scholarly journals Assessment of Shape Variation Patterns in Triatoma infestans (Klug 1834) (Hemiptera: Reduviidae: Triatominae): A First Report in Populations from Bolivia

Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 274
Author(s):  
Carolina Vilaseca ◽  
Marco A. Méndez ◽  
Carlos F. Pinto ◽  
Hugo A. Benítez
Keyword(s):  
Permutation Test ◽  
Principal Component ◽  
Multivariate Regression Analysis ◽  
Climatic Conditions ◽  
Triatoma Infestans ◽  
Canonical Variate ◽  
Shape Variation ◽  
Morphological Variations ◽  
Variation Patterns ◽  
Variate Analysis

The morphological variations of four populations of geographically isolated Triatoma infestans located in the area of inter-Andean valleys and Chaco of Chuquisaca, Bolivia, were evaluated. Fifty-three females and sixty-one males were collected in the peri-domicile and analyzed with geometric morphometrics tools to study the patterns of the head and wing shape variation. The principal component analysis and canonical variate analysis revealed morphological variations between the populations studied, which were then confirmed by the permutation test of the differences between populations using Mahalanobis and Procustes distances. The multivariate regression analysis shows that the centroid size influences the shape of the heads and wings. T. infestans of the inter-Andean valleys are longer in the head and wings compared to the population of the Chaco. We propose that the geometric shape variation may be explained by geographical changes in climatic conditions, peri-domiciliar habitats, food source quality, and the use of insecticides.

scholarly journals Craniometric geographical variation in Hylaeamys megacephalus populations

2020 ◽  
Vol 40 (9) ◽  
pp. 726-732
Author(s):  
Paola S. Mata ◽  
Matheus S.L. Ribeiro ◽  
Michel B. Faria ◽  
Fabiano C. Lima
Keyword(s):  
Eating Habits ◽  
Principal Component ◽  
Arithmetic Mean ◽  
Canonical Variate ◽  
Group Method ◽  
Morphological Variations ◽  
Pair Group ◽  
Wide Geographical Distribution ◽  
Variate Analysis ◽  
Great Genetic Diversity

ABSTRACT: Hylaeamys megacephalus (G. Fisher, 1814) presents great genetic diversity and wide geographical distribution, and occurs in both the Amazon and Cerrado biomes. Because of its generalist aspect, this species tolerates different eating habits and habitats. It occurs in flooded and dry areas and is predominantly terrestrial, which allows greater gene flow between populations even over long distances. Studies that seek a better understanding of morphological variations resulting from differences imposed by the environment throughout this species’ distribution are still lacking. This study aimed to analyze the differences between H. megacephalus populations based on craniometry, investigating whether the environment has an influence on morphology. We analyzed a total of 142 specimens from three scientific mammal collections: National Museum, “Universidade Federal do Rio de Janeiro” (MN-UFRJ); “Laboratório de Biologia e Parasitologia de Mamíferos Reservatórios Silvestres”, “Instituto Oswaldo Cruz”, “Fundação Oswaldo Cruz”(LBCE-Fiocruz); and “Laboratório de Biodiversidade”, “Universidade Federal de Goiás”, “Regional Jataí” (LZE-UFG), and took 20 craniometric measurements. Craniometry was explored using unweighted pair group method with arithmetic mean (UPGMA), canonical variate analysis, and principal component analysis (PCA). The results led us to conclude that there are three craniometric groups of H. megacephalus with a tendency to differentiate as a result of geographical influences.

scholarly journals Leaf geometric morphometrics among populations of Dalbergia ecastaphyllum (L.) Taub.

2019 ◽  
Vol 35 (6) ◽  
Author(s):  
Daniel Vieira de Morais ◽  
Lorena Andrade Nunes ◽  
Vandira Pereira da Mata ◽  
Maria Angélica Pereira de Carvalho Costa ◽  
Geni da Silva Sodré ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Geometric Morphometrics ◽  
Cross Validation ◽  
Abiotic Factors ◽  
Principal Component ◽  
Canonical Variate ◽  
Validation Test ◽  
Significant Difference ◽  
Variate Analysis ◽  
Geographical Distances

Leaves are plant structures that express important traits of the environment where they live. Leaf description has allowed identification of plant species as well as investigation of abiotic factors effects on their development, such as gases, light, temperature, and herbivory. This study described populations of Dalbergia ecastaphyllum through leaf geometric morphometrics in Brazil. We evaluated 200 leaves from four populations. The principal component analysis (PCA) showed that the first four principal components were responsible for 97.81% of variation. The non-parametric multivariate analysis of variance (NPMANOVA) indicated significant difference between samples (p = 0.0001). The Mentel test showed no correlation between geographical distances and shape. The canonical variate analysis (CVA) indicated that the first two variables were responsible for 96.77 % of total variation, while the cross-validation test showed an average of 83.33%. D. ecastaphyllum leaves are elliptical and ovate.

scholarly journals Comparison of Wing, Ovipositor, and Cornus Morphologies between Sirex noctilio and Sirex nitobei Using Geometric Morphometrics

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 84
Author(s):  
Ming Wang ◽  
Lixiang Wang ◽  
Ningning Fu ◽  
Chenglong Gao ◽  
Tegen Ao ◽  
...  
Keyword(s):  
Geometric Morphometrics ◽  
North Africa ◽  
Principal Component ◽  
Canonical Variate ◽  
Native Range ◽  
Sirex Noctilio ◽  
Variate Analysis ◽  
Global Presence ◽  
And Cluster Analysis ◽  
Taxonomic Studies

Sirex noctilio F. (Hymenoptera: Siricidae) is an invasive woodwasp from Europe and North Africa. Globalization has led to an expanding global presence in pine forests. S. noctilio has been previously introduced outside of its native range and now co-occurs in trees with native S. nitobei Matsumura (first discovered in 2016). Damage to Pinus sylvestris var. mongolica Litv in northeast China can be attributed to two types of woodwasp. To distinguish the two species by the traditional taxonomic morphology, we mainly differentiate the color of the male’s abdomen and the female’s leg. There remains intraspecific variation like leg color in the delimitation of related genera or sibling species of Sirex woodwasps. In this study, we used landmark-based geometric morphometrics including principal component analysis, canonical variate analysis, thin-plate splines, and cluster analysis to analyze and compare the wings, ovipositors, and cornus of two woodwasps to ascertain whether this approach is reliable for taxonomic studies of this group. The results showed significant differences in forewing venation and the shapes of pits in the middle of ovipositors among the two species, whereas little difference in hindwings and cornus was observed. This study assists in clarifying the taxonomic uncertainties of Siricidae and lays a foundation for further studies of the interspecific relationships of the genus Sirex.

scholarly journals Ιχνηλασιμότητα πληθυσμών ιριδίζουσας πέστροφας Oncorhynchus mykiss (Walbaum, 1792) στην Ελλάδα

2018 ◽  
Author(s):  
Πέτρος Μαρτσικάλης
Keyword(s):  
Oncorhynchus Mykiss ◽  
High Performance ◽  
Linear Models ◽  
Fragment Length Polymorphism ◽  
Principal Component ◽  
Reversed Phase ◽  
Canonical Variate ◽  
Rp Hplc ◽  
Variate Analysis ◽  
Polymerase Chain

Για την επίτευξη της ιχνηλασιμότητας των πληθυσμών ιριδίζουσας πέστροφας Oncorhynchus mykiss (Walbaum, 1792) στην Ελλάδα υιοθετήθηκε μια διαθεματική προσέγγιση, η οποία ως αλληλένδετους πυλώνες της περιελάμβανε α) την πληθυσμιακή γενετική μελέτη στο μιτοχονδριακό DNA των ιχθύων, β) την ταυτοποίηση και ποσοτικοποίηση των ελεύθερων αμινοξέων στο μυϊκό ιστό των ιχθύων και γ) τη γεωμετρική μορφομετρία του σώματος των ιχθύων, εκφράζοντας ένα αντιπροσωπευτικό δείγμα των εντατικών εκτροφών της ελληνικής επικράτειας. Η ιριδίζουσα πέστροφα αποτελεί μη γηγενές είδος των ευρωπαϊκών εσωτερικών υδάτων. Εξαιτίας όμως του γεγονότος ότι παρουσιάζει αξιοσημείωτα πλεονεκτήματα, όπως είναι η ταχεία αύξηση και η προσαρμοστικότητά της σε ποικίλα ενδιαιτήματα υπό διαφορετικές συνθήκες, εξελίχθηκε σε κυρίαρχο εντατικά εκτρεφόμενο είδος στα εσωτερικά ύδατα της Ελλάδας. Παρά τη σημαντική οικονομική σημασία της, υφίσταται παντελής έλλειψη πληθυσμιακών γενετικών μελετών αναφορικά με την προέλευση των αθρόων εισαγωγών γόνου που έλαβαν χώρα τις προηγούμενες δεκαετίες στον κλάδο της ελληνικής πεστροφοκαλλιέργειας. Για τη διενέργεια της πληθυσμιακής γενετικής μελέτης πραγματοποιήθηκε πέψη τμημάτων του μιτοχονδριακού DNA (mtDNA) που ενισχύθηκαν με την αλυσιδωτή αντίδραση πολυμεράσης (Polymerase Chain Reaction-PCR) με τη χρήση περιοριστικών ενζύμων (Restriction Fragment Length Polymorphism-RFLP). Τα τμήματα-στόχοι του mtDNA που πολλαπλασιάστηκαν με την τεχνική της PCR ήταν ολόκληρη η περιοχή του βρόχου εκτόπισης, τα tRNA γονίδια της προλίνης και της θρεονίνης, το κυτόχρωμα β, τα γονίδια ND-5 και ND-6 και τμήμα των γονιδίων ATPάση VI και κυτόχρωμα c οξειδάσης 3 (COIII) περιλαμβάνοντας περισσότερα από 5.500 ζεύγη βάσεων DNA από τα περίπου 16.600 ζεύγη βάσεων που απαρτίζουν το συνολικό mtDNA της ιριδίζουσας πέστροφας. Η ανάλυση της πληθυσμιακής δομής αποκάλυψε ότι οι απλότυποι διακρίνονται σε δύο κεντρικούς κλάδους. Η συνύπαρξη απλότυπων και από τους δύο κλάδους σε όλους τους πληθυσμούς ενδέχεται να υποδηλώνει την ύπαρξη κοινής γονιδιακής δεξαμενής. Επίσης, η συνολική γενετική ποικιλότητα οφειλόταν σε σημαντικό βαθμό στην ύπαρξη ποικιλότητας ενδοπληθυσμιακά παρά στην ύπαρξη ποικιλότητας ανάμεσα στους πληθυσμούς. Το ποσοστό γενετικής ποικιλότητας ανάμεσα στους πληθυσμούς σε σύγκριση με τη συνολική παρατηρούμενη ποικιλότητα αντανακλά την πανμιξία δύο αρχικών πληθυσμών (γενεών), υπογραμμίζοντας την ύπαρξη μια κοινής δεξαμενής γονιδίων σε όλες τις εντατικές εκτροφές ιριδίζουσας πέστροφας στην Ελλάδα. Αυτό το γεγονός ενισχύεται και από το δίκτυο απλότυπων που δημιουργήθηκε και αποκάλυψε την ύπαρξη δύο αρχικών κλάδων σε όλο το φάσμα των εντατικών εκτροφών. Παράλληλα, η ταυτοποίηση και ποσοτικοποίηση των ελεύθερων αμινοξέων στο μυϊκό ιστό των ιχθύων διενεργήθηκε με τη χρήση Αντίστροφης Φάσης - Υγρής Χρωματογραφίας Υψηλής Απόδοσης (Reversed Phase – High Performance Liquid Chromatography, RP-HPLC). Τα εξεταζόμενα δείγματα παρουσίασαν διαφορετικά προφίλ ελεύθερων αμινοξέων ανάλογα με τη γεωγραφική τους προέλευση. Η Ανάλυση Κύριων Συνιστωσών (Principal Component Analysis – PCA) αποκάλυψε τον σαφή διαχωρισμό των πληθυσμών μεταξύ ανατολικής και δυτικής Ελλάδας, ο οποίος ενδέχεται να οφείλεται στην ύπαρξη διακυμάνσεων στις κλιματικές συνθήκες που επικρατούν και επηρεάζουν καταλυτικά τους αβιοτικούς παράγοντες κάθε εντατικής εκτροφής. Η γεωμετρική μορφομετρία του σώματος των ιχθύων κατέδειξε την ύπαρξη σημαντικών διαφορών μεταξύ των πληθυσμών διαφορετικής προέλευσης. Η Ανάλυση Κανονικών Μεταβλητών (Canonical Variate Analysis – CVA) διέκρινε τους πληθυσμούς σε δύο ομάδες παρουσιάζοντας σε πολύ μεγάλο βαθμό ομοιότητες με τη διενεργηθείσα πληθυσμιακή γενετική μελέτη. Η διεξαγωγή των Γενικών Γραμμικών Μοντέλων (General Linear Models – GLM) δεν επέδειξε συσχέτιση των απλότυπων και της διατροφής με το σχήμα του σώματος των ιχθύων. Εντούτοις, το σχήμα του σώματος των ιχθύων παρουσίασε σημαντική συσχέτιση με τη γεωγραφική προέλευση, τη θερμοκρασία νερού, τις γεωλογικο-χημικο-κλιματικές ζώνες, την ιστιδίνη και την αργινίνη. Επομένως, η παρατηρούμενη μορφολογική διαφοροποίηση δύναται να οφείλεται στις διαφορές των αβιοτικών παραγόντων που υφίστανται μεταξύ αυτών των ζωνών όντας το αποτέλεσμα του φαινομένου της φαινοτυπικής πλαστικότητας.Συμπερασματικά, οι αβιοτικοί παράγοντες και οι συνθήκες εκτροφής διαδραματίζουν τον κυρίαρχο ρόλο σε σύγκριση με την προέλευση του γόνου. Η παρούσα διαθεματική προσέγγιση αποτελεί ένα πολύτιμο και χρήσιμο εργαλείο στην αποτελεσματική ιχνηλασιμότητα των εντατικά εκτρεφόμενων πληθυσμών ιριδίζουσας πέστροφας, έχοντας καθοριστική συνεισφορά και προάγοντας την έρευνα σε τομείς, όπως η περιβαλλοντική ανάλυση κινδύνων για την αξιολόγηση ενδεχόμενων οικολογικών επιπτώσεων που στοχεύουν στην επίτευξη της αειφορικής διαχείρισης των ιχθυοκαλλιεργειών.

scholarly journals Differentiation of Five Species of Megachile (Hymenoptera: Megachilidae), based on Wing Shape

2016 ◽  
Vol 60 (2) ◽  
pp. 41-50 ◽  
Author(s):  
Shahram Falamarzi ◽  
Behzad Habibpour ◽  
Mohammad S. Mossadegh ◽  
Alireza Monfared
Keyword(s):  
Geometric Morphometrics ◽  
Cross Validation ◽  
Principal Component ◽  
Wing Shape ◽  
Canonical Variate ◽  
Effective Technique ◽  
Validation Test ◽  
Variate Analysis ◽  
Clear Differentiation ◽  
Respective Species

Abstract In the present work we used landmark-based geometric morphometrics to compare the wing shapes of five species of Megachile (belonging to three subgenera) to confirm whether this technique may be used reliably for differentiation of this group. Analyses of wing shape by the use of principal component analysis (PCA), and canonical variate analysis (CVA) led to a clear differentiation among species. We found a close phenotypic similarity in wing shape between M. albisecta (belonging to the subgenus Creightonella) and M. picicornis (belonging to the subgenus Eutricharaea). According to the results of UPGMA, a higher degree of divergence between M. farinosa (belonging to the subgenus Pseudomegachile) and species belonging to other subgenera, was detected. The results of a cross-validation test indicated that geometric morphometrics is an effective technique to use for distinguishing between Megachile species. The reliability rate of this technique was between 85.71-100%. Using only two submarginal cell landmarks for generating shape variables, the cross-validation test correctly assigned individuals to their respective species, with a 92.85-100% reliability rate. Significant differences in wing size were obtained among the analysed species.

scholarly journals Studying the Shape Variations of the Back, the Neck, and the Mandibular Angle of Horses Depending on Specific Feeding Postures Using Geometric Morphometrics

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 763
Author(s):  
Federica Raspa ◽  
Angela Roggero ◽  
Claudia Palestrini ◽  
Martina Marten Canavesio ◽  
Domenico Bergero ◽  
...  
Keyword(s):  
Geometric Morphometrics ◽  
Management Practices ◽  
Mixed Model ◽  
Principal Component ◽  
Canonical Variate ◽  
Long Term Effects ◽  
Mandibular Angle ◽  
Variate Analysis ◽  
The Right

The effects of specific feeding positions upon the horse’s shape variations of the back and neck postures as well as the variations of the mandibular angle have never been objectively studied. For this reason, geometric morphometrics was applied. Six horses, aged 14 ± 8 years (mean ± standard deviation, SD), were video-recorded while using three different feeding positions: on the ground—control position (CP); neck held 15 ± 3° below withers height with low hay net position (LP); neck held 15 ± 3° above withers height with high hay net position (HP). Data were analyzed using principal component analysis (PCA), multivariate analysis of variance (MANOVA), and partial least squares (PLS). A mixed model procedure was applied to evaluate differences in the magnitude of the mandibular angle. Whilst differences between individual horses were confirmed by canonical variate analysis (CVA), PCA analysis showed that a characteristic feeding position could also be identified on a group level. During the HP hay net position, the back and neck postures as well the mandibular angle were different compared to those exhibited by horses feeding from CP. In LP hay net position, the back posture more closely resembled those exhibited while feeding from CP; however, no similarity between LP and CP was found for neck posture and mandibular angle. Since only a few degrees of variation of the feeding position can influence back and neck postures, this aspect should be further investigated. The right compromise between horse welfare, horse safety, and management practices need to be further explored and long-term effects should be investigated.

Tissue preservation can affect geometric morphometric analyses: a case study using fish body shape

2019 ◽  
Vol 188 (1) ◽  
pp. 148-162 ◽  
Author(s):  
Carmelo Fruciano ◽  
Dominik Schmidt ◽  
Marcia Maria Ramírez Sanchez ◽  
Witold Morek ◽  
Zamira Avila Valle ◽  
...  
Keyword(s):  
Body Shape ◽  
Canonical Variate ◽  
Shape Variation ◽  
Substantial Variation ◽  
Geometric Morphometric ◽  
Fresh Fish ◽  
Morphometric Analyses ◽  
Variate Analysis ◽  
Shape Data

Abstract In geometric morphometrics, the extent of variation attributable to non-biological causes (i.e. measurement error) is sometimes overlooked. The effects of this variation on downstream statistical analyses are also largely unknown. In particular, it is unclear whether specimen preservation induces substantial variation in shape and whether such variation affects downstream statistical inference. Using a combination of empirical fish body shape data and realistic simulations, we show that preservation introduces substantial artefactual variation and significant non-random error (i.e. bias). Most changes in shape occur when fresh fish are frozen and thawed, whereas a smaller change in shape is observed when frozen and thawed fish are fixed in formalin and transferred to ethanol. Surprisingly, we also show that, in our case, preservation produces only minor effects on three downstream analyses of shape variation: classification using canonical variate analysis, permutation tests of differences in means and computations of differences in mean shape between groups. Even mixing of differently preserved specimens has a relatively small effect on downstream analyses. However, we suggest that mixing fish with different preservation should still be avoided and discuss the conditions in which this practice might be justified.

Biosystematics of the Cotesia flavipes species complex (Hymenoptera: Braconidae): morphometrics of selected allopatric populations

1997 ◽  
Vol 87 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Susan W. Kimani-Njogu ◽  
William A. Overholt ◽  
James Woolley ◽  
Annette Walker
Keyword(s):  
Principal Component Analysis ◽  
Species Complex ◽  
Principal Component ◽  
Cotesia Flavipes ◽  
Canonical Variate Analysis ◽  
Canonical Variate ◽  
Allopatric Populations ◽  
Putative Species ◽  
Variate Analysis ◽  
China And Japan

AbstractMorphometric studies of allopatric populations of the Cotesia flavipes species complex representing three putative species; C. flavipes Cameron, C. sesamiae (Cameron) and C. chilonis (Matsumura), were conducted. Sixteen characters were measured. Principal component analysis separated the complex into three somewhat overlapping groups that corresponded well with previous concepts of the species. Canonical variate analysis separated the complex into three distinct clusters with populations from Africa together, populations from Asia and the Neotropics forming a second cluster, and material from China and Japan forming a third cluster. The Mahalanobis squared distances between the three clusters were nearly equal. Results support recognition of three species in the C. flavipes complex.

A review of the moss bug genus Xenophyes (Hemiptera: Coleorrhyncha: Peloridiidae) from New Zealand: systematics and biogeography

Zootaxa ◽  
2011 ◽  
Vol 2923 (1) ◽  
pp. 1 ◽  
Author(s):  
DANIEL BURCKHARDT ◽  
ESTÉE BOCHUD ◽  
JAKOB DAMGAARD ◽  
GEORGE W. GIBBS ◽  
VIKTOR HARTUNG ◽  
...  
Keyword(s):  
New Zealand ◽  
Principal Component ◽  
Morphological Characters ◽  
Canonical Variate ◽  
Morphometric Characters ◽  
The North ◽  
Variate Analysis ◽  
Width Measurements ◽  
North And South ◽  
Important Structure

The moss bug genus Xenophyes from New Zealand is revised. Six species are recognised, four of which are described as new: X. adelphus, X. goniomus, X. metoponcus, and X. rhachilophus. The synonymy of Xenophyes forsteri with X. cascus is confirmed. Illustrated descriptions and identification keys are provided for the adult and the last instar. The male aedeagus is recognised as the most important structure to diagnose species. Other useful morphological characters include body shape, head, pronotum, and tegmina expressed as length and width measurements. The Principal Component Analysis (PCA) shows that five species are well separated from each other, but X. goniomus greatly overlaps with X. cascus, X. kinlochensis, and X. rhachilophus. There is also broad morphometric overlap between North Island and South Island specimens of X. cascus, confirming their conspecificity. Results from a Canonical Variate Analysis (CVA) determined which morphometric characters are most suitable for use in keys and descriptions. X. cascus is the only species occurring on both the North and South Islands. Other species are restricted to the South Island.

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