Journal of Morphology最新文献

{"title":"Gastrotheca Fitzinger, 1843 tadpole morphology: Larval cranium description and its evolutionary implications (Amphibia: Anura: Hemiphractidae)","authors":"Manuella Folly,&nbsp;Lucas C. Amaral,&nbsp;Luiz F. L. da Silveira,&nbsp;Sergio P. de Carvalho-e-Silva,&nbsp;Pedro Henrique dos Santos Dias","doi":"10.1002/jmor.21766","DOIUrl":"10.1002/jmor.21766","url":null,"abstract":"<p>Hemiphractids have a singular mode of reproduction that involves maternal care. The Andean-endemic <i>Gastrotheca marsupiata</i> species group includes direct-developing and tadpole-bearing species, the latter trait being unique among <i>Gastrotheca</i>. Larval morphology has proven to be a valuable source of evidence to understand the taxonomy and evolution of frogs but remains understudied in Hemiphractids. Herein, we redescribe the larval cranium of <i>G. espeletia</i>, <i>G. gracilis</i>, <i>G. marsupiata</i>, <i>G. peruana</i>, <i>G. pseustes</i>, and <i>G. riobambae</i>, and describe those of <i>G. aureomaculata</i>, <i>G. chrysosticta</i>, <i>G. litonedis</i>, <i>G. monticola</i> and <i>G. psychrophila</i>. Additionally, based on the data gathered, we explore their phylogenetic significance, expanding the knowledge regarding <i>Gastrotheca</i> larval internal morphology. We suggest that the presence of the posterolateral process of crista parotica, the concave palatoquadrate, the quadratoorbital commissure, and the proximal commissures II and III are putative synapomorphies for <i>Gastrotheca</i>. Furthermore, we suggest the long pseudopterygoid process as a putative synapomorphy for Hemiphractyidae.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 9","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142017753","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":"Patterns of dermal denticle loss in sharks","authors":"Michael A. Fath,&nbsp;Greta Wong,&nbsp;Chloé-Rose Colombero,&nbsp;Molly K. Gabler-Smith,&nbsp;George V. Lauder,&nbsp;Dylan K. Wainwright","doi":"10.1002/jmor.21764","DOIUrl":"https://doi.org/10.1002/jmor.21764","url":null,"abstract":"<p>As they grow, sharks both replace lost denticles and proliferate the number of denticles by developing new (de novo) denticles without prior denticle shedding. The loss and replacement of denticles has potential impacts on the energetic cost of maintaining the skin surface, the biomechanical functions of shark skin, as well as our ability to predict shark abundance from fossil denticle occurrence in sediment cores. Here, we seek to better understand patterns of denticle loss and to show how denticles are being replaced in mature sharks. We illustrate shark skin surfaces with missing denticles and quantify both within-species and between-species patterns of missing denticles using images from across regions of the body for two species and images at similar body regions for 16 species of sharks. Generally, sharks are missing similar numbers of denticles (0%–6%) between species and regions. However, there are exceptions: in the smooth dogfish, the nose region is missing significantly more denticles than most posterior-body and fin regions, and the common thresher shark is missing significantly more denticles than the smooth dogfish, leopard shark, angel shark, bonnethead, and gulper shark. Denticle regrowth starts with crown development and mineralization beneath the epidermis, followed by eruption of the crown, and finally the mineralization of the root. The pulp cavity of replacement denticles is initially large and surrounded by a thin shell of enameloid upon eruption of the denticle. After eruption of the denticle, the deposition of dentine continues internally after the denticle reaches its final position. Replacement of missing denticles, representing less than 6% of the skin surface at any one time, may not compromise hydrodynamic function, but by constantly updating the skin surface throughout life, sharks may reduce surface fouling and maintain a functional complex skin surface by repairing local damage to individual denticles.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 9","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21764","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142013663","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":"Ultrastructure of the extraordinary pedal gland in Asplanchna aff. herricki (Rotifera: Monogononta)","authors":"Rick Hochberg,&nbsp;Robert L. Wallace,&nbsp;Elizabeth J. Walsh,&nbsp;Thiago Q. Araújo","doi":"10.1002/jmor.21765","DOIUrl":"https://doi.org/10.1002/jmor.21765","url":null,"abstract":"<p>Rotifers possess complex morphologies despite their microscopic size and simple appearance. Part of this complexity is hidden in the structure of their organs, which may be cellular or syncytial. Surprisingly, organs that are cellular in one taxon can be syncytial in another. Pedal glands are widespread across Rotifera and function in substrate attachment and/or egg brooding. These glands are normally absent in <i>Asplanchna</i>, which lack feet and toes that function as outlets for pedal glandular secretions in other rotifers. Here, we describe the ultrastructure of a pedal gland that is singular and syncytial in <i>Asplanchna</i> aff. <i>herricki</i>, but is normally paired and cellular in all other rotifers. <i>Asplanchna</i> aff. <i>herricki</i> has a single large pedal gland that is active and secretory; it has a bipartite, binucleate, syncytial body and a cytosol filled with rough endoplasmic reticulum, Golgi, and several types of secretory vesicles. The most abundant vesicle type is large and contains a spherical electron-dense secretion that appears to be produced through homotypic fusion of condensing vesicles produced by the Golgi. The vesicles appear to undergo a phase transition from condensed to decondensed along their pathway toward the gland lumen. Decondensation changes the contents to a mucin-like matrix that is eventually exocytosed in a “kiss-and-run” fashion with the plasma membrane of the gland lumen. Exocytosed mucus enters the gland lumen and exits through an epithelial duct that is an extension of the syncytial integument. This results in mucus that extends from the rotifer as a long string as the animal swims through the water. The function of this mucus is unknown, but we speculate it may function in temporary attachment, prey capture, or floatation.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 9","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21765","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141994209","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":"Development of the cranial lateral line system of Brook Trout, Salvelinus fontinalis (Teleostei: Salmonidae): Evolutionary and ecological implications","authors":"Aubree E. Jones,&nbsp;Pedro P. Rizzato,&nbsp;Jacqueline F. Webb","doi":"10.1002/jmor.21754","DOIUrl":"10.1002/jmor.21754","url":null,"abstract":"<p>The mechanosensory lateral line (LL) system of salmonid fishes has been the focus of comparative morphological studies and behavioral and physiological analyses of flow sensing capabilities, but its morphology and development have not been studied in detail in any one species. Here, we describe the post-embryonic development of the cranial LL system in Brook Trout, <i>Salvelinus fontinalis</i>, using vital fluorescent staining (4-Di-2-ASP), scanning electron microscopy, µCT, and clearing and staining to visualize neuromasts and the process of cranial LL canal morphogenesis. We examined the relationship between the timing of LL development, the prolonged life history of salmonids, and potential ecological implications. The LL system is composed of seven canals containing canal neuromasts (CNs) and four lines of superficial neuromasts (SNs) on the skin. CNs and SNs increase in number and size during the alevin (larval) stage. CN number stabilizes as canal morphogenesis commences, but SN number increases well into the parr (juvenile) stage. CNs become larger and more elongated than SNs, but the relative area occupied by sensory hair cells decreases during ontogeny in both types of neuromasts. Neuromast-centered canal morphogenesis starts in alevins (yolk sac larvae), as they swim up into the water column from their gravel nests (~4 months post-fertilization), after which yolk sac absorption is completed and exogenous feeding begins. Canal morphogenesis proceeds asynchronously within and among canal series and is not complete until ~8 months post-fertilization (the parr stage). Three characters in the LL system and associated dermal bones were used to identify their homologs in other actinopterygians and to consider the evolution of LL canal reduction, thus demonstrating the value of salmonids for the study of LL evolution. The prolonged life history of Brook Trout and the onset of canal morphogenesis at swim-up are predicted to have implications for neuromast function at these critical behavioral and ecological transitions.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141971312","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":"Comparative anatomy of siphons in tellinoidean clams (Bivalvia, Tellinoidea)","authors":"Alan R. Batistão,&nbsp;Jorge A. Audino,&nbsp;Flávio D. Passos","doi":"10.1002/jmor.21762","DOIUrl":"10.1002/jmor.21762","url":null,"abstract":"<p>Siphons are tubular organs formed by fusion and posterior extension of the marginal mantle folds. They are supposed to have performed key roles in the evolution of bivalves by enabling these animals to occupy several ecological niches. However, anatomical details of these organs are scarce for one of the most diverse lineages of tropical bivalves, the superfamily Tellinoidea. We investigated the siphonal morphology of 15 species, sampling five tellinoidean families, by integrating scanning electron microscopy, confocal microscopy, and histology. The siphons revealed variations in length, pigmentation, tentacles, papillae, and number of nerve cords. Due to the presence of sensorial structures, such as papillae and tentacles, we reclassify the siphons of Tellinoidea from type A to A+. Additional anatomical patterns were identified at family and genus levels. For example, the incurrent siphon shorter than the excurrent and 24 tentacles are putative synapomorphies of Donacidae. We also highlight shared siphonal traits between Donacidae and Solecurtidae as well as between Semelidae and Tellinidae. In addition, our data support the idea of Psammobiidae as a paraphyletic lineage. Overall, we provide an extensive comparative data set on siphonal traits with significant relevance for bivalve taxonomy, functional anatomy, and evolutionary investigations.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141916986","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":"How anatomy influences measurements of snakes","authors":"David Cundall,&nbsp;Alexandra Deufel,&nbsp;Abigail Pattishall","doi":"10.1002/jmor.21758","DOIUrl":"10.1002/jmor.21758","url":null,"abstract":"<p>Anatomy compromises the precision and accuracy of measurements made of the body length and head size of live snakes. Body measures (snout-vent length, SVL) incorporate many synovial intervertebral joints, each allowing flexion and limited extension and compression. Radiographs of the trunk in 14 phylogenetically diverse species in resting and stretched conditions combined with dissections and histological analysis of intervertebral joints show that the synovial nature of these joints underlies the variance in SVL measures. Similarly, the ubiquity and variety of viscoelastic tissues connecting mobile snout and jaw elements of alethinophidian snakes underlie variances in length and width measures of the head. For the overall size of the head and jaw apparatus, the part that can be most easily and relatively precisely measured for many snakes is the mandible because it has only one mobile joint. As to accuracy, the anatomy of intervertebral and cranial joints supports the hypothesis that in living snakes, the head and trunk have no exact size.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21758","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141902018","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 morphology in the context of facial reduction: Modularity in primate, dog, and bat crania","authors":"Molly C. Selba,&nbsp;Federico R. Vilaplana Grosso,&nbsp;Valerie B. DeLeon","doi":"10.1002/jmor.21759","DOIUrl":"10.1002/jmor.21759","url":null,"abstract":"<p>Biological variation in the mammalian skull is the product of a series of factors including changes in gene expression, developmental timing, and environmental pressures. When considering the diversity of extant mammalian crania, it is important to understand these mechanisms that contribute to cranial growth and in turn, how differences in cranial morphology have been attained. Various researchers, including Dr. Sue Herring, have proposed a variety of mechanisms to explain the process of cranial growth. This work has set the foundation on which modern analysis of craniofacial morphology happens today. This study focused on the analysis of modularity in three mammalian taxa, all of which exhibit facial reduction. Specifically, we examined facial reduction as a morphological phenomenon through the use of two-module and six-module modularity hypotheses. We recorded three-dimensional coordinate data for 55 cranial landmarks that allowed us to analyze differences in cranial shape in these three taxa (primates <i>n</i> = 88, bats <i>n</i> = 64, dogs <i>n</i> = 81). When assessing modularity within the two-module modularity hypothesis specifically, dogs exhibited the lowest levels of modularity, while bats and primates both showed a slightly more modular covariance structure. We further assessed modularity in the same sample using the Goswami six-module model, where again dogs exhibited a low degree of modularity, with bats and primates being more moderate. We then broke the sample into subsets by analyzing each morphotype separately. We hypothesized that the modularity would be more pronounced in the brachycephalic morphotype. Surprisingly, we found that in brachycephalic dogs, normocephalic dogs, brachycephalic primates, and normocephalic primates, there was a moderate degree of modularity. Brachycephalic bats had a low degree of modularity, while normocephalic bats were the most modular group observed in this study. Based on these results, it is evident that facial reduction is a complex and multifaceted phenomenon with unique morphological changes observed in each of the three taxa studied.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 8","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141902017","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":"The effect of occlusal loading on secondary tooth eruption: An experimental study using a rat model","authors":"Ourania Stergiopulos,&nbsp;Aikaterini Lagou,&nbsp;Gregory S. Antonarakis,&nbsp;Nikolaos Pandis,&nbsp;Stavros Kiliaridis","doi":"10.1002/jmor.21755","DOIUrl":"10.1002/jmor.21755","url":null,"abstract":"<p>This study aimed to assess the impact of occlusal loading on secondary tooth eruption and to determine the extent to which altering the occlusal loading influences the magnitude of secondary eruption through an experimental rat model. The present sample consisted of 48 male Wistar rats. At the onset of the experiment, 24 rats were 4 weeks old (young rats) and 24 rats were 26 weeks old (adult). Within each age group, the rats were further divided into two equal subgroups (12 rats each), receiving either a soft- or hard-food diet for the 3-month duration of the experiment. The primary outcome was the tooth position changes relative to stable references in the coronal plane by evaluating the distance between the mandibular first molars and the inferior alveolar canal. Microcomputed tomography scans were taken from all rats at three standardized intervals over the 3-month study period. Descriptive statistics were calculated by age and diet over time, and the evolution of the outcomes were plotted by age and diet over time. Longitudinal data analysis via generalized estimating equations was performed to examine the effect of age, diet and time on the primary outcomes. Secondary tooth eruption was observed in all age groups (young and adult) regardless of diet consistency (soft or hard food). In young rats, the secondary eruption was greater in the animals fed a soft diet than those fed a hard diet. In adult rats, minimal difference in secondary tooth eruption were found between different diet consistencies. Occlusal loading influences secondary tooth eruption in teeth with an established occlusal contact. The quantity of eruption in growing rats is higher when occlusal loading is less, providing a certain amount of secondary tooth eruption occurs. This difference, however, is not evident in adult rats, at least during the given 3-month time frame.</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":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21755","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141860056","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":"Morphometric analysis and functional insights into the serotonergic system of Girardia tigrina (Tricladida, Platyhelminthes)","authors":"Natalia D. Kreshchenko,&nbsp;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⁻¹) 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,&nbsp;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}