scholarly journals Integrative taxonomy resolves species identities within the Macrobiotus pallarii complex (Eutardigrada: Macrobiotidae)

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Daniel Stec ◽  
Matteo Vecchi ◽  
Magdalena Dudziak ◽  
Paul J. Bartels ◽  
Sara Calhim ◽  
...  
Keyword(s):  
Small Body ◽  
Morphological Characters ◽  
Integrative Taxonomy ◽  
Molecular Techniques ◽  
Integrative Approach ◽  
Similar Species ◽  
Morphometric Traits ◽  
South Italy ◽  
Dichotomous Key ◽  
The Usa

AbstractThe taxonomy of many groups of meiofauna is challenging due to their low number of diagnostic morphological characters and their small body size. Therefore, with the advent of molecular techniques that provide a new source of traits, many cryptic species have started to be discovered. Tardigrades are not an exception, and many once thought to be cosmopolitan taxa are being found to be complexes of phenotypically similar species. Macrobiotus pallarii Maucci, 1954 was originally described in South Italy and has been subsequently recorded in Europe, America, and Asia. This allegedly wide geographic range suggests that multiple species may be hidden under this name. Moreover, recently, genetic evidence to support this was put forward, and the Macrobiotus pallarii complex has been proposed to accommodate putative species related to M. pallarii. Here, we describe three new pseudocryptic species based on populations that would have been all classified as Macrobiotus pallarii if molecular methods were not employed. Using an integrative taxonomy approach, we analyzed animals and eggs from the topotypic population of Macrobiotus pallarii, together with four other populations of the complex. We recovered four distinct phylogenetic lineages that, despite the overlap of morphometric traits, can be separated phenotypically by subtle but discrete morphological characters. One lineage corresponds to Macrobiotus pallarii, whereas the other three are newly described as Macrobiotus margoae Stec, Vecchi & Bartels, sp. nov. from the USA, Macrobiotus ripperi Stec, Vecchi & Michalczyk, sp. nov. from Poland and Finland, and Macrobiotus pseudopallarii Stec, Vecchi & Michalczyk, sp. nov. from Montenegro. To facilitate species identification, we provide a dichotomous key for species of the M. pallarii complex. Delimitation of these pseudocryptic taxa highlights the need for an integrative approach to uncover the phylum’s diversity in full.

A revised dichotomous key for the mangrove crab genus Scylla De Haan, 1833 (Brachyura, Portunidae)

Crustaceana ◽  
2018 ◽  
Vol 91 (7) ◽  
pp. 847-865 ◽  
Author(s):  
Chona C. Vincecruz-Abeledo ◽  
Ma. Carmen A. Lagman
Keyword(s):  
Species Identification ◽  
Morphological Characters ◽  
The Philippines ◽  
Molecular Techniques ◽  
Diagnostic Features ◽  
Geometric Patterns ◽  
Dichotomous Key ◽  
Mangrove Crab ◽  
Mangrove Crabs ◽  
Morphological Species

Abstract Species identification in mangrove crabs of the genus Scylla De Haan, 1833 is problematic, due to the high intraspecific variation and the continuity of diagnostic features. To determine the hierarchy of characters that are most useful in differentiating Scylla species from the Philippines, 1,185 mangrove crabs were collected from seven sites across the Philippines. Morphological species identification was contrasted with morphometric and molecular techniques. The hierarchy of characters in the existing dichotomous key resulted in the misidentification of 245 samples. Errors stem from asymmetry in the features of the chelipeds and the continuity in the features of the frontal lobe spines. Considering mainly morphological characters, the most reliable traits were the geometric patterns in the swimming and walking legs. Nonetheless, 27 individuals with morphological ambiguities exhibited unique patterns in digested nuclear ITS-1 fragments, unreported in any known species of Scylla. A revised hierarchy of characters resulted in a 97.8% match with molecular species identification.

scholarly journals Dead man’s fingers point towards new species: A taxonomic revision of Alcyonium aurantiacum with statistical discrimination methods and a survey of integrative taxonomy in Octocorallia

2021 ◽  
Author(s):  
◽  
Gustav Kessel
Keyword(s):  
New Species ◽  
New Zealand ◽  
Legal Protection ◽  
Molecular Data ◽  
Integrative Taxonomy ◽  
Colony Morphology ◽  
Integrative Approach ◽  
Species Discrimination ◽  
Similar Species ◽  
Anthropogenic Pressure

<p><b>Octocorals are a diverse group of sessile, colonial, filter-feeding anthozoan cnidarians, which form significant components of benthic marine communities worldwide. Globally, the most critical hurdle to the effective management of octocorals in the face of increasing anthropogenic pressure is the poor state of their species-level taxonomy, which hinders understanding of their biodiversity. New Zealand’s octocoral assemblage is among the most diverse of any country and is characterised by high levels of endemism, yet over half of its octocoral species remain undescribed. While progress is being made, this has focussed almost exclusively on protected deep-sea gorgonian octocorals.</b></p> <p>Unprotected coastal soft corals are less studied in New Zealand. This includes the endemic Alcyonium aurantiacum Quoy and Gaimard, 1833. Multiple, morphologically diverse forms have been attributed to this species. Here, the taxonomic status of A. aurantiacum is reviewed, and its phylogenetic relationships are examined using molecular data (nuclear 28S and mitochondrial MutS genes), which is compared to morphology in an integrative approach. As a result, evidence for two new, endemic genera and ten new species is presented. Alcyonium aurantiacum is referred to Kotatea gen. n. (as K. aurantiaca comb. n.), which contains seven additional new species. A second genus, Ushanaia gen. n., contains three new species.</p> <p>Of the new taxa described herein, K. aurantiaca and K. lobata sp. n. are the most commonly encountered and widespread, yet little is known regarding their biology. Both species co-occur in their natural habitat, could not be differentiated genetically with the tools used here, and can be difficult to distinguish without microscopic sclerite examinations. To facilitate the identification of these two similar species by non-taxonomists, a statistical model was developed that can discriminate them with up to 90% accuracy using easily obtainable measurements of gross colony morphology. Relationships between colony morphology and depth are also examined.</p> <p>Considering the difficulties associated with species discrimination among octocorals, a literature survey was conducted to review the use of integrative taxonomy in this group since the start of the 21st century, focusing particularly on morpho-molecular data comparisons. This revealed that, while description rates at family, genus, and species levels over the last twenty-one years rank among the highest ever, integrative techniques have been applied unevenly across taxonomic groups and geographic regions and overall remain a minority compared to taxonomic research based solely on morphology. Implementation of the integrative approach is increasing, however, as are the per-annum number of taxonomic publications and the total pool of authors associated with these publications.</p> <p>It is hoped that the research presented herein can contribute to ongoing global efforts of revising octocoral systematics and that the examination of integrative practices in octocoral taxonomy will serve as a baseline against which future taxonomic progress can be compared and promoted. For New Zealand specifically, elucidating the taxonomy and variability of these endemic taxa will enable aspects such as their contribution to ecosystem functioning and management needs to be examined accurately for the first time, which in turn may lead to their recognition as organisms worthy of legal protection.</p>

scholarly journals Dead man’s fingers point towards new species: A taxonomic revision of Alcyonium aurantiacum with statistical discrimination methods and a survey of integrative taxonomy in Octocorallia

2021 ◽  
Author(s):  
◽  
Gustav Kessel
Keyword(s):  
New Species ◽  
New Zealand ◽  
Legal Protection ◽  
Molecular Data ◽  
Integrative Taxonomy ◽  
Colony Morphology ◽  
Integrative Approach ◽  
Species Discrimination ◽  
Similar Species ◽  
Anthropogenic Pressure

<p><b>Octocorals are a diverse group of sessile, colonial, filter-feeding anthozoan cnidarians, which form significant components of benthic marine communities worldwide. Globally, the most critical hurdle to the effective management of octocorals in the face of increasing anthropogenic pressure is the poor state of their species-level taxonomy, which hinders understanding of their biodiversity. New Zealand’s octocoral assemblage is among the most diverse of any country and is characterised by high levels of endemism, yet over half of its octocoral species remain undescribed. While progress is being made, this has focussed almost exclusively on protected deep-sea gorgonian octocorals.</b></p> <p>Unprotected coastal soft corals are less studied in New Zealand. This includes the endemic Alcyonium aurantiacum Quoy and Gaimard, 1833. Multiple, morphologically diverse forms have been attributed to this species. Here, the taxonomic status of A. aurantiacum is reviewed, and its phylogenetic relationships are examined using molecular data (nuclear 28S and mitochondrial MutS genes), which is compared to morphology in an integrative approach. As a result, evidence for two new, endemic genera and ten new species is presented. Alcyonium aurantiacum is referred to Kotatea gen. n. (as K. aurantiaca comb. n.), which contains seven additional new species. A second genus, Ushanaia gen. n., contains three new species.</p> <p>Of the new taxa described herein, K. aurantiaca and K. lobata sp. n. are the most commonly encountered and widespread, yet little is known regarding their biology. Both species co-occur in their natural habitat, could not be differentiated genetically with the tools used here, and can be difficult to distinguish without microscopic sclerite examinations. To facilitate the identification of these two similar species by non-taxonomists, a statistical model was developed that can discriminate them with up to 90% accuracy using easily obtainable measurements of gross colony morphology. Relationships between colony morphology and depth are also examined.</p> <p>Considering the difficulties associated with species discrimination among octocorals, a literature survey was conducted to review the use of integrative taxonomy in this group since the start of the 21st century, focusing particularly on morpho-molecular data comparisons. This revealed that, while description rates at family, genus, and species levels over the last twenty-one years rank among the highest ever, integrative techniques have been applied unevenly across taxonomic groups and geographic regions and overall remain a minority compared to taxonomic research based solely on morphology. Implementation of the integrative approach is increasing, however, as are the per-annum number of taxonomic publications and the total pool of authors associated with these publications.</p> <p>It is hoped that the research presented herein can contribute to ongoing global efforts of revising octocoral systematics and that the examination of integrative practices in octocoral taxonomy will serve as a baseline against which future taxonomic progress can be compared and promoted. For New Zealand specifically, elucidating the taxonomy and variability of these endemic taxa will enable aspects such as their contribution to ecosystem functioning and management needs to be examined accurately for the first time, which in turn may lead to their recognition as organisms worthy of legal protection.</p>

scholarly journals Rapid, large-scale species discovery in hyperdiverse taxa using 1D MinION sequencing

BMC Biology ◽  
2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Amrita Srivathsan ◽  
Emily Hartop ◽  
Jayanthi Puniamoorthy ◽  
Wan Ting Lee ◽  
Sujatha Narayanan Kutty ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Large Scale ◽  
Low Cost ◽  
Small Body ◽  
Small Subset ◽  
Similar Species ◽  
Large Species ◽  
Morphological Examination ◽  
Species Discovery ◽  
Short Period

Abstract Background More than 80% of all animal species remain unknown to science. Most of these species live in the tropics and belong to animal taxa that combine small body size with high specimen abundance and large species richness. For such clades, using morphology for species discovery is slow because large numbers of specimens must be sorted based on detailed microscopic investigations. Fortunately, species discovery could be greatly accelerated if DNA sequences could be used for sorting specimens to species. Morphological verification of such “molecular operational taxonomic units” (mOTUs) could then be based on dissection of a small subset of specimens. However, this approach requires cost-effective and low-tech DNA barcoding techniques because well-equipped, well-funded molecular laboratories are not readily available in many biodiverse countries. Results We here document how MinION sequencing can be used for large-scale species discovery in a specimen- and species-rich taxon like the hyperdiverse fly family Phoridae (Diptera). We sequenced 7059 specimens collected in a single Malaise trap in Kibale National Park, Uganda, over the short period of 8 weeks. We discovered > 650 species which exceeds the number of phorid species currently described for the entire Afrotropical region. The barcodes were obtained using an improved low-cost MinION pipeline that increased the barcoding capacity sevenfold from 500 to 3500 barcodes per flowcell. This was achieved by adopting 1D sequencing, resequencing weak amplicons on a used flowcell, and improving demultiplexing. Comparison with Illumina data revealed that the MinION barcodes were very accurate (99.99% accuracy, 0.46% Ns) and thus yielded very similar species units (match ratio 0.991). Morphological examination of 100 mOTUs also confirmed good congruence with morphology (93% of mOTUs; > 99% of specimens) and revealed that 90% of the putative species belong to the neglected, megadiverse genus Megaselia. We demonstrate for one Megaselia species how the molecular data can guide the description of a new species (Megaselia sepsioides sp. nov.). Conclusions We document that one field site in Africa can be home to an estimated 1000 species of phorids and speculate that the Afrotropical diversity could exceed 200,000 species. We furthermore conclude that low-cost MinION sequencers are very suitable for reliable, rapid, and large-scale species discovery in hyperdiverse taxa. MinION sequencing could quickly reveal the extent of the unknown diversity and is especially suitable for biodiverse countries with limited access to capital-intensive sequencing facilities.

scholarly journals Tardigrades of Kristianstads Vattenrike Biosphere Reserve with description of four new species from Sweden

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Edoardo Massa ◽  
Roberto Guidetti ◽  
Michele Cesari ◽  
Lorena Rebecchi ◽  
K. Ingemar Jönsson
Keyword(s):  
New Species ◽  
Laser Scanning ◽  
New Records ◽  
Biosphere Reserve ◽  
Morphological Characters ◽  
Sem Analysis ◽  
Morphological Data ◽  
Integrative Approach ◽  
Confocal Laser ◽  
Biological Value

AbstractKristianstads Vattenrike Biosphere Reserve [KVBR] is a UNESCO designated area of Sweden possessing high biological value. Although several studies on tardigrades inhabiting Sweden have been performed, the KVBR area has been neglected. The current study investigates the tardigrade fauna of five areas of the biosphere reserve and includes 34 samples of different substrates analysed quantitatively and qualitatively. In total, 33 species of tardigrades were found in the samples, including 22 new records for the Skåne region, 15 new records for Sweden, and four species new to science. Mesobiotus emiliae sp. nov., Xerobiotus gretae sp. nov., Itaquascon magnussoni sp. nov., and Thulinius gustavi sp. nov. were described with an integrative approach (when possible) using morphological characters (light, electron scanning, and confocal laser scanning microscopies) and molecular markers (ITS2, 18S, 28S, cox1). A new protocol to increase morphological data was developed recovering mounted specimens within old slides for SEM analysis. Emended diagnoses for the genus Itaquascon and the transfer of Platicrista itaquasconoide to the genus Meplitumen are proposed. This study enriches the knowledge of the tardigrade biodiversity both within the KVBR and in Sweden and contributes to the rapidly increasing number of tardigrade species reported worldwide. The 33 species identified in the KVBR area represents 28% of all water bear species found in Sweden so far. The restricted study areas and limited number of samples collected suggests that the KVBR is very rich of tardigrades.

scholarly journals New Species and New Records of Sponge-Inhabiting Barnacles (Cirripedia, Balanidae, Acastinae) from Australia

Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 290
Author(s):  
Andrew M. Hosie ◽  
Jane Fromont ◽  
Kylie Munyard ◽  
Diana S. Jones
Keyword(s):  
New Species ◽  
New Records ◽  
Morphological Characters ◽  
Genetic Distances ◽  
Similar Species ◽  
Diverse Group ◽  
Undescribed Species

The subfamily Acastinae contains a diverse group of barnacles that are obligate symbionts of sponges and alcyonacean and antipatharian corals. Integrating morphological and genetic (COI) data to compare against known species, this paper reports on nine species of sponge-inhabiting barnacles of the subfamily Acastinae, including three undescribed species (Acasta caveata sp. nov., Euacasta acutaflava sp. nov., and E. excoriatrix sp. nov.) and three species previously not recorded in Australian waters (A. sandwichi, Pectinoacasta cancellorum, and P. sculpturata). The new species are distinguished from similar species by a suite of morphological characters as well as genetic distances. A lectotype for Pectinoacasta cancellorum is designated. Sponge hosts were identified for all specimens where possible and are represented by 19 species from eight families and five orders.

scholarly journals Nothing in (sponge) biology makes sense – except when based on holotypes

2015 ◽  
Vol 96 (2) ◽  
pp. 305-311 ◽  
Author(s):  
Dirk Erpenbeck ◽  
Merrick Ekins ◽  
Nicole Enghuber ◽  
John N.A. Hooper ◽  
Helmut Lehnert ◽  
...  
Keyword(s):  
New Species ◽  
Reference Material ◽  
Species Identification ◽  
Dna Sequences ◽  
Morphological Plasticity ◽  
Morphological Characters ◽  
Molecular Techniques ◽  
Reference Sequences ◽  
Species Descriptions ◽  
Preservation History

Sponge species are infamously difficult to identify for non-experts due to their high morphological plasticity and the paucity of informative morphological characters. The use of molecular techniques certainly helps with species identification, but unfortunately it requires prior reference sequences. Holotypes constitute the best reference material for species identification, however their usage in molecular systematics and taxonomy is scarce and frequently not even attempted, mostly due to their antiquity and preservation history. Here we provide case studies in which we demonstrate the importance of using holotype material to answer phylogenetic and taxonomic questions. We also demonstrate the possibility of sequencing DNA fragments out of century-old holotypes. Furthermore we propose the deposition of DNA sequences in conjunction with new species descriptions.

Two new species in the Ficinia indica complex (Cyperaceae, tribe Cypereae) from South Africa

Phytotaxa ◽  
2017 ◽  
Vol 295 (1) ◽  
pp. 49
Author(s):  
ALUWANI A. TSHIILA ◽  
SAMSON B.M. CHIMPHANGO ◽  
JAN-ADRIAAN VILJOEN ◽  
A. MUTHAMA MUASYA
Keyword(s):  
New Species ◽  
Region Growing ◽  
Distinct Species ◽  
Cape Floristic Region ◽  
Morphological Data ◽  
Similar Species ◽  
Ecological Features ◽  
Dichotomous Key ◽  
As Species ◽  
Two New Species

Unclear boundaries between species hinder identification in the field and in herbaria, especially in species groups that can only be distinguished on the basis of subtle morphological and ecological features. One such taxon is Ficinia indica, widespread in the Greater Cape Floristic Region, growing on deep sandy soils between sea level and 1000 m elevation. Within its range, several phylogenetically related and morphologically similar species co-occur or occupy distinct habitats. Studies in herbaria show species in the Ficinia indica complex to be largely misidentified based on the use of qualitative information. Here, we investigate whether the six taxa recognized, based on one or a few characters, are supported as distinct species based on multivariate analysis of macro-morphological data. Two of the taxa were mostly separated whereas the other four taxa overlapped in multivariate space, but all the taxa could be distinguished using a single or a combination of morphological and ecological characters. We uphold the four previously recognized taxa (Ficinia argyropus, F. elatior, F. indica, F. laevis) as species, describe two new species (F. arnoldii and F. montana), and provide a dichotomous key for their identification.

scholarly journals Colouration, chaetotaxy and molecular data provide species-level resolution in a species complex of Dicranocentrus (Collembola : Entomobryidae)

2018 ◽  
Vol 32 (6) ◽  
pp. 1298 ◽  
Author(s):  
Feng Zhang ◽  
Daoyuan Yu ◽  
Mark I. Stevens ◽  
Yinhuan Ding
Keyword(s):  
Species Complex ◽  
Instar Larva ◽  
Molecular Data ◽  
Integrative Taxonomy ◽  
Species Level ◽  
Integrative Approach ◽  
Gene Markers ◽  
Late Neogene ◽  
Taxonomic Approach ◽  
Colour Patterns

Integrative taxonomic approaches are increasingly providing species-level resolution to ‘cryptic’ diversity. In the absence of an integrative taxonomic approach, formal species validation is often lacking because of inadequate morphological diagnoses. Colouration and chaetotaxy are the most commonly used characters in collembolan taxonomy but can cause confusion in species diagnoses because these characters often have large intraspecific variation. Here, we take an integrative approach to the genus Dicranocentrus in China where four species have been previously recognised, but several members of the genus have been morphologically grouped as a species complex based on having paired outer teeth on unguis and seven colour patterns. Molecular delimitations based on distance- and evolutionary models recovered four candidate lineages from three gene markers and revealed that speciation events likely occurred during the late Neogene (4–13million years ago). Comparison of intact dorsal chaetotaxy, whose homologies were erected on the basis of first instar larva, further validated these candidates as formal species: D. gaoligongensis, sp. nov., D. similis, sp. nov., D. pallidus, sp. nov. and D. varicolor, sp. nov., and increase the number of Dicranocentrus species from China to eight. Our study further highlights the importance of adequate taxonomy in linking morphological and molecular characters within integrative taxonomy.

Reestablishment of Cabomba schwartzii (Cabombaceae), an aquatic plant species endemic to the Brazilian Amazon

Phytotaxa ◽  
2018 ◽  
Vol 367 (3) ◽  
pp. 245 ◽  
Author(s):  
TIAGO D. M. BARBOSA ◽  
RAFAELA J. TRAD ◽  
MIKLOS M. BAJAY ◽  
MARIA I. ZUCCHI ◽  
MARIA DO CARMO E. DO AMARAL
Keyword(s):  
Geographical Distribution ◽  
Plant Species ◽  
Genetic Study ◽  
Aquatic Plant ◽  
Brazilian Amazon ◽  
Distinct Species ◽  
Morphological Characters ◽  
Species Description ◽  
Dichotomous Key ◽  
Herbarium Collections

Cabomba schwartzii was described by Rataj in 1977. The species discovered in the Brazilian Amazon was said to differ from other Cabomba species in having two sepals, two petals and a lobate petal base. According to the 1991 study of Ørgaard, C. schwartzii is similar to C. aquatica in other morphological characters (C. aquatica has flowers with three sepals and three petals) and since variation in number of floral parts is common in the genus, Ørgaard synonymized both species. After an analysis of C. schwartzii type material, other herbarium collections and location of four populations (two with C. schwartzii characteristics and two with C. aquatica characteristics), we conducted an integrated morphological and genetic study to evaluate whether or not C. schwartzii is a distinct species from C. aquatica. The results reveal the species to be distinct from each other and therefore C. schwartzii should be reestablished. The floral formula for C. schwartzii is K2 C2 A2+2 G1, versus K3 C3 A3+3 G2 for C. aquatica. A detailed species description and the geographical distribution of C. schwartzii are presented with a dichotomous key to distinguish both species, together with illustrations.

Sign in / Sign up

Export Citation Format

Share Document