scholarly journals Phylogeography and molecular species delimitation reveal cryptic diversity in Potamolithus (Caenogastropoda: Tateidae) of the southwest basin of the Andes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gonzalo A. Collado ◽  
Cristian Torres-Díaz ◽  
Moisés A. Valladares

AbstractThe species of the genus Potamolithus inhabiting the southwestern basin of the Andes are difficult to distinguish due to small size and similar shell morphology. Only Potamolithus australis and Potamolithus santiagensis have been traditionally recognized in this region, but the occurrence of several morphologically similar undescribed populations could increase the regional richness. Here we delimit described and potentially undescribed cryptic species of the genus using partial sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Network analysis and diversity indices inferred six highly differentiated haplogroups, many of them sympatric and widespread in the study area. Phylogeographic analyses suggest a scenario of recent diversification and the occurrence of multiple refuges during the successive Pleistocene glaciations. Phylogenetic analysis also recovered six major clades that showed no relationship with physiography. Species delimitation analyses consistently recognized three or four candidate species apart from P. australis and P. santiagensis. Divergence times indicate that speciation of Chilean Potamolithus began at the end of the Pliocene, probably driven by climatic rather than geographic events. Considering the high inter- and intra-basin genetic diversity, conservation efforts should be focused on protecting sympatric taxa in the basins with the highest species richness.

2020 ◽  
Author(s):  
Kevin I. Sánchez ◽  
Luciano J. Avila ◽  
Jack W. Sites ◽  
Mariana Morando

AbstractRecent conceptual and methodological advances have enabled an increasing number of studies to address the problem of species delimitation in a comprehensive manner. This is of particular interest in cases of species whose divergence times are recent, where the conclusions obtained from a single source of evidence can lead to the incorrect delimitation of entities or assignment of individuals to species. The southernmost species of the Liolaemus kingii group (namely L. baguali, L. escarchadosi, L. sarmientoi, L. tari and the candidate species L. sp. A) show widely overlapping distributions as well as recent mitochondrial divergences, thus phylogenetic relationships and species boundaries are ambiguous. Here we use a comprehensive approach to assess species limits and corroborate their status as independent lineages through the use of four sources of molecular and morphological information (mitochondrial cytochrome-b, nuclear sequences collected by ddRADseq, and linear, meristic and landmark-based morphometrics). We found concordance among the different datasets, but signs of admixture were detected between some of the species. Our results indicate that the L. kingii group can serve as a model system in studies of diversification accompanied by hybridization in nature. We emphasize the importance of using multiple lines of evidence in order to solve evolutionary stories, and minimizing potential erroneous results that may arise when relying on a single source of information.


2020 ◽  
Vol 190 (2) ◽  
pp. 532-557 ◽  
Author(s):  
Paul Zaharias ◽  
Yuri I Kantor ◽  
Alexander E Fedosov ◽  
Francesco Criscione ◽  
Anders Hallan ◽  
...  

Abstract The practice of species delimitation using molecular data commonly leads to the revealing of species complexes and an increase in the number of delimited species. In a few instances, however, DNA-based taxonomy has led to lumping together of previously described species. Here, we delimit species in the genus Cryptogemma (Gastropoda: Conoidea: Turridae), a group of deep-sea snails with a wide geographical distribution, primarily by using the mitochondrial COI gene. Three approaches of species delimitation (ABGD, mPTP and GMYC) were applied to define species partitions. All approaches resulted in eight species. According to previous taxonomic studies and shell morphology, 23 available names potentially apply to the eight Cryptogemma species that were recognized herein. Shell morphometrics, radular characters and geographical and bathymetric distributions were used to link type specimens to these delimited species. In all, 23 of these available names are here attributed to seven species, resulting in 16 synonymizations, and one species is described as new: Cryptogemma powelli sp. nov. We discuss the possible reasons underlying the apparent overdescription of species within Cryptogemma, which is shown here to constitute a rare case of DNA-based species lumping in the hyper-diversified superfamily Conoidea.


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 290
Author(s):  
Hua-Yan Chen ◽  
Hong-Liang Li ◽  
Hong Pang ◽  
Chao-Dong Zhu ◽  
Yan-Zhou Zhang

The cotton mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae), is an emerging invasive insect pest in China. Hymenopteran parasitoids are the key organisms for suppressing populations of P. solenopsis in the field, and therefore could be used as biological agents. Accurate identification of the associated parasitoids is the critical step to assess their potential role in biological control. In this study, we facilitated the identification of the parasitoid composition of P. solenopsis using an integrated approach of species delimitation, combining morphology with molecular data. Eighteen Hymenoptera parasitoid species belonging to 11 genera of four families are recognized based on morphological examination and molecular species delimitation of the mitochondrial cytochrome c oxidase 1 (COI) gene and the 28S rDNA using the automatic barcode gap discovery (ABGD) and the Bayesian Poisson tree processes model (bPTP). Among these species, eight species are primary parasitoids with Aenasius arizonensis (Girault) (Hymenoptera: Encyrtidae) being the dominant taxon, while the other 10 species are probably hyperparasitoids, with a prevalence of Cheiloneurus nankingensis Li & Xu (Hymenoptera: Encyrtidae). These results indicate that parasitoid wasps associated with P. solenopsis from China are diverse and the integrated taxonomic approach applied in this study could enhance the accurate identification of these parasitoids that should be assessed in future biological control programs.


Zootaxa ◽  
2021 ◽  
Vol 5040 (3) ◽  
pp. 334-364
Author(s):  
MAURICIO RIVERA-CORREA ◽  
GUSTAVO A. GONZÁLEZ-DURÁN ◽  
ANA M. SALDARRIAGA-GÓMEZ ◽  
SEBASTIÁN DUARTE-MARÍN

Frequent biodiversity sampling and monitoring programs often lead to relevant taxonomic findings. Here, as a product of different field expeditions to two places in the northern Andes, we discover and describe two new species of rain frogs of the genus Pristimantis from the cloud forests of the Central Cordillera of Colombia. Pristimantis chocolatebari sp. nov. is diagnosed by having the following character states: dentigerous process of vomer triangular, snout large and protruding, dorsum smooth, vocal slits and vocal sac present, groin and hidden part of the thighs yellow. Pristimantis carylae sp. nov. is diagnosed by having iris copper red, dentigerous process of vomer oval, snout short and rounded, dorsum finely shagreen with scattered tubercles, double nuptial pad in males, groin and hidden part of thighs pink. We also infer, for the first time, the phylogenetic position of P. permixtus, P. platychilus, and two candidate new species. In addition, we emphasize not to use genetic distance as the only source of evidence for species delimitation, considering the high intraspecific diversity found in one of the species described here. Finally, we highlight the relevance of different habitat and ecosystem conservation strategies to promote amphibian diversity studies in the Andes.  


2016 ◽  
Vol 94 (suppl_4) ◽  
pp. 76-77
Author(s):  
R. Xiang ◽  
J. McNally ◽  
S. J. Rowe ◽  
A. Jonker ◽  
C. Pinares-Patino ◽  
...  

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