Journal of Morphology最新文献

{"title":"Ecomorphological Decoupling and Integration in Structures to Detect, Capture, and Process Food in Damselfishes","authors":"Rosalía Aguilar-Medrano","doi":"10.1002/jmor.70095","DOIUrl":"10.1002/jmor.70095","url":null,"abstract":"<div>\u0000 \u0000 <p>Some of the most extensively studied phenotypic adaptations in reef fish pertain to trophic diversification. Within the Pomacentridae family, a strong correlation between head morphology and diet has been identified. The relationship between structures involved in food detection (eyes) and capture (mouth) has been demonstrated, prompting the question of whether pharyngeal jaws vary in an integrated manner with the eyes and mouth to detect, capture, and process food according to different trophic guilds. In this study, morphometric analyses were applied to X-rays of the 24 damselfishes of the eastern Pacific. A comprehensive database of dietary items for all species was constructed. The species were grouped according to their diet in trophic groups, which were tested on the morphometric data to determine ecomorphological groups. Six ecomorphological groups were determined: three benthic feeders, one benthopelagic, and two pelagic. Phylogenetic (phy) and nonphylogenetic (n-phy) modulatory analyses were conducted on the entire sample, three broad ecomorphological categories (phy-benthic, pelagic, pelagic–benthopelagic; n-phy, benthic, benthopelagic, pelagic), and the six specific ecomorphological groups (n-phy). Four modularity hypotheses were tested: three modules, the eye (E), mouth (M), and pharyngeal jaws (PJ), and two modules, PJ&amp;E versus M, M&amp;PJ versus E, and M&amp;E versus PJ. Across all groupings, the hypothesis of three distinct modules was most strongly supported, followed by PJ&amp;E versus M, with M&amp;E versus PJ being the least supported. These findings suggest that the eye and mouth are more functionally decoupled than the pharyngeal jaws. It was evident that these structures exhibit a greater decoupling in benthic species than in benthopelagic and pelagic species. Our results indicate that different trophic groups show different levels of decoupling and integration in structures to detect, capture, and process food, and that, despite operating within a relatively narrow range of ecomorphological variation, damselfishes display a remarkable array of ecomorphological combinations.</p></div>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 10","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145238772","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":"Supramedullary Neurons in Teleost Fishes: Distribution and Putative Functions","authors":"Christopher Tyler,&nbsp;Lahari Koganti,&nbsp;Jun Liu,&nbsp;Ashley Ngo,&nbsp;Tina W. Wong,&nbsp;Xin (Tina) Zeng,&nbsp;Ernst-August Seyfarth,&nbsp;Steven J. Zottoli","doi":"10.1002/jmor.70090","DOIUrl":"10.1002/jmor.70090","url":null,"abstract":"<div>\u0000 \u0000 <p>Supramedullary neurons (SMNs) were described almost 150 years ago as large, unipolar cells whose somata are located on the dorsal aspect of the medulla oblongata and spinal cord in adults of teleost fishes. SMNs are either aligned in a single, median longitudinal row, generally extending over the rostral third of the spinal cord, or clustered over the medulla oblongata and rostral spinal cord. We add to the list of species that have SMNs and provide the first description of a novel distribution of SMNs along most of the spinal cord in the oyster toadfish (<i>Opsanus tau</i>) and sea raven (<i>Hemitripterus americanus</i>). The number of SMNs ranges from 27 in the Atlantic butterfish (<i>Peprilus triacanthus</i>) to 3712 in the oyster toadfish (<i>Opsanus tau</i>), and soma diameter ranges from an average of 23 µm in the Atlantic butterfish to 232 µm in the Southern pufferfish (<i>Sphoeroides nephelus</i>). SMNs could not be identified in 11 species, including seven freshwater fishes. We discuss factors that may affect the presence/absence of SMNs including age, length of time in captivity, and habitat salinity. Proposed functions of SMNs include neurosecretion and mucous secretion, and we suggest approaches that may aid in the discovery of the role of these fascinating neurons.</p></div>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 10","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145199451","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":"Balancing Body Size and Respiratory Surface: A Morphometric Analysis of the Caribbean King Crab (Maguimithrax spinosissimus) and Caribbean Spiny Lobster (Panulirus argus).","authors":"Morgan L Jarrett, Angel Avedo, Jessica Newland, Daniel Pauly, Mark J Butler","doi":"10.1002/jmor.70098","DOIUrl":"https://doi.org/10.1002/jmor.70098","url":null,"abstract":"<p><p>The respiratory organs of water-breathing ectotherms (WBEs), typically in the form of gills, extract oxygen from the water. The size and shape of respiratory organs are vital to the efficiency of oxygen diffusion and often unique to each species. Oxygen concentrations in water are < 1%, far lower than in the atmosphere, so WBEs have evolved gill morphologies that maximize their oxygen uptake but are also shaped by their life history and the environment. Gill surface area is related to the body mass of an individual, scaling as a power-law function whose exponent, based on theory and empirical evidence, generally lies between 0.6 and 0.9. However, nearly all estimates of gill surface area are based on 2-dimensional rather than 3-dimensional measurements, assuming that gill thickness is negligible and unimportant to respiration in accord with the physics of oxygen diffusion. This study aimed to develop methods to measure gills in three dimensions and then convert 2-dimensional gill surface area to the 3-dimensional gill surface area. The body mass and gill surface area scaling relationship was then determined for two decapod crustaceans with contrasting life histories: the Caribbean Spiny Lobster (Panulirus argus) and the Caribbean King Crab (Maguimithrax spinosissimus). We found a positive relationship between gill lamellae thickness and body mass for both species, which could be beneficial or detrimental to larger, oxygen-limited WBEs depending on the balance between oxygen diffusion through the additional surface area and the dynamics of oxygen diffusion into a larger volume. The 2-dimensional scaling exponent between gill surface area and body mass was 0.626 for lobsters and 0.779 for crabs, compared to their 3-dimensional scaling exponents (0.809 and 0.702, respectively). These are the first 2D and 3D body mass and gill surface area scaling exponents determined for these species and will set the basis for future physiological research.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 10","pages":"e70098"},"PeriodicalIF":1.4,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145280468","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":"Sall Genes and Proteins Activation during Early Tail and Limb Regeneration in the Lizard Podarcis muralis Suggests Dedifferentiation","authors":"Alibardi Lorenzo","doi":"10.1002/jmor.70091","DOIUrl":"10.1002/jmor.70091","url":null,"abstract":"<div>\u0000 \u0000 <p>Lizards represent the closest amniotes to mammals able to regenerate many tissues, therefore are useful models for studies of mammalian regeneration. Tail regeneration occurs by stem cells but tissue dedifferentiation may also be involved. When injury damages numerous tissues they may undergo dedifferentiation (re-programming). This was indicated especially in muscles and connectives of the tail 7–10 days postamputation. The transcriptome of regenerating tail and limb from the lizard <i>Podarcis muralis</i> detected upregulation of spalt-like genes (sall 1–4), known to be involved in re-programming. Here, immunolocalization of the sall4 protein and 5BrdU-labeled cells (proliferating) was conducted. A variable number of 5BrdU and sall4-positive cells are detected among stump connective tissues, injured muscles, and dermis. Labeling for sall4 is cytoplasmic and also nuclear, and it is also noted in cytoplasmic muscle fragments. The latter likely derived from the fragmentation of injured muscles in both tail and limb stumps at 7–16 days postamputation. Occasional, isolated sall4-labeled cells are rarely detected in the blastema, and none in the wound epidermis or regenerating spinal cord and muscles. The present study indicates that cell dedifferentiation occurs during early stages of tail and limb amputation in lizards, contributing with activated stem cells to their regeneration or scarring.</p></div>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 10","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145191963","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":"Feeding Ecology, Evolutionary Allometry, and Convergence in the Lower Jaw of New World Blackbirds and Allied Passerine Birds (Emberizoidea)","authors":"Nahuel A. Liendro-Bataglia,&nbsp;Luca N. Martini,&nbsp;L. Muriel Pereyra-Civiello,&nbsp;Zoe C. Ascune-Wachsmuth,&nbsp;Jimena Lois-Milevicich,&nbsp;Raúl O. Gómez","doi":"10.1002/jmor.70092","DOIUrl":"10.1002/jmor.70092","url":null,"abstract":"<div>\u0000 \u0000 <p>New World Blackbirds (Icteridae) are a diverse group of Neotropical passerines and an important component of the continental radiation of nine-primaried songbirds (Emberizoidea). Icterids and other emberizoids are chiefly omnivorous, but with variable predilection for invertebrates, fruits, and seeds. The icterids also exhibit a peculiar “gaping” behavior, whereby they insert their beaks into soil, fruits or bark and then open them inside the substrate. Cowbirds (<i>Molothrus</i>) stand out among the icterids for not being gapers and, with the exception of the Giant Cowbird, for a marked tendency towards a granivorous diet. To explore the signal of trophic ecology in the lower jaw of icterids and other emberizoids, we applied three-dimensional geometric morphometrics on Microcomputed tomography data and phylogenetic comparative methods. Phylomorphospaces were constructed and possible correlates with diet, gaping, and evolutionary allometry were assessed through phylogenetic ANOVA. Convergence between seed-eater species was also estimated by recently developed measures (<i>Ct</i>1). Results show a significant signal of trophic ecology in the mandible, with seed-eater species occupying a narrow domain of morphospace, partially overwhelming the signal of evolutionary allometry. The cowbird <i>Molothrus ater</i> stands out for clearly diverging from most icterids, showing significant convergence with other seed-eater emberizoids. Mandibular morphology, often neglected in avian ecomorphological studies, is informative of the trophic ecology of these birds.</p></div>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 10","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145186083","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 the Tympano-Periotic Complex in Stranded Odontocetes in Northeast Brazil","authors":"Gabriela Colombini-Corrêa,&nbsp;Maria Morell,&nbsp;Ana Bernadete Lima Fragoso,&nbsp;Daniel Solon Dias de Farias,&nbsp;Flávio José de Lima Silva,&nbsp;Simone Almeida Gavilan","doi":"10.1002/jmor.70089","DOIUrl":"https://doi.org/10.1002/jmor.70089","url":null,"abstract":"<p>Morphological descriptions of the tympano-periotic complex (TPC) are fundamental for understanding odontocete auditory adaptations, as well as their relationships with habitat, behavior, and evolutionary processes. This study analyzed the TPC morphology of six Delphinidae species stranded along the northeastern coast of Brazil: <i>Peponocephala electra</i> (<i>n</i> = 4), <i>Pseudorca crassidens</i> (<i>n</i> = 2), <i>Sotalia guianensis</i> (<i>n</i> = 39), <i>Stenella attenuata</i> (<i>n</i> = 4), <i>Stenella longirostris</i> (<i>n</i> = 4), and <i>Tursiops truncatus</i> (<i>n</i> = 4). A total of 57 TPCs were examined, with 24 morphometric measurements taken, including two novel parameters introduced in this study. The results revealed similarities in TPC morphology among species, particularly among <i>S. guianensis, S. attenuata</i>, <i>and S. longirostris</i>, which exhibited more comparable anatomical features in the structures analyzed. Species identification was supported by distinct features: in the tympanic bone, the posterior process, inner and outer prominences, and sigmoid process; and in the periotic bone, the cochlear portion, apertures for the cochlear and vestibular aqueducts, and the transverse crest. A previously undescribed anatomical structure, termed the “mesocochlear opening,” was identified in <i>S. attenuata</i>. No remarkable ontogenetic variations were observed in the TPC of <i>S. guianensis</i>, <i>P. electra</i>, or <i>S. longirostris</i>, supporting the hypothesis that auditory structures reach full development early in life. These findings highlight key morphological features of the tympano-periotic complex that contribute to species differentiation while providing new insights into the evolutionary and ecological adaptations of odontocetes. Furthermore, this study underscores the value of detailed morphological analyses for elucidating structural taxonomic variation and supporting future studies on the auditory capabilities of odontocetes.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 10","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.70089","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145135630","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 Hynobiid Complex Liua-Protohynobius-Pseudohynobius (Amphibia, Urodela): II. Anatomy and Taxonomic Revision of Enigmatic Protohynobius puxiongensis","authors":"Jia Jia,&nbsp;Mei-Hua Zhang,&nbsp;Bin Wang,&nbsp;Gabriel S. Bever,&nbsp;Liang Fei,&nbsp;Chang-Yuan Ye,&nbsp;Jian-Ping Jiang,&nbsp;Ke-Qin Gao","doi":"10.1002/jmor.70087","DOIUrl":"10.1002/jmor.70087","url":null,"abstract":"<div>\u0000 \u0000 <p>An enigmatic salamander species <i>Protohynobius puxiongensis</i> was named 25 years ago but since then has been disputed as a genus and species of its own or a species in the genus <i>Pseudohynobius</i>. Here, we provide a detailed anatomical account for <i>P. puxiongensis</i> based on micro-CT scans of five specimens, including one larva, one subadult and three adults. For the first time we reveal anatomical details in the braincase, hyobranchium and the postcranial skeleton. Our comparative study with species of <i>Pseudohynobius</i> and <i>Liua</i> clarified previous disputes over the anatomy of the skull, and confirmed that the internasal bone is an intraspecific variation that is present in several hynobiid species. Our study found that <i>P. puxiongensis</i> possesses fundamental morphological features that distinguish this enigmatic salamander from all species in the genus <i>Pseudohynobius</i>; therefore, the results of our study provide evidence to reject the combination of “<i>Pseudohynobius puxiongensis</i>”, and support <i>Protohynobius</i> as the valid generic name for the species in question for the purpose of the Principle of Priority. The extensive morphological disparities between <i>Protohynobius</i> and <i>Pseudohynobius</i> identified herein combined with their relatively short genetic distances recognized by previous studies indicate that these hynobiids have had a high evolutionary rate that may be associated with the intense orogenies around the eastern edge of the Qinghai-Tibetan Plateau during the Neogene.</p></div>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 9","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145137857","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 Paragenital Organ of Stylopidae (Insecta: Strepsiptera) and the Functional Incorporation of the Secondary Larval Exuvia","authors":"Kenny Jandausch,&nbsp;Jakub Straka,&nbsp;Thomas van de Kamp,&nbsp;Heiko Stark,&nbsp;Rolf G. Beutel,&nbsp;Oliver Niehuis,&nbsp;Hans Pohl","doi":"10.1002/jmor.70088","DOIUrl":"10.1002/jmor.70088","url":null,"abstract":"<p>Females of the insect order Strepsiptera are known to be traumatically inseminated. Traumatic insemination is the process of insemination by sperm transfer through a wound inflicted by the male in the female's integument, rather than by the male transferring sperm through the female's genital opening. Females fertilised by traumatic insemination are likely to exhibit morphological adaptations that help them to reduce the fitness costs associated with the integument wounding. One such adaptation is the presence of a paragenital organ. It has been described in traumatically inseminated bugs of the superfamily Cimicoidea and in species of the Strepsiptera genus <i>Stylops</i>. Although the paragenital organ appears to play a critical role in the mating biology of <i>Stylops</i> species, its phylogenetic roots are unknown. Here, we show that the paragenital organ in Strepsiptera may be an autapomorphy of the family Stylopidae, where we found it present in all species of the genera we studied (i.e., <i>Eurystylops</i>, <i>Halictoxenos</i>, <i>Hylecthrus</i>, <i>Kinzelbachus</i>). Our data thus refute the notion that the paragenital organ in Strepsiptera is exclusive to the genus <i>Stylops</i>. Integument relative thickness assessment based on µCT data revealed that regardless of the presence of a paragenital organ in Strepsiptera, penetration sites in the female's integument are thickened relative to control sites. In addition, we found evidence for the lateral processes of the secondary larval exuvia stabilising the paragenital organ. Our study contributes to the basic understanding of the evolution and the function of the paragenital organ in Strepsiptera and suggests potentially important morphological characters for a species-level phylogeny of the Stylopidae.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 9","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.70088","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145137842","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":"Fused Testes in Neotropical Frogs of the Genus Pristimantis (Anura, Craugastoridae): New Insights Into a Poorly Known Character in Vertebrates","authors":"Jhon Jairo Ospina-Sarria,&nbsp;Martha Patricia Ramírez-Pinilla,&nbsp;Taran Grant","doi":"10.1002/jmor.70086","DOIUrl":"https://doi.org/10.1002/jmor.70086","url":null,"abstract":"<div>\u0000 \u0000 <p>Amphibian testes vary in shape, from multilobed in caecilians and salamanders to compact, ovoid organs in anurans. Although these variations have been studied extensively in amphibians, there has been little investigation into the structural, copulatory, and reproductive behavioral consequences of unpaired testes, a character shared among some amphibians, cyclostomates, and some teleosts. We analyzed the morphology and structure of unpaired testes in <i>Pristimantis fetosus</i> and <i>Pristimantis permixtus</i>. We also report a single testis in <i>P. hernandezi</i>. Our results suggest that the testis arrangement in these species results from the hypertrophy and fusion of two testes rather than the loss or reduction of one testis. Furthermore, the occurrence of germ cells at different stages of development suggests that spermatogenesis is similar to that described for vertebrates, with spermatogonia undergoing mitosis to form spermatocytes, which then undergo meiosis to form spermatids. Like other brachycephaloid frogs, <i>Pristimantis</i> with fused testes exhibit direct development and reproduction on land, but they are the only anurans known to undergo testicular fusion. We propose to recognize the occurrence of fused testes as a unique putative synapomorphy for a new species group distributed in the Colombian Andes, which we refer to as the <i>P. hernandezi</i> species group. A comparative survey among vertebrates reveals no apparent variations in testicular organization, sperm development, or copulative and reproductive behavioral characters associated with the fusion of testes, suggesting that its occurrence might not have functional implications for vertebrate testes. The independently evolved occurrence of fused testes in cyclostomates, teleosts, and amphibians raises an exciting perspective on the study of the molecular origin, evolution, and functional significance of testis variation in vertebrate reproduction and biology.</p></div>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 9","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145038081","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":"Surface Topography and Ultrastructure of the Spectacular Cells in the Eyes of Land and Sea Snakes (Squamata, Reptilia): Functional Adaptations of Micro-Ornamentation","authors":"H. Barry Collin,&nbsp;Myoung Hoon Ha,&nbsp;Alizee Wagner,&nbsp;Megan Folwell,&nbsp;Nathan Dunstan,&nbsp;Jenna Crowe-Riddell,&nbsp;Shaun P. Collin","doi":"10.1002/jmor.70084","DOIUrl":"https://doi.org/10.1002/jmor.70084","url":null,"abstract":"<p>Although the surface micro-ornamentation of the scales within the skin of snakes has been the subject of many previous studies, there has been little work done on the spectacle, a protective (keratinised) goggle separated from the underlying cornea by a sub-spectacular space. The surface ultrastructure of the “Oberhäutchen” of the spectacle is examined in nine species of snakes (five aquatic and four terrestrial) using light and electron microscopy, micro-computed tomography and gel-based profilometry. Significant topographic differences in cell size (increases of between 5.4% and 165% in the periphery), shape (central pentagonal/hexagonal to long peripheral) and density (2579–10,391 cells/mm² in the centre vs. 2315–4291 cells/mm² in the periphery) are revealed. Small indentations in the surface (micropits) and/or microholes in the cell membrane decorate the epithelial surface of all species, which also show a centre-to-periphery gradient in diameter (42.39–120.55 nm in the centre vs<i>.</i> 63.76–182.60 nm in the periphery). Microridges are found on the superficial cells of the spectacle of only one species (the terrestrial Cantil Viper, <i>Agkistrodon bilineatus</i>) with straight, parallel ridges in the centre (138.4 ± 28.2 nm wide) and a more complex pattern of ridges (143.1 ± 19.1 nm wide) in the periphery. The micro-ornamentation of the spectacle in both land and sea snakes is compared with those found over the body scales and discussed with respect to a range of potential functions, while still allowing a clear optical pathway for vision.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":"286 9","pages":""},"PeriodicalIF":1.4,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.70084","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145021961","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}