{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T17:34:12Z","timestamp":1788888852272,"version":"build-2803163510"},"reference-count":45,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2025,10,29]],"date-time":"2025-10-29T00:00:00Z","timestamp":1761696000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Space Station Science Data Center","award":["Y6140711WN"],"award-info":[{"award-number":["Y6140711WN"]}]},{"name":"Microgravity Multidisciplinary Database at the National Basic Science Data Center","award":["NBSDC-DB-17"],"award-info":[{"award-number":["NBSDC-DB-17"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Multi-animal pose estimation is a critical technique for enabling fine-grained quantification of group animal behaviors, which holds significant scientific value for uncovering behavioral changes under space environmental factors such as microgravity and radiation. Currently, the China Space Station has conducted a series of space biology experiments involving typical model organisms, including Caenorhabditis elegans (C. elegans), zebrafish, and Drosophila. However, substantial differences in species types, body scales, and posture dynamics among these animals pose serious challenges to the generalization and robustness of traditional pose estimation methods. To address this, we propose a novel, flexible, and general single-stage multi-animal pose estimation method. The method constructs species-specific pose group representations based on anatomical priors, incorporates a multi-scale feature-sampling module to integrate shallow and deep visual cues, and employs a structure-guided learning mechanism to enhance keypoint localization robustness under occlusion and overlap. We evaluate our method on the SpaceAnimal dataset\u2014the first public benchmark for pose estimation and tracking of model organisms in space\u2014containing multi-species samples from both spaceflight and ground-based experiments. Our method achieves AP scores of 72.8%, 62.1%, and 67.1% on C. elegans, zebrafish, and Drosophila, respectively, surpassing the state-of-the-art performance. These findings demonstrate the effectiveness and robustness of the proposed method across species and imaging conditions, offering strong technical support for on-orbit behavior modeling and large-scale quantitative analysis.<\/jats:p>","DOI":"10.3390\/ani15213139","type":"journal-article","created":{"date-parts":[[2025,10,30]],"date-time":"2025-10-30T00:50:19Z","timestamp":1761785419000},"page":"3139","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Structure-Aware Multi-Animal Pose Estimation for Space Model Organism Behavior Analysis"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9825-1390","authenticated-orcid":false,"given":"Kang","family":"Liu","sequence":"first","affiliation":[{"name":"Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences, Beijing 100094, China"},{"name":"Key Laboratory of Space Utilization, Chinese Academy of Sciences, Beijing 100094, China"},{"name":"University of Chinese Academy of Sciences, Beijing 100049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9888-9869","authenticated-orcid":false,"given":"Shengyang","family":"Li","sequence":"additional","affiliation":[{"name":"Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences, Beijing 100094, China"},{"name":"Key Laboratory of Space Utilization, Chinese Academy of Sciences, Beijing 100094, China"},{"name":"University of Chinese Academy of Sciences, Beijing 100049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9007-3822","authenticated-orcid":false,"given":"Yixuan","family":"Lv","sequence":"additional","affiliation":[{"name":"Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences, Beijing 100094, China"},{"name":"Key Laboratory of Space Utilization, Chinese Academy of Sciences, Beijing 100094, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rong","family":"Yang","sequence":"additional","affiliation":[{"name":"Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences, Beijing 100094, China"},{"name":"Key Laboratory of Space Utilization, Chinese Academy of Sciences, Beijing 100094, China"},{"name":"University of Chinese Academy of Sciences, Beijing 100049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xuzhi","family":"Li","sequence":"additional","affiliation":[{"name":"Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences, Beijing 100094, China"},{"name":"Key Laboratory of Space Utilization, Chinese Academy of Sciences, Beijing 100094, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1089\/ast.2012.0876","article-title":"Ground-Based Facilities for Simulation of Microgravity: Organism-Specific Recommendations for Their Use, and Recommended Terminology","volume":"13","author":"Herranz","year":"2013","journal-title":"Astrobiology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1185","DOI":"10.1016\/j.cell.2020.11.002","article-title":"Comprehensive Multi-Omics Analysis Reveals Mitochondrial Stress as a Central Biological Hub for Spaceflight Impact","volume":"183","author":"Fazelinia","year":"2020","journal-title":"Cell"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1038\/s41526-025-00460-5","article-title":"The Utility of Animal Models to Inform the Next Generation of Human Space Exploration","volume":"11","author":"Duporge","year":"2025","journal-title":"NPJ Microgravity"},{"key":"ref_4","first-page":"10","article-title":"Integrated Spaceflight Transcriptomic Analyses and Simulated Space Experiments Reveal Key Molecular Features and Functional Changes Driven by Space Stressors in Space-Flown C. 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