scholarly journals Mitochondrial and morphological differentiation in a previously unrecognized radiation of the land snail genus Parachloritis Ehrmann, 1912 on Timor (Pulmonata: Camaenidae)

2014 ◽  
Vol 83 (1) ◽  
pp. 1-40 ◽  
Author(s):  
Frank Köhler ◽  
Vince Kessner

The present work revises the taxonomy of one group of camaenid gastropods from Timor-Leste based on the study of a large number of recently collected ethanol preserved samples as well as historic museum material, including types. By employing comparative analyses of the variation in morphological features (shell, penial anatomy) and the differentiation in mitochondrial DNA sequences of the cytochrome c oxidase subunit 1 gene (COI) and the 16S rDNA (16S), altogether nineteen species are recognized from Timor-Leste and adjacent areas in the Lesser Sunda and Moluccas, such as West-Timor, Adonara, Leti and Sermata Islands (Indonesia). Four of these species were described previously and have mostly been placed within the genus Chloritis Beck, 1837 in the few historic treatments available. Fifteen species found to be new are formally described. In contrast to the previous taxonomic treatment, placement in the genus Parachloritis Ehrmann, 1912 is proposed on grounds of comparative shell morphology. Molecular phylogenetic analyses revealed that all examined species form a monophyletic group, which encompasses diverse shell forms. While most species have shells of the general chloritid type, which are of little taxonomic utility, highly distinct shell morphs (trochoid shells, dwarf forms) have originated within this radiation in independent lineages. Morphological change has occurred in some taxonomic lineages while the bulk of Parachloritis species has maintained an ancestral shell phenotype. This phenotypic stasis is attributed to stabilizing selection in species, which have maintained associations with ancestral habitats, while distinct shell forms have evolved as result of habitat shifts. Consequently, purely shellbased taxonomies are prone to errors due to misjudging the significance of shell characters. While some Parachloritis species uncovered here were found to be narrowly endemic, others had wide distributions that include more than one island. Narrow range endemism was predominantly found in dwarf species and in species that live in high altitudes.

ZooKeys ◽  
2020 ◽  
Vol 996 ◽  
pp. 37-58
Author(s):  
Pei Wang ◽  
Mei-Ling Hu ◽  
Jun-Hong Lin ◽  
Hai-Fang Yang ◽  
Xiao-Jing Li ◽  
...  

In this study, four new dextral camaenid from China are reported, based on shell morphology, reproductive system anatomy, and molecular phylogenetic analyses: Camaena funingensis Zhou, Wang & Lin, sp. nov., Camaena gaolongensis Zhou, Wang & Lin, sp. nov., Camaena maguanensis Zhou, Wang & Hu, sp. nov., and Camaena yulinensis Zhou, Wang & Hu, sp. nov. Detailed descriptions of the morphological characteristics including shells and genitalia, DNA sequences, and living environments of the four new species are provided, with further comparisons with congeners.


2012 ◽  
Vol 279 (1737) ◽  
pp. 2396-2401 ◽  
Author(s):  
Rachunliu G. Kamei ◽  
Diego San Mauro ◽  
David J. Gower ◽  
Ines Van Bocxlaer ◽  
Emma Sherratt ◽  
...  

The limbless, primarily soil-dwelling and tropical caecilian amphibians (Gymnophiona) comprise the least known order of tetrapods. On the basis of unprecedented extensive fieldwork, we report the discovery of a previously overlooked, ancient lineage and radiation of caecilians from threatened habitats in the underexplored states of northeast India. Molecular phylogenetic analyses of mitogenomic and nuclear DNA sequences, and comparative cranial anatomy indicate an unexpected sister-group relationship with the exclusively African family Herpelidae. Relaxed molecular clock analyses indicate that these lineages diverged in the Early Cretaceous, about 140 Ma. The discovery adds a major branch to the amphibian tree of life and sheds light on both the evolution and biogeography of caecilians and the biotic history of northeast India—an area generally interpreted as a gateway between biodiversity hotspots rather than a distinct biogeographic unit with its own ancient endemics. Because of its distinctive morphology, inferred age and phylogenetic relationships, we recognize the newly discovered caecilian radiation as a new family of modern amphibians.


Phytotaxa ◽  
2019 ◽  
Vol 427 (1) ◽  
pp. 31-42
Author(s):  
LEI SHU ◽  
RUI-LIANG ZHU

Based on molecular phylogenetic analyses and morphological characters, a new species from Bangladesh, northern Vietnam, and southwestern China, Leptolejeunea nigra, is described. It is mostly similar to L. balansae but remarkable for having brownish black ocelli in its leaf lobes. In the molecular phylogeny, the samples of L. nigra are not nested within any clade and form an independent lineage. In particular, the molecular dating suggested that the divergence of L. nigra happened in time span of the formation of the Himalayas.


2016 ◽  
Vol 4 (1) ◽  
pp. 35 ◽  
Author(s):  
Topik Hidayat ◽  
Adi Pancoro

<p>Early information<br />resulted from molecular phylogenetic studies of many important<br />ornamental crops is often less attention to many<br />growers and farmers. Phylogenetics is one of the most preferable<br />method in systematics to reconstruct evolutionary<br />relationships of groups of biological organisms in order to<br />understand their biodiversities. This has been revolutionized<br />by DNA sequences data. In this method, a group of organisms<br />that shares many identical characteristics are considered<br />to be closely related; deriving from a common<br />ancestor and is assumed to have similar genetic patterns<br />and biochemical properties. By these basic principles,<br />molecular phylogenetics plays important roles in revealing a<br />basic knowledge on pattern of relationships to which<br />genetic resources can be improved. Over the past decade,<br />botanists have done several thousand phylogenetic analyses<br />based on molecular data of economically and horticulturally<br />important crops. Orchids are the best example for this.<br />There is no doubt that most orchid plants had played roles in<br />horticulture and hybridization. At present, many infrageneric<br />and intergeneric hybrids are available commercially. Successful<br />hybridization can be achieved if two or more individual<br />plants understudy are closely related in respect to their<br />genetics and evolution.</p>


Author(s):  
Alexander Kieneke ◽  
M Antonio Todaro

Abstract Sublittoral sand from the islands of Sardinia (Italy) and Flores (Azores) – separated by more than 3700 km linear distance and 8 years between two independent sampling campaigns – yielded conspicuous specimens of two bizarre, yet undescribed, species of the marine gastrotrich clade Macrodasyida. These gastrotrichs combine several character traits that were already known from two, non-related genera. Morphological data were carefully analysed and digitally documented, and nuclear and mitochondrial DNA sequences were used for phylogenetic inference. The results of these analyses claim for the erection of a new genus. Specimens of the new taxon have a body length of less than 400 µm and are characterized by a wide, funnel-shaped mouth opening shielded dorsally by an oral hood and possess a posterior peduncle that ends with a Y-shaped pair of appendages that carry the posterior adhesive tubes. Further tubes occur as anterior, ventrolateral and lateral series; the gonads are unpaired and there is a set of two accessory reproductive organs. Molecular phylogenetic analyses confirm the results of former studies and clearly place the new taxon in Thaumastodermatidae. We hereby propose the establishment of Chimaeradasys gen. nov. and describe C. oligotubulatus sp. nov. from the Azores and C. polytubulatus sp. nov. from Sardinia.


Zootaxa ◽  
2021 ◽  
Vol 4948 (3) ◽  
pp. 439-446
Author(s):  
XUAN AN ◽  
WA DA ◽  
MIN WANG ◽  
HOUSHUAI WANG

A new species, Daplasa medoga sp. nov., is described from Tibet, China. The new species can be distinguished morphologically from all other known Daplasa species by its male genitalia with a sagittate uncus and distally broadly crotched valvae. The validity of new species is well supported by the molecular phylogenetic analyses of one mitochondrial gene (COI) and two nuclear genes (EF-1α & RPS5), with a total length of 2,324 bp. 


2020 ◽  
Vol 194 (4) ◽  
pp. 439-459
Author(s):  
Elisa Silva Cândido ◽  
Mohammad Vatanparast ◽  
Wanderleia de Vargas ◽  
Luísa M P A Bezerra ◽  
Gwilym P Lewis ◽  
...  

Abstract Eriosema comprises c. 150 species and has a pantropical distribution and two centres of diversity, Africa and America. The species occur in tropical savannas and grasslands, including the cerrado in Brazil. They have adapted to these environments by developing specialized underground organs, and an abundance of trichomes. Here we present the first comprehensive molecular phylogenetic analysis of Eriosema, including species from its entire distribution range and generating 391 new DNA sequences. We sampled 140 species from nine genera of Cajaninae, of which 94 (60% of the genus) were Eriosema. Our analyses were based on the nuclear ITS and plastid rpl32 and trnQ regions, and used maximum likelihood and Bayesian phylogenetic analyses of individual and combined data sets. In all analyses, Eriosema was resolved as monophyletic, but its interspecific relationships are not well resolved. Rhynchosia is not monophyletic, and some African Rhynchosia spp. emerged together as sister to Eriosema. Our study supports the monophyly of Adenodolichos, Dunbaria, Flemingia and Cajanus, but Chrysoscias and Bolusafra formed a clade that is sister to a group of Rhynchosia spp. Paracalyx was resolved as paraphyletic and nested among African Rhynchosia spp. Divergence time analysis suggested that the Eriosema lineages diverged 6.5–10.7 Mya. Two major lineages have diversified in Eriosema, one including most of the African species (4.41–6.68 Mya), the other mainly composed of the South American cerrado species (3.56–5.78 Mya). These results revealed that Eriosema is a recent and tropical savanna-adapted group, and its diversification occurred in the late Miocene in parallel with the expansion of C4 grasslands.


2020 ◽  
Vol 94 ◽  
Author(s):  
G. Pérez-Ponce de León ◽  
A.L. Sereno-Uribe ◽  
M. García-Varela ◽  
B. Mendoza-Garfias ◽  
D.I. Hernández-Mena ◽  
...  

Abstract Species of the allocreadiid genus Creptotrema are parasites of freshwater fishes in the Americas. Species in the genus possess one pair of muscular oral lobes on the oral sucker. Currently, the genus contains eight species, six distributed in South America, one in Middle America and one in North America. Genetic data are only available for the North American species, Creptotrema funduli, a parasite of fundulids originally described from Oneida Lake, New York State. In this study, we obtained 28S ribosomal DNA sequences of trematodes morphologically similar to Creptotrema agonostomi from the mountain mullet, Dajaus monticola, across a wide geographical range in Middle America. Our molecular phylogenetic analyses showed that (1) the genus Creptotrema, as currently conceived, is not monophyletic; (2) the allocreadiids in mountain mullets should be re-allocated in the genus Pseudoparacreptotrema; and (3) the allocreadiid trematodes from D. monticola across Middle America represent four morphologically similar species, three of which can be distinguished genetically. These three new species are described herein using an integrative taxonomy approach. We contend that accurate estimates of species diversity and phylogenetic relationships among allocreadiids, and most likely other species of trematodes, necessarily require an integrative taxonomy approach that should consider at least DNA sequences and scanning electron microscopy.


Phytotaxa ◽  
2017 ◽  
Vol 296 (2) ◽  
pp. 171 ◽  
Author(s):  
SAROJ RUCHISANSAKUN ◽  
PIYAKASET SUKSATHAN ◽  
TIMOTHEÜS VAN DER NIET ◽  
SAW LWIN ◽  
STEVEN B. JANSSENS

Impatiens tanintharyiensis Ruchisansakun, Suksathan & Saw-Lwin from the Tanintharyi region of Southern Myanmar is described and illustrated as a new species. The presence of connate lateral united petals and a four-locular ovary, as well as results of molecular phylogenetic analyses of nuclear ITS and plastid atpB-rbcL spacer DNA sequences, suggest that the new species is a member of Impatiens section Semeiocardium (Zoll.) S.X. Yu & Wei Wang. The new species is morphologically most similar to I. spectabilis Triboun & Suksathan, but can be distinguished by its asymmetric flowers, saccate-bucciniform lower sepal, and shorter, slightly incurved spur. Floral traits, including the presence of a large floral chamber with a wide entrance, are consistent with the bee-pollination syndrome in Impatiens. Since I. tanintharyiensis is only known from two small populations, its conservation status is assessed as Endangered.


ZooKeys ◽  
2020 ◽  
Vol 943 ◽  
pp. 119-144 ◽  
Author(s):  
Ning Xu ◽  
Shi-Ze Li ◽  
Jing Liu ◽  
Gang Wei ◽  
Bin Wang

A new species of the genus Megophrys is described from Guizhou Province, China. Molecular phylogenetic analyses based on mitochondrial DNA and nuclear DNA sequences all strongly supported the new species as an independent clade sister to M. minor and M. jiangi. The new species could be distinguished from its congeners by a combination of the following characters: body size moderate (SVL 43.4–44.1 mm in males, and 44.8–49.8 mm in females; vomerine teeth absent; tongue not notched behind; a small horn-like tubercle at the edge of each upper eyelid; tympanum distinctly visible, rounded; two metacarpal tubercles on palm; relative finger lengths II &lt; I &lt; V &lt; III; toes without webbing; heels overlapping when thighs are positioned at right angles to the body; tibiotarsal articulation reaching the level between tympanum and eye when leg stretched forward; in breeding males, an internal single subgular vocal sac in male, and the nuptial pads with black spines on dorsal surface of bases of the first two fingers.


Sign in / Sign up

Export Citation Format

Share Document