{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,12]],"date-time":"2026-05-12T22:13:50Z","timestamp":1778624030953,"version":"3.51.4"},"reference-count":17,"publisher":"The Royal Society","issue":"109","license":[{"start":{"date-parts":[[2015,8,1]],"date-time":"2015-08-01T00:00:00Z","timestamp":1438387200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/royalsociety.org\/journals\/ethics-policies\/data-sharing-mining\/"}],"content-domain":{"domain":["royalsocietypublishing.org"],"crossmark-restriction":true},"short-container-title":["J. R. Soc. Interface."],"published-print":{"date-parts":[[2015,8]]},"abstract":"<jats:p>\n                    Presumably as an adaptation for mouthbrooding, many cichlid fish species have evolved a prominent sexual dimorphism in the adult head. Since the head of fishes serves as a bow during locomotion, an evolutionary increase in head volume to brood more eggs can trade-off with the hydrodynamic efficiency of swimming. Here, the differences between males and females in three-dimensional shape and size of the external head surfaces and the effect thereof on drag force during locomotion was analysed for the Nile tilapia (\n                    <jats:italic>Oreochromis niloticus<\/jats:italic>\n                    ), a maternal mouthbrooder. To do so, three-dimensional body surface reconstructions from laser scans and computational fluid dynamics simulations were performed. After scaling the scanned specimens to post-cranial body volume, in order to theoretically equalize propulsive power, the external volume of the head of females was 27% larger than that of males (head length + 14%; head width + 9%). These differences resulted in an approximate 15% increase in drag force. Yet, hydrodynamics imposed important constraints on the adaptation for mouthbrooding as a much more drastic drop in swimming efficiency seems avoided by mainly enlarging the head along the swimming direction.\n                  <\/jats:p>","DOI":"10.1098\/rsif.2015.0461","type":"journal-article","created":{"date-parts":[[2015,7,29]],"date-time":"2015-07-29T17:11:33Z","timestamp":1438189893000},"page":"20150461","update-policy":"https:\/\/doi.org\/10.1098\/crossmark-policy","source":"Crossref","is-referenced-by-count":20,"title":["Hydrodynamic drag constrains head enlargement for mouthbrooding in cichlids"],"prefix":"10.1098","volume":"12","author":[{"given":"Sam","family":"Van Wassenbergh","sequence":"first","affiliation":[{"name":"Evolutionary Morphology of Vertebrates, Ghent University, K.L. Ledeganckstraat 35, 9000 Gent, Belgium"},{"name":"Department of Biology, Universiteit Antwerpen, Universiteitsplein 1, 2610 Antwerpen, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nuno Zavattieri","family":"Potes","sequence":"additional","affiliation":[{"name":"Evolutionary Morphology of Vertebrates, Ghent University, K.L. Ledeganckstraat 35, 9000 Gent, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dominique","family":"Adriaens","sequence":"additional","affiliation":[{"name":"Evolutionary Morphology of Vertebrates, Ghent University, K.L. Ledeganckstraat 35, 9000 Gent, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"175","published-online":{"date-parts":[[2015,8,6]]},"reference":[{"key":"e_1_3_5_2_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0506649102"},{"key":"e_1_3_5_3_2","doi-asserted-by":"publisher","DOI":"10.1098\/rspb.2007.0444"},{"key":"e_1_3_5_4_2","volume-title":"The cichlid fishes of the Great Lakes of Africa: their biology and evolution","author":"Fryer G","year":"1972"},{"key":"e_1_3_5_5_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1080699"},{"key":"e_1_3_5_6_2","doi-asserted-by":"publisher","DOI":"10.2307\/1940633"},{"key":"e_1_3_5_7_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1227710"},{"key":"e_1_3_5_8_2","doi-asserted-by":"publisher","DOI":"10.1098\/rspb.1998.0569"},{"key":"e_1_3_5_9_2","doi-asserted-by":"publisher","DOI":"10.1007\/s10641-007-9251-4"},{"key":"e_1_3_5_10_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0031117"},{"key":"e_1_3_5_11_2","doi-asserted-by":"publisher","DOI":"10.1186\/1742-9994-7-4"},{"key":"e_1_3_5_12_2","doi-asserted-by":"publisher","DOI":"10.1098\/rspb.2011.2679"},{"key":"e_1_3_5_13_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1095-8649.2001.tb00530.x"},{"key":"e_1_3_5_14_2","doi-asserted-by":"publisher","DOI":"10.1016\/0003-3472(70)90045-X"},{"key":"e_1_3_5_15_2","doi-asserted-by":"publisher","DOI":"10.1098\/rspb.2004.2700"},{"key":"e_1_3_5_16_2","volume-title":"Fluid-dynamic drag","author":"Hoerner SF","year":"1965"},{"key":"e_1_3_5_17_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0031-9384(97)00347-8"},{"key":"e_1_3_5_18_2","first-page":"321","article-title":"Beitr\u00e4ge zur vergleichenden und functionellen Anatomie des Kopfes von Tilapia (Cichlidae, Teleostei) Teil 2","volume":"92","author":"Goedel W","year":"1974","journal-title":"Zool. Jb. Anat"}],"container-title":["Journal of The Royal Society Interface"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/royalsocietypublishing.org\/doi\/pdf\/10.1098\/rsif.2015.0461","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/royalsocietypublishing.org\/doi\/full-xml\/10.1098\/rsif.2015.0461","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/royalsocietypublishing.org\/doi\/pdf\/10.1098\/rsif.2015.0461","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,12]],"date-time":"2026-05-12T21:20:48Z","timestamp":1778620848000},"score":1,"resource":{"primary":{"URL":"http:\/\/royalsocietypublishing.org\/rsif\/article\/64520"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,8]]},"references-count":17,"journal-issue":{"issue":"109","published-print":{"date-parts":[[2015,8]]}},"alternative-id":["10.1098\/rsif.2015.0461"],"URL":"https:\/\/doi.org\/10.1098\/rsif.2015.0461","relation":{},"ISSN":["1742-5689","1742-5662"],"issn-type":[{"value":"1742-5689","type":"print"},{"value":"1742-5662","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,8]]},"assertion":[{"value":"2015-05-19","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2015-07-08","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2015-08-06","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}