collected from the Clear Water Bay, Hong Kong, was investigated. Additionally, the SSrRNA gene was sequenced in order to make a comparison at molecular level. Based on both morphological and molecular data, descriptions and comparisons with its congeners are provided. Apokeronopsis sinica is characterized by: body size about 150–200 × 50–65 µm in vivo; two kinds of cortical granules; about 20 cirri in frontal area which form the non-typical bicorona; 2 frontoterminal, ca. 4 buccal and 10 transverse cirri; midventral complex consists of 21–32 pairs of cirri; on average 35 right and 30 left marginal cirri; about 50 membranelles; invariably 3 dorsal kineties. A key to the identification of the known Apokeronopsis species was suggested. The small subunit rRNA gene sequence differences between Apokeronopsis sinica and its congeners range from 1.64% to 3.72%.


Phytotaxa ◽  
2016 ◽  
Vol 280 (1) ◽  
pp. 1 ◽  
Author(s):  
ALFREDO VIZZINI ◽  
MIRCA ZOTTI ◽  
MIDO TRAVERSO ◽  
ENRICO ERCOLE ◽  
PIERRE-ARTHUR MOREAU ◽  
...  

Several collections of Amanita species from section Vaginatae have been reported to be strictly associated with Helianthemum plants growing in grasslands, a still largely under-explored ectomycorrhizal habitat. The main aim of this study was to investigate the taxonomic status and phylogenetic position of strictly Helianthemum-associated Amanita sect. Vaginatae taxa, informally named Amanita “helianthemicola”. Collections from Italy, England and France were included in this study. The morphologically closely related species complex A. lividopallescens was also examined. Analyses were carried out based on both morphological and molecular data (phylogenetic analysis of the nrITS sequences). All investigated Amanita collections, which are strictly associated with Helianthemum nummularium, turned out to be conspecific with A. simulans. Amanita simulans was recently described from Sardinia (Italy) from Populus nigra habitats based on morphological characters only. As the holotype of A. simulans was lost, a neotype is designated here based on a voucher from the original collecting area. Amanita simulans is re-described, and an extensive discussion on the morphological variability, host species range, distribution and related taxa is provided. Amanita lividopallescens was confirmed as a good species, and re-delimited based on our phylogenetic analysis; moreover, it was epitypified with a recent and well-documented collection from Corse (France). Amanita stenospora is a synonym of A. lividopallescens, being a colour form of the latter without taxonomic value.


2021 ◽  
Author(s):  
Robin M. D. Beck ◽  
Robert Voss ◽  
Sharon Jansa

The current literature on marsupial phylogenetics includes numerous studies based on analyses of morphological data with relatively limited sampling of Recent and fossil taxa, and many studies based on analyses of molecular data that include a dense sampling of Recent taxa, but relatively few that combine both data types. Another dichotomy in the marsupial phylogenetic literature is between studies that focus on New World taxa, others that focus on Sahulian taxa. To date, there has been no attempt to assess the phylogenetic relationships of the global marsupial fauna, based on combined analyses of morphology and molecular sequences, for a dense sampling of Recent and fossil taxa. For this report, we compiled morphological and molecular data from an unprecedented number of Recent and fossil marsupials. Our morphological data consist of 180 craniodental characters that we scored for 97 species representing every currently recognized Recent genus, 42 additional ingroup (crown-clade marsupial) taxa represented by well-preserved fossils, and 5 outgroups (non-marsupial metatherians). Our molecular data comprise 24.5 kb of DNA sequences from whole-mitochondrial genomes and six nuclear loci (APOB, BRCA1, GHR, RAG1, RBP3 and VWF) for 97 marsupial terminals (the same Recent taxa scored for craniodental morphology) and several placental and monotreme outgroups. The results of separate and combined analyses of these data using a wide range of phylogenetic methods support many currently accepted hypotheses of ingroup (marsupial) relationships, but they also underscore the difficulty of placing fossils with key missing data (e.g., †Evolestes), and the unique difficulty of placing others that exhibit mosaics of plesiomorphic and autapomorphic traits (e.g., †Yalkaparidon). Unique contributions of our study are (1) critical discussions and illustrations of marsupial craniodental morphology, including descriptions and illustrations of some features never previously coded for phylogenetic analysis; (2) critical assessments of relative support for many suprageneric clades; (3) estimates of divergence times derived from tip-and-node dating based on uniquely taxon-dense analyses; and (4) a revised, higher-order classification of marsupials accompanied by lists of supporting craniodental synapomorphies. Far from the last word on these topics, this report lays the foundation for future research that may be enabled by the discovery of new fossil taxa, better-preserved material of previously described taxa, novel morphological characters, and improved methods of phylogenetic analysis.


Zootaxa ◽  
2012 ◽  
Vol 3437 (1) ◽  
pp. 43 ◽  
Author(s):  
CHARLES H. J. M. FRANSEN ◽  
BASTIAN T. REIJNEN

A second discovery of the cockscomb oyster associated shrimp species Lacertopontonia chadi is recorded from Sabah (Malaysia). The material is compared with the type description and paratypic material. The systematic position of the genus is reevaluated on the basis of morphological and molecular data focusing on the genera Conchodytes and Chernocaris. It is concluded that Lacertopontonia and Chernocaris fall within the present definition of Conchodytes and should be regarded as synonyms of the latter.


Biologia ◽  
2011 ◽  
Vol 66 (4) ◽  
Author(s):  
Christina Bock ◽  
Marie Pažoutová ◽  
Lothar Krienitz

AbstractFollowing traditional morphological concepts, the genus Coronastrum is considered to be a rare member of the Scenedesmaceae (Chorophyceae). This classification may be called into question when molecular data are taken into account as well. Recent molecular phylogenetic studies revealed the polyphyletic origin of the family Scenedesmaceae within the Chlorophyceae and Trebouxiophyceae. In a combined approach of morphological analyses, SSU/ITS rRNA gene phylogeny and comparison of the ITS secondary structure, we analysed the systematics of Coronastrum strains available in public strain collections. Our molecular analyses revealed a new subclade within the Chlorella clade of the Chlorellaceae consisting of Coronastrum ellipsoideum, two strains with Dictyosphaerium-like morphology and one strain which fits the description of the genus Parachlorella. Four additional strains formed together a new lineage within the genus Parachlorella in the Parachlorella clade of the Chlorellaceae. These strains differ from the already known Parachlorella species in complementary base changes within the ITS2 and are here described for the first time as Parachlorella hussii sp. nov.


2015 ◽  
Vol 29 (5) ◽  
pp. 473 ◽  
Author(s):  
Takafumi Nakano ◽  
Son Truong Nguyen

The family Salifidae is a predaceous leech taxon in the suborder Erpobdelliformes. Although Salifidae is widely distributed in the African, Oriental, Indo-Malayan, Sino-Japanese and Australasian regions, the phylogenetic relationships of the family Salifidae have never been tested using molecular data obtained from leeches collected from the family distributional range. A salifid species was collected for the first time in Vietnam, and relevant morphological and molecular data are presented here. Because the Vietnamese salifid species possesses unique morphological characteristics among the known salifid species, this species is herein described as a new species, Salifa motokawai, sp. nov. Phylogenetic analyses based on nuclear 18S rRNA and histone H3, as well as mitochondrial cytochrome c oxidase subunit I, tRNACys, tRNAMet, 12S rRNA, tRNAVal, 16S rRNA, tRNALeu and NADH dehydrogenase subunit 1 markers demonstrate that the Vietnamese salifid species is a close congener with the African Salifa perspicax and the Malagasy Linta be. Furthermore, molecular data revealed non-monophyly of the Asian salifid leeches. According to the observed phylogenetic relationships and morphological characteristics of the Vietnamese Salifa motokawai, sp. nov., the current classification of salifid taxa should be revised.


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