Unraveling hidden biodiversity: An example of integrative taxonomy applied to the hybridizing Brachionus calyciflorus species complex

10.33540/427 ◽  
2021 ◽  
Author(s):  
◽  
Wei Zhang
2018 ◽  
Vol 32 (6) ◽  
pp. 1298 ◽  
Author(s):  
Feng Zhang ◽  
Daoyuan Yu ◽  
Mark I. Stevens ◽  
Yinhuan Ding

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.


2018 ◽  
Vol 14 (11) ◽  
pp. 20180498 ◽  
Author(s):  
Sofia Paraskevopoulou ◽  
Ralph Tiedemann ◽  
Guntram Weithoff

Under global warming scenarios, rising temperatures can constitute heat stress to which species may respond differentially. Within a described species, knowledge on cryptic diversity is of further relevance, as different lineages/cryptic species may respond differentially to environmental change. The Brachionus calyciflorus species complex (Rotifera), which was recently described using integrative taxonomy, is an essential component of aquatic ecosystems. Here, we tested the hypothesis that these (formerly cryptic) species differ in their heat tolerance. We assigned 47 clones with nuclear ITS1 (nuITS1) and mitochondrial COI (mtCOI) markers to evolutionary lineages, now named B. calyciflorus sensu stricto (s.s.) and B. fernandoi . We selected 15 representative clones and assessed their heat tolerance as a bi-dimensional phenotypic trait affected by both the intensity and duration of heat stress. We found two distinct groups, with B. calyciflorus s.s. clones having higher heat tolerance than the novel species B. fernandoi . This apparent temperature specialization among former cryptic species underscores the necessity of a sound species delimitation and assignment, when organismal responses to environmental changes are investigated.


2020 ◽  
Vol 4 (6) ◽  
Author(s):  
Nikolas P Johnston ◽  
James F Wallman ◽  
Thomas Pape

Abstract A taxonomic revision of all Australian species of Metopia Meigen (Sarcophagidae: Miltogramminae) is completed using an integrated approach combining molecular and morphological data. Metopia nudibasis (Malloch) is redescribed as a species complex and a new endemic Australian species, Metopia sputnik sp. n., is described. Evidence is presented that Metopia sauteri (Townsend) is absent from Australia and this species is therefore removed from the known Australian fauna. Molecular phylogenetics is used to reconstruct interspecific and generic relationships and support morphology-based species hypotheses. Phylogenetic analysis splits Metopia Meigen into two clades, separated by Aenigmetopia Malloch, rendering the former genus nonmonophyletic. The implications of this are discussed.


Diversity ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 522
Author(s):  
Karin Seger ◽  
Bernardo da Veiga Teixeira ◽  
Fabiane Annibale ◽  
Denise de Cerqueira Rossa-Feres ◽  
Albertina Lima ◽  
...  

One of the many taxonomic challenges found in the Dendropsophus microcephalus species group is the Dendropsophus walfordi distinction from D. nanus. Recent phylogenetic inferences have indicated the paraphyly of these species, although they were not designed to assess this issue. To contribute to the delimitation of these species, we analyzed the 12S, 16S and COI mitochondrial genes, the morphological traits, and the advertisement calls of specimens from northern Amazonia to Argentina, including the type localities of D. nanus and D. walfordi. Paraphyly of D. nanus with respect to D. walfordi was inferred by maximum-parsimony and Bayesian analyses, and five major clades exhibiting nonoverlapping geographic distributions were recognized. The bPTP and ABGD analyses supported the existence of five independently evolving lineages in this complex. Acoustic and morphological data clearly distinguished the clade that included the topotypes of D. walfordi from the others, corroborating the validity of this species. To avoid the paraphyly of D. nanus with respect to D. walfordi, we recognize the clade distributed from central-southern Brazil to Argentina as D. nanus, the clade distributed in Amazonia as D. walfordi, and discuss the existence of unnamed cryptic species closely related to D. nanus and D. walfordi.


Author(s):  
Thomas Hertach

Abstract Integrative taxonomy combines different data sources as a way to detect separately evolving metapopulation lineages or species. This method is applied to cicada populations found in northern Sardinia, based on acoustic, morphological and ecological data. Thereby, the genus Tibicina turned out to be more diverse than previously expected. Besides the anticipated Tibicina corsica corsica and T. nigronervosa, both scientifically described from the neighbouring island of Corsica, two poorly or previously unknown species have been discovered. Tibicina longisyllaba sp. nov. is here described as new. Tibicina corsica s.l. forms a small species complex where syllable periods of the song – the movement cycle of the acoustic organs – are specific without overlaps. Some coloration and hair cover characters, as well as the shape of the song apparatus, are not diagnostic on their own, but highly significant between species. Species occur sympatrically, parapatrically or allopatrically and prefer specific habitats from grassland to closed forests. All four Tibicina taxa are endemic to parts of Sardinia or to the Corso-Sardinian archipelago. The new findings are important for biodiversity conservation and public awareness. The loud, strident calling songs dominate the summer sounds of the islands. The group could form a showcase with respect to biogeography, phylogeny, speciation and sound production.


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