Journal of Morphology最新文献

{"title":"The effect of tessellation on stiffness in the hyoid arch of elasmobranchs","authors":"Cheryl Wilga,&nbsp;Elizabeth Dumont,&nbsp;Lara Ferry","doi":"10.1002/jmor.21681","DOIUrl":"10.1002/jmor.21681","url":null,"abstract":"<p>Tessellated cartilage forms much of the skeleton of sharks and rays, in contrast to most other aquatic vertebrates who possess a skeleton of bone. Interestingly, many species of sharks and rays also regularly generate exceptionally high forces in the execution of day-to-day activities, such as when feeding on bony fish, mammals, and hard-shelled invertebrates. Tessellated cartilage differs from other types of cartilage in that they are covered by an outer layer of small mineralized tiles (tesserae) that are connected by fibrous connective tissue. Tesserae, therefore, are hypothesized to play a role in stiffening the cartilaginous skeleton for food capture and other activities that require the generation of high forces. In this study, the hyomandibula and ceratohyal cartilages, which support the jaw and throat regions of sharks and rays, were tested under compressive load in a material testing system to determine the contribution of tesserae to stiffness. Previous hypotheses suggest an abrupt upward shift in the slope of the stress–strain curve in tessellated materials due to collision of tesserae. Young's Modulus (E) was calculated and used to evaluate cartilage stiffness in a range of elasmobranch species. Our results revealed that there was an abrupt shift in Young's Modulus for elements loaded in compression. We postulate that this shift, characterized by an inflection point in the stress–strain curve, is the result of the tesserae approaching one another and compressing the intervening fibrous tissue, supporting the hypothesis that tesserae function to stiffen these cartilages under compressive loading regimes. Using published data for nontessellated cartilage for comparison, we show that this shift is, as expected, unique to tessellated cartilage.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139746757","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":"To be a transit link: Similarity in the structure of colonial system of integration and communication pores in autozooids and avicularia of Terminoflustra membranaceotruncata (Bryozoa: Cheilostomata)","authors":"Natalia Shunatova","doi":"10.1002/jmor.21679","DOIUrl":"10.1002/jmor.21679","url":null,"abstract":"<p>Bryozoan colonies consist of zooids, which can differ in structure and function. Most heteromorphic zooids are unable to feed and autozooids supply them with nutrients. The structure of the tissues providing nutrient transfer is poorly investigated. Here, I present a detailed description of the colonial system of integration (CSI) and communication pores in autozooids and avicularia of the cheilosome bryozoan <i>Terminoflustra membranaceotruncata</i>. The CSI is the nutrient transport and distribution system in the colony. In both autozooids and avicularia it consists of a single cell type, that is, elongated cells, and has a variable branching pattern, except for the presence of a peripheral cord. The general similarity in the CSI structure in avicularia and autozooids is probably due to the interzooidal type of the avicularium. Interzooidal avicularia are likely to consume only a part of the nutrients delivered to them by the CSI, and they transit the rest of the nutrients further. The variability and irregularity of branching pattern of the CSI may be explained by the presence of single communication pores and their varying number. The structure of communication pores is similar regardless of their location (in the transverse or lateral wall) and the type of zooid in contact. Rosette complexes include a cincture cell, a few special cells, and a few limiting cells. Along each zooidal wall, there are communication pores with both unidirectional and bidirectional polarity of special cells. However, the total number of nucleus-containing lobes of special cells is approximately the same on each side of any zooidal wall. Supposing the polarity of special cells reflects the direction of nutrient transport, the pattern of special cells polarity is probably related to the need for bidirectional transport through each zooidal wall. The possibility for such transport is important in large perennial colonies with wide zones of autozooids undergoing polypide degeneration.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139702745","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":"Morphological variations of auditory bullae in otomyine rodents (Rodentia: Otomyini) in southern African biomes","authors":"Shelley Edwards,&nbsp;Rochelle Bessinger","doi":"10.1002/jmor.21680","DOIUrl":"https://doi.org/10.1002/jmor.21680","url":null,"abstract":"<p>Mammalian middle ear cavities differ from those of other taxa as they comprise three ossicles and in rodents, can be encapsulated by an auditory bulla. In small mammals, the middle ear cavity (bulla) was found to be enlarged in the desert-dwelling species; however, differences in bullar size could have been due to ancestry. In this study, we sampled seven species from three genera (<i>Myotomys, Otomys</i>, and <i>Parotomys</i>) of the African murid tribe Otomyini (laminated-toothed rats), and compared the bullar volumes and shapes between the otomyine species and within the species <i>Myotomys unisulcatus</i>. Photographs of museum skull specimens were taken from ventral and lateral views, and the volumes of the bullae were estimated digitally from the photographs. No sexual dimorphism in bullar volumes was found in any of the species. Corrected bullar volumes were significantly different between species and larger bullae were seen in individuals inhabiting regions with lower annual rainfall. Bullar shape (estimated using geometric morphometrics) was significantly different between the genera and the species. <i>Parotomys</i> have tympanic meatuses that face more anteriorly compared to both, <i>Otomys</i> and <i>Myotomys</i>. When comparing bullae within <i>M. unisulcatus</i>, those inhabiting regions with lower annual rainfall had significantly larger bullar volumes, but no significant difference was found in bullar shape between the regions. This study shows that otomyine rodents in more xeric habitats have different auditory structures to those inhabiting wetter habitats.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21680","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139704671","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":"Morphology and distribution of sensilla on head appendages in the water beetle Hygrobia hermanni (Coleoptera: Adephaga: Hygrobiidae)","authors":"Muriel Jager,&nbsp;Walid Errais,&nbsp;Michaël Trichet,&nbsp;Michaël Manuel","doi":"10.1002/jmor.21677","DOIUrl":"https://doi.org/10.1002/jmor.21677","url":null,"abstract":"<p>Sensilla on head appendages were studied in detail for the first time in a member of the relict family Hygrobiidae (squeak beetles), closely related to Dytiscidae (diving beetles). Adult and third instar larval stage specimens of <i>Hygrobia hermanni</i> (Fabricius, 1775) were examined using scanning electron microscopy, focusing on antennae, palps and larval mandibles. In total, 37 sensilla subtypes are described, including 22 observed in the adult (basiconica: 3; Böhm's bristles: 2; circumvallate sensilla: 2; coeloconica: 10; ovoid placodea: 3; digitiform placodea: 2) and 16 in the larva (basiconica: 4; campaniformia: 1; chaetica: 4; coeloconica: 5; trichodea: 1; unnamed: 1). Only one subtype (of sensilla coeloconica) was shared between the adult and the larva. Autapomorphies of Hygrobiidae and Dytiscidae, and putatively shared derived characters (synapomorphies) of Hygrobiidae + Dytiscidae are discussed. Among the latter, the most remarkable is the acquisition of a special sensory field, located on the apical segment of the adult maxillary palp, subapically and postero-dorsally. This sensory field is made up of ovoid multiporous sensilla placodea otherwise present on the anterior (internal) surface of antennal segments, suggesting that in a common ancestor of Hygrobiidae and Dytiscidae, maxillary palps might have taken over enhanced capacities of longe-range molecule detection.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139695461","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":"Morphology of ctenostome bryozoans: 7. Hislopia, Echinella and Timwoodiellina","authors":"Thomas Schwaha,&nbsp;Masato Hirose,&nbsp;Timothy S. Wood","doi":"10.1002/jmor.21678","DOIUrl":"10.1002/jmor.21678","url":null,"abstract":"<p>Ctenostome bryozoans are a small group of gymnolaemates comprising less than 400 recent species. They are paraphyletic and ctenostome-grade ancestors gave rise to Cheilostomata, the most dominant and speciose taxon of Bryozoa in the present day. Investigations into ctenostomes are important for reconstructing character evolution among Gymnolaemata. As a continuation of studies on a morphological series of ctenostome bryozoans, we herein investigate six species of hislopiids, a small clade of three genera occurring in freshwater habitats. The general morphology of all species is similar in having primarily uniserial chains of encrusting zooids, which are mostly oval to ellipsoid and have a flattened frontobasal axis. <i>Hislopia prolixa</i> and <i>Echinella placoides</i> often have more slender zooids with a higher frontobasal axis. Apertures of hislopiids are quadrangular, lined by a thickened cuticle. Apertural spines are present in various lengths in <i>E. placoides</i>, <i>Hislopia lacustris</i> and <i>Hislopia corderoi</i>. The remaining cuticle is rather thin except at lateral areas, close to the pore-plates which are prominent in hislopiids because of abundant special and limiting cells. All species except <i>H. corderoi</i> and <i>Timwoodiellina natans</i> have a prominent collar obstructing the vestibulum, whereas the latter two species instead have an ‘external collar’ as cuticular, outer folds projecting over the aperture. Hislopiid lophophores carry eight, or more commonly 12−18 tentacles. The digestive tract is distinguished by an often highly elongated esophagus and/or cardia, with the latter always having a prominent bulbous part in the form of a proventriculus—or gizzard in <i>E. placoides</i>. The caecum is extensive in all species. In <i>Hislopia</i> the intestine is characteristically two-chambered with a proximal and distal part before entering an anal tube of various length. The latter is present in all species except <i>T. natans</i> and terminates in mid-lophophoral area. Oocytes in <i>E. placoides</i> are large and macrolecithal indicating brooding and the production of lecithotrophic larvae. <i>Hislopia</i> species produce small, oligolecithal ones, which suggests zygote spawning and planktotrophy. In general, the morphology is similar among the different hislopiids with characters of the gut aiding in delineating the genera <i>Echinella</i> and <i>Timwoodiellina</i>.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21678","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139657775","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":"Morphology of the epididymal duct of the domestic pig (Sus scrofa domesticus)","authors":"Ferial Hassan,&nbsp;Wolfgang Holtz","doi":"10.1002/jmor.21675","DOIUrl":"https://doi.org/10.1002/jmor.21675","url":null,"abstract":"<p>The study provides a general overview of the morphology of the epididymal duct in pigs. Four epididymides from two sexually mature boars were dissected into 32 segments and examined histologically. Duct lumen and wall thickness were measured and relative surface area of different components was assessed by Chalkley's random hit method. The epithelial lining was characterized at X1000. Lumen diameter and wall thickness of efferent ductules averaged 177 and 30 µm, respectively. Of the epididymal duct from caput to distal corpus the luminal diameter was 332 µm, with a narrower section in the proximal corpus. Wall thickness averaged 70 µm. In the cauda, luminal diameter and wall thickness increased to 717 and 751 µm, respectively. The epithelial lining of the efferent ductules consists of a single layer of columnar cells with average height 21 µm. The lining of the epididymal duct consists of ciliated, pseudo-stratified columnar epithelium composed of “basal cells” and “principal cells.” Particularly tall principal cells (96 µm) were found in the proximal caput. Height decreased to 40 µm at the distal cauda. Microvilli from principal cells were 14−17 µm long in the distal caput but decreased to 5 µm in the distal cauda. The epithelial lining was folded in the proximal caput and more so in the distal cauda. Secretory granules (epididymosomes) were present in small amounts in efferent ductules and epididymal duct; the largest quantities occurred in the distal cauda. Leukocytes were present throughout the duct, albeit in insignificant numbers. Chalkley's random hit method showed rapid spermatozoan transport through efferent ductules and proximal caput in large amounts of fluid. Sperm concentration increased due to fluid resorption in the proximal caput, was highest from caput flexure to proximal cauda and decreased at the caudal flexure, indicating secretory activity.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21675","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139488508","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":"Cranial muscle architecture in wild boar: Does captivity drive ontogenetic trajectories?","authors":"Anthony Herrel,&nbsp;Yann Locatelli,&nbsp;Katia Ortiz,&nbsp;Jean-Christophe Theil,&nbsp;Raphaël Cornette,&nbsp;Thomas Cucchi","doi":"10.1002/jmor.21676","DOIUrl":"https://doi.org/10.1002/jmor.21676","url":null,"abstract":"<p>The jaw system in mammals is complex and different muscle morphotypes have been documented. Pigs are an interesting group of animals as they are omnivorous and have a bunodont crushing dentition. Moreover, they have interacted with humans for over 10,000 years and grow nearly two orders of magnitude in size. Despite being a model system for studies on cranial form and function, data on the growth of the jaw adductor muscles are scant. Moreover, whether captivity impacts the growth and architecture of the jaw adductors remains unknown. Based on dissection data of the jaw adductors of 45 animals ranging from less than 1 kg to almost 100 kg, we show that muscle masses, muscle fiber lengths, and cross-sectional areas scale as predicted for geometrically similar systems or with slight negative allometry. Only the fiber length of the lateral pterygoid muscle grew with slight positive allometry. Animals raised in captivity in stalls or in an enclosure were overall very similar to wild animals. However, some muscles were larger in captive animals. Interestingly, variation in bite force in captive animals was well predicted by the variation in the size of the superficial masseter muscle relative to the overall jaw adductor mass.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21676","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139468251","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 anatomy of the spinneret musculature in cribellate and ecribellate spiders (Araneae)","authors":"Josefine Kreuz,&nbsp;Peter Michalik,&nbsp;Jonas O. Wolff","doi":"10.1002/jmor.21670","DOIUrl":"https://doi.org/10.1002/jmor.21670","url":null,"abstract":"<p>Silk production is a prominent characteristic of spiders. The silk is extruded through spigots located on the spinnerets, which are single- to multimembered paired appendages at the end of the abdomen. Most extant spiders have three pairs of spinnerets, and in between either a cribellum (spinning plate) or a colulus (defunct vestigial organ), dividing these spiders into cribellate and ecribellate species. Previous research has shown that cribellate and ecribellate spiders differ not only in the composition of their spinning apparatus but also in the movements of their spinnerets during silk spinning. The objective of this study was to determine whether the differences in spinneret movements are solely due to variations in spinneret shape or whether they are based on differences in muscular anatomy. This was accomplished by analyzing microcomputed tomography scans of the posterior abdomen of each three cribellate and ecribellate species. It was found that the number of muscles did not generally differ between cribellate and ecribellate species, but varied considerably between the species within each of these two groups. Muscle thickness, particularly of the posterior median spinneret, varied slightly between groups, with cribellate spiders exhibiting more robust muscles, possibly to aid in the combing process during cribellar thread production. Interestingly, the vestigial colulus still possesses muscles, that can be homologized with those of the cribellum. This exploration into spinneret anatomy using microcomputed tomography data reveals that despite being small appendages, the spider spinnerets are equipped with a complex musculature that enables them to perform fine-scaled maneuvers to construct different fiber-based materials.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21670","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139431060","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":"Ontogenetic shifts in body form in the bull shark Carcharhinus leucas","authors":"Joel H. Gayford,&nbsp;Darren A. Whitehead,&nbsp;Sébastien Jaquemet","doi":"10.1002/jmor.21673","DOIUrl":"https://doi.org/10.1002/jmor.21673","url":null,"abstract":"<p>Recent studies have uncovered mosaic patterns of allometric and isometric growth underlying ontogenetic shifts in the body form of elasmobranch species (shark and rays). It is thought that shifts in trophic and spatial ecology through ontogeny drive these morphological changes; however, additional hypotheses relating to developmental constraints have also been posed. The bull shark (<i>Carcharhinus leucas</i>) is a large-bodied coastal shark that exhibits strong ontogenetic shifts in trophic and spatial ecology. In this study, we utilise a large data set covering a large number of morphological structures to reveal ontogenetic shifts in the body form of <i>C. leucas</i>, stratifying analyses by sex and size classes to provide fine-scale, more ecomorphologically relevant results. Our results indicate shifts in functional demands across the body through ontogeny, driven by selective pressures relating to trophic and spatial ecology driving the evolution of allometry. We also find significant differences in scaling trends between life stages, and between the sexes, highlighting the importance of utilising large, diverse datasets that can be stratified in this way to improve our understanding of elasmobranch morphological evolution. Ultimately, we discuss the implications of these results for existing ecomorphological hypotheses regarding the evolution of specific morphological structures, and pose novel hypotheses where relevant.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21673","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139406896","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 shingled girl: Catherine Janet Hill and her contributions to embryology","authors":"Anthony M. Carter","doi":"10.1002/jmor.21674","DOIUrl":"https://doi.org/10.1002/jmor.21674","url":null,"abstract":"<p>Catherine J. Hill is best remembered for her dedication to cataloguing the comprehensive embryological collection of her father J. P. Hill. Yet, her own research, during the interwar years, is little known. She made a significant contribution to interpreting the autonomic innervation of the gut, work that was presented to The Royal Society and earned her a PhD. Working in her father's laboratory, she then set about solving the sequence of secretions from the tubal epithelium and uterine glands that contributed the two layers of egg albumen and three shell layers of the monotreme egg. She was also the first to understand twinning in the marmoset and how two embryos came to share a single extraembryonic coelom, work that often is credited to J. P. Hill. Here. I explain how that happened and explore the context in which she and other female scientists worked at the time.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"285 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139109802","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}