Pacher Korbinian, Breuker Michael, Hansen Matthew J, Kurvers Ralf H J M, Häge Jan, Dhellemmes Felicie, Domenici Paolo, Steffensen John F, Krause Stefan, Hildebrandt Thomas, Fritsch Guido, Bach Pascal, Sabarros Philippe S, Zaslansky Paul, Mahlow Kristin, Müller Johannes, Armas Rogelio González, Ortiz Hector Villalobos, Galván-Magaña Felipe, Krause Jens
Faculty of Life Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.
Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany.
J Fish Biol. 2024 Mar;104(3):713-722. doi: 10.1111/jfb.15608. Epub 2023 Nov 29.
Billfish rostra potentially have several functions; however, their role in feeding is unequivocal in some species. Recent work linked morphological variation in rostral micro-teeth to differences in feeding behavior in two billfish species, the striped marlin (Kajikia audax) and the sailfish (Istiophorus platypterus). Here, we present the rostral micro-tooth morphology for a third billfish species, the blue marlin (Makaira nigricans), for which the use of the rostrum in feeding behavior is still undocumented from systematic observations in the wild. We measured the micro-teeth on rostrum tips of blue marlin, striped marlin, and sailfish using a micro-computed tomography approach and compared the tooth morphology among the three species. This was done after an analysis of video-recorded hunting behavior of striped marlin and sailfish revealed that both species strike prey predominantly with the first third of the rostrum, which provided the justification to focus our analysis on the rostrum tips. In blue marlin, intact micro-teeth were longer compared to striped marlin but not to sailfish. Blue marlin had a higher fraction of broken teeth than both striped marlin and sailfish, and broken teeth were distributed more evenly on the rostrum. Micro-tooth regrowth was equally low in both marlin species but higher in sailfish. Based on the differences and similarities in the micro-tooth morphology between the billfish species, we discuss potential feeding-related rostrum use in blue marlin. We put forward the hypothesis that blue marlin might use their rostra in high-speed dashes as observed in striped marlin, rather than in the high-precision rostral strikes described for sailfish, possibly focusing on larger prey organisms.
旗鱼的吻部可能具有多种功能；然而，在某些物种中，其在捕食中的作用是明确的。最近的研究将吻部微齿的形态变化与两种旗鱼——条纹枪鱼（Kajikia audax）和旗鱼（Istiophorus platypterus）的捕食行为差异联系起来。在这里，我们展示了第三种旗鱼——蓝枪鱼（Makaira nigricans）的吻部微齿形态，对于这种旗鱼，在野外系统观察中仍未记录到其吻部在捕食行为中的使用情况。我们使用微计算机断层扫描方法测量了蓝枪鱼、条纹枪鱼和旗鱼吻部尖端的微齿，并比较了这三个物种的牙齿形态。这是在对条纹枪鱼和旗鱼的视频记录捕食行为进行分析之后进行的，分析表明这两个物种主要用吻部的前三分之一攻击猎物，这为我们将分析重点放在吻部尖端提供了依据。与条纹枪鱼相比，蓝枪鱼完整的微齿更长，但与旗鱼相比则不然。蓝枪鱼的断齿比例高于条纹枪鱼和旗鱼，并且断齿在吻部的分布更均匀。两种枪鱼的微齿再生率同样较低，但旗鱼的较高。基于旗鱼物种之间微齿形态的差异和相似性，我们讨论了蓝枪鱼在捕食中吻部的潜在用途。我们提出一个假设，即蓝枪鱼可能像条纹枪鱼那样在高速冲刺中使用它们的吻部，而不是像旗鱼那样进行高精度的吻部攻击，可能专注于更大的猎物生物。
