scholarly journals Consolidated data on the phylogeny and evolution of the family Tritoniidae (Gastropoda: Nudibranchia) contribute to genera reassessment and clarify the taxonomic status of the neuroscience models Tritonia and Tochuina

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242103
Author(s):  
Tatiana Korshunova ◽  
Alexander Martynov

Nudibranch molluscs of the family Tritoniidae are widely used neuroscience model systems for understand the behavioural and genetic bases of learning and memory. However species identity and genus-level taxonomic assignment of the tritoniids remain contested. Herein we present a taxonomic review of the family Tritoniidae using integration of molecular phylogenetic analysis, morphological and biogeographical data. For the first time the identity of the model species Tritonia tetraquetra (Pallas, 1788) and Tritonia exsulans Bergh, 1894 is confirmed. T. tetraquetra distributes across the large geographic and bathymetric distances in the North-Eastern (NE) and North-Western (NW) Pacific. In turn, at NE Pacific coasts the separate species T. exsulans is commonly occured. Thus, it reveals a misidentification of T. tetraquetra and T. exsulans species in neuroscience applications. Presence of more hidden lineages within NW Pacific T. tetraquetra is suggested. The long lasting confusion over identity of the species from the genera Tritonia and Tochuina is resolved using molecular and morphological data. We also disprove a common indication about “edible T. tetraquetra” at the Kuril Islands. It is shown that Tochuina possesses specialized tritoniid features and also some characters of “arminacean nudibranchs”, such as Doridoxa and Heterodoris. Diagnoses for the families Doridoxidae and Heterodorididae are provided. Taxonomy of the genus Doridoxa is clarified and molecular data for the genus Heterodoris presented for the first time. A taxonomic synopsis for the family Tritoniidae is provided. A new genus among tritoniid taxa is proposed. Importance of the ontogeny-based taxonomy is highlighted. The cases when apomorphic characters considerably modified in a crown group due to the paedomorphosis are revealed. Tracing of the character evolution is presented for secondary gills–a key external feature of the family Tritoniidae and traditional dendronotacean nudibranchs.

Zootaxa ◽  
2019 ◽  
Vol 4551 (5) ◽  
pp. 556 ◽  
Author(s):  
TATIANA KORSHUNOVA ◽  
RAHUL MEHROTRA ◽  
SPENCER ARNOLD ◽  
KENNET LUNDIN ◽  
BERNARD PICTON ◽  
...  

An integrative molecular and morphological study is presented for the family Unidentiidae. Molecular phylogenetic analyses were conducted with the inclusion of all previous and newly obtained molecular data for the family Unidentiidae Millen & Hermosillo 2012. A new species of the genus Unidentia Millen & Hermosillo 2012, U. aliciae sp. nov., is described from Thailand as part of an inventory of sea slugs at Koh Tao. All up-to-date available morphological data for the species of the genus Unidentia is for the first time summarized. Morphological differences among the different species of Unidentia are clarified showing that every species has its own distinguishable morphological traits. According to the new molecular and morphological data, the family Unidentiidae is re-confirmed as a well-supported taxon of the aeolidacean nudibranchs. The taxonomy and phylogeny of the Aeolidacea in the light of the family Unidentiidae is briefly discussed and necessity of a fine-scale and narrowly-defined taxa approach instead of a ‘‘superlumping’’ one is highlighted. 


2017 ◽  
Vol 7 (3) ◽  
pp. 134-138 ◽  
Author(s):  
N. A. Shapoval ◽  
R. V. Yakovlev ◽  
G. N. Kuftina

<p>In our study we use a 658 bp fragment of the <em>COI</em> gene to analyze a taxon from Afghanistan usually treated in literature as <em>Cossus cossus afghanistanus </em>(Daniel, 1953)<em>.</em> The previous conclusions on taxonomy and nomenclature were not supported by molecular data therefore the question of identity of this taxon has remained unverified. Phylogenetic analysis revealed <em>C. c. afghanistanus </em>to be strongly differentiated from nominotypical <em>Cossus cossus</em> (Linnaeus, 1758) (p-distance: 6.7% ± 1.5%). <em>Cossus c. afghanistanus </em>forms a distinct well-supported clade in ML and BI trees. This fact, together with prominent morphological differences (wing color and genitalia structure) shows that <em>C. c. afghanistanus </em>represent a separate species rather than a subspecies of <em>Cossus cossus</em>.</p>


2017 ◽  
Vol 59 (1) ◽  
pp. 35-53 ◽  
Author(s):  
Iryna Bednarska ◽  
Igor Kostikov ◽  
Andrii Tarieiev ◽  
Vaclovas Stukonis

AbstractUntil recently,Festuca arietinawas practically an unknown species in the flora of Eastern Europe. Such a situation can be treated as a consequence of insufficient studying ofFestuca valesiacagroup species in Eastern Europe and misinterpretation of the volume of some taxa. As a result of a complex study ofF. arietinapopulations from the territory of Ukraine (including the material fromlocus classicus), Belarus and Lithuania, original anatomy, morphology and molecular data were obtained. These data confirmed the taxonomical status ofF. arietinaas a separate species. Eleven morphological and 12 anatomical characters, ITS1-5.8S-ITS2 cluster of nuclear ribosomal genes, as well as the models of secondary structure of ITS1 and ITS2 transcripts were studied in this approach. It was found for the first time thatF. arietinais hexaploid (6x = 42), which is distinguished from all the other narrow-leaved fescues by specific leaf anatomy as well as in ITS1-5.8S-ITS2 sequences. Molecular data indicating possible hybridogenous origin ofF. arietina, fall in line with the anatomical-morphological data and explain the tendency toward sclerenchyma strands fusion with formation of a continuous ring inF. arietina, as well asF. arietinaecological confinement to psammophyte biotopes.


ZooKeys ◽  
2019 ◽  
Vol 840 ◽  
pp. 133-155 ◽  
Author(s):  
Arkady A. Schileyko ◽  
Evgeniya N. Solovyeva

The taxonomic position of the monotypic Vietnamese genus Tonkinodentus Schileyko, 1992 (for T. lestes Schileyko, 1992) has been considered in the light of the first obtained molecular data. Both molecular (28S rRNA) and morphological data support the position of this extraordinary eye-less genus within the family Scolopendridae Leach, 1814, a sighted clade, and thus suggests the polyphyly of blind scolopendromorphs. The species diagnosis has been amended and color images of T. lestes provided for the first time.


2019 ◽  
Vol 28 (2) ◽  
pp. 305-316
Author(s):  
M.A. Chursina ◽  
I.Ya. Grichanov

The recent catalogues of the family Dolichopodidae considered Syntormon pallipes (Fabricius, 1794) and S. pseudospicatus Strobl, 1899 as separate species. In this study, we used three approaches to estimate the significance of differences between the two species: molecular analysis (COI and 12S rRNA sequences), analysis of leg colour characters and geometric morphometric analysis of wing shape. The morphological data confirmed the absence of significant differences between S. pallipes and S. pseudospicatus found in the DNA analysis. Significant differences in the wing shape of two species have not been revealed. Hence, according to our data, there is no reason to consider S. pseudospicatus as a distinct species.


2021 ◽  
Vol 7 (6) ◽  
pp. 478
Author(s):  
Xue-Wei Wang ◽  
Tom W. May ◽  
Shi-Liang Liu ◽  
Li-Wei Zhou

Hyphodontia sensu lato, belonging to Hymenochaetales, accommodates corticioid wood-inhabiting basidiomycetous fungi with resupinate basidiocarps and diverse hymenophoral characters. Species diversity of Hyphodontia sensu lato has been extensively explored worldwide, but in previous studies the six accepted genera in Hyphodontia sensu lato, viz. Fasciodontia, Hastodontia, Hyphodontia, Kneiffiella, Lyomyces and Xylodon were not all strongly supported from a phylogenetic perspective. Moreover, the relationships among these six genera in Hyphodontia sensu lato and other lineages within Hymenochaetales are not clear. In this study, we performed comprehensive phylogenetic analyses on the basis of multiple loci. For the first time, the independence of each of the six genera receives strong phylogenetic support. The six genera are separated in four clades within Hymenochaetales: Fasciodontia, Lyomyces and Xylodon are accepted as members of a previously known family Schizoporaceae, Kneiffiella and Hyphodontia are, respectively, placed in two monotypic families, viz. a previous name Chaetoporellaceae and a newly introduced name Hyphodontiaceae, and Hastodontia is considered to be a genus with an uncertain taxonomic position at the family rank within Hymenochaetales. The three families emerged between 61.51 and 195.87 million years ago. Compared to other families in the Hymenochaetales, these ages are more or less similar to those of Coltriciaceae, Hymenochaetaceae and Oxyporaceae, but much older than those of the two families Neoantrodiellaceae and Nigrofomitaceae. In regard to species, two, one, three and 10 species are newly described from Hyphodontia, Kneiffiella, Lyomyces and Xylodon, respectively. The taxonomic status of additional 30 species names from these four genera is briefly discussed; an epitype is designated for X. australis. The resupinate habit and poroid hymenophoral configuration were evaluated as the ancestral state of basidiocarps within Hymenochaetales. The resupinate habit mainly remains, while the hymenophoral configuration mainly evolves to the grandinioid-odontioid state and also back to the poroid state at the family level. Generally, a taxonomic framework for Hymenochaetales with an emphasis on members belonging to Hyphodontia sensu lato is constructed, and trait evolution of basidiocarps within Hymenochaetales is revealed accordingly.


Author(s):  
Antonio Zurita ◽  
Cristina Cutillas

AbstractCtenophthalmus is considered the largest genus within the Order Siphonaptera. From a morphological point of view, only males of this genus can be identified at species and subspecies levels using morphological keys, whereas there are no morphological criteria in order to classify females at these taxonomical levels. Furthermore, the amount of available molecular and phylogenetic data for this genus is quite scarce so far. The main objective of this work was to assess the utility of the combination of nuclear and mitochondrial markers with respect to their ability to differentiate among different subspecies within the Ctenophthalmus genus. With this purpose, we carried out a comparative morphological and molecular study of three different subspecies (Ctenophthalmus baeticus arvernus, Ctenophthalmus nobilis dobyi, and Ctenophthalmus andorrensis catalaniensis) in order to clarify and discuss its taxonomic status. In addition, our study complemented the molecular data previously provided for Ctenophthalmus baeticus boisseauorum and Ctenophthalmus apertus allani subspecies. We sequenced five different molecular markers: EF1-α, ITS1, ITS2, cox1, and cytb. Our results confirmed that morphological data by themselves are not able to discriminate among Ctenophthalmus female taxa; however, the combination of the nuclear marker EF1-α together with mtDNA markers cytb and cox1 constituted a useful taxonomical and phylogenetic tool to solve this issue. Based on these results, we consider that the use of this molecular approach should be gradually used within Ctenophthalmus genus in order to complement its classical taxonomy and clarifying the complex taxonomy of other congeneric species of fleas.


Author(s):  
Chelladurai Stella ◽  
Packiam Paul ◽  
Chelladurai Ragunathan

The new occurrence of Three species of bivalves from Pinnidae family  is recorded for the first time from Palk Bay area based on a live and dead shells collected from the Intertidal area . All the three species are under the family of  Pinnidae, Pinna bicolor, Pinna deltodes and Pinna incurva . In seagrass bed of Thondi Coast, all the species of Pen shells Pinna bicolor, Pinna deltodes and Pinna incurva  were embedded in muddy sand and found associated with seagrasses at inter-tidal area. It was also found buried in hard substratum associated with living zoanthids and soft coral. The collected specimens were identified as, (1) Pinna bicolor, (2) Pinna deltodes and (3) Pinna Incurva by using both morphometric and meristic characters. The paper described the taxonomic status and the description of the three species of bivalves collected from Palk Bay areas.


2020 ◽  
Vol 94 ◽  
Author(s):  
D. Krupenko ◽  
A. Uryadova ◽  
A. Gonchar ◽  
G. Kremnev ◽  
V. Krapivin

Abstract Few digeneans of the family Fellodistomidae are known from the Russian Arctic seas. The taxonomic status of these species, their life cycles and host range raised recurrent questions, some of which remain unanswered. To revise the species composition and life cycles of fellodistomids in the White Sea, we searched for them in several known and suspected hosts: wolffish, flatfishes (definitive), gastropods of the family Buccinidae (second intermediate) and protobranch bivalves (first intermediate). Species identification was based both on morphology and 28S ribosomal RNA gene sequences. We found Fellodistomum agnotum in the White Sea for the first time. Buccinum undatum was proved to be intermediate host of both F. agnotum and Fellodistomum fellis, and metacercariae of F. fellis were registered from two more buccinid species: Buccinum scalariforme and Neptunea despecta. We also found metacercariae of F. agnotum and F. fellis producing eggs in the second intermediate host. Two fellodistomids were found in protobranch bivalves: sporocysts and cercariae of Steringophorus furciger in Nuculana pernula, and sporocysts with large furcocercous cercariae in Ennucula tenuis. The latter were identified as F. agnotum by molecular analysis; thus, the entire life cycle of this species was reconstructed.


2020 ◽  
Vol 34 (2) ◽  
pp. 113 ◽  
Author(s):  
Rafael Robles ◽  
Peter C. Dworschak ◽  
Darryl L. Felder ◽  
Gary C. B. Poore ◽  
Fernando L. Mantelatto

The axiidean families Callianassidae and Ctenochelidae, sometimes treated together as Callianassoidea, are shown to represent a monophyletic taxon. It comprises 265 accepted species in 74 genera, twice this number of species if fossil taxa are included. The higher taxonomy of the group has proved difficult and fluid. In a molecular phylogenetic approach, we inferred evolutionary relationships from a maximum-likelihood (ML) and Bayesian analysis of four genes, mitochondrial 16S rRNA and 12S rRNA along with nuclear histone H3 and 18S rRNA. Our sample consisted of 298 specimens representing 123 species plus two species each of Axiidae and Callianideidae serving as outgroups. This number represented about half of all known species, but included 26 species undescribed or not confidently identified, 9% of all known. In a parallel morphological approach, the published descriptions of all species were examined and detailed observations made on about two-thirds of the known fauna in museum collections. A DELTA (Description Language for Taxonomy), database of 135 characters was made for 195 putative species, 18 of which were undescribed. A PAUP analysis found small clades coincident with the terminal clades found in the molecular treatment. Bayesian analysis of a total-evidence dataset combined elements of both molecular and morphological analyses. Clades were interpreted as seven families and 53 genera. Seventeen new genera are required to reflect the molecular and morphological phylograms. Relationships between the families and genera inferred from the two analyses differed between the two strategies in spite of retrospective searches for morphological features supporting intermediate clades. The family Ctenochelidae was recovered in both analyses but the monophyly of Paragourretia was not supported by molecular data. The hitherto well recognised family Eucalliacidae was found to be polyphyletic in the molecular analysis, but the family and its genera were well defined by morphological synapomorphies. The phylogram for Callianassidae suggested the isolation of several species from the genera to which they had traditionally been assigned and necessitated 12 new generic names. The same was true for Callichiridae, with stronger ML than Bayesian support, and five new genera are proposed. Morphological data did not reliably reflect generic relationships inferred from the molecular analysis though they did diagnose terminal taxa treated as genera. We conclude that discrepancies between molecular and morphological analyses are due at least in part to missing sequences for key species, but no less to our inability to recognise unambiguously informative morphological synapomorphies. The ML analysis revealed the presence of at least 10 complexes wherein 2–4 cryptic species masquerade under single species names.


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