{"title":"Morphometric analysis and functional insights into the serotonergic system of Girardia tigrina (Tricladida, Platyhelminthes)","authors":"Natalia D. Kreshchenko, Artem M. Ermakov","doi":"10.1002/jmor.21756","DOIUrl":"10.1002/jmor.21756","url":null,"abstract":"<p>Using immunocytochemistry, serotonergic nerve elements were documented in the nervous system of the planarian <i>Girardia tigrina</i>. Serotonin-immunopositive components were observed in the brain, ventral, dorsal and longitudinal nerve cords, transverse nerve commissures connecting the nerve cords, and in the nerve plexus. Whole-mount preparations of <i>G. tigrina</i> were analyzed by fluorescent and confocal laser scanning microscopy. An essential quantitative morphometric measurement of serotonin-immunopositive structures was conducted in three body regions (anterior, middle, and posterior) of the planarian. The number of serotonin neurons was maximal in the head region. The ventral nerve cords gradually decreased in thickness from anterior to posterior body ends. Physiological action of exogenously applied serotonin was studied in <i>G. tigrina</i> for the first time. It was found that serotonin (0.1 and 1 µmol L<sup>−1</sup>) accelerated eye regeneration. The transcriptome sequencing performed for the first time for the planarian <i>G. tigrina</i> revealed the transcripts of the tryptophan hydroxylase (<i>trph</i>), amino acid decarboxylase (<i>aadc</i>) and serotonin transporter (<i>sert</i>) genes. The data obtained indicate the presence of the components of serotonin pathway in <i>G. tigrina</i>. The identified transcripts can take part in serotonin turnover and participate in the realization of biological effects of serotonin in planarians, associated with eyes regeneration and differentiation.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141860055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Novel neurocranial fenestrae and expansions in Monomitopus and Selachophidium (Teleostei: Ophidiidae), with comments on the morphology, taxonomy, and evolution of the genera","authors":"Matthew G. Girard, G. David Johnson","doi":"10.1002/jmor.21753","DOIUrl":"10.1002/jmor.21753","url":null,"abstract":"<p>The Ophidiidae is a group of more than 300 species of fishes characterized by elongated, snake-like bodies and continuous dorsal, anal, and caudal fins. While describing a new species in the genus <i>Monomitopus</i>, we discovered a bilaterally paired fenestra on the dorsomedial surface of the neurocranium. We surveyed the distribution of this fenestra across species of <i>Monomitopus</i> and previously hypothesized allies in the genera <i>Dannevigia</i>, <i>Dicrolene</i>, <i>Homostolus</i>, <i>Neobythites</i>, and <i>Selachophidium</i>, finding variation in its presence and size. We also found a prominent bilaterally paired lateral fenestra and a posterior expansion of the exoccipital in the neurocrania of <i>M. americanus</i> and <i>S. guentheri</i>, with soft tissue connecting the back of the neurocranium to the first epineural and pectoral girdle in <i>S. guentheri</i>. In this study, we describe the distribution of and variation in these features. We integrate morphological characters and DNA data to generate a phylogeny of <i>Monomitopus</i> and allies to understand their relationships and trace the evolutionary history of these novel features. Our results call the monophyly of <i>Monomitopus</i> into question. The presence of the lateral neurocranial fenestra and posterior expansion of the exoccipital support the reclassification of <i>M. americanus</i> as a species of <i>Selachophidium.</i></p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141759244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Odair M. Meira, Rolf G. Beutel, Hans Pohl, Thomas van de Kamp, Eduardo A. B. Almeida, Brendon E. Boudinot
{"title":"Bee morphology: A skeletomuscular anatomy of Thyreus (Hymenoptera: Apidae)","authors":"Odair M. Meira, Rolf G. Beutel, Hans Pohl, Thomas van de Kamp, Eduardo A. B. Almeida, Brendon E. Boudinot","doi":"10.1002/jmor.21751","DOIUrl":"10.1002/jmor.21751","url":null,"abstract":"<p>Although the knowledge of the skeletal morphology of bees has progressed enormously, a corresponding advance has not happened for the muscular system. Most of the knowledge about bee musculature was generated over 50 years ago, well before the digital revolution for anatomical imaging, including the application of microcomputed tomography. This technique, in particular, has made it possible to dissect small insects digitally, document anatomy efficiently and in detail, and visualize these data three dimensionally. In this study, we document the skeletomuscular system of a cuckoo bee, <i>Thyreus albomaculatus</i> and, with that, we provide a 3D atlas of bee skeletomuscular anatomy. The results obtained for <i>Thyreus</i> are compared with representatives of two other bee families (Andrenidae and Halictidae), to evaluate the generality of our morphological conclusions. Besides documenting 199 specific muscles in terms of origin, insertion, and structure, we update the interpretation of complex homologies in the maxillolabial complex of bee mouthparts. We also clarify the complicated 3D structure of the cephalic endoskeleton, identifying the tentorial, hypostomal, and postgenal structures and their connecting regions. We describe the anatomy of the medial elevator muscles of the head, precisely identifying their origins and insertions as well as their homologs in other groups of Hymenoptera. We reject the hypothesis that the synapomorphic propodeal triangle of Apoidea is homologous with the metapostnotum, and instead recognize that this is a modification of the third phragma. We recognize two previously undocumented metasomal muscle groups in bees, clarifying the serial skeletomusculature of the metasoma and revealing shortcomings of Snodgrass' “internal–external” terminological system for the abdomen. Finally, we elucidate the muscular structure of the sting apparatus, resolving previously unclear interpretations. The work conducted herein not only provides new insights into bee morphology but also represents a source for future phenomic research on Hymenoptera.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21751","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141748445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the wing: Morphological variation in the osteology of Mediterranean, Near Eastern, and European Anatidae (excluding Anserinae)","authors":"Ashleigh Haruda, Camilla Mazzucato, Lisa Yeomans","doi":"10.1002/jmor.21750","DOIUrl":"10.1002/jmor.21750","url":null,"abstract":"<p>Accurate identification of waterfowl bones in archaeological and fossil assemblages has potential to unlock new methods of past environmental reconstruction, as species have differing habitat preferences and migration patterns. Therefore, identifying the presence of avian species with different ecological niches is key to determining past environments and ultimately how prehistoric people responded to climatic and environmental realignments. However, the identification of osteological remains of waterbirds such as ducks to species level is notoriously challenging. We address this by presenting a new two-dimensional geometric morphometric protocol on wing elements from over 20 duck species and test the utility of these shape data for correct species identification. This is an ideal starting point to expand utilization of these types of approaches in avifaunal research and test applicability to an extremely difficult taxonomic group.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21750","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141731283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Comparative osteology of the skull of cowbirds (Icteridae: Molothrus)","authors":"Raúl O. Gómez, Jimena Lois-Milevicich","doi":"10.1002/jmor.21752","DOIUrl":"10.1002/jmor.21752","url":null,"abstract":"<p>Detailed osteological descriptions of the craniomandibular complex of passerine birds are lacking for most species, limiting our understanding of their diversity and evolution. Cowbirds (genus <i>Molothrus</i>) are a small but widespread group of New World nine-primaried songbirds, well-known for their unique brooding parasitic behavior. However, detailed osteological data for cowbirds and other Icteridae are currently scarce and several features of their skulls remain undescribed or poorly known. To address this issue, a detailed comparative osteology of cowbird skulls is presented here for the first time based on data from x-ray microcomputed tomography, dry skeletal data, and multivariate analyses of linear morphometric data. Cowbird skulls offer some functional insights, with many finch-like features probably related to a seed-rich diet that distinguishes them from most other icterids. In addition, features previously overlooked in earlier studies might provide valuable phylogenetic information at different levels of passerine phylogeny (Passerida, Emberizoidea, Icteridae, and Agelaiinae), including some of the otic region and nasal septum. Comparisons among cowbirds show that there is substantial cranial variation within the genus, with <i>M. oryzivorus</i> being the most divergent cowbird species. Within the genus, distantly related species share similar overall skull morphology and proportions, but detailed osteological data allow species identification even in cases of strong convergence. Further efforts are warranted to furnish baseline data for future studies of this iconic group of Neotropical birds and to fully integrate it into phylogenetic comparative frameworks.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141626944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Carpal variability and asymmetry in limb reduced Western lesser sirens (Siren nettingi)","authors":"Gibson M. Barlow, Nicholus M. Ledbetter","doi":"10.1002/jmor.21749","DOIUrl":"10.1002/jmor.21749","url":null,"abstract":"<p>Trait functionality can act as a constraint on morphological development. Traits that become vestigialized can exhibit unstable developmental patterns such as fluctuating asymmetry (FA) and variation in populations. We use clearing and staining along with morphometric analyzes to compare FA and allometry of limbs in Western lesser sirens (<i>Siren nettingi</i>) to Ouachita dusky salamanders (<i>Desmognathus brimleyorum</i>)<i>.</i> Our results describe new carpal phenotypes and carpal asymmetry in our sample of <i>S. nettingi</i>. However, we found no significant evidence of limb length asymmetry in <i>S. nettingi</i>. The degree of relative limb asymmetry correlates inversely with body size in both of our samples. This work provides strong evidence of increased mesopodal variation within a population of <i>S. nettingi</i>. Our work provides a basis for further study of a broader range of morphological traits across salamanders.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 7","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141563565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Chondrocranial anatomy of Testudo hermanni (Testudinidae, Testudines) with a comparison to other turtles","authors":"Carola Mauel, Luca Leicht, Yevhenii Broshko, Oleksandr Yaryhin, Ingmar Werneburg","doi":"10.1002/jmor.21747","DOIUrl":"10.1002/jmor.21747","url":null,"abstract":"<p>Using histological cross-sections, the chondrocranium anatomy was reconstructed for two developmental stages of Hermann's tortoise (<i>Testudo hermanni</i>). The morphology differs from the chondrocrania of most other turtles by a process above the ectochoanal cartilage with <i>Pelodiscus sinensis</i> being the only other known species with such a structure. The anterior and posterior processes of the tectum synoticum are better developed than in most other turtles and an ascending process of the palatoquadrate is missing, which is otherwise only the case in pleurodiran turtles. The nasal region gets proportionally larger during development. We interpret the enlargement of the nasal capsules as an adaption to increase the surface area of the olfactory epithelium for better perception of volant odors. Elongation of the nasal capsules in trionychids, in contrast, is unlikely to be related to olfaction, while it is ambiguous in the case of <i>Sternotherus odoratus</i>. However, we have to conclude that research on chondrocranium anatomy is still at its beginning and more comprehensive detailed descriptions in relation to other parts of the anatomy are needed before providing broad-scale ecological and phylogenetic interpretations.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 7","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21747","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141492299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maxime Taverne, Laura Lalieve, Sylvain Persohn, Roman Hossein Khonsari, Giovanna Paternoster, Syril James, Thomas Blauwblomme, Sandro Benichi, Sébastien Laporte
{"title":"Anatomy and mobility in the adult cadaveric craniocervical junction","authors":"Maxime Taverne, Laura Lalieve, Sylvain Persohn, Roman Hossein Khonsari, Giovanna Paternoster, Syril James, Thomas Blauwblomme, Sandro Benichi, Sébastien Laporte","doi":"10.1002/jmor.21748","DOIUrl":"10.1002/jmor.21748","url":null,"abstract":"<p>Genetic diseases with craniofacial malformations can be associated with anomalies of the craniocervical joint (CCJ). The functions of the CCJ are thus impaired, as mobility may be either limited by abnormal bone fusion causing headaches, or exaggerated in the case of hypermobility, which may cause irreparable damage to the spinal cord<b>.</b> Restoring the balance between mobility and stability requires surgical correction in children. The anatomy and biomechanics of the CCJ are quite unique, yet have been overlooked in the past decades. Pediatric evidence is so scarce, that investigating the adult CCJ is our best shot to disentangle the form-function relationships of this anatomical region. The motivation of the present study was to understand the morphological and functional basis of motion in the CCJ, in the hope to find morphological features accessible from medical imaging able to predict mobility. To do so, we have quantified the in-vitro kinematics of the CCJ in nine cadaveric asymptomatic adults, and estimated a wide range of mobility variables covering the complexity of spinal motion. We compared these variables with the shape of the occipital, the atlas and the axis, obtained using a dense geometric morphometric approach. Morphological joint congruence was also quantified. Our results suggest a strong relationship between bone shape and motion, with the overall geometry predicting best the primary movements, and the joint facets predicting best the secondary movements. We propose a functional hypothesis stating that the musculoligamental system determines movements of great amplitude, while the shape and congruence of joint facets determine the secondary and coupled movements, especially by varying the geometry of bone stops and the way ligaments are tensioned. We believe this work will provide valuable insights in understanding the biomechanics of the CCJ. Furthermore, it should help surgeons treating CCJ anomalies by enabling them to translate objectives of functional and clinical outcome into clear objectives of morphological outcome.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 7","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21748","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141468755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The effect of jaw suspension on cartilage strength in elasmobranchs","authors":"Cheryl Wilga, Lara Ferry, Elizabeth Dumont","doi":"10.1002/jmor.21745","DOIUrl":"10.1002/jmor.21745","url":null,"abstract":"<p>The jaws and their supporting cartilages are tessellated in elasmobranchs and exhibit an abrupt increase in stiffness under compression. The major jaw-supporting cartilage, the hyomandibula, varies widely by shape and size and the extent of the load-bearing role is hypothesized to be inversely related to the number of craniopalatine articulations. Here, we test this hypothesis by evaluating the strength of the hyomandibular cartilage under compression in 13 species that represent all four jaw suspension systems in elasmobranchs (amphistyly, orbitostyly, hyostyly, and euhyostyly). The strength of the hyomandibular cartilages was measured directly using a material testing machine under compressive load, and indirectly by measuring morphological variables putatively associated with strength. The first measure of strength is force to yield (<i>F</i><sub>y</sub>), which was the peak force (N) exerted on the hyomandibula before plastic deformation. The second measure was compressive yield strength (<i>σ</i><sub>y,</sub> also called yield stress), which is calculated as peak force (N) before plastic deformation/cross-sectional area (mm<sup>2</sup>) of the specimen. Our results show that the load-bearing role of the hyomandibular cartilage, as measured by yield strength, is inversely related to the number of craniopalatine articulations, as predicted. Force to yield was lower for euhyostylic jaw suspensions and similar for the others. We also found that mineralization is associated with greater yield strength, while the second moment of area is associated with greater force to yield.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 7","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141327594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexey V. Romanov, Vladimir V. Shakhparonov, Kyrill B. Gerasimov, Leonid P. Korzun
{"title":"Occipital-synarcual joint mobility in ratfishes (Chimaeridae) and its possible adaptive role","authors":"Alexey V. Romanov, Vladimir V. Shakhparonov, Kyrill B. Gerasimov, Leonid P. Korzun","doi":"10.1002/jmor.21740","DOIUrl":"10.1002/jmor.21740","url":null,"abstract":"<p>The neurocranial elevation generated by axial muscles is widespread among aquatic gnathostomes. The mechanism has two functions: first, it contributes to the orientation of the mouth gape, and second, it is involved in suction feeding. To provide such mobility, anatomical specialization of the anterior part of the vertebral column has evolved in many fish species. In modern chimaeras, the anterior part of the vertebral column develops into the synarcual. Possible biological roles of the occipital-synarcual joint have not been discussed before. Dissections of the head of two species of ratfishes (<i>Chimaera monstrosa</i> and <i>Chimaera phantasma</i>) confirmed the heterocoely of the articulation surface between the synarcual and the neurocranium, indicating the possibility of movements in the sagittal and frontal planes. Muscles capable of controlling the movements of the neurocranium were described. The <i>m. epaxialis</i> is capable of elevating the head, the <i>m. coracomandibularis</i> is capable of lowering it if the mandible is anchored by the adductor. Lateral flexion is performed by the <i>m. lateroventralis</i>, for which this function was proposed for the first time. The first description of the <i>m. epaxialis profundus</i> is given, its function is to be elucidated in the future. Manipulations with joint preparations revealed a pronounced amplitude of movement in the sagittal and frontal planes. Since chimaeras generate weak decrease in pressure in the oropharyngeal cavity when sucking in prey, we hypothesised the primary effect of neurocranial elevation, in addition to the evident lateral head mobility, is accurate prey targeting.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 6","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141300858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}