An unfinished speciation process revealed by geometric morphometrics, horn allometries and biomolecular analyses: The case of the fracticornis–similis–opacicollis species complex of the genus Onthophagus (Coleoptera: Scarabaeidae)

In the subfamily Triatominae, Triatoma exhibits the largest number of species, which are arranged in complexes. For the T.brasiliensis species complex, recent investigations based on results of geometric morphometrics combined with phylogeny have provided evidence that it should be composed of seven species: T.brasiliensis, T.bahiensis, T.juazeirensis, T.lenti, T.melanica, T.petrocchiae, and T.sherlocki, in which T.brasiliensis is divided in two subspecies: T.b.brasiliensis and T.b.macromelasoma. A taxonomic key is presented to identify each taxon. Among members of this complex, T.b.brasiliensis is the most important in an epidemiologic context, due to its high prevalence in natural infection by Trypanosomacruzi combined with a pronounced adaptation to domiciliary habitats. However, some members may be currently invading and colonizing homes, a process known as domiciliation. Therefore, the key presented here may be potentially useful for researchers as well as those involved in vector control measures.

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Too many species: morphometrics, molecular phylogenetics and genome structure of a Brazilian species complex in Epidendrum (Laeliinae; Orchidaceae) reveal fewer species than previously thought

Botanical Journal of the Linnean Society ◽

10.1093/botlinnean/boaa071 ◽

2020 ◽

Author(s):

Edlley M Pessoa ◽

Joel M P Cordeiro ◽

Leonardo P Felix ◽

Erton M Almeida ◽

Lucas Costa ◽

...

Keyword(s):

Geometric Morphometrics ◽

Genome Size ◽

Species Complex ◽

Molecular Phylogenetics ◽

Genome Structure ◽

Dapi Staining ◽

Canonical Variables ◽

Floral Variation ◽

Brazilian Species ◽

Species Complexes

Abstract In this study, we analyse a species complex in Epidendrum, a mega-diverse Neotropical orchid genus, that is formed by the 11 Brazilian species of the E. difforme group. Although this group (c. 100 taxa) exhibits relatively high levels of floral variation, the Brazilian species are similar, making delimitation problematic. Here we combine molecular (phylogenetics), morphological (geometric morphometrics), genome size and cytogenetic (chromosome counts and CMA/DAPI staining) data to investigate circumscription of these species. Our results were interpreted by looking for congruence of the results as a means to delimit species. The studied taxa appear to be monophyletic, and karyotypically all analysed accessions were 2n = 40. Their 1C values vary from 1.99 ± 07 pg to 2.84 ± 0.12 pg. We did not find evidence for recent polyploidy or dysploidy and, apparently, these phenomena have not been important in the evolution of this species complex. On the other hand, we found high levels of polymorphism for CMA/DAPI banding, and variation in genome size appears to be positively correlated with latitude. Geometric morphometrics indicate that E. sanchezii and E. anatipedium/E. amarajiense are distinct from the remaining species, and three groups of other species can be separated using canonical variables analysis (CVA). Variation in lip shape, genome size and heterochromatin patterns of the taxa are not fully congruent with the phylogenetic analysis, but our results allowed us to delimit with full confidence four species: E. amapense, E. anatipedium (including E. amarajiense), E. pseudodifforme (including E. campaccii and E. thiagoi) and E. sanchezii. Four others will be tentatively maintained but need further study. Our results indicate that it will be necessary to reassess many of the species complexes in the genus using a similar multidisciplinary perspective to evaluate the number of taxa that should be recognized.

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Assessment of traditional versus geometric morphometrics for discriminating populations of the Tropheus moorii species complex (Teleostei: Cichlidae), a Lake Tanganyika model for allopatric speciation

Journal of Zoological Systematics & Evolutionary Research ◽

10.1111/j.1439-0469.2007.00447.x ◽

2008 ◽

Vol 46 (2) ◽

pp. 153-161 ◽

Cited By ~ 55

Author(s):

M. Maderbacher ◽

C. Bauer ◽

J. Herler ◽

L. Postl ◽

L. Makasa ◽

...

Keyword(s):

Geometric Morphometrics ◽

Species Complex ◽

Lake Tanganyika ◽

Allopatric Speciation

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The Bunocephalus coracoideus Species Complex (Siluriformes, Aspredinidae). Signs of a Speciation Process through Chromosomal, Genetic and Ecological Diversity

Frontiers in Genetics ◽

10.3389/fgene.2017.00120 ◽

2017 ◽

Vol 8 ◽

Cited By ~ 8

Author(s):

Milena Ferreira ◽

Caroline Garcia ◽

Daniele A. Matoso ◽

Isac S. de Jesus ◽

Marcelo de B. Cioffi ◽

...

Keyword(s):

Species Complex ◽

Ecological Diversity ◽

Speciation Process

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Exploring Rattus praetor (Rodentia, Muridae) as a possible species complex using geometric morphometrics on dental morphology

Mammalian Biology ◽

10.1016/j.mambio.2018.04.002 ◽

2018 ◽

Vol 92 ◽

pp. 62-67 ◽

Cited By ~ 4

Author(s):

Ardern Hulme-Beaman ◽

Thomas Cucchi ◽

Allowen Evin ◽

Jeremy B. Searle ◽

Keith Dobney

Keyword(s):

Geometric Morphometrics ◽

Species Complex ◽

Dental Morphology

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Identification of sibling species in the genus Eucyclops from water-bodies of Ukraine and Russia using crossbreeding studies

Ecology and Noospherology ◽

10.15421/031406 ◽

2014 ◽

Vol 25 (1-2) ◽

pp. 61-68 ◽

Cited By ~ 1

Author(s):

V. I. Monchenko ◽

L. P. Gaponova ◽

V. R. Alekseev

Keyword(s):

Cryptic Species ◽

River Basin ◽

Black Sea ◽

Species Complex ◽

River Basins ◽

Water Bodies ◽

Similar Species ◽

Basin Water ◽

Different Populations ◽

Baltic Sea Basin

Crossbreeding experiments were used to estimate cryptic species in water bodies of Ukraine and Russia because the most useful criterion in species independence is reproductive isolation. The problem of cryptic species in the genus Eucyclops was examined using interpopulation crosses of populations collected from Baltic Sea basin (pond of Strelka river basin) and Black Sea basin (water-reservoires of Dnieper, Dniester and Danube rivers basins). The results of reciprocal crosses in Eucyclops serrulatus-group are shown that E. serrulatus from different populations but from water bodies belonging to the same river basin crossed each others successfully. The interpopulation crosses of E. serrulatus populations collected from different river basins (Dnipro, Danube and Dniester river basins) were sterile. In this group of experiments we assigned evidence of sterility to four categories: 1) incomplete copulation or absence of copulation; 2) nonviable eggs; 3) absence of egg membranes or egg sacs 4) empty egg membranes. These crossbreeding studies suggest the presence of cryptic species in the E. serrulatus inhabiting ecologically different populations in many parts of its range. The same crossbreeding experiments were carries out between Eucyclops serrulatus and morphological similar species – Eucyclops macruroides from Baltic and Black Sea basins. The reciprocal crossings between these two species were sterile. Thus taxonomic heterogeneity among species of genus Eucyclops lower in E. macruroides than in E. serrulatus. The interpopulation crosses of E. macruroides populations collected from distant part of range were fertile. These crossbreeding studies suggest that E. macruroides species complex was evaluated as more stable than E. serrulatus species complex.

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Colletotrichum Gloeosporioides Species Complex: Pathogen Causing Anthracnose, Gummosis and Die-Back Diseases of Cashew (Anacardium Occidentale L.) In Ghana

European Journal of Agriculture and Food Sciences ◽

10.24018/ejfood.2020.2.6.146 ◽

2020 ◽

Vol 2 (6) ◽

Author(s):

A. Muntala ◽

P. M. Norshie ◽

K. G. Santo ◽

C. K. S. Saba

Keyword(s):

Species Complex ◽

Colletotrichum Gloeosporioides ◽

Potato Dextrose Agar ◽

Causal Agent ◽

Anacardium Occidentale ◽

Causative Organism ◽

Pathogenicity Test ◽

Small Water ◽

Colletotrichum Gloeosporioides Species Complex

A survey was conducted in twenty-five cashew (Anacardium occidentale) orchards in five communities in the Dormaa-Central Municipality of Bono Region of Ghana to assess the incidence and severity of anthracnose, gummosis and die-back diseases on cashew. Cashew diseased samples of leaves, stem, inflorescences, twigs, flowers, nuts and apples showing symptoms (e. g. small, water-soaked, circular or irregular yellow, dark or brown spots or lesions on leaves, fruits and flowers, sunken surface, especially on the apples, blight, gum exudates) were collected for isolation of presumptive causative organism. The pathogen was isolated after disinfecting the excised diseased pieces in 70% ethanol, plated on potato dextrose agar (PDA) and incubated at 28 oC for 3 to 7 days. The identity of the putative pathogen was morphologically and culturally confirmed as belonging to Colletotrichum gloeosporioides species complex using standard mycological identification protocols. The pathogen had varied conidia sizes of between 9-15 up to 20 μm in length and diameter of 3-6 μm. The conidia were straight and cylindrically shaped with rounded or obtuse ends. The septate mycelium was whitish-grey, velvety and cotton-like in appearance from the top. The results confirmed the presence of the pathogen in the orchards with incidence ranging from 6.9% and 14.0% for gummosis and averaged 22.9% for anthracnose infected orchards. The result of the pathogenicity test confirmed the isolates to be pathogenic on inoculated cashew seedlings and were consistently re-isolated, thereby establishing the pathogen as the true causal agent of the said diseases in cashew trees and thus completed the Koch’s postulate.

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