Scott Cramer

Woods Hole Oceanographic Institution

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Darlene R. Ketten

Harvard University

Julie Arruda

Massachusetts Eye and Ear Infirmary

José Roberto de França Arruda

Universidade Estadual de Campinas (UNICAMP)

Maya Yamato

Tohoku University

James A. Simmons

University of Waterloo

Hiroshi Riquimaroux

Doshisha University

J. O’Malley

Massachusetts Eye and Ear Infirmary

Jeffrey T. Laitman

Morpho (United States)

Daphne Manoussaki

Technical University of Crete

Emilios K. Dimitriadis

National Institute of Biomedical Imaging and Bioengineering

Cooperative Institutions

Woods Hole Oceanographic Institution

National Museum of Natural History

Brown University

Harvard University

University of Rostock

Morpho (United States)

Icahn School of Medicine at Mount Sinai

John Wiley & Sons (United States)

Hudson Institute

National Institute on Deafness and Other Communication Disorders

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Hyperbaric computed tomographic measurement of lung compression in seals and dolphins

Journal of Experimental Biology (2011)

Michael J. Moore Terrence Hammar Julie Arruda Scott Cramer Sophie Dennison

Lung compression of vertebrates as they dive poses anatomical and physiological challenges. There has been little direct observation of this. A harbor and a gray seal, a common dolphin and a harbor porpoise were each imaged post mortem under pressure using a radiolucent, fiberglass, water-filled pressure vessel rated to a depth equivalent of 170 m. The vessel was scanned using computed tomography (CT), and supported by a rail and counterweighted carriage magnetically linked to the CT table movement. As pressure increased, total buoyancy of the animals decreased and lung tissue CT attenuation increased, consistent with compression of air within the lower respiratory tract. Three-dimensional reconstructions of the external surface of the porpoise chest showed a marked contraction of the chest wall. Estimation of the volumes of different body compartments in the head and chest showed static values for all compartments except the lung, which showed a pressure-related compression. The depth of estimated lung compression ranged from 58 m in the gray seal with lungs inflated to 50% total lung capacity (TLC) to 133 m in the harbor porpoise with lungs at 100% TLC. These observations provide evidence for the possible behavior of gas within the chest of a live, diving mammal. The estimated depths of full compression of the lungs exceeds previous indirect estimates of the depth at which gas exchange ceases, and concurs with pulmonary shunt measurements. If these results are representative for living animals, they might suggest a potential for decompression sickness in diving mammals.

Phocoena

Elephant seal

Minke whale

10.1242/jeb.055020

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Citations (60)

Non anthropogenic deafness in marine mammals: Hearing that is going, going, gone.

The Journal of the Acoustical Society of America (2008)

Darlene R. Ketten José Roberto de França Arruda J. O’Malley Scott Cramer Jen Hammock

In humans, hearing is absent or diminished as a result of congenital defects, aging, noise exposures, traumatic events, and disease. Until concern arose about anthropogenic noise impacts on marine mammals, little was known about the mechanisms or incidence of marine mammal hearing losses. Over the past decade, we have gained substantial information from behavioral and electrophysiologic audiometres, in vivo imaging, and postmortem examinations. Dr. Sam Ridgway has been a pivotal element in these investigations, pioneering many of the techniques and facilitating broad collaborative studies. In this paper, the results of computerized tomographic and histologic studies of pinniped and cetacean ears, the majority of which Dr. Ridgway supplied, will be presented. The data show that marine mammals sustain precipitous and progressive hearing loss from multiple etiologies, including labyrinthitis, infestations, trauma, chronic multistage otitis, and presbycusis. In particular, older dolphins and seals develop degenerative pathologies (neural, hair cell, support cell loss, and demineralization) paralleling presbycusic changes in older humans. For captive cases, the distribution of inner ear pathologies will be compared with their premortem hearing curves to demonstrate the feasibility of back-projection hearing analyses on ears from noncaptive animals to better understand hearing status of wild populations. [Work supported by the ONR and the NIH/NIDCD]

Presbycusis

Marine mammal

Audiogram

10.1121/1.4782877

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Citations (1)

Evidence of hearing loss in marine mammals via auditory evoked potentials, otoacoustic emissions, and computerized tomography

Darlene R. Ketten T. Aran Mooney Scott Cramer José Roberto de França Arruda

Otoacoustic emission

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Great ears: Functional comparisons of land and marine leviathan ears

The Journal of the Acoustical Society of America (2006)

Darlene R. Ketten José Roberto de França Arruda Scott Cramer Maya Yamato J. O’Malley

Elephants and baleen whales are massive creatures that respond to exceptionally low frequency signals. Although we have many elephant and whale vocalization recordings, little is known about their hearing. Playback experiments suggest hearing in both proboscideans and mysticetes is tuned similarly to low or even infrasonic signals. This raises several interesting issues. First, they emit and perceive signals in two media, air and water, with radically different physical acoustic properties: 4.5-fold differences in sound speed, three-fold magnitude difference in acoustic impedance, and, for common percepts, whales must accommodate 60-fold acoustic pressures. Also, a commonly held tenet is that upper hearing limit is inversely correlated with body mass, implying there should be virtually no whale-elephant hearing overlap given body mass differences. This study analyzed how inner ears in these groups are structured and specialized for low-frequency hearing. Computerized tomography and celloidin histology sections were analyzed in six baleen whale (n=15) and two elephant species (n=7). The data show mysticetes have a substantially greater hearing range than elephants but that coiling and apical cochlear structures are similar, suggesting common mechanical underpinnings for LF hearing, including cochlear radii consistent with the Whispering Gallery propagation effect. [Work supported by ONR, NIH, WHOI OLI, Seaver Foundation.]

Baleen

Creatures

Bioacoustics

10.1121/1.4776837

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A manual for the removal, fixation and preservation of cetacean ears

Darlene R. Ketten Scott Cramer Julie Arruda

10.1575/1912/5276

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Critical cranial and cochlear structures in echolocators

Darlene R. Ketten James A. Simmons Hiroshi Riquimaroux Scott Cramer José Roberto de França Arruda

D. R. Ketten Woods Hole Oceanographic Institution, Woods Hole, MA USA Harvard Medical School, Boston, MA USA J. Simmons Brown University, Neurosciences, Providence, RI USA H. Riquimaroux Doshisha University, Graduate School of Life and Medical Sciences, Kyoto, Japan S, Cramer Woods Hole Oceanographic Institution, Woods Hole, MA USA Julie Arruda, Woods Hole Oceanographic Institution, Woods Hole, MA USA

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BIOMECHANICAL AND STRUCTURAL MODELING OF HEARING IN BALEEN WHALES

Bioacoustics (2008)

Maya Yamato Darlene R. Ketten Julie Arruda Scott Cramer

Anthropogenic noise may be a major source of habitat degradation for cetaceans. To assess and mitigate the effects of noise pollution on marine mammals, we need information on how and what they hear. Although hearing in odontocetes, or toothed whales, is well studied, few data are available for mysticetes, or baleen whales. Behavioural and electrophysiological hearing tests are presently impractical for mysticetes, but biomechanical, structural modelling provides hearing estimates based on auditory system anatomy. In this research, three101 dimensional models were produced for minke Balaenoptera acutorostrata, blue Balaenoptera musculus, and humpback Balaenoptera novaeangliae whale inner ears from CT scans and histology to measure key features for estimating hearing ranges, e.g., basilar membrane thickness-towidth ratios. Full head reconstructions were also produced for minke whales based on head CT images and dissections.

Baleen

10.1080/09524622.2008.9753781

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Citations (6)

Twists and turns, in cochlear anatomy: Curvatures related to infra vs ultrasonic hearing

The Journal of the Acoustical Society of America (2014)

Darlene R. Ketten James A. Simmons Hiroshi Riquimaroux Scott Cramer Julie Arruda

Microchiropteran bats and odontocete cetaceans are sophisticated echolocators with acute ultrasonic hearing operating in radically different media. Similarly, elephants and mysticetes share the ability to generate and respond to infrasonics. In this study, the heads, outer, middle, and inner ears of 32 specimens from 11 species of bats, dolphins, elephants, and whales were analyzed with microCT (11 to 100 micron isotropic voxel imaging; Siemens Volume Zoom and X-Tek CT units). Canal length, basilar membrane dimensions, and cochlear curvatures varied widely among all species. Length correlates with body mass, not hearing ranges. High and low frequency limits correlate with basilar membrane ratios and radii ratios, which are a measure of the radius of curvature. The ears of the known echolocators were significantly different from the mid to low frequency ears, with increased stiffness, thicker membranes, and outer osseous laminae supporting up to 60% of the basilar membrane. Anatomical correlates of “foveal” regions with stretched representation for peak echolocation spectra were found in both bat and porpoise ears. Radii and membrane ratios are consistent despite media and are predictive of high and low frequency hearing limits in all ear types. [Work supported by NIH, JIP, N45/LMRS -US Navy Environmental Division, and ONR Global.]

Basilar membrane

Human echolocation

10.1121/1.4877426

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Citations (2)

Crooked crania and lop‐sided larynges: New insights from CT imaging of the cranio‐cervical region in odontocetes (toothed whales, dolphins, porpoises)

The FASEB Journal (2008)

Joy S. Reidenberg Julie Arruda Scott Cramer Darlene R. Ketten Jeffrey T. Laitman

Cranio‐hyolaryngeal relationships are important in regulating respiration, vocalization, deglutition, and regurgitation/reflux. In marine mammals, this area has critical adaptations for these functions underwater. This study explores the in situ configuration of the cranio‐cervical region through CT imaging of 45 specimens from 9 genera of odontocetes (toothed whales, dolphins, porpoises). Analyses of shape of the skull and position of hyoid and larynx show extent of cranial and hyolaryngeal asymmetry is related. Asymmetry is predominately left directed (most pronounced in sperm and beaked whales) and marked by an enlarged left nasal aperture and tilted hyoid. The right side of the hyoid is depressed ventrally, resulting in a larger right piriform sinus. Deviations from typical terrestrial mammal symmetry may be linked to aquatic constraints. Pharyngeal asymmetry may facilitate swallowing larger prey. Lateral displacements of respiratory and digestive tracts assure their complete separation, thus protecting the respiratory tract from fluid entry during feeding. Asymmetry of larynx and pharyngeal spaces allows simultaneous airflow and swallowing, consistent with generating echolocation or communication sounds in tandem with open‐mouthed prey capture.

Human echolocation

Hyoid bone

10.1096/fasebj.22.1_supplement.771.11

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The Auditory Anatomy of the Minke Whale (Balaenoptera acutorostrata): A Potential Fatty Sound Reception Pathway in a Baleen Whale

The Anatomical Record (2012)

Maya Yamato Darlene R. Ketten Julie Arruda Scott Cramer Kathleen N. Moore

Abstract Cetaceans possess highly derived auditory systems adapted for underwater hearing. Odontoceti (toothed whales) are thought to receive sound through specialized fat bodies that contact the tympanoperiotic complex, the bones housing the middle and inner ears. However, sound reception pathways remain unknown in Mysticeti (baleen whales), which have very different cranial anatomies compared to odontocetes. Here, we report a potential fatty sound reception pathway in the minke whale ( Balaenoptera acutorostrata ), a mysticete of the balaenopterid family. The cephalic anatomy of seven minke whales was investigated using computerized tomography and magnetic resonance imaging, verified through dissections. Findings include a large, well‐formed fat body lateral, dorsal, and posterior to the mandibular ramus and lateral to the tympanoperiotic complex. This fat body inserts into the tympanoperiotic complex at the lateral aperture between the tympanic and periotic bones and is in contact with the ossicles. There is also a second, smaller body of fat found within the tympanic bone, which contacts the ossicles as well. This is the first analysis of these fatty tissues' association with the auditory structures in a mysticete, providing anatomical evidence that fatty sound reception pathways may not be a unique feature of odontocete cetaceans. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.

Minke whale

Baleen

Ossicles

Cetacea

10.1002/ar.22459

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Citations (36)