Anatomical predictions of hearing in the North Atlantic right whale

Woods Hole Oceanographic Institution, Woods Hole, Massachusetts
The Anatomical Record Advances in Integrative Anatomy and Evolutionary Biology (Impact Factor: 1.54). 06/2007; 290(6):734 - 744. DOI: 10.1002/ar.20527
Source: PubMed


Some knowledge of the hearing abilities of right whales is important for understanding their acoustic communication system and possible impacts of anthropogenic noise. Traditional behavioral or physiological techniques to test hearing are not feasible with right whales. Previous research on the hearing of marine mammals has shown that functional models are reliable estimators of hearing sensitivity in marine species. Fundamental to these models is a comprehensive analysis of inner ear anatomy. Morphometric analyses of 18 inner ears from 13 stranded North Atlantic right whales (Eubalaena glacialis) were used for development of a preliminary model of the frequency range of hearing. Computerized tomography was used to create two-dimensional (2D) and 3D images of the cochlea. Four ears were decalcified and sectioned for histologic measurements of the basilar membrane. Basilar membrane length averaged 55.7 mm (range, 50.5 mm–61.7 mm). The ganglion cell density/mm averaged 1,842 ganglion cells/mm. The thickness/width measurements of the basilar membrane from slides resulted in an estimated hearing range of 10 Hz–22 kHz based on established marine mammal models. Additional measurements from more specimens will be necessary to develop a more robust model of the right whale hearing range. Anat Rec, 290:734–744, 2007. © 2007 Wiley-Liss, Inc.

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Available from: Susan Elizabeth Parks
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    • "Those animals were faced with physiological challenges, especially when considering the special senses that had been evolving for hundreds of millions of years to function on land. The sense of hearing in stem cetaceans is of particular interest, given the physiological differences in the extant biota – the toothed whales (Odontoceti) are sensitive to high frequency and ultrasonic sound vibrations (Hall & Johnson, 1972; Ridgway et al. 1981; Brill et al. 2001; Hemil€ a et al. 2001; Ketten, 2004; Au et al. 2007; Nachtigall et al. 2007; Popov et al. 2007), whereas baleen whales (Mysticeti) are likely sensitive to lower frequency and potentially infrasonic noises based on behavioral models (Houser et al. 2001; Erbe, 2002; Parks et al. 2007). There is a great deal of interest in studying the evolution of hearing in cetaceans and two general hypotheses have been proposed for the attainment of the different auditory capabilities between the extant clades of whales. "
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    ABSTRACT: The evolution of hearing in cetaceans is a matter of current interest given that odontocetes (toothed whales) are sensitive to high frequency sounds and mysticetes (baleen whales) are sensitive to low and potentially infrasonic noises. Earlier diverging stem cetaceans (archaeocetes) were hypothesized to have had either low or high frequency sensitivity. Through CT scanning, the morphology of the bony labyrinth of the basilosaurid archaeocete Zygorhiza kochii is described and compared to novel information from the inner ears of mysticetes, which are less known than the inner ears of odontocetes. Further comparisons are made with published information for other cetaceans. The anatomy of the cochlea of Zygorhiza is in line with mysticetes and supports the hypothesis that Zygorhiza was sensitive to low frequency noises. Morphological features that support the low frequency hypothesis and are shared by Zygorhiza and mysticetes include a long cochlear canal with a high number of turns, steeply graded curvature of the cochlear spiral in which the apical turn is coiled tighter than the basal turn, thin walls separating successive turns that overlap in vestibular view, and reduction of the secondary bony lamina. Additional morphology of the vestibular system indicates that Zygorhiza was more sensitive to head rotations than extant mysticetes are, which likely indicates higher agility in the ancestral taxon.
    Full-text · Article · Nov 2014 · Journal of Anatomy
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    • "er way to understand what kinds of sounds mysticetes may hear . Yamada and Yoshizaki ( 1959 ) noted the lack of high - frequency specializations in mys - ticete cochleae , in contrast to the cochleae of odontocetes . Mysticetes also possess massive , loosely joined ossicles and wide BMs , consistent with low - frequency hearing ( Ketten , 1994 ) . Parks et al . ( 2007 ) predicted that the total possible hearing range for the North Atlantic right whale ( Eubalaena glacialis ) is approximately 10 Hz to 22 kHz , based on measurements of their BMs . These anatomical studies are promising for studying hearing in rare and inaccessible species , especially if they can be validated by future physiolog - ical"
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    ABSTRACT: Sound is a primary sensory cue for most marine mammals, and this is especially true for cetaceans. To passively and actively acquire information about their environment, cetaceans have some of the most derived ears of all mammals, capable of sophisticated, sensitive hearing and auditory processing. These capabilities have developed for survival in an underwater world where sound travels five times faster than in air, and where light is quickly attenuated and often limited at depth, at night, and in murky waters. Cetacean auditory evolution has capitalized on the ubiquity of sound cues and the efficiency of underwater acoustic communication. The sense of hearing is central to cetacean sensory ecology, enabling vital behaviours such as locating prey, detecting predators, identifying conspecifics, and navigating. Increasing levels of anthropogenic ocean noise appears to influence many of these activities. Here, we describe the historical progress of investigations on cetacean hearing, with a particular focus on odontocetes and recent advancements. While this broad topic has been studied for several centuries, new technologies in the past two decades have been leveraged to improve our understanding of a wide range of taxa, including some of the most elusive species. This chapter addresses topics including how sounds are received, what sounds are detected, hearing mechanisms for complex acoustic scenes, recent anatomical and physiological studies, the potential impacts of noise, and mysticete hearing. We conclude by identifying emerging research topics and areas which require greater focus.
    Full-text · Article · Aug 2012 · Advances in Marine Biology
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    • "As traditional behavioral or physiological hearing tests are not feasible with right whales, a functional model was developed based upon the ear anatomy. Parks et al. (2007, this issue) examined right whale ears by means of histologic measurements of the basilar membrane and 2D and 3D computerized tomography reconstructions of the cochlea. An estimated hearing range of 10 Hz–22 kHz based on established marine mammal models was obtained. "
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    ABSTRACT: This special issue of the Anatomical Record explores many of the anatomical adaptations exhibited by aquatic mammals that enable life in the water. Anatomical observations on a range of fossil and living marine and freshwater mammals are presented, including sirenians (manatees and dugongs), cetaceans (both baleen whales and toothed whales, including dolphins and porpoises), pinnipeds (seals, sea lions, and walruses), the sea otter, and the pygmy hippopotamus. A range of anatomical systems are covered in this issue, including the external form (integument, tail shape), nervous system (eye, ear, brain), musculoskeletal systems (cranium, mandible, hyoid, vertebral column, flipper/forelimb), digestive tract (teeth/tusks/baleen, tongue, stomach), and respiratory tract (larynx). Emphasis is placed on exploring anatomical function in the context of aquatic life. The following topics are addressed: evolution, sound production, sound reception, feeding, locomotion, buoyancy control, thermoregulation, cognition, and behavior. A variety of approaches and techniques are used to examine and characterize these adaptations, ranging from dissection, to histology, to electron microscopy, to two-dimensional (2D) and 3D computerized tomography, to experimental field tests of function. The articles in this issue are a blend of literature review and new, hypothesis-driven anatomical research, which highlight the special nature of anatomical form and function in aquatic mammals that enables their exquisite adaptation for life in such a challenging environment.
    Full-text · Article · Jun 2007 · The Anatomical Record Advances in Integrative Anatomy and Evolutionary Biology
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