{"title":"Paternal care plasticity: males care more for early- than late-developing embryos in an arboreal breeding treefrog","authors":"Yuan-Cheng Cheng, Cai-Han Xie, Yu-Chen Chen, Nien-Tse Fuh, Ming-Feng Chuang, Yeong-Choy Kam","doi":"10.1186/s12983-024-00537-z","DOIUrl":"https://doi.org/10.1186/s12983-024-00537-z","url":null,"abstract":"Parental care benefits offspring but comes with costs. To optimize the trade-off of costs and benefits, parents should adjust care based on intrinsic and/or extrinsic conditions. The harm to offspring hypothesis suggests that parents should invest more in younger offspring than older offspring because younger offspring are more vulnerable. However, this hypothesis has rarely been comprehensively tested, as many studies only reveal an inverse correlation between parental care and offspring age, without directly testing the effects of offspring age on their vulnerability. To test this hypothesis, we studied Kurixalus eiffingeri, an arboreal treefrog with paternal care. We first performed a field survey by monitoring paternal care during embryonic development. Subsequently, we conducted a field experiment to assess the prevalence of egg predators (a semi-slug, Parmarion martensi) and the plasticity of male care. Finally, we conducted a laboratory experiment to assess how embryo age affects predation by P. martensi. Our results showed that (1) male attendance and brooding frequency affected embryo survival, and (2) males attended and brooded eggs more frequently in the early stage than in the late stage. The experimental results showed that (3) males increased attendance frequency when the predators were present, and (4) the embryonic predation by the semi-slug during the early was significantly higher than in the late stage. Our findings highlight the importance of paternal care to embryo survival, and the care behavior is plastic. Moreover, our results provide evidence consistent with the predictions of the harm to offspring hypothesis, as males tend to care more for younger offspring which are more vulnerable.","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":"79 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141425424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhi Huang, Dandan Wang, Jinrui Zhou, Hong He, Cong Wei
{"title":"Segregation of endosymbionts in complex symbiotic system of cicadas providing novel insights into microbial symbioses and evolutionary dynamics of symbiotic organs in sap-feeding insects","authors":"Zhi Huang, Dandan Wang, Jinrui Zhou, Hong He, Cong Wei","doi":"10.1186/s12983-024-00536-0","DOIUrl":"https://doi.org/10.1186/s12983-024-00536-0","url":null,"abstract":"The most extraordinary systems of symbiosis in insects are found in the suborder Auchenorrhyncha of Hemiptera, which provide unique perspectives for uncovering complicated insect-microbe symbiosis. We investigated symbionts associated with bacteriomes and fat bodies in six cicada species, and compared transmitted cell number ratio of related symbionts in ovaries among species. We reveal that Sulcia and Hodgkinia or a yeast-like fungal symbiont (YLS) are segregated from other host tissues by the bacteriomes in the nymphal stage, then some of them may migrate to other organs (i.e., fat bodies and ovaries) during host development. Particularly, YLS resides together with Sulcia in the “symbiont ball” of each egg and the bacteriomes of young-instar nymphs, but finally migrates to the fat bodies of adults in the majority of Hodgkinia-free cicadas, whereas it resides in both bacteriome sheath and fat bodies of adults in a few other species. The transmitted Sulcia/YLS or Sulcia/Hodgkinia cell number ratio in ovaries varies significantly among species, which could be related to the distribution and/or lineage splitting of symbiont(s). Rickettsia localizes to the nuclei of bacteriomes and fat bodies in some species, but it was not observed to be transmitted to the ovaries, indicating that this symbiont may be acquired from environments or from father to offspring. The considerable difference in the transovarial transmission process of symbionts suggests that cellular mechanisms underlying the symbiont transmission are complex. Our results may provide novel insights into insect-microbe symbiosis.","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":"51 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141304360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Agnieszka Murawska, Paweł Migdał, Moritz Mating, Paweł Bieńkowski, Ewelina Berbeć, Ralf Einspanier
{"title":"Metabolism gene expression in worker honey bees after exposure to 50Hz electric field - semi-field analysis.","authors":"Agnieszka Murawska, Paweł Migdał, Moritz Mating, Paweł Bieńkowski, Ewelina Berbeć, Ralf Einspanier","doi":"10.1186/s12983-024-00535-1","DOIUrl":"10.1186/s12983-024-00535-1","url":null,"abstract":"<p><p>The investigation of the effects of artificial 50 Hz electric field (E-field) frequency on Apis mellifera is a relatively new field of research. Since the current literature focuses mainly on short-term effects, it is unknown whether E-fields have permanent effects on bees or whether their effects can be neutralized. In this study we assessed gene expression immediately after exposure to the E-field, as well as 7 days after exposure. The aim of this work was to identify potentially dysregulated gene transcripts in honey bees that correlate with exposure time and duration to E-fields.Newly emerged bees were marked daily with a permanent marker (one color for each group). Then bees were exposed to the 50 Hz E-field with an intensity of 5.0 kV/m or 10.0 kV/m for 1-3 h. After exposure, half of the bees were analyzed for gene expression changes. The other half were transferred to a colony kept in a mini-hive. After 7 days, marked bees were collected from the mini-hive for further analysis. Six regulated transcripts were selected of transcripts involved in oxidative phosphorylation (COX5a) and transcripts involved in endocrine functions (HBG-3, ILP-1), mitochondrial inner membrane transport (TIM10), and aging (mRPL18, mRPS30).Our study showed that in Apis mellifera the expression of selected genes is altered in different ways after exposure to 50 Hz electric fields -. Most of those expression changes in Cox5a, mRPL18, mRPS30, and HGB3, were measurable 7 days after a 1-3 h exposure. These results indicate that some E-field effects may be long-term effects on honey bees due to E-field exposure, and they can be observed 7 days after exposure.</p>","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":"21 1","pages":"14"},"PeriodicalIF":2.8,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11134740/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141163022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Postembryonic development and lifestyle shift in the commensal ribbon worm","authors":"Natsumi Hookabe, Rei Ueshima, Toru Miura","doi":"10.1186/s12983-024-00533-3","DOIUrl":"https://doi.org/10.1186/s12983-024-00533-3","url":null,"abstract":"Various morphological adaptations are associated with symbiotic relationships between organisms. One such adaptation is seen in the nemertean genus Malacobdella. All species in the genus are commensals of molluscan hosts, attaching to the surface of host mantles with a terminal sucker. Malacobdella possesses several unique characteristics within the order Monostilifera, exhibiting the terminal sucker and the absence of eyes and apical/cerebral organs, which are related to their adaptation to a commensal lifestyle. Nevertheless, the developmental processes that give rise to these morphological characteristics during their transition from free-living larvae to commensal adults remain uncertain. In the present study, therefore, we visualized the developmental processes of the internal morphologies during postembryonic larval stages using fluorescent molecular markers. We demonstrated the developmental processes, including the formation of the sucker primordium and the functional sucker. Furthermore, our data revealed that sensory organs, including apical/cerebral organs, formed in embryonic and early postembryonic stages but degenerated in the late postembryonic stage prior to settlement within their host using a terminal sucker. This study reveals the formation of the terminal sucker through tissue invagination, shedding light on its adhesion mechanism. Sucker muscle development likely originates from body wall muscles. Notably, M. japonica exhibits negative phototaxis despite lacking larval ocelli. This observation suggests a potential role for other sensory mechanisms, such as the apical and cerebral organs identified in the larvae, in facilitating settlement and adhesive behaviors. The loss of sensory organs during larval development might reflect a transition from planktonic feeding to a stable, host-associated lifestyle. This study also emphasizes the need for further studies to explore the phylogenetic relationships within the infraorder Amphiporiina and investigate the postembryonic development of neuromuscular systems in closely related taxa to gain a more comprehensive understanding of ecological adaptations in Nemertea.","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":"8 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140845151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dariusz Jakubas, Katarzyna Wojczulanis-Jakubas, Lech Marek Iliszko
{"title":"Sex differences in foraging ecology of a zooplanktivorous little auk Alle alle during the pre-laying period: insights from remote sensing and animal-tracking","authors":"Dariusz Jakubas, Katarzyna Wojczulanis-Jakubas, Lech Marek Iliszko","doi":"10.1186/s12983-024-00534-2","DOIUrl":"https://doi.org/10.1186/s12983-024-00534-2","url":null,"abstract":"Energy and time allocation in seabirds differ between consecutive stages of breeding given various requirements of particular phases of the reproductive period. Theses allocations may also be sex-specific considering differential energetic or nutritional requirements of males and females and/or sexual segregation in foraging niches and/or areas. In this study we investigated the foraging ecology of an Arctic, zooplanktivorous seabird, the little auk Alle alle during the pre-laying period using remote sensing of the environment and GPS-TDR loggers deployed on birds. We compared foraging trips range and habitats of birds with other stages of the breeding period and between sexes. We found that little auks during the pre-laying period foraged exclusively in cold sea surface temperature zones (with temperatures < 5 ºC) but in various sea depth zones. They dived to similar depths ranging from -4.0 to -10.9 m, exploring various thermal microhabitats (with mean temperatures values ranging from 2.2 °C in Shelf sea depth zone to 5.9 °C in Deep sea depth zone). The majority of foraging trips and dives characteristics were similar to subsequent phases of breeding. However, home ranges during the pre-laying trips were wider compared to the incubation period. As expected, females exhibited wider foraging niches compared to males (wider range of sea surface temperature and sea depth in foraging locations), which could be explained by sex specific energetic and/or nutritional requirements (females producing an egg). We also delineated local foraging areas important for little auks during their whole breeding season. Protection of these areas is crucial for sustaining the local marine biodiversity. We found that little auks females during the pre-laying period explored wider foraging niches compared to males. These differences may be attributed to sex-specific nutritional or/and energetical constraints at this stage of breeding. The results of this study also emphasize the importance of shelf Arctic-type water masses as the foraging areas for little auks during successive stages of breeding.","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":"30 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140603631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"What frog gill resorption brings: loss of function, cell death, and metabolic reorganization","authors":"Liming Chang, Wei Zhu, Jianping Jiang","doi":"10.1186/s12983-024-00532-4","DOIUrl":"https://doi.org/10.1186/s12983-024-00532-4","url":null,"abstract":"Anuran metamorphosis, which is driven by thyroid hormone (TH)-mediated processes, orchestrates intricate morphological and functional transformations for the transition from aquatic tadpoles to terrestrial life, providing a valuable model for studying organ functionalization, remodeling, and regression. Larva-specific organ regression is one of the most striking phenomena observed during the anuran metamorphic climax. While previous studies extensively analyzed the regression mechanisms of the tail, the molecular processes governing gill resorption remain elusive. We employed Microhyla fissipes as a model, and utilized a comprehensive approach involving histological analysis, transmission electron microscopy, and transcriptomics to unravel gill development and resorption. The pro-metamorphic stages revealed highly developed gill structures, emphasizing their crucial role as the primary respiratory organ for tadpoles. The transcriptomic analysis highlighted the upregulation of genes associated with enhanced respiratory efficiency, such as hemoglobin and mucins. However, as metamorphosis progressed, gill filaments underwent shrinkage, decreases in blood vessel density, and structural changes that signified a decline in respiratory function. The molecular mechanisms driving gill resorption involved the TH pathway—in particular, the upregulation of thyroid hormone receptor (TR) β, genes associated with the tumor necrosis factor pathway and matrix metalloproteinases. Two distinct pathways orchestrate gill resorption, involving apoptosis directly induced by TH and cell death through the degradation of the extracellular matrix. In addition, metabolic reorganization during metamorphosis is a complex process, with tadpoles adapting their feeding behavior and mobilizing energy storage organs. The gills, which were previously overlooked, have been unveiled as potential energy storage organs that undergo metabolic reorganization. The transcriptomic analysis revealed dynamic changes in metabolism-related genes, indicating decreased protein synthesis and energy production and enhanced substrate transport and metabolism during metamorphic climax. This study sheds light on the structural, molecular, and metabolic dynamics during gill development and resorption in M. fissipes. The findings deepen our understanding of the intricate mechanisms governing organ regression and underscore the pivotal role of the gills in facilitating the transition from aquatic to terrestrial habitats.","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":"25 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140557220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fine-grained image classification on bats using VGG16-CBAM: a practical example with 7 horseshoe bats taxa (CHIROPTERA: Rhinolophidae: Rhinolophus) from Southern China.","authors":"Zhong Cao, Kunhui Wang, Jiawei Wen, Chuxian Li, Yi Wu, Xiaoyun Wang, Wenhua Yu","doi":"10.1186/s12983-024-00531-5","DOIUrl":"10.1186/s12983-024-00531-5","url":null,"abstract":"<p><strong>Background: </strong>Rapid identification and classification of bats are critical for practical applications. However, species identification of bats is a typically detrimental and time-consuming manual task that depends on taxonomists and well-trained experts. Deep Convolutional Neural Networks (DCNNs) provide a practical approach for the extraction of the visual features and classification of objects, with potential application for bat classification.</p><p><strong>Results: </strong>In this study, we investigated the capability of deep learning models to classify 7 horseshoe bat taxa (CHIROPTERA: Rhinolophus) from Southern China. We constructed an image dataset of 879 front, oblique, and lateral targeted facial images of live individuals collected during surveys between 2012 and 2021. All images were taken using a standard photograph protocol and setting aimed at enhancing the effectiveness of the DCNNs classification. The results demonstrated that our customized VGG16-CBAM model achieved up to 92.15% classification accuracy with better performance than other mainstream models. Furthermore, the Grad-CAM visualization reveals that the model pays more attention to the taxonomic key regions in the decision-making process, and these regions are often preferred by bat taxonomists for the classification of horseshoe bats, corroborating the validity of our methods.</p><p><strong>Conclusion: </strong>Our finding will inspire further research on image-based automatic classification of chiropteran species for early detection and potential application in taxonomy.</p>","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":"21 1","pages":"10"},"PeriodicalIF":2.8,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10983684/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140337805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elena Buzan, Hubert Potočnik, Boštjan Pokorny, Sandra Potušek, Laura Iacolina, Urška Gerič, Felicita Urzi, Ivan Kos
{"title":"Molecular analysis of scats revealed diet and prey choice of grey wolves and Eurasian lynx in the contact zone between the Dinaric Mountains and the Alps.","authors":"Elena Buzan, Hubert Potočnik, Boštjan Pokorny, Sandra Potušek, Laura Iacolina, Urška Gerič, Felicita Urzi, Ivan Kos","doi":"10.1186/s12983-024-00530-6","DOIUrl":"10.1186/s12983-024-00530-6","url":null,"abstract":"<p><p>A comprehensive understanding of the dietary habits of carnivores is essential to get ecological insights into their role in the ecosystem, potential competition with other carnivorous species, and their effect on prey populations. Genetic analysis of non-invasive samples, such as scats, can supplement behavioural or microscopic diet investigations. The objective of this study was to employ DNA metabarcoding to accurately determine the prey species in grey wolf (Canis lupus) and Eurasian lynx (Lynx lynx) scat samples collected in the Julian Alps and the Dinaric Mountains, Slovenia. The primary prey of wolves were red deer (Cervus elaphus) (detected in 96% scat samples), European roe deer (Capreolus capreolus) (68%), and wild boar (Sus scrofa) (45%). A smaller portion of their diet consisted of mesocarnivores, small mammals, and domestic animals. In contrast, the lynx diet mostly consisted of European roe deer (82%) and red deer (64%). However, small mammals and domestic animals were also present in lynx diet, albeit to a lesser extent. Our findings indicate that the dietary habits of wolves and lynx are influenced by geographical location. Snapshot dietary analyses using metabarcoding are valuable for comprehending the behaviour and ecology of predators, and for devising conservation measures aimed at sustainable management of both their natural habitats and prey populations. However, to gain a more detailed understanding of wolf and lynx dietary habits and ecological impact, it would be essential to conduct long-term genetic monitoring of their diet.</p>","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":"21 1","pages":"9"},"PeriodicalIF":2.8,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10949697/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140159589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alison G. Cole, Julia Steger, Julia Hagauer, Andreas Denner, Patricio Ferrer Murguia, Paul Knabl, Sanjay Narayanaswamy, Brittney Wick, Juan D. Montenegro, Ulrich Technau
{"title":"Updated single cell reference atlas for the starlet anemone Nematostella vectensis","authors":"Alison G. Cole, Julia Steger, Julia Hagauer, Andreas Denner, Patricio Ferrer Murguia, Paul Knabl, Sanjay Narayanaswamy, Brittney Wick, Juan D. Montenegro, Ulrich Technau","doi":"10.1186/s12983-024-00529-z","DOIUrl":"https://doi.org/10.1186/s12983-024-00529-z","url":null,"abstract":"The recent combination of genomics and single cell transcriptomics has allowed to assess a variety of non-conventional model organisms in much more depth. Single cell transcriptomes can uncover hidden cellular complexity and cell lineage relationships within organisms. The recent developmental cell atlases of the sea anemone Nematostella vectensis, a representative of the basally branching Cnidaria, has provided new insights into the development of all cell types (Steger et al Cell Rep 40(12):111370, 2022; Sebé-Pedrós et al. Cell 173(6):1520–1534.e20). However, the mapping of the single cell reads still suffers from relatively poor gene annotations and a draft genome consisting of many scaffolds. Here we present a new wildtype resource of the developmental single cell atlas, by re-mapping of sequence data first published in Steger et al. (2022) and Cole et al. (Nat Commun 14(1):1747, 2023), to the new chromosome-level genome assembly and corresponding gene models in Zimmermann et al. (Nat Commun 14, 8270 (2023). https://doi.org/10.1038/s41467-023-44080-7 ). We expand the pre-existing dataset through the incorporation of additional sequence data derived from the capture and sequencing of cell suspensions from four additional samples: 24 h gastrula, 2d planula, an inter-parietal region of the bodywall from a young unsexed animal, and another adult mesentery from a mature male animal. Our analyses of the full cell-state inventory provide transcriptomic signatures for 127 distinct cell states, of which 47 correspond to neuroglandular subtypes. We also identify two distinct putatively immune-related transcriptomic profiles that segregate between the inner and outer cell layers. Furthermore, the new gene annotation Nv2 has markedly improved the mapping on the single cell transcriptome data and will therefore be of great value for the community and anyone using the dataset.","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":"105 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140146019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Obituary: Claus Nielsen 1938–2024","authors":"Jürgen Heinze, Ulrich Technau","doi":"10.1186/s12983-024-00528-0","DOIUrl":"https://doi.org/10.1186/s12983-024-00528-0","url":null,"abstract":"<p>Few scholars have left a deep and remaining influence on generations of zoologists. One of them is certainly Claus Nielsen, who recently passed away at the age of 85 years. Claus Nielsen was on the editorial board of Frontiers in Zoology, the journal of the German Zoological Society, for the last 20 years, since 2003. On behalf of the whole Editorial board and the publisher team, we would like to acknowledge the many years of commitment of Claus to our journal.</p><p>Claus was born in Copenhagen in 1938, and has for almost all his life studied and worked in Copenhagen. He obtained his Dr. Phil. in 1972 at the University of Copenhagen with a work on entoprocts, for which he became one of the world specialists. After several years of working as a lecturer and Associate Professor at the Zoological Museum in Copenhagen and the University of Copenhagen, he became Professor of Evolutionary Invertebrate Embryology in 2005. At the Zoological Museum, he served as a curator of entoprocts, ectoprocts, phoronids, brachiopods, pterobranchs, enteropneusts as well as later of urochordates and echinoderms.</p><p>Claus Nielsen had a world-wide recognition as an expert of marine invertebrates, with a strong interest in ciliary larvae, their evolutionary origin and relationships. Based on his thorough knowledge on all developmental forms of marine invertebrates, he was convinced that the common ancestor of Bilateria evolved from such ciliary larvae. His book “Animal Evolution: Interrelationships of the Living Phyla” published by Oxford University Press in 1995 was a guide and standard textbook for many evolutionary biologists and zoologists for several decades and remains influential up to this day. Claus received many honors, among them the prestigious Alexander Kovalevsky medal of the St. Petersburg Society of Naturalists (2001). In 2006 he became a foreign member of the Linnean Society of London and received the Linnean Medal for Zoology in 2015. He was an honorary member of the Society for Integrative and Comparative Biology and of the International Society for Invertebrate Morphology. He served in many academic committees and review panels. What is more, he was a fantastic, inspiring teacher in numerous field courses at marine stations, where his enthusiasm and witty charm has inspired and motivated generations of students. I also witnessed his tireless fascination and love for marine organisms, as well as his humor in practical courses taught to international Ph.D. students at the Marine station in Kristineberg, Sweden. His spirit, his scholarship and his friendly nature will be missed.</p><h3>Authors and Affiliations</h3><ol><li><p>LS Zoologie/Evolutionsbiologie, Universität Regensburg, Regensburg, Germany</p><p>Jürgen Heinze</p></li><li><p>Department for Neurosciences and Developmental Biology, Division of Molecular Evolution and Development, Research Platform Single Cell Regulation of Stem Cells, Faculty of Life Sciences, University of Vienna, Vienna, A","PeriodicalId":55142,"journal":{"name":"Frontiers in Zoology","volume":"56 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140104796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}