{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T05:14:17Z","timestamp":1790745257291,"version":"4.1.0"},"reference-count":48,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2023,4,27]],"date-time":"2023-04-27T00:00:00Z","timestamp":1682553600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior\u2013Brazil","award":["001"],"award-info":[{"award-number":["001"]}]},{"name":"the Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior\u2013Brazil","award":["303929\/2018-9"],"award-info":[{"award-number":["303929\/2018-9"]}]},{"DOI":"10.13039\/501100003593","name":"the National Council for the Scientific Development","doi-asserted-by":"publisher","award":["001"],"award-info":[{"award-number":["001"]}],"id":[{"id":"10.13039\/501100003593","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003593","name":"the National Council for the Scientific Development","doi-asserted-by":"publisher","award":["303929\/2018-9"],"award-info":[{"award-number":["303929\/2018-9"]}],"id":[{"id":"10.13039\/501100003593","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>The objective was to characterize morphological, morphometric, and ultrastructural changes in rhea spermatozoa between the epididymis and the vas deferens. Sperm samples were collected from the reproductive tracts of seven adult individuals and evaluated for sperm characteristics using brightfield microscopy as well as ultrastructural features using scanning electron microscopy (SM). Mean sperm count tended to increase in the vas deferens (378.0 \u00b1 135.0 \u00d7 106) compared to the epididymis (201.0 \u00b1 77.4 \u00d7 106). Percentages of motile sperm grew from 37.0 \u00b1 4.9% in the epididymis to 58.5 \u00b1 7.7% in the vas deferens. The proportion of normal spermatozoa was 75.6 \u00b1 1.8% and most common defects were bent tails (9.7 \u00b1 0.9%). However, these proportions were not different between epididymis and vas deferens. SM analysis revealed further features of rhea spermatozoa. Normal rhea spermatozoa were threadlike with an acrosome (0.95 \u00b1 0.0 \u00b5m), head (7.53 \u00b1 0.01 \u00b5m), midpiece (2.08 \u00b1 0.01 \u00b5m), and tail (30.7 \u00b1 0.06 \u00b5m). Lengths of sperm acrosome, head, midpiece, and tail were longer in the vas deferens compared to the epididymis. Our findings suggest that rhea spermatozoa undergo a maturation process during the passage from the epididymis to the vas deferens.<\/jats:p>","DOI":"10.3390\/ani13091483","type":"journal-article","created":{"date-parts":[[2023,4,27]],"date-time":"2023-04-27T02:18:34Z","timestamp":1682561914000},"page":"1483","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Changes in Sperm Morphology, Morphometry, and Motility from the Epididymis to the Vas Deferens in Rheas (Rhea americana, Linnaeus, 1758)"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1691-8815","authenticated-orcid":false,"given":"Luana G. P.","family":"Bezerra","sequence":"first","affiliation":[{"name":"Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-\u00c1rido (UFERSA), Mossor\u00f3 59625-900, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andr\u00e9ia M.","family":"Silva","sequence":"additional","affiliation":[{"name":"Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-\u00c1rido (UFERSA), Mossor\u00f3 59625-900, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-6071-537X","authenticated-orcid":false,"given":"Artur P.","family":"Jurema","sequence":"additional","affiliation":[{"name":"Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-\u00c1rido (UFERSA), Mossor\u00f3 59625-900, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maiko R. T.","family":"Dantas","sequence":"additional","affiliation":[{"name":"Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-\u00c1rido (UFERSA), Mossor\u00f3 59625-900, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ana G.","family":"Pereira","sequence":"additional","affiliation":[{"name":"Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-\u00c1rido (UFERSA), Mossor\u00f3 59625-900, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Moacir F.","family":"Oliveira","sequence":"additional","affiliation":[{"name":"Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-\u00c1rido (UFERSA), Mossor\u00f3 59625-900, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pierre","family":"Comizzoli","sequence":"additional","affiliation":[{"name":"Smithsonian National Zoo and Conservation Biology Institute, Washington, DC 20008, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6027-1062","authenticated-orcid":false,"given":"Alexandre R.","family":"Silva","sequence":"additional","affiliation":[{"name":"Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-\u00c1rido (UFERSA), Mossor\u00f3 59625-900, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,4,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1071\/MU12070","article-title":"Effect of passage through the gut of Greater Rheas on the germination of seeds of plants of cerrado and caatinga grasslands","volume":"113","author":"Azevedo","year":"2013","journal-title":"Emu"},{"key":"ref_2","unstructured":"BirdLife International (2016). 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