morphologic variation
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Diversity ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 512
Author(s):  
Allana Novais Aranda ◽  
Marcelo Corrêa da Silva ◽  
Bruno do Amaral Crispim ◽  
Luana Liz Medina Ledesma ◽  
Patrícia Roseti Lenis ◽  
...  

For centuries, indigenous sheep have been bred in extensive low-input systems in Midwestern Brazil. The hypothesis of this study was the assumption that phenotypic evaluation of indigenous livestock may drive the establishment of breed standards and official breed recognition, and, therefore, promote more local business opportunities. On the basis of more integrative and participatory theoretical background to applying any decision based on phenotype, we designed this research to determine the most typical and unusual phenotypes of Pantaneiro sheep. Pantaneiro ewes (281 ewes from five conservation units in five counties) were evaluated, bearing in mind both conservation and development. Descriptive statistics were used to classify ewes into typical, intermediate, and unusual phenotypes. Chi-squared tests for association were performed to test if morphological variation in the different sampling sites occurred randomly (p > 0.05) or not (p < 0.05). Some results suggest some sort of diversifying selection pressure, i.e., distinct preferences among keepers. We observed considerable morphologic variation among ewes, but it was straightforward to determine the predominant phenotypes. The study evokes integrative agrobiodiversity by putting phenotypical characterization of indigenous livestock into perspective. Discussions coming from this study may support innovative governance and participative decision-making, allied with strategies that value the socioeconomic, biocultural, and adaptive aspects of indigenous livestock in tropical regions and developing countries. This is a challenge for government, rare-breed keepers, value-chain actors, and civil society.


2021 ◽  
Author(s):  
Leandro Nicolas Getino Mamet ◽  
Gaspar Soria ◽  
Laura Schejter ◽  
Federico Marquez

Tehuelche scallop, Aequipecten tehuelchus, is a commercially exploited species in Northern Patagonia, Argentina. Without genetic differentiation at the species level, A. tehuelchus presents three morphotypes: tehuelchus, madrynensis, and a non-common variant felipponei. The main goal of this study was to analyze the shell shape variation of Tehuelche scallop to differentiate and identify the phenotypic stocks. The shape differences between and within the two main morphotypes (tehuelchus and madrynensis) were assessed using geometric morphometrics in nine localities. The shell shape presented variability at geographic scale, with the morphologic traits that maximized the differentiation among localities between the tehuelchus and madrynensis morphotypes. Scallops from madrynensis morphotype presented higher and circular shell discs with smaller auricles than those from tehuelchus morphotype. Morphometric differentiation was also detected among localities of each morphotype, wherein most of the variability was related to the disc circularity and the symmetry of the auricles. The presence of morphologic variation in San Matias and San Josi gulfs, wherein a single genetic pool is shared, evidenced the plastic nature of the species. Given the distribution of this resource in distinct provincial jurisdictions, the differentiation of phenotypic stocks has relevance in the context of fishery management, especially if zoning and rotational strategies are implemented.


Botany ◽  
2021 ◽  
pp. 531-539
Author(s):  
Kenneth H. Nicholls

Light and scanning electron microscopy were used to describe Neidium petersiveri sp. nov., a previously unnamed diatom found in the Canadian waters of Lake Superior. It had been reported previously as single cells of an unidentified Neidium species from four widely separated regions in North America: Michipicoten Island (Lake Superior, Ontario, Canada), Cape Cod (Massachusetts, United States), a Quebec river (Quebec, Canada), and the Back River (Nunavut, Canada). There are superficial resemblances to Neidium mirum Krasske and Neidium calvum Østrup, but there are significant differences in frustule size and shape as well as the pattern of striae on the valve face that render N. petersiveri unique. There was not a significant correlation between frustule lengths and widths in N. petersiveri, owing to a relatively small range within the width data that resulted in much higher width-to-length ratios among shorter cells than for longer cells (74 cells measured). Other significant aspects of morphologic variation include various shapes and configurations of the lacinial fissures and of the proximal raphe fissures, and the sporadic occurrence of pit-like depressions in the axial and central regions of the valves, which suggest that variations in these characters likely have limited value as discriminating characters at the species or subspecies levels.


2021 ◽  
Vol 8 (5) ◽  
pp. 47
Author(s):  
Joshua C. Peterson ◽  
Tim P. Kelder ◽  
Marie José T. H. Goumans ◽  
Monique R. M. Jongbloed ◽  
Marco C. DeRuiter

Whilst knowledge regarding the pathophysiology of congenital heart disease (CHDs) has advanced greatly in recent years, the underlying developmental processes affecting the cardiac outflow tract (OFT) such as bicuspid aortic valve, tetralogy of Fallot and transposition of the great arteries remain poorly understood. Common among CHDs affecting the OFT, is a large variation in disease phenotypes. Even though the different cell lineages contributing to OFT development have been studied for many decades, it remains challenging to relate cell lineage dynamics to the morphologic variation observed in OFT pathologies. We postulate that the variation observed in cellular contribution in these congenital heart diseases might be related to underlying cell lineage dynamics of which little is known. We believe this gap in knowledge is mainly the result of technical limitations in experimental methods used for cell lineage analysis. The aim of this review is to provide an overview of historical fate mapping and cell tracing techniques used to study OFT development and introduce emerging technologies which provide new opportunities that will aid our understanding of the cellular dynamics underlying OFT pathology.


Zootaxa ◽  
2021 ◽  
Vol 4948 (2) ◽  
pp. 151-183
Author(s):  
DANIEL CHIRIVI JOYA

Mexico is the country with the largest diversity of the genus Phrynus (Amblypygi: Phrynidae); however, many species could remain hidden due to the conservative morphology of the group. Two of the Mexican species, P. operculatus, and P. jalisco show enough variation, between populations from different localities, to be considered as possible species complexes. The scarce taxonomic information of these species and the few analyses of their variation could cause misidentifications and sub estimation of the diversity. Specimens morphologically similar to P. operculatus from different Mexican localities were analyzed, using characters from the male and female genitals. Four new species are described, presenting illustrations of SEM for the male genitals. Details of the morphologic variation in this group of species are discussed, as well as the usefulness of sexual characters like the size proportions, and sclerotization in the female gonopods, and ornaments in males, to improve the diagnoses of the Mexican Phrynus. The known distribution of P. operculatus is large in comparison with those of the other species, after the result of this research, the possibility that it is a larger species complex is evident, thus, it is necessary to increase the morphologic and genetic population studies in this group. 


2020 ◽  
Vol 12 (13) ◽  
pp. 5481
Author(s):  
Ji Hyoun Kang ◽  
Changseob Lim ◽  
Sung Hwan Park ◽  
Wang Gyu Kim ◽  
Nattawut Sareein ◽  
...  

Hydrochara affinis (Coleoptera: Hydrophilidae), a water scavenger beetle, was recently identified as a natural and effective agent for biological mosquito control; it was reported to exhibit high rates of mosquito larvae predation. However, maintaining the quality (i.e., natural ecological attributes, such as genetic variation) of laboratory-reared populations is essential for ensuring the long-term success of biological control programs. Accordingly, here, we aimed to use mitochondrial Cytochrome c oxidase subunit I (COI) sequences to document the genetic diversity, population structure, and phylogenetic position of natural and lab-reared H. affinis populations in South Korea and use geometric morphometric analysis to investigate the populations’ morphological divergence. The natural H. affinis populations possessed high genetic diversity and numerous COI haplotypes, suggesting that these populations were healthy and could be directly applied to mosquito habitats without alterations to their natural genetic attributes. The lab-reared populations also possessed high genetic diversity and, thus, the potential for high adaptive capacity to new environments. Although no distinct population genetic structures were observed, quantitative variation was observed in the body shape of both the natural and lab-reared populations. The high levels of genetic and morphologic variation observed in the H. affinis populations examined here indicate the species’ favorable conservation status, genetic diversity, adaptive capacity, and, thus, “suitability” for field application as an effective mosquito control agent.


Zootaxa ◽  
2020 ◽  
Vol 4803 (1) ◽  
pp. 1-41
Author(s):  
DANIEL CHIRIVI-JOYA ◽  
JAIRO A. MORENO-GONZÁLEZ ◽  
GIOVANNY FAGUA

The family Phrynidae has been mainly recorded from America, including the Antilles, and Heterophrynus is one of its genera endemic of South America and is mainly associated with Amazonian ecosystems. Currently, the genus has 16 valid species, but many original descriptions are ambiguous or incomplete. The more complete work about this genus only includes seven of the currently valid species, and in some cases, some characters useful for the species identification, were not described. This situation hampers the species recognition and the comparison among species to propose diagnosis accurate. Using characters from the male and female genitalia to improve the diagnosis, we present complementary descriptions for four species of Heterophrynus and describe two new species. We present details of morphologic variation, compare the pedipalp spines among the species, present actualized distributions, and for first time, we present a complete illustration of the male genital of eight species using SEM pictures. 


Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 667
Author(s):  
Christine Gee ◽  
Alison Small ◽  
Kathleen Shorter ◽  
Wendy Y. Brown

Equine Caudal Cervical Morphologic Variation (ECCMV) is a congenital malformation of the caudal cervical spine distinct from the more commonly recognized Cervical Vertebral Stenotic Myelopathy (CVSM). The most common presentation of ECCMV is recognized on the sixth cervical vertebra (C6). In “normal” presentations, the transverse processes on the left and right sides have a caudal lamina projecting ventrally below the caudal vertebral body in a heel shape. With ECCMV, variations occur to the structure of the caudal ventral lamina on one or both sides of C6 and may include the seventh cervical (C7) and first thoracic (T1) vertebrae and ribs, in varying configurations. Whereas the prevalence of ECCMV is not known, it has been recognized for many years and has been reported to occur with relatively high frequency within multiple populations of domesticated horses. To date, there is no documented link between the occurrence of ECCMV and clinical signs. However, based on retrospective studies, multiple authors have recognized the potential impact on performance that this condition may have. Establishing a reliable radiographic protocol for the consistent diagnosis of ECCMV would allow quantitative, scientific evaluation of the problem and support clinicians working in this field. We present a radiographic technique, which has been illustrated by diagnosis of ECCMV in three horses and confirmation of the diagnoses in two cases via postmortem examination.


Author(s):  
Gunes Bolatli ◽  
Nadire Unver Dogan ◽  
Zeliha Fazliogullari ◽  
Ali Sami Kivrak ◽  
Ismihan Ilknur Uysal ◽  
...  

The hyoid is a U shaped bone with a backward concavity. Locates at the lower edge of the mandible and lies parallel to the floor — functions as an attachment point for muscles and soft tissues of head and neck. The aim is to examine the variations and ossification of the hyoid. This study was performed retrospectively in 2010 - 2013 on 200 CT images. 3D volume rendering images of pure hyoid bone created from the axial CT images in 1 mm slice thickness. The morphological variation count was 23; ossification variations were 9 cases. No difference observed by gender, but there are differences between the age groups for ossification. Ossification rates were found as; partial 34 %, unilateral 33%, complete 22%, early 11%. Most of the morphologic variation were belong to minor horn (57%), variations of major horn were 30%. The clinical importance of hyoid bone has realized in recent years. Due to the close relationship of this bone with the muscles, ligaments, fascias, sternum, clavicles, its dysfunction can lead to general problems. Studies about the variations of hyoid bone found to be quite low, and we believe that our research will contribute to the content of literature.


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