Anatomy and Functional Morphology of the Mysticete Rorqual Whale Larynx: Phonation Positions of the U‐Fold

• Published in: The Anatomical Record
• Main Authors: Damien, Juliette, Adam, Olivier, Cazau, Dorian, White, Paul, Laitman, Jeffrey, Reidenberg, Joy
• Other Authors: Institute of Sound and Vibration Research (ISVR), University of Southampton, Institut Jean Le Rond d'Alembert (DALEMBERT), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Lab-STICC_ENSTAB_CID_TOMS, Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance (Lab-STICC), École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom Paris (IMT)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom Paris (IMT)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom Paris (IMT)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom Paris (IMT)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: larynx; rorqual; anatomy; sound production; U‐fold; [SDV]Life Sciences [q-bio]; Rorqual; baleen whale; baleen whales; Fin whale; Humpback Whale; Megaptera novaeangliae; minke whale; Sei Whale; toothed whales
• Online Access: https://ensta-bretagne.hal.science/hal-02123110; https://doi.org/10.1002/ar.24034

International audience Many Mysticetes (baleen whales) are acoustically active marine mammals. This is epitomized by rorquals, and specifically male humpback whales (Megaptera novaeangliae) whose complex songs comprise a wide range of vocalizations. The sound production mechanism of odontocetes (toothed whales, including dolphins and porpoises) is well described, in contrast to that of mysticetes whose vocalization mechanism remains a subject of active scientific investigation. Anatomical observations and acoustic signal processing have led to divergent hypotheses under the framework of a production-based approach. We attempt to unify these hypotheses by broadening existing data with our new anatomical investigation, interpreted in light of known acoustical properties of mysticete vocalizations. We examined 15 specimens of four rorqual species: sei whale (Baleanoptera borealis), fin whale (Baleanoptera physalus), minke whale (Baleanoptera acutorostrata), and humpback whale (Megaptera novaeangliae). Based on these data and on previous literature, we propose a description of three functional positions (rest, breathing, and recirculation), unidirectional egressive airflow for sound production (from lungs to laryngeal sac), and new nomenclature for different parts of the U-fold (distal section, midsection, and corniculate flaps). Each of these sections has specific morphological and acoustical properties that support the concept of “mode variation” in baleen whale vocalizations.