Intraspecific and Interspecific Phenotypic Differences Confirm the Absence of Cryptic Speciation in Triatoma sordida (Hemiptera, Triatominae)

Triatoma sordida is an endemic Chagas disease vector in South America, distributed in Brazil, Bolivia, Paraguay, and Uruguay. Chromosomal, molecular, isoenzimatic, and cuticular hydrocarbon pattern studies indicate cryptic speciation in T. sordida. Recently, T. rosai was described from specimens from Argentina initially characterized as T. sordida. Although several authors assume that the speciation process that supports this differentiation in T. sordida is the result of cryptic speciation, further morphological and/or morphometric studies are necessary to prove the application of this evolutionary event, because the only morphological intraspecific comparison performed in T. sordida is based on geometric morphometry and the only interspecific comparison made is between T. rosai and T. sordida from Brazil that evaluated morphological and morphometric differences. Based on this, morphological analyses of thorax and abdomen using Scanning Electron Microscopy and morphometric analyses of the head, thorax, and abdomen among T. sordida from Brazil, Bolivia, and Paraguay, as well as T. rosai, were performed to assess whether the evolutionary process responsible for variations is the cryptic speciation phenomenon. Morphological differences in the thorax and female external genitalia, as well as morphometric differences in the head, thorax, abdomen, pronotum, and scutellum structures, were observed. Based on this, the evolutionary process that supports, so far, these divergences observed for T. sordida populations/T. sordida subcomplex is not cryptic speciation. Moreover, we draw attention to the necessity for morphological/morphometric studies to correctly apply the cryptic species/speciation terms in triatomines.

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Morphological and ecological variation among populations and subspecies of Burbot (Lota lota [L, 1758]) from the Mackenzie River Delta, Canada

The Canadian Field-Naturalist ◽

10.22621/cfn.v128i4.1632 ◽

2015 ◽

Vol 128 (4) ◽

pp. 377 ◽

Cited By ~ 6

Author(s):

Hans Recknagel ◽

Amy Amos ◽

Kathryn R. Elmer

Keyword(s):

River Delta ◽

Pungitius Pungitius ◽

Local Conditions ◽

Lota Lota ◽

Phenotypic Differences ◽

Carbon And Nitrogen ◽

Stable Isotope Signatures ◽

Morphological Differences ◽

Eastern Edge ◽

Mackenzie River

The Burbot (Lota lota [L, 1758]) is a holarctic distributed freshwater fish in the Gadidae family. In northwestern Canada, it has an important value for local and traditional fisheries. We describe the morphology and ecology of Burbot from four populations in the Mackenzie River Delta. Two subspecies come into contact in this area, which is the western edge of Lota lota maculosa distribution (one population in our study) and the eastern edge of Lota lota lota distribution (three populations in our study). We found the combined length–weight relationship in these four populations to be log10 (weight) = −3.986 + 2.617 * log10 (length). There was no difference in mean body length (overall mean and standard deviation 73.4 ± 8.7 cm), although the L. l. lota populations were heavier than the L. l. maculosa population. All populations differed in their carbon and nitrogen stable isotope signatures (δ15N overall mean 12.1 ± 1.59; δ13C overall mean −25.54 ± 1.11). Main prey items were four fish species: Ninespine Stickleback (Pungitius pungitius [L, 1758]), Broad Whitefish (Coregonus nasus [Pallas, 1776]), Burbot, and Northern Pike (Esox lucius [L, 1758]). Ecological and morphological differences may be due to local conditions and population variability or to the different Lota lota subspecies. More ecological and morphological information from this region is needed to resolve possible phenotypic differences between the subspecies.

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Sexual dimorphism in the carapace shape and length of the freshwater palaemonid shrimp Macrobrachium potiuna (Müller, 1880) (Decapoda: Caridea: Palaemonidae): geometric and traditional morphometric approaches

Animal Biology ◽

10.1163/15707563-00002522 ◽

2017 ◽

Vol 67 (2) ◽

pp. 93-103 ◽

Cited By ~ 3

Author(s):

Madson Silveira de Melo ◽

Setuko Masunari

Keyword(s):

Body Weight ◽

Sexual Dimorphism ◽

Behavioral Differences ◽

Geometric Morphometric ◽

Freshwater Shrimps ◽

Morphometric Analyses ◽

Males And Females ◽

Morphological Differences ◽

Three Rivers ◽

Coastal Basin

Sexual dimorphism is characterized by morphological, physiological, or behavioral differences between males and females. The genus Macrobrachium is a diverse group of freshwater shrimps distributed throughout tropical and subtropical regions. They have a great intra- and interspecific morphological variation, with some species showing sexual dimorphism. We investigated the sexual dimorphism of the size and shape of the carapace and body weight of Macrobrachium potiuna (Müller, 1880) in three populations of the State of Paraná through traditional and geometric morphometric techniques. The populations were sampled from three rivers: the Pombas River, Coastal Basin, the Piraquara River, First Plateau, and the Guabiroba River, Second Plateau. Morphometric analyses indicated that male shrimps showed differences in carapace length and body weight: the higher the distance from the sea, the smaller and lighter the shrimps. Carapace shape also differed significantly between the sexes in all three populations, with males having a less robust carapace, but a more elongated rostrum than females. The morphological differences between the genders seem to reflect the reproductive roles of males and females in this environment.

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Systematics, distribution and morphology of the newt parasitic water mites of the subgenus Lurchibates Goldschmidt & Fu, 2011 (Acari, Hydrachnidia, Hygrobatidae, Hygrobates Koch, 1837), including the description of four new species and a key to all so far known species

Zootaxa ◽

10.11646/zootaxa.4985.1.1 ◽

2021 ◽

Vol 4985 (1) ◽

pp. 1-36

Author(s):

TOM GOLDSCHMIDT ◽

KANTO NISHIKAWA ◽

SHIMPEI F. HIRUTA ◽

TOBIAS PFINGSTL ◽

JIAN-PING JIANG ◽

...

Keyword(s):

New Species ◽

Sexual Dimorphism ◽

Phylogenetic Relationships ◽

Mite Species ◽

Water Mites ◽

Water Mite ◽

Male And Female ◽

Se Asia ◽

Morphometric Analyses ◽

Morphological Differences

Four new water mite species of the genus Hygrobates, subgenus Lurchibates (Acari, Hydrachnidia, Hygrobatidae) are described. Hygrobates (Lurchibates) macrochela sp. nov. Goldschmidt, Nishikawa & Shimano is described in male and female; Hygrobates (Lurchibates) malosimilis sp. nov. Goldschmidt, Nishikawa & Shimano is described in male, both new water mite species were collected from newts of the species Pachytriton inexpectatus Nishikawa, Jiang, Matsui & Mo, 2011; Hygrobates (Lurchibates) incognitus sp. nov. Goldschmidt, Nishikawa & Shimano is described in female collected from newts of the species Paramesotriton guangxiensis (Huang, Tang and Tang, 1983); Hygrobates (Lurchibates) fragmentarius sp. nov. Goldschmidt, Nishikawa & Shimano is described in a single severely fragmented specimen (sex could not be determined) collected from a newt of the species Paramesotriton yunwuensis Wu, Jiang, and Hanken, 2010. Principal differences between the subgenus Lurchibates and the nominal subgenus Hygrobates s. str. are illustrated and discussed as well as the sexual dimorphism of Lurchibates. Morphometric analyses confirmed the morphological differences of ten out of the eleven so far described species (H. (L.) fragmentarius could not be included in the analysis); two morphological groups became evident mainly based upon the shape of the anterior coxae. These analyses as well provide an idea of possible phylogenetic relationships among the species. A key to all currently known species of the subgenus Lurchibates is given. So far the subgenus is restricted to SE-Asia, a map showing the distribution of all species is presented.

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Another brick in the wall: population dynamics of a symbiotic species of Oxydromus (Annelida, Hesionidae), described as new based on morphometry

Contributions to Zoology ◽

10.1163/18759866-08603001 ◽

2017 ◽

Vol 86 (3) ◽

pp. 181-211 ◽

Cited By ~ 2

Author(s):

Daniel Martin ◽

Miguel A. Meca ◽

João Gil ◽

Pilar Drake ◽

Arne Nygren

Keyword(s):

Population Dynamics ◽

Current Knowledge ◽

Seasonal Pattern ◽

Dorsal Lobe ◽

Mature Adults ◽

Iberian Population ◽

Morphometric Analyses ◽

Ripe Female ◽

Clear Seasonal Pattern ◽

Morphological Differences

Oxydromus humesi is an annelid polychaete living as a strict bivalve endosymbiont (likely parasitic) of Tellina nymphalis in Congolese mangrove swamps and of Scrobicularia plana and Macomopsis pellucida in Iberian saltmarshes. The Congolese and Iberian polychaete populations were previously considered as belonging to the same species, the latter showing regular distribution, intra-specific aggressive behaviour, and complex hostentering behaviour. The fresh Iberian samples enabled us to undertake consistent morphometric analyses, as well as to further analyse the characteristics of the association and the population dynamics of the Iberian population hosted by S. plana. Among the morphological differences between the Congolese and Iberian specimens, leading to the description of the latter as Oxydromus okupa sp. nov., the most important are: 1) longer cephalic appendages, 2) greater distance between the eyes, 3) larger dorsal cirrostyle in relation to the corresponding dorsal lobe and cirrophore. Moreover, dorsal and ventral lobes are similar in length, with the tip of the former reaching the tip of the latter in O. okupa sp. nov., while the dorsal lobe is much shorter than the ventral one in O. humesi. Mature adults of O. okupa sp. nov. occurred during the whole study period, with a higher percentage of ripe females in spring and, particularly, in summer. Numerous host specimens showed the symbiont’s most preferred shell length (>26 - 36 mm). However, the prevalence was very low (usually <5%) and showed a clear seasonal pattern, being lower during spring/summer. This suggests that males are able to leave their hosts during this period, most likely to improve fertilization by directly entering or approaching a host occupied by a ripe female, while females usually remain inside. Based on the new results, the current knowledge of symbiotic Hesionidae and their relationships with invertebrate hosts is updated and discussed.

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Testing species hypotheses for Fridericia magna, an enchytraeid worm (Annelida: Clitellata) with great mitochondrial variation

BMC Evolutionary Biology ◽

10.1186/s12862-020-01678-5 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Svante Martinsson ◽

Mårten Klinth ◽

Christer Erséus

Keyword(s):

Species Delimitation ◽

Single Species ◽

The Other ◽

Cryptic Speciation ◽

Incipient Speciation ◽

Nuclear Markers ◽

Separate Species ◽

Mitochondrial Markers ◽

Morphological Differences ◽

Barcode Gap

Abstract Background Deep mitochondrial divergences were observed in Scandinavian populations of the terrestrial to semi-aquatic annelid Fridericia magna (Clitellata: Enchytraeidae). This raised the need for testing whether the taxon is a single species or a complex of cryptic species. Results A total of 62 specimens from 38 localities were included in the study, 44 of which were used for species delimitation. First, the 44 specimens were divided into clusters using ABGD (Automatic Barcode Gap Discovery) on two datasets, consisting of sequences of the mitochondrial markers COI and 16S. For each dataset, the worms were divided into six not completely congruent clusters. When they were combined, a maximum of seven clusters, or species hypotheses, were obtained, and the seven clusters were used as input in downstream analyses. We tested these hypotheses by constructing haplowebs for two nuclear markers, H3 and ITS, and in both haplowebs the specimens appeared as a single species. Multi-locus species delimitation analyses performed with the Bayesian BPP program also mainly supported a single species. Furthermore, no apparent morphological differences were found between the clusters. Two of the clusters were partially separated from each other and the other clusters, but not strongly enough to consider them as separate species. All 62 specimens were used to visualise the Scandinavian distribution, of the species, and to compare with published COI data from other Fridericia species. Conclusion We show that the morphospecies Fridericia magna is a single species, harbouring several distinct mitochondrial clusters. There is partial genetic separation between some of them, which may be interpreted as incipient speciation. The study shows the importance of rigorous species delimitation using several independent markers when deep mitochondrial divergences might give the false impression of cryptic speciation.

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Arceuthobium tsugense (Viscaceae): four subspecies with contrasting morphologies and host distributions

Journal of the Botanical Research Institute of Texas ◽

10.17348/jbrit.v11.i2.1076 ◽

2017 ◽

Vol 11 (2) ◽

pp. 363-390

Author(s):

Robert L. Mathiasen ◽

Shawn C. Kenaley

Keyword(s):

Morphological Characteristics ◽

Morphological Characters ◽

Flowering Plants ◽

The Other ◽

Multivariate Statistical Analyses ◽

Dwarf Mistletoe ◽

Multivariate Statistical ◽

Morphometric Analyses ◽

Morphological Differences ◽

Discriminant Function Analyses

There have been four subspecies of hemlock dwarf mistletoe (Arceuthobium tsugense: Viscaceae) described by various investigators of this complex group of parasitic flowering plants: subsp. tsugense, subsp. amabilae, subsp. contortae, and subsp. mertensianae. As suggested by their subspecific epithets, these taxa differ in their host affinities; parasitizing different and the same hosts to varying degrees. Although these taxa also have morphological differences, their classifica-tion has been under debate for many years. Therefore, we compared the morphological characteristics of each subspecies using both univariate and multivariate statistical analyses in order to better assess their differences. Because some investigators have grouped hemlock dwarf mistletoe with western dwarf mistletoe (A. campylopodum), we also compared the subspecies of hemlock dwarf mistletoe with western dwarf mistletoe. Our morphometric analyses demonstrated that all of the subspecies are morphologically distinct from western dwarf mistletoe and that subsp. contortae is the most morphologically differentiated of the subspecies. Overlap in the morphological characters across two of the other three subspecies was evident; yet, subsp. amabilae and subsp. mertensianae were also consistently delimited using female and male plant morphologies. Statistical comparisons of female or male plants via standard and stepwise discriminant function analyses demonstrated that without consideration of host plant, female and male A. tsugense subsp. tsugense are morphologically similar to corresponding plants of subsp. amabilae and mertensianae but not subsp. contortae or A. campylopodum.

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Silencing Doublesex expression triggers three-level pheromonal feminization in Nasonia males

10.1101/2021.05.21.445141 ◽

2021 ◽

Author(s):

Yidong Wang ◽

Weizhao Sun ◽

Sonja Fleischmann ◽

Jocelyn Millar ◽

Joachim Ruther ◽

...

Keyword(s):

Rna Interference ◽

Molecular Mechanisms ◽

Sexual Communication ◽

Cuticular Hydrocarbon ◽

Parasitoid Wasp ◽

Sex Discrimination ◽

Wild Type ◽

Multi Level ◽

Morphological Differences ◽

Aphrodisiac Pheromone

The transcription factor Doublesex (Dsx) has a conserved function in controlling sexual morphological differences in insects, but our knowledge on its role in regulating sexual behavior is widely limited to Drosophila. Here, we show in the parasitoid wasp Nasonia vitripennis that males whose Dsx gene had been silenced by RNA interference (NvDsx-i) underwent a three-level pheromonal feminization: (1) NvDsx-i males were no longer able to attract females from a distance, owing to drastically reduced titers of the abdominal long-range sex pheromone. (2) NvDsx-i males were courted by wild-type males like females which correlated with a lower abundance of alkenes in their cuticular hydrocarbon (CHC) profiles. Supplementation of NvDsx-i male CHC profiles with realistic amounts of synthetic (Z)-9-hentriacontene (Z9C31), the most significantly reduced alkene in NvDsx-i males, interrupted courtship by wild-type conspecific males. Supplementation of female CHC profiles with Z9C31 reduced courtship and mating attempts by wild-type males. These results prove that Z9C31 is crucial for sex discrimination in Nasonia. (3) Nvdsx-i males were hampered in eliciting female receptivity during courtship and thus experienced severely reduced mating success, suggesting that they are unable to produce the hitherto unidentified oral aphrodisiac pheromone reported in N. vitripennis males. We conclude that Dsx is a multi-level key regulator of pheromone-mediated sexual communication in N. vitripennis. Silencing Dsx by RNA interference provides a new avenue for unraveling the molecular mechanisms underlying the pheromone-mediated sexual communication in insects.

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Chemotaxonomy of Five South American Species of the Triatoma genus (Hemiptera: Reduviidae: Triatominae) Based on Their Cuticle Hydrocarbon Pattern

Journal of Medical Entomology ◽

10.1093/jme/tjab199 ◽

2021 ◽

Author(s):

Débora E Moriconi ◽

Catarina Macedo-Lopes ◽

Adriana Sartorio ◽

M Patricia Juárez ◽

Juan R Girotti ◽

...

Keyword(s):

Cuticular Hydrocarbon ◽

Intraspecific Variability ◽

Taxonomic Status ◽

South American ◽

South American Species ◽

Linear Discriminant ◽

Eastern Brazil ◽

Triatoma Sordida ◽

Triatomine Species ◽

Group 2

Abstract The Triatoma sordida subcomplex traditionally included four triatomine species, T. sordida, Triatoma garciabesi, Triatoma guasayana, and Triatoma patagonica, distributed in the Southern Cone of South America. These species have a large intraspecific variability together with an overall similarity, making difficult to establish their taxonomic status. Many cytogenetic, morphometric, and molecular markers have been applied to address this. Recent studies have posed concerns on the inclusion of T. guasayana and T. patagonica within the subcomplex. Also, T. sordida from Argentina has been designed as a new species, Triatoma rosai. Using the cuticular hydrocarbon pattern as chemotaxonomic marker, the relationships among several populations of these species were analyzed by capillary gas chromatography and linear discriminant analysis along 25 collection sites in Argentina, Bolivia, Brazil, and Paraguay. T. sordida and T. rosai populations were differentially clustered in two CHC-based groups: “Group 1” included T. sordida from Eastern Brazil, Eastern Paraguay, and the Bolivian populations from La Paz and Izozog G1; “Group 2” included T. rosai, and T. sordida from Izozog G2 (Bolivia), and Western Paraguay. Whereas T. garciabesi remained closely related to T. sordida and T. rosai, T. guasayana, and T. patagonica were clearly separated from the species of the T. sordida subcomplex. Our results agree with those from other several techniques suggesting that the taxonomy of the T. sordida subcomplex should be revised.

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Characterization of the Buccula, Rostrum, Stridulatory Sulcus, Scutellum, and External Female Genitalia of Triatoma carcavalloi (Jurberg, Rocha & Lent, 1998), Triatoma circummaculata (Stål, 1859), and Triatoma rubrovaria (Blanchard, 1843) (Hemiptera, Reduviidae, Triatominae)

Journal of Parasitology Research ◽

10.1155/2019/3517098 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9

Author(s):

Margareth Alves Ribeiro Cardozo de Almeida ◽

Simone Patrícia Carneiro Freitas ◽

Maria Luiza Ribeiro de Oliveira ◽

Nathanielly Rocha Casado de Lima ◽

Elizabeth Ferreira Rangel ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

External Genitalia ◽

Female Genitalia ◽

Ventral Region ◽

Important Species ◽

Wide Geographical Distribution ◽

Morphological Differences ◽

Scanning Electron

In Brazil, Triatoma rubrovaria (Blanchard, 1843) is the most important species in epidemiological terms in the State of Rio Grande do Sul, due to its wide geographical distribution in this state, followed by T. carcavalloi (Jurberg, Rocha & Lent, 1998) and T. circummaculata (Stål, 1859). Structural analysis of the ventral region of the head (rostrum and buccula), thorax (stridulatorium sulcus and scutellum), and external female genitalia of adults of T. rubrovaria, T. carcavalloi, and T. circummaculata is described here. Scutellum, head, rostrum, and part of the thorax (prosternum) containing the stridulatory sulcus, in both male and female, and the sixth abdominal segment of the female, containing the external genitalia, were processed for scanning electron microscopy studies as routine. Morphological differences in the analyzed structures for all the three Triatoma species studied were detected under scanning electron microscopy. This study confirms the grouping of the T. rubrovaria, T. carcavalloi, and T. circummaculata in ‘T. rubrovaria subcomplex’ by their morphological similarities.

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Supplementary description of Novophytoptus stipae Keifer 1962 (Acariformes, Eriophyoidea) with LT-SEM observation on mites from putatively conspecific populations: cryptic speciation or polyphagy of novophytoptines on phylogenetically remote hosts?

Systematic and Applied Acarology ◽

10.11158/saa.22.2.9 ◽

2017 ◽

Vol 22 (2) ◽

pp. 253 ◽

Cited By ~ 2

Author(s):

Philipp E. Chetverikov ◽

James Amrine ◽

Gary Bauchan ◽

Ron Ochoa ◽

Sogdiana I. Sukhareva ◽

...

Keyword(s):

West Virginia ◽

New Taxa ◽

Life Style ◽

Plant Material ◽

Cryptic Speciation ◽

Anal Region ◽

Sem Observation ◽

Eriophyoid Mites ◽

Morphological Differences

Supplementary descriptions of an infrequently encountered species Novophytoptus stipae Keifer 1962 (Eriophyoidea, Phytoptidae) from Achnatherum speciosum (Poaceae) based on topotypes recovered from dry plant material from California is given. Comparison of topotypes of N. stipae with fresh Novophytoptus mites from Juncus tenuis and J. balticus (Juncaceae) collected in West Virginia and Ohio failed to reveal distinct morphological differences sufficient enough to establish new taxa. All studied mites are considered belonging to one species, N. stipae. This is putatively an example of polyphagous eriophyoid species inhabiting phylogenetically remote hosts. Remarks on polyphagy and dispersal modes in eriophyoids are addressed. Uncommon features of the gnathosoma and the anal region of novophytoptines were discovered under LT-SEM. These findings emphasize peculiarities of novophytoptines in relation to their endoparasitic life style and underline numerous gaps in our knowledge on anatomy and functioning of the organism of eriophyoid mites.

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