Dhellemmes F. auteur aut IRD Hansen M. J. auteur aut IRD Bouet S. D. auteur aut IRD Videler J. J. auteur aut IRD Domenici P. auteur aut IRD Steffensen J. F. auteur aut IRD Hildebrandt T. auteur aut IRD Fritsch G. auteur aut IRD Bach Pascal auteur aut IRD Sabarros Philippe S. auteur aut IRD Kruger A. auteur aut IRD Kurvers Rhjm auteur aut IRD Krause J. auteur aut IRD text journalArticle eng text/pdf born digital access Billfishes are well known for their distinctive elongated rostra, i.e. bills. The functional significance of billfish rostra has been frequently discussed and the recent discovery of an oil gland ( glandula oleofera) at the base of the rostrum in swordfish, Xiphias gladius, has added an interesting facet to this discussion regarding the potential co-evolution of gland and rostra. Here, we investigated the oil gland and oil pores (through which the oil is brought to the skin surface) of four billfish species - swordfish, Atlantic blue marlin (Makaira nigricans), Indo-Pacific sailfish (Istiophorus platypterus) and striped marlin(Kajikia audax) - and provide detailed evidence for the presence of an oil gland in the last three. All four species had a high density of oil pores on the forehead which is consistent with the hypothesis of hydrodynamic benefits of the oil. The extension of the pores onto the front half of the rostrumin sailfish and striped marlin, but not in swordfish or blue marlin, suggests that the oil may have additional functions. One such function could be linked to the antibacterial and anti-inflammatory properties of the oil. However, the available evidence on predatory rostrum use (and hence the likelihood of tissue damage) is only partly consistent with the extension of pores on rostra across species. We conclude that the oil gland probably serves multiple, non-mutually exclusive functions. More detailed information on rostrum use in blue marlin and swordfish is needed to better link behavioural and morphological data with the aim of accomplishing a full comparative analysis. specialized Comparative method Functional morphology Rostrum Glandula oleofera Rete lubricans Fatty acids Co-evolution 034 223 19 jeb224956 [7 p.] 2020 0022-0949 https://www.documentation.ird.fr/hor/fdi:010079923 10.1242/jeb.224956 0022-0949 [F B010079923] https://www.documentation.ird.fr/hor/fdi:010079923 https://www.documentation.ird.fr/intranet/publi/2020/11/010079923.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2020-12-08 2025-02-24 fdi:010079923 fre