scholarly journals A review of the taxonomy of spiny-backed orb-weaving spiders of the subfamily Gasteracanthinae (Araneae, Araneidae) in Thailand

ZooKeys ◽  
2021 ◽  
Vol 1032 ◽  
pp. 17-62
Author(s):  
Kongkit Macharoenboon ◽  
Warut Siriwut ◽  
Ekgachai Jeratthitikul
Keyword(s):  
Phylogenetic Tree ◽  
Cryptic Species ◽  
Species Identification ◽  
Intraspecific Variation ◽  
Molecular Species ◽  
Species Delimitation ◽  
Coi Gene ◽  
Nominal Species ◽  
Model Species ◽  
And Behavior

Spiny-backed orb-weaving spiders of the subfamily Gasteracanthinae are broadly distributed in the Old World. Despite their use as a model species in biology, evolution, and behavior because of their extraordinary characteristics, the systematics of this group of spiders are still poorly understood. This study elucidates the systematics of Gasteracanthinae in Thailand based on morphological and molecular-based analyses. In total, seven species from three genera, namely Gasteracantha, Macracantha, and Thelacantha, were recorded in Thailand. Shape of abdominal spines, pattern of sigilla, and female genitalia are significant characters for species identification. In contrast, coloration shows highly intraspecific variation in most species within Gasteracanthinae. A phylogenetic tree based on partial sequences of COI, 16S, and H3 genes recovered Gasteracanthinae as a monophyletic group and supports the existence of three clades. Gasteracantha hasselti is placed as a sister taxon to Macracantha arcuata. Hence, we propose to transfer G. hasselti to Macracantha. Moreover, molecular species delimitation analyses (ABGD, bPTP, and GMYC) using 675 bp of COI gene support all nominal species, with evidence of possible additional cryptic species.

scholarly journals Hidden biodiversity revealed by integrated morphology and genetic species delimitation of spring dwelling water mite species (Acari, Parasitengona: Hydrachnidia)

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Lucas Blattner ◽  
Reinhard Gerecke ◽  
Stefanie von Fumetti
Keyword(s):  
Species Identification ◽  
Molecular Species ◽  
Species Delimitation ◽  
Mite Species ◽  
Water Mites ◽  
Water Mite ◽  
Barcoding Gap ◽  
Molecular Species Identification ◽  
True Diversity ◽  
Genetic Species

Abstract Background Water mites are among the most diverse organisms inhabiting freshwater habitats and are considered as substantial part of the species communities in springs. As parasites, Hydrachnidia influence other invertebrates and play an important role in aquatic ecosystems. In Europe, 137 species are known to appear solely in or near springheads. New species are described frequently, especially with the help of molecular species identification and delimitation methods. The aim of this study was to verify the mainly morphology-based taxonomic knowledge of spring-inhabiting water mites of central Europe and to build a genetic species identification library. Methods We sampled 65 crenobiontic species across the central Alps and tested the suitability of mitochondrial (cox1) and nuclear (28S) markers for species delimitation and identification purposes. To investigate both markers, distance- and phylogeny-based approaches were applied. The presence of a barcoding gap was tested by using the automated barcoding gap discovery tool and intra- and interspecific genetic distances were investigated. Furthermore, we analyzed phylogenetic relationships between different taxonomic levels. Results A high degree of hidden diversity was observed. Seven taxa, morphologically identified as Bandakia concreta Thor, 1913, Hygrobates norvegicus (Thor, 1897), Ljania bipapillata Thor, 1898, Partnunia steinmanni Walter, 1906, Wandesia racovitzai Gledhill, 1970, Wandesia thori Schechtel, 1912 and Zschokkea oblonga Koenike, 1892, showed high intraspecific cox1 distances and each consisted of more than one phylogenetic clade. A clear intraspecific threshold between 5.6–6.0% K2P distance is suitable for species identification purposes. The monophyly of Hydrachnidia and the main superfamilies is evident with different species clearly separated into distinct clades. cox1 separates water mite species but is unsuitable for resolving higher taxonomic levels. Conclusions Water mite species richness in springs is higher than has been suggested based on morphological species identification alone and further research is needed to evaluate the true diversity. The standard molecular species identification marker cox1 can be used to identify species but should be complemented by a nuclear marker, e.g. 28S, to resolve taxonomic relationships. Our results contribute to the taxonomical knowledge on spring inhabiting Hydrachnida, which is indispensable for the development and implementation of modern environment assessment methods, e.g. metabarcoding, in spring ecology.

Molecular analysis reveals a new cryptic species in a limpet Lottia kogamogai (Patellogastropoda: Lottiidae) from Japan

Zootaxa ◽  
2017 ◽  
Vol 4277 (2) ◽  
pp. 237 ◽  
Author(s):  
RYO NAKAYAMA ◽  
TAKENORI SASAKI ◽  
TOMOYUKI NAKANO
Keyword(s):  
New Species ◽  
Cryptic Species ◽  
Intraspecific Variation ◽  
Molecular Analysis ◽  
Coi Gene ◽  
Northern Population ◽  
Mitochondrial Coi ◽  
Mitochondrial Coi Gene ◽  
Shell Sculpture

A group of small lottiid species in Japan, the Lottia kogamogai complex, was phylogenetically analyzed based on the mitochondrial COI gene. As a result, L. kogamogai is subdivided into two geographic clades. Lottia kogamogai s.s. is limited to southern temperate Japan. The northern population formerly considered an intraspecific variation of the species is shown to be a distinct new species, here described as Lottia goshimai n. sp. The new species is distinguishable from L. kogamogai not only genetically, but in radular morphology and shell sculpture. 

scholarly journals Species diversity of freshwater shrimp in Henan Province, China, based on morphological characters and COI mitochondrial gene

2021 ◽  
Author(s):  
Chuanjiang Zhou ◽  
Mengxia Feng ◽  
Yongtao Tang ◽  
Changxing Yang ◽  
Xiaolin Meng ◽  
...  
Keyword(s):  
Species Diversity ◽  
Cryptic Species ◽  
Dna Barcoding ◽  
Species Identification ◽  
High Efficiency ◽  
Morphological Characteristics ◽  
Henan Province ◽  
Coi Gene ◽  
Morphological Identification ◽  
Freshwater Shrimp

Freshwater shrimp is an extremely rich species group with a long and problematic taxonomic history, attributed to its wide distribution, numerous species and similar morphology. Shrimp diversity and species identification is utmost important for fisheries management. However, identification based on morphological characteristics is difficult and complex for a non-specialist to perform. The water system of Henan Province is relatively abundant, but there are few investigations of freshwater shrimps and no description of molecular features. The aim of this study was to uncover the species diversity and phylogenetic of freshwater shrimp in Henan province by combining morphological identification and molecular species delimitation (barcoding gene: COI gene). About 1,200 freshwater shrimp samples from 46 sampling sites were collected for preliminary traditional morphological identification, 222 samples of these were been further microscopic examination and molecular delimitation. Here we used tree based method (NJ, ML) and distance based method (ABGD, bPTP) mainly to define species, detect the cryptic species and assess the validity of the barcoding in molecular. Comprehensive morphological identification and molecular delimitation results, there were 9 effective species and more than one cryptic species of freshwater shrimp in the province and moreover all of them can be identified by DNA barcoding. The results of morphological identification and molecular identification show high consistency, which proves the high efficiency in freshwater shrimp species identification of the DNA barcoding and the presence of cryptic species.

scholarly journals The screening and identification of DNA barcode sequences for Rehmannia

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hongying Duan ◽  
Wanshen Wang ◽  
Yunpeng Zeng ◽  
Mengmeng Guo ◽  
Yanqing Zhou
Keyword(s):  
Genetic Variation ◽  
Phylogenetic Tree ◽  
Species Identification ◽  
Intraspecific Variation ◽  
Systematic Study ◽  
Dna Barcode ◽  
Barcoding Gap ◽  
Screening And Identification ◽  
Interspecific And Intraspecific Variation ◽  
Interspecific Diversity

AbstractIn this study, ITS, ITS2, matK, rbcL and psbA-trnH in Rehmannia were successfully amplified and sequenced, but some ITS sequences need to be proofread according to ITS2 sequences. Compared with rbcL, matK and psbA-trnH, ITS and ITS2 had higher mutation rate and more information sites, and ITS2 had higher interspecific diversity and lower intraspecific variation in Rehmannia, but the interspecific genetic variation of rbcL and matK was lower. Furthermore, the obvious barcoding gap was found in psbA-trnH or ITS2 + psbA-trnH, and the overlap between interspecific and intraspecific variation of ITS, ITS2 or matK was less. In addition, the phylogenetic tree based on ITS or ITS2 indicated that R. glutinosa, R. chingii or R. henryi with obvious monophyly could be successfully identified, but R. piasezkii and R. elata were clustered into one branch, R. solanifolia could not be distinguished from R. glutinosa, and R. chingii was closer to R. henryi. In phylogenetic tree based on psbA-trnH or ITS2 + psbA-trnH, cultivars and wild varieties of R. glutinosa could be distinguished, were clearly separated from other Rehmannia species, and cultivars or wild varieties of R. glutinosa could be also distinguished by matK. Taken together, ITS2 has great potential in systematic study and species identification of Rehmannia, the combination of ITS2 and psbA-trnH might be the most suitable DNA barcode for Rehmannia species.

scholarly journals Morphological and Molecular Assessments of Bobtail Squids (Cephalopoda: Sepiolidae) Reveal a Hidden History of Biodiversity

2021 ◽  
Vol 7 ◽  
Author(s):  
Fernando Á. Fernández-Álvarez ◽  
Pilar Sánchez ◽  
Roger Villanueva
Keyword(s):  
Molecular Species ◽  
Species Delimitation ◽  
Sequence Data ◽  
Morphological Evolution ◽  
Morphological Characters ◽  
Molecular Data ◽  
Medium Size ◽  
Nominal Species ◽  
Cryptic Biodiversity ◽  
New Research

Molecular species delimitation assists taxonomic decisions for challenging species, like cryptic species complexes. Bobtail squids (Family Sepiolidae Leach, 1817) are a very diverse group of benthic and nektonic small to medium size cephalopods with many taxonomic questions to solve. In this study we provided new sequence data for 12 out 17 Mediterranean bobtail squid species including all the genera present i n the area. Other relevant species from other parts of the world were used as comparison. The combined use of several molecular species delimitation methods consistently showed a picture of hidden biodiversity within this family which hinders the use of molecular data isolated from morphological characters. On the one hand, those methods provided contrasting results for the number of recognized species of some morphologically well-defined species. We suggest this can be an effect of recent speciation phenomena followed by an intense morphological drift. On the other hand, cryptic biodiversity was detected among members of several monophyletic clades assigned to the same nominal species, pointing to recent speciation phenomena without a parallel morphological evolution. Although Mediterranean bobtail diversity has been extensively studied for more than a century, a new species of Stoloteuthis Verrill (1881) was discovered and described here, both using molecular and morphological methods. This new research stresses the necessity of combined morphological and molecular studies to correctly assess cephalopod diversity. urn:lsid:zoobank.org:act:57AFBB38-18EA-4F80-B1D4-73519C12694F.

scholarly journals When morphometry meets taxonomy: morphological variation and species boundaries in Proboscoida (Cnidaria: Hydrozoa)

2020 ◽  
Vol 190 (2) ◽  
pp. 417-447
Author(s):  
Amanda F Cunha ◽  
Allen G Collins ◽  
Antonio C Marques
Keyword(s):  
Intraspecific Variation ◽  
Morphological Variation ◽  
Species Delimitation ◽  
Species Boundaries ◽  
Nominal Species ◽  
Genetic Sampling ◽  
Taxonomic Implications ◽  
Obelia Geniculata

Abstract Species delimitation in marine taxa is often problematic given large intraspecific variation. Based on extensive, recently published genetic sampling from specimens of the hydrozoan families Campanulariidae, Clytiidae and Obeliidae, we evaluate morphological variation in this group, correlating morphometric and phylogenetic patterns for species delimitation. Several species of Campanulariidae are confidently delimited based on differences in size (e.g. Bonneviella species, Tulpa tulipifera and Rhizocaulus verticillatus), while others are re-identified and corroborated based on differences in perisarc thickness (e.g. Silicularia rosea, Orthopyxis and Campanularia species). In Clytiidae, the length and diameter of hydrothecae, height of hydrothecal cusps and perisarc thickness delimit the species Clytia linearis, C. elsaeoswaldae and C. noliformis from others. However, few characters reliably differentiate the clades associated with the nominal species C. gracilis and C. hemisphaerica. In Obeliidae, Obelia geniculata is distinctive in its higher perisarc thickness, and corroborated as a widely distributed species. Obelia longissima and clades refered to O. dichotoma are subtly distinguished, showing a few differences in size and branching of colonies. The taxonomic implications of these results are discussed. With a few exceptions, species can be delimited based on morphometric patterns, once morphological variation is compared.

Sampling and processing of freshwater nematodes with emphasis on molecular methods.

2021 ◽  
pp. 31-57
Author(s):  
Janina Schenk ◽  
Walter Traunspurger
Keyword(s):  
Cryptic Species ◽  
Species Identification ◽  
Molecular Species ◽  
Sampling Methods ◽  
Nematode Species ◽  
Molecular Methods ◽  
Specific Gene ◽  
Molecular Species Identification ◽  
Molecular Approaches ◽  
Freshwater Nematodes

Abstract This chapter provides an introduction to current methods of nematode sampling and processing, with the latter including molecular methods as well. It highlights that nematode sampling and processing for different habitats will require different sampling methods; nematode identification can be achieved with morphological or molecular approaches; the analysis of specific gene fragments can be used to delimitate nematode species; and molecular species identification can give further information about phylogenetic background and cryptic species.

scholarly journals Molecular species delimitation of the genera Anodus, Argonectes, Bivibranchia and Micromischodus (Ostariophysi: Characiformes)

2021 ◽  
Vol 19 (4) ◽  
Author(s):  
Acácio Freitas Nogueira ◽  
Claudio Oliveira ◽  
Francisco Langeani ◽  
Andre Luiz Netto-Ferreira
Keyword(s):  
Molecular Species ◽  
Species Delimitation ◽  
Valid Species ◽  
Species Boundaries ◽  
Nominal Species ◽  
Sources Of Information ◽  
Biological Studies ◽  
The Family ◽  
Living Organisms ◽  
Neotropical Ichthyofauna

ABSTRACT A good taxonomic assessment of specimens is an essential task to many biological studies and DNA data have provided additional sources of information to assist in the disentanglement of taxonomic problems among living organisms, as has been the case of some taxa of the megadiverse Neotropical ichthyofauna. Here we assessed all valid species in the Neotropical freshwater fish genera Anodus, Argonectes, Bivibranchia and Micromischodus of the family Hemiodontidae to establish molecular species boundaries among them. All species delimitation methods defined exactly only one MOTU for Anodus elongatus, Argonectes longiceps, A. robertsi, Bivibranchia bimaculata, B. notata, B. velox, and Micromischodus sugillatus, resulting in total congruence between nominal species and MOTUs for these seven taxa. The three species having discordant results across analyses: Anodus orinocensis, Bivibranchia fowleri, and Bivibranchia simulata, matched more than one MOTU per species in some methods, meaning that cryptic diversity may exist within these taxa. Overall, this great correspondence among morphological and molecular boundaries for thae species analysed seem to be indicative of a reasonably stable taxonomy within these Hemiodontidae genera.

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