Humpback Whale
Whales
Fin Whale
Atlantic Ocean
Maine
Sound Spectrography
Pacific Ocean
Animal Migration
Dolphins
Acoustics
Antarctic Regions
Minke Whale
Sperm Whale
Against the current: an inter-oceanic whale migration event. (1/32)
Humpback whales seasonally migrate long distances between tropical and polar regions. However, inter-oceanic exchange is rare and difficult to document. Using skin biopsy samples collected in the Indian Ocean and in the South Atlantic Ocean, and a genetic capture-recapture approach based on microsatellite genotyping, we were able to reveal the first direct genetic evidence of the inter-oceanic migration of a male humpback whale. This exceptional migration to wintering grounds of two different ocean basins questions traditional notions of fidelity to an ocean basin, and demonstrates how the behaviour of highly mobile species may be elucidated from combining genetics with long-term field studies. Our finding has implications for management of humpback whale populations, as well as for hypotheses concerning cultural transmission of behaviour. (+info)Larval development and settlement of a whale barnacle. (2/32)
Larval development and settlement of whale barnacles have not previously been described, unlike intertidal barnacles. Indeed, the mechanisms of the association between barnacles and whales have not been studied. Here we describe the larval development and settlement of the whale barnacle, Coronula diadema, and possible involvement of a cue from the host in inducing larval settlement. Eight-cell stage embryos were collected from C. diadema on a stranded humpback whale, incubated in filtered seawater for 7 days, and nauplius larvae hatched out. When fed with Chaetoceros gracilis, the nauplii developed to stage VI, and finally metamorphosed to the cypris stage. The larval development looked similar to that of intertidal barnacles with planktotrophic larval stages. The cyprids did not settle in normal seawater, but did settle in polystyrene Petri dishes when incubated in seawater with a small piece of skin tissue from the host whale. This strongly suggests the involvement of a chemical cue from the host whale tissue to induce larval settlement. (+info)Southern Hemisphere humpback whales wintering off Central America: insights from water temperature into the longest mammalian migration. (3/32)
We report on a wintering area off the Pacific coast of Central America for humpback whales (Megaptera novaeangliae) migrating from feeding areas off Antarctica. We document seven individuals, including a mother/calf pair, that made this migration (approx. 8300km), the longest movement undertaken by any mammal. Whales were observed as far north as 11 degrees N off Costa Rica, in an area also used by a boreal population during the opposite winter season, resulting in unique spatial overlap between Northern and Southern Hemisphere populations. The occurrence of such a northerly wintering area is coincident with the development of an equatorial tongue of cold water in the eastern South Pacific, a pattern that is repeated in the eastern South Atlantic. A survey of location and water temperature at the wintering areas worldwide indicates that they are found in warm waters (21.1-28.3 degrees C), irrespective of latitude. We contend that while availability of suitable reproductive habitat in the wintering areas is important at the fine scale, water temperature influences whale distribution at the basin scale. Calf development in warm water may lead to larger adult size and increased reproductive success, a strategy that supports the energy conservation hypothesis as a reason for migration. (+info)Structure of the cerebral cortex of the humpback whale, Megaptera novaeangliae (Cetacea, Mysticeti, Balaenopteridae). (4/32)
Cetaceans diverged from terrestrial mammals between 50 and 60 million years ago and acquired, during their adaptation to a fully aquatic milieu, many derived features, including echolocation (in odontocetes), remarkable auditory and communicative abilities, as well as a complex social organization. Whereas brain structure has been documented in detail in some odontocetes, few reports exist on its organization in mysticetes. We studied the cerebral cortex of the humpback whale (Megaptera novaeangliae) in comparison to another balaenopterid, the fin whale, and representative odontocetes. We observed several differences between Megaptera and odontocetes, such as a highly clustered organization of layer II over the occipital and inferotemporal neocortex, whereas such pattern is restricted to the ventral insula in odontocetes. A striking observation in Megaptera was the presence in layer V of the anterior cingulate, anterior insular, and frontopolar cortices of large spindle cells, similar in morphology and distribution to those described in hominids, suggesting a case of parallel evolution. They were also observed in the fin whale and the largest odontocetes, but not in species with smaller brains or body size. The hippocampal formation, unremarkable in odontocetes, is further diminutive in Megaptera, contrasting with terrestrial mammals. As in odontocetes, clear cytoarchitectural patterns exist in the neocortex of Megaptera, making it possible to define many cortical domains. These observations demonstrate that Megaptera differs from Odontoceti in certain aspects of cortical cytoarchitecture and may provide a neuromorphologic basis for functional and behavioral differences between the suborders as well as a reflection of their divergent evolution. (+info)Blowing bubbles: an aquatic adaptation that risks protection of the respiratory tract in humpback whales (Megaptera novaeangliae). (5/32)
Cetaceans (whales, dolphins, and porpoises) have developed extensive protective barriers to exclude water or food from the respiratory tract, including valvular nostrils, an intranarial elongated larynx, and a sphincteric soft palate. A barrier breach can be lethal, as asphyxiation may occur from incursions of water (drowning) or food (choking). Humpback whales (Megaptera novaeangliae), however, exhibit a possibly unique and paradoxical behavior concerning respiratory protection: they release a "bubble cloud" (a cluster of tiny bubbles) underwater from the mouth. How they do this remains unclear. This study tests the hypothesis that the larynx plays a role in enabling bubble cloud emission. The anatomy and position of the larynx was examined in seven specimens of Megaptera novaeangliae. Results indicate that the epiglottis can be manually removed from behind the soft palate and placed in the oral cavity during dissection. Unlike that of toothed whales (odontocetes), the humpback whale larynx does not appear to be permanently intranarial. The elongated and trough-shaped epiglottis may function as a tube when placed against the undersurface of the soft palate and, thus, facilitate channeling air from the larynx to the oral cavity. The pointed tip and lateral edges of the epiglottis fit tightly against the undersurface of the soft palate, perhaps functioning as a one-way valve that lets air out but prevents water from entering. Bubble cloud generation likely involves air passing directly from the larynx into the oral cavity, and then expulsion through the mesh of the baleen plates. A laryngeal-oral connection, however, compromises the anatomical aquatic adaptations that normally protect the respiratory tract. A potential for drowning exists during the critical interval in which the larynx is intraoral and during re-insertion back to the normal intranarial position. The retention of this risky behavior indicates the importance of bubble clouds in predator avoidance, prey capture, and/or social signaling. (+info)Spondylitis in a humpback whale (Megaptera novaeangliae) from the southeast Pacific. (6/32)
A 7.25 m long male humpback whale (Megaptera novaeangliae) with spondylitis was found beached on August 13, 1994 at Ancon, Ecuador (2 degrees 23' S, 80 degrees 47' W). The condition involved at least 11 vertebrae, 7 lumbar (L4 to L11) and 4 caudal (Ca1 to Ca4). Partial fusion of vertebrae was observed as a result of intervertebral bony proliferation, likely impeding full motion. The relatively young age of this specimen and the severity of the deformities suggest an infectious, rather than degenerative, process. The gross findings are most consistent with some type of spondyloarthritis. Although this condition has previously been identified in a number of cetacean species, the pathogenesis, population impact and ecologic implications have not been fully assessed. This is the third case described for humpback whales and the first for a humpback whale from the SE Pacific. (+info)'Megapclicks': acoustic click trains and buzzes produced during night-time foraging of humpback whales (Megaptera novaeangliae). (7/32)
Humpback whales (Megaptera novaeangliae) exhibit a variety of foraging behaviours, but neither they nor any baleen whale are known to produce broadband clicks in association with feeding, as do many odontocetes. We recorded underwater behaviour of humpback whales in a northwest Atlantic feeding area using suction-cup attached, multi-sensor, acoustic tags (DTAGs). Here we describe the first recordings of click production associated with underwater lunges from baleen whales. Recordings of over 34000 'megapclicks' from two whales indicated relatively low received levels at the tag (between 143 and 154dB re 1 microPa pp), most energy below 2kHz, and interclick intervals often decreasing towards the end of click trains to form a buzz. All clicks were recorded during night-time hours. Sharp body rolls also occurred at the end of click bouts containing buzzes, suggesting feeding events. This acoustic behaviour seems to form part of a night-time feeding tactic for humpbacks and also expands the known acoustic repertoire of baleen whales in general. (+info)Neuromuscular anatomy and evolution of the cetacean forelimb. (8/32)
The forelimb of cetaceans (whales, dolphins, and porpoises) has been radically modified during the limb-to-flipper transition. Extant cetaceans have a soft tissue flipper encasing the manus and acting as a hydrofoil to generate lift. The neuromuscular anatomy that controls flipper movement, however, is poorly understood. This study documents flipper neuromuscular anatomy and tests the hypothesis that antebrachial muscle robustness is related to body size. Data were gathered during dissections of 22 flippers, representing 15 species (7 odontocetes, 15 mysticetes). Results were compared with published descriptions of both artiodactyls and secondarily aquatic vertebrates. Results indicate muscle robustness is best predicted by taxonomic distribution and is not a function of body size. All cetaceans have atrophied triceps muscles, an immobile cubital joint, and lack most connective tissue structures and manus muscles. Forelimbs retain only three muscle groups: triceps (only the scapular head is functional as the humeral heads are vestigal), and antebrachial extensors and flexors. Well-developed flexor and extensor muscles were found in mysticetes and basal odontocetes (i.e., physeterids, kogiids, and ziphiids), whereas later diverging odontocetes (i.e., monodontids, phocoenids, and delphinids) lack or reduce these muscles. Balaenopterid mysticetes (e.g., fin and minke whales) may actively change flipper curvature, while basal odontocetes (e.g., sperm and beaked whales) probably stiffen the flipper through isometric contraction. Later diverging odontocetes lack musculature supporting digital movements and are unable to manipulate flipper curvature. Cetacean forelimbs are unique in that they have lost agility and several soft tissue structures, but retain sensory innervations. (+info)I'm sorry for any confusion, but the term "Humpback Whale" is not a medical term. It is a species of baleen whale. Here's a common name definition:
Humpback Whales (Megaptera novaeangliae) are a species of baleen whale known for their long pectoral fins, which can be up to one-third of their body length, and their distinctive humped back when they breach the water's surface. They are also famous for their complex and varied songs, which can be heard for miles and play a significant role in their mating rituals. Humpback Whales are found in oceans all around the world and are currently not listed as endangered, although they have been heavily impacted by whaling in the past.
I believe there may be some confusion in your question. Whales are not a medical term but rather large marine mammals. They belong to the Cetacean family, which includes dolphins and porpoises. If you're asking about a medical condition or something similar that might be associated with the word "whales," I would need more information to provide an accurate response.
I'm sorry for any confusion, but "Fin Whale" is not a medical term. It is a species of whale, and it's the second largest mammal after the blue whale. The fin whale (Balaenoptera physalus) is a fast-swimming, long-bodied whale that's variously known as the finback, razorback, or common rorqual. Fin whales are cosmopolitan and can be found in all oceans of the world. They prefer deep offshore waters and migrate to tropical and subtropical waters in the winter to breed and give birth.
If you have any medical terms that you would like me to define, please let me know!
I'm sorry for any confusion, but the term "Atlantic Ocean" is a geographical term referring to one of the five oceans on Earth. It doesn't have a medical definition. The Atlantic Ocean is the second largest ocean, covering approximately 20% of the Earth's surface. It stretches from the Arctic Ocean in the north to the Southern Ocean (or, alternatively, to the Antarctica region) in the south, and is bounded by the Americas to the west and Europe and Africa to the east.
I'm sorry for any confusion, but "Maine" is not a medical term or concept. It is actually the name of a state, the 23rd state to join the United States of America. Maine is located in the northeastern part of the country and is known for its rocky coastline, maritime history, and natural beauty. If you have any questions about medical terms or concepts, I'd be happy to help answer those!
Sound spectrography, also known as voice spectrography, is a diagnostic procedure in which a person's speech sounds are analyzed and displayed as a visual pattern called a spectrogram. This test is used to evaluate voice disorders, speech disorders, and hearing problems. It can help identify patterns of sound production and reveal any abnormalities in the vocal tract or hearing mechanism.
During the test, a person is asked to produce specific sounds or sentences, which are then recorded and analyzed by a computer program. The program breaks down the sound waves into their individual frequencies and amplitudes, and displays them as a series of horizontal lines on a graph. The resulting spectrogram shows how the frequencies and amplitudes change over time, providing valuable information about the person's speech patterns and any underlying problems.
Sound spectrography is a useful tool for diagnosing and treating voice and speech disorders, as well as for researching the acoustic properties of human speech. It can also be used to evaluate hearing aids and other assistive listening devices, and to assess the effectiveness of various treatments for hearing loss and other auditory disorders.
I'm sorry for any confusion, but the term "Pacific Ocean" is a geographical term referring to the largest single body of saltwater on Earth, extending from the Arctic in the north to the Antarctic in the south. It covers an area of about 63,800,000 square miles (165,200,000 square kilometers).
If you're looking for a medical term or definition, I'd be happy to help with that as well. Could you please provide more context?
Animal migration is a seasonal movement of animals from one place to another, typically over long distances, to find food, reproduce, or escape harsh conditions. This phenomenon is observed in various species, including birds, mammals, fish, and insects. The routes and destinations of these migrations are often genetically programmed and can be quite complex. Animal migration has important ecological consequences and is influenced by factors such as climate change, habitat loss, and human activities.
"Dolphins" is a common name that refers to several species of marine mammals belonging to the family Delphinidae, within the larger group Cetacea. Dolphins are known for their intelligence, social behavior, and acrobatic displays. They are generally characterized by a streamlined body, a prominent dorsal fin, and a distinctive "smiling" expression created by the curvature of their mouths.
Although "dolphins" is sometimes used to refer to all members of the Delphinidae family, it is important to note that there are several other families within the Cetacea order, including porpoises and whales. Therefore, not all small cetaceans are dolphins.
Some examples of dolphin species include:
1. Bottlenose Dolphin (Tursiops truncatus) - This is the most well-known and studied dolphin species, often featured in aquariums and marine parks. They have a robust body and a prominent, curved dorsal fin.
2. Common Dolphin (Delphinus delphis) - These dolphins are characterized by their hourglass-shaped color pattern and distinct, falcate dorsal fins. There are two subspecies: the short-beaked common dolphin and the long-beaked common dolphin.
3. Spinner Dolphin (Stenella longirostris) - Known for their acrobatic behavior, spinner dolphins have a slender body and a long, thin beak. They are named for their spinning jumps out of the water.
4. Risso's Dolphin (Grampus griseus) - These dolphins have a unique appearance, with a robust body, a prominent dorsal fin, and a distinctive, scarred skin pattern caused by social interactions and encounters with squid, their primary food source.
5. Orca (Orcinus orca) - Also known as the killer whale, orcas are the largest dolphin species and are highly intelligent and social predators. They have a distinctive black-and-white color pattern and a prominent dorsal fin.
In medical terminology, "dolphins" do not have a specific relevance, but they can be used in various contexts such as therapy, research, or education. For instance, dolphin-assisted therapy is an alternative treatment that involves interactions between patients and dolphins to improve psychological and physical well-being. Additionally, marine biologists and researchers study dolphin behavior, communication, and cognition to understand their complex social structures and intelligence better.
Acoustics is a branch of physics that deals with the study of sound, its production, transmission, and effects. In a medical context, acoustics may refer to the use of sound waves in medical procedures such as:
1. Diagnostic ultrasound: This technique uses high-frequency sound waves to create images of internal organs and tissues. It is commonly used during pregnancy to monitor fetal development, but it can also be used to diagnose a variety of medical conditions, including heart disease, cancer, and musculoskeletal injuries.
2. Therapeutic ultrasound: This technique uses low-frequency sound waves to promote healing and reduce pain and inflammation in muscles, tendons, and ligaments. It is often used to treat soft tissue injuries, arthritis, and other musculoskeletal conditions.
3. Otology: Acoustics also plays a crucial role in the field of otology, which deals with the study and treatment of hearing and balance disorders. The shape, size, and movement of the outer ear, middle ear, and inner ear all affect how sound waves are transmitted and perceived. Abnormalities in any of these structures can lead to hearing loss, tinnitus, or balance problems.
In summary, acoustics is an important field of study in medicine that has applications in diagnosis, therapy, and the understanding of various medical conditions related to sound and hearing.
Animal vocalization refers to the production of sound by animals through the use of the vocal organs, such as the larynx in mammals or the syrinx in birds. These sounds can serve various purposes, including communication, expressing emotions, attracting mates, warning others of danger, and establishing territory. The complexity and diversity of animal vocalizations are vast, with some species capable of producing intricate songs or using specific calls to convey different messages. In a broader sense, animal vocalizations can also include sounds produced through other means, such as stridulation in insects.
The Antarctic regions typically refer to the geographical areas surrounding the continent of Antarctica, including the Southern Ocean and various subantarctic islands. These regions are known for their extreme cold, ice-covered landscapes, and unique wildlife adapted to survive in harsh conditions. The Antarctic region is also home to important scientific research stations focused on topics such as climate change, marine life, and space exploration. It's worth noting that the Antarctic Treaty System governs these regions, which prohibits military activity, mineral mining, nuclear testing, and nuclear waste disposal, and promotes scientific research and cooperation among nations.
A Minke Whale is not a medical term. It is a type of baleen whale, which is one of the two major groups of whales and dolphins, the other being the toothed whales. There are two species of minke whales: the common minke whale (Balaenoptera acutorostrata) and the Antarctic minke whale (Balaenoptera bonaerensis). They are relatively small oceanic creatures, with a robust body and a pointed head. The common minke whale is found in both hemispheres, while the Antarctic minke whale is found only in the Southern Ocean.
Minke whales are not typically associated with medical definitions or terminology, unless in the context of a medical condition affecting the species or its population, such as a disease outbreak or injury.
I'm sorry for the confusion, but "Sperm Whale" is not a medical term. It is a species of whale, scientifically known as Physeter macrocephalus. Sperm whales are the largest toothed whales and have distinctive square-shaped heads that can make up to one-third of their body length. They are named for the waxy substance called spermaceti found in their heads, which was once mistakenly thought to be sperm.
If you're looking for a medical definition or information related to human health, please provide more details so I can assist you better.