Beaked whale necropsy findings for strandings in the Bahamas, Puerto Rico, and Madeira, 1999-2002

Necropsy and histologic findings for examinations performed on beaked whales stranding between October, 1999 and June, 2002 are summarized and the finding interpreted. They are presented in chronological order of exams and comprise strandings from the following areas: I. Puerto Rican collections from Virgin Islands and Puerto Rican waters, 1999-2000 II. Northern Bahamas III. Madeira IV. Puerto Rico coastal, 2002.Funding was provided by the Office of Naval Research under Contract Number N0000140010284 and NOAA Fisheries under Grant Number 44221200

La Castagnette : Caprice Espagnol

https://digitalcommons.library.umaine.edu/mmb-ps/3340/thumbnail.jp

Imaging procedures for stranded marine mammals

This section provides an introduction to biomedical imaging techniques and guidelines for diagnostic imaging of marine mammals to assist with both live examination and necropsy procedures. The procedures described are based on imaging equipment and techniques that are relatively common in human and veterinary facilities and to provide the majority of stranding response groups with the most likely options that will assist their efforts. The imaging techniques described include basic radiography, computed tomography (CT), and magnetic resonance imaging (MRI) and are applicable to both live and post-mortem cases. Special emphasis has been placed on whole body, airway, head and ear imaging procedures. Sub-sections cover basic information on the basic principles and appropriate applications for radiography vs. CT vs. MRI, handling and preparation of live and dead animals in clinical settings, and image and data formats that may be encountered. The protocols are also listed in outline form in order to provide a rapid overview. The introductory discussion of principles behind techniques is not required to employ the protocols but does provide additional information that can aid in deciding which techniques are most efficacious and what the limitations are for interpretation of imaging data. Examples of some pathology imaged with these procedures are also provided.Funding was provided by the Office of Naval Research through Contract No. N00244-071-0022

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

This chapter is intended as an instructional guide for the removal, fixation and preservation of auditory system tissues of marine mammals. Each section describes procedures for a major ear type for marine mammals. The main intention is to provide both inexperienced and seasoned stranding responders with sufficient instructions to locate, document and remove all structures related to the ears and hearing in order to optimize the fixation and preservation of these tissues for later, more extensive examination. It is strongly recommended that examination be performed collaboratively with auditory system experts, but careful documentation and preservation are the critical first steps that will allow accurate diagnoses.Funding was provided by the Office of Naval Research under contract No. 13123100

Functional Analyses of Whale Ears: Adaptations for Underwater Hearing,

Abstract -The echolocation ability of several dolphin species is well documented, but little is known about hearing characteristics of most marine mammals. This paper describes the major features of the peripheral auditory system in both large and small whales and presents a three-dimensional morphometric analysis of the inner ear in 12 species. Correlation analyses of inner ear morphometry vs. hearing characteristics in terrestrial and aquatic species for which audiograms are available were applied to dolphin and whale data to derive estimates of hearing ranges of larger, non-captive whales

A model and experimental approach to the middle ear transfer function related to hearing in the humpback whale (Megaptera novaeangliae)

At present, there are no direct measures of hearing for any baleen whale (Mysticeti). The most viable alternative to in vivo approaches to simulate the audiogram is through modeling outer, middle, and inner ear functions based on the anatomy and material properties of each component. This paper describes a finite element model of the middle ear for the humpback whale (Megaptera novaeangliae) to calculate the middle ear transfer function (METF) to determine acoustic energy transmission to the cochlea. The model was developed based on high resolution computed tomography imaging and direct anatomical measurements of the middle ear components for this mysticete species. Mechanical properties for the middle ear tissues were determined from experimental measurements and published values. The METF for the humpback whale predicted a better frequency range between approximately 15 Hz and 3 kHz or between 200 Hz and 9 kHz based on two potential stimulation locations. Experimental measures of the ossicular chain, tympanic membrane, and tympanic bone velocities showed frequency response characteristics consistent with the model. The predicted best sensitivity hearing ranges match well with known vocalizations of this species

Digital three-dimensional imaging techniques provide new analytical pathways for malacological research

Author Posting. © BioOne Complete, 2019. This article is posted here by permission of BioOne Complete for personal use, not for redistribution. The definitive version was published in Ziegler, A., Bock, C., Ketten, D. R., Mair, R. W., Mueller, S., Nagelmann, N., Pracht, E. D., & Schroeder, L. Digital three-dimensional imaging techniques provide new analytical pathways for malacological research. American Malacological Bulletin, 36(2), (2018):248-273, doi:10.4003/006.036.0205.Research on molluscan specimens is increasingly being carried out using high-throughput molecular techniques. Due to their efficiency, these technologies have effectively resulted in a strong bias towards genotypic analyses. Therefore, the future large-scale correlation of such data with the phenotype will require a significant increase in the output of morphological studies. Three-dimensional (3D) scanning techniques such as magnetic resonance imaging (MRI) or computed tomography (CT) can achieve this goal as they permit rapidly obtaining digital data non-destructively or even entirely non-invasively from living, fixed, and fossil samples. With a large number of species and a relatively complex morphology, the Mollusca would profit from a more widespread application of digital 3D imaging techniques. In order to provide an overview of the capacity of various MRI and CT techniques to visualize internal and external structures of molluscs, more than twenty specimens ranging in size from a few millimeters to well over one meter were scanned in vivo as well as ex vivo. The results show that all major molluscan organ systems can be successfully visualized using both MRI and CT. The choice of a suitable imaging technique depends primarily on the specimen's life condition, its size, the required resolution, and possible invasiveness of the approach. Apart from visual examples derived from more than two dozen scans, the present article provides guidelines and best practices for digital 3D imaging of a broad range of molluscan taxa. Furthermore, a comprehensive overview of studies that previously have employed MRI or CT techniques in malacological research is given.We would like to express our gratitude to Adam J. Baldinger, Thomas Bartolomaeus, Patrick Beckers, Rüdiger Bieler, Roger T. Hanlon, Carsten Lüter, Iliana Ruiz-Cooley, Tom Schiøtte, Andreas Schmidt-Rhaesa, and Sid Staubach for help with specimen collection or for providing access to museum material. Cornelius Faber, Julia Koch, Tony Stöcker, and W. Caroline West kindly facilitated use of scanning systems. We would also like to thank Julie Arruda, Scott Cramer, Jörg Döpfert, Charlotte Eymann, Bastian Maus, Malte Ogurreck, Christina L. Sagorny, Gillian Trombke, and Christopher Witte for support with data acquisition and analysis. We are particularly grateful to Elizabeth K. Shea for inviting the present contribution and for her extensive commentary on the manuscript. We also thank two anonymous reviewers for their helpful criticisms. Funding for this study was provided by the Ocean Life Institute, the Office of Naval Research, the Seaver Institute, and the Deutsche Forschungsgemeinschaft (INST 217/849-1 FUGG)

Neuroanatomy of the Subadult and Fetal Brain of the Atlantic White-Sided Dolphin (Lagenorhynchus acutus) from In Situ Magnetic Resonance Images

This article provides the first anatomically labeled, magnetic resonance imaging (MRI) -based atlas of the subadult and fetal Atlantic white-sided dolphin (Lagenorhynchus acutus) brain. It differs from previous MRI-based atlases of cetaceans in that it was created from images of fresh, postmortem brains in situ rather than extracted, formalin-fixed brains. The in situ images displayed the classic hallmarks of odontocete brains: fore-shortened orbital lobes and pronounced temporal width. Olfactory structures were absent and auditory regions (e.g., temporal lobes and inferior colliculi) were enlarged. In the subadult and fetal postmortem MRI scans, the hippocampus was identifiable, despite the relatively small size of this structure in cetaceans. The white matter tracts of the fetal hindbrain and cerebellum were pronounced, but in the telencephalon, the white matter tracts were much less distinct, consistent with less myelin. The white matter tracts of the auditory pathways in the fetal brains were myelinated, as shown by the T2 hypointensity signals for the inferior colliculus, cochlear nuclei, and trapezoid bodies. This finding is consistent with hearing and auditory processing regions maturing in utero in L. acutus, as has been observed for most mammals. In situ MRI scanning of fresh, postmortem specimens can be used not only to study the evolution and developmental patterns of cetacean brains but also to investigate the impacts of natural toxins (such as domoic acid), anthropogenic chemicals (such as polychlorinated biphenyls, polybrominated diphenyl ethers, and their hydroxylated metabolites), biological agents (parasites), and noise on the central nervous system of marine mammal species

Potential for sound sensitivity in cephalopods

Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Advances in Experimental Medicine and Biology 730 (2012): 125-128, doi:10.1007/978-1-4419-7311-5_28.Hearing is a primary sense in many marine animals and we now have a reasonable understanding of what stimuli generate clear responses, the frequency range of sensitivity, expected threshold values and mecha-nisms of sound detection for several species of marine mammals and fishes (Fay 1988; Au et al. 2000). For marine invertebrates, our knowledge of hearing capabilities is relatively poor and a definition or even certainty of sound detection is not agreed upon (Webster et al. 1992) despite their magnitude of biomass and often central role in ocean ecosystems. Cephalopods (squid, cuttlefish, octopods and nautilus) are particularly interesting subjects for inver-tebrate sound detection investigations for several reasons. Ecologically, they occupy many of the same niches as sound-sensitive fish (Budelmann 1994) and may benefit from sound perception and use for the same reasons, such as to detect predators, navigate, or locate conspecifics. Squid, for example, are often the prey of loud, echolocating marine mammals (Clarke 1996), and may therefore be expected to have evolved hearing to avoid predators. Anatomically, squid have complex statocysts that are considered to serve primarily as vestibular and acceleration detectors (Nixon and Young 2003). However, statocysts may also be analogs for fish otolithic organs, detecting acoustic stimuli (Budelmann 1992). Previous studies have debated the subject of squid hearing and recently there has been a revival of research on the subject. Here, we briefly review what is known about squid sound detection, revisit hearing definitions, discuss potential squid susceptibility to anthropogenic noise and suggest potential future research direc-tions to examine squid acoustic sensitivity.2013-01-2

Behavioural effects of exposure to underwater explosions in humpback whales (Megaptera novaeangliae

Abstract: Humpback whale (Megaptera novaeangliae) entrapment in nets is a common phenomenon in Newfoundland. In 1991, unusually high entrapment rates were recorded in Trinity Bay on the northeast coast of Newfoundland. The majority of cases occurred in the southern portion of the bay close to Mosquito Cove, a site associated with construction operations (including explosions and drilling) that presumably modified the underwater acoustic environment of lower Trinity Bay. This study reports the findings of the resulting assessment conducted in June 1992 on the impact of the industrial activity on humpback whales foraging in the area. Although explosions were characterized by high-energy signatures with principal energies under 1 kHz, humpback whales showed little behavioural reaction to the detonations in terms of decreased residency, overall movements, or general behaviour. However, it appears that the increased entrapment rate may have been influenced by the long-term effects of exposure to deleterious levels of sound. Resume: L'enchevetrement de Rorquals 11 bosse (Megaptera novaeangliae) dans des filets de peche est un phenomene frequent 11 Terre-Neuve. En 1991-1992, un nombre particulierement eleve de cas d'enchevetrements ont ete rapportes 11 Trinity Bay, sur la cote nord-est de Terre-Neuve, et la plupart ont ete enregistres dans la portion sud de la baie, au voisinage de Mosquito Cove, un site de manoeuvres de construction (explosions, forage) qui ont probablement pour effet de modifier l'environnement acoustique sous-marin dans la partie basse de la baie. Les resultats que nous presentons ici sont ceux d'une etude effectuee en juin 1992 sur les effets de l'activite industrielle sur les rorquals qui se nourrissent dans ces eaux. Les explosions etaient caracterisees par une energie tres forte (energies principales de moins de 1 kHz), mais les rorquals ont reagi tres peu aux detonations et nous n'avons pas observe de diminution des individus residants, ni d'emigrations massives ou de modifications du comportement general. Toutefois, l'augmentation du nombre d'enchevetrements peut avoir ete influencee par les effets 11 long terme d'une exposition 11 des phenomenes acoustiques dangereux. [Traduit par la Redaction