scholarly journals Marine Mammal and Sea Turtle Sightings During a Survey of the Endeavour Segment of the Juan de Fuca Ridge, British Columbia

2017 ◽  
Vol 131 (2) ◽  
pp. 120-124
Author(s):  
Meike Holst
Keyword(s):  
British Columbia ◽  
Marine Mammals ◽  
Current Knowledge ◽  
Sea Turtles ◽  
Sperm Whale ◽  
Sea Turtle ◽  
Elephant Seal ◽  
Physeter Macrocephalus ◽  
Northern Elephant Seal ◽  
Leatherback Turtle

Marine mammals and sea turtles were documented as part of a monitoring and mitigation program during a seismic study offshore (~250 km) from Vancouver island, British Columbia, during August–September 2009. Forty-one marine mammals in nine groups were sighted. Dall’s Porpoise (Phocoenoides dalli) was the most frequently sighted species. A Sperm Whale (Physeter macrocephalus), a pod of Pacific White-sided Dolphins (Lagenorhynchus obliquidens), an unidentified toothed whale, a Northern Elephant Seal (Mirounga angustirostris), and a leatherback Turtle (Dermochelys coriacea) were also observed. These data augment current knowledge on the occurrence of marine mammals and sea turtles in the offshore waters of British Columbia.

scholarly journals In-air hearing in Hawaiian monk seals: implications for understanding the auditory biology of Monachinae seals

2021 ◽  
Author(s):  
Brandi Ruscher ◽  
Jillian M. Sills ◽  
Beau P. Richter ◽  
Colleen Reichmuth
Keyword(s):  
Marine Mammals ◽  
Elephant Seal ◽  
Critical Ratio ◽  
Mirounga Angustirostris ◽  
Northern Elephant Seal ◽  
Hearing Ability ◽  
Highly Sensitive ◽  
Monk Seals ◽  
Management And Conservation ◽  
Hearing Abilities

AbstractThe auditory biology of Monachinae seals is poorly understood. Limited audiometric data and certain anatomical features suggest that these seals may have reduced sensitivity to airborne sounds compared to related species. Here, we describe the in-air hearing abilities of a Hawaiian monk seal (Neomonachus schauinslandi) trained to participate in a psychophysical paradigm. We report absolute (unmasked) thresholds for narrowband signals measured in quiet conditions across the range of hearing and masked thresholds measured in the presence of octave-band noise at two frequencies. The behavioral audiogram indicates a functional hearing range from 0.1 to 33 kHz and poor sensitivity, with detection thresholds above 40 dB re 20 µPa. Critical ratio measurements are elevated compared to those of other seals. The apparently reduced terrestrial hearing ability of this individual—considered with available auditory data for a northern elephant seal (Mirounga angustirostris)—suggests that hearing in Monachinae seals differs from that of the highly sensitive Phocinae seals. Exploration of phylogenetic relationships and anatomical traits support this claim. This work advances understanding of the evolution of hearing in amphibious marine mammals and provides updated information that can be used for management and conservation of endangered Hawaiian monk seals.

scholarly journals Chelonicola and Poulinea, two new gomphonemoid diatom genera (Bacillariophyta) living on marine turtles from Costa Rica

Phytotaxa ◽  
2015 ◽  
Vol 233 (3) ◽  
pp. 236 ◽  
Author(s):  
Roksana Majewska ◽  
J. P. Kociolek ◽  
Evan W. Thomas ◽  
Mario De Stefano ◽  
Mario Santoro ◽  
...  
Keyword(s):  
Costa Rica ◽  
Marine Mammals ◽  
Sea Turtles ◽  
Sea Turtle ◽  
New Genera ◽  
Olive Ridley ◽  
Lepidochelys Olivacea ◽  
Marine Turtles ◽  
The Family ◽  
Long Time

Marine mammals such as whales and dolphins have been known for a long time to host a very specific epizoic community on their skin. Less known however is the presence of a similar community on the carapaces of sea turtles. The present study is the first describing new taxa inhabiting sea turtle carapaces. Samples, collected from nesting olive ridley sea turtles (Lepidochelys olivacea) on Ostional Beach (Costa Rica), were studied using light and scanning electron microscopy. Two unknown small-celled gomphonemoid taxa were analysed in more detail and are described as two new genera, closely related to other gomphonemoid genera with septate girdle bands, such as Tripterion, Cuneolus and Gomphoseptatum. Chelonicola Majewska, De Stefano & Van de Vijver gen. nov. has a flat valve face, uniseriate striae composed of more than three areolae, simple external raphe endings, internally a siliceous flap over the proximal raphe endings and lives on mucilaginous stalks. Poulinea Majewska, De Stefano & Van de Vijver gen. nov. has at least one concave valve, uniseriate striae composed of only two elongated areolae, external distal raphe endings covered by thickened siliceous flaps and lives attached to the substrate by a mucilaginous pad. Chelonicola costaricensis Majewska, De Stefano & Van de Vijver sp. nov. and Poulinea lepidochelicola Majewska, De Stefano & Van de Vijver sp. nov. can be separated based on stria structure, girdle structure composed of more than 10 copulae, raphe structure and general valve outline. A cladistics analysis of putative members of the Rhoicospheniaceae indicates that the family is polyphyletic. Chelonicola and Poulinea are sister taxa, and form a monophyletic group with Cuneolus and Tripterion, but are not closely related to Rhoicosphenia, or other genera previously assigned to this family. Features used to help diagnose the family such as symmetry and presence of septa and pseudosepta are homoplastic across the raphid diatom tree of life.

scholarly journals Cetacean diversity on the Parnaiba Delta, Maranhão state, northeastern Brazil

2008 ◽  
Vol 68 (3) ◽  
pp. 545-551 ◽  
Author(s):  
FA. Magalhães ◽  
CH. Tosi ◽  
RG. Garri ◽  
S. Chellappa ◽  
FL. Silva
Keyword(s):  
Killer Whale ◽  
Current Knowledge ◽  
Sperm Whale ◽  
Distinct Species ◽  
Significant Degree ◽  
Northeastern Brazil ◽  
Brazilian Coast ◽  
Physeter Macrocephalus ◽  
Balaenoptera Acutorostrata ◽  
Estuarine Dolphin

The increase in the research of cetacean surveys on the Brazilian coast has brought new data on the distribution of species never reported before. The present work reviews the current knowledge on cetaceans species and extends this knowledge with an analysis of cetaceans stranded in the Parnaiba Delta, on the coast of Maranhão State, Brazil. The studies on cetacean diversity on the coast of the Parnaíba Delta were made from August 2004 to August 2006. Fourteen strandings were reported, representing six distinct species, such as the estuarine dolphin (Sotalia guianensis), humpback whale (Megaptera novaeangliae), Bryde's whales (Balaenoptera edeni), dwarf minke whale (Balaenoptera acutorostrata), pigmy killer whale (Feresa attenuata), sperm whale (Physeter macrocephalus) and two specimens which have not yet been identified. The significant degree of cetacean diversity in the region shows that the Parnaíba Delta is, possibly, of an important area for cetacean studies in Brasil.

A new perspective on adiposity in a naturally obese mammal

2001 ◽  
Vol 281 (6) ◽  
pp. E1347-E1351 ◽  
Author(s):  
Rudy M. Ortiz ◽  
Dawn P. Noren ◽  
Beate Litz ◽  
C. Leo Ortiz
Keyword(s):  
Body Fat ◽  
Marine Mammals ◽  
Tritiated Water ◽  
Elephant Seal ◽  
Mirounga Angustirostris ◽  
Prolonged Fasting ◽  
Northern Elephant Seal ◽  
Fat Stores ◽  
New Perspective ◽  
Water Dilution

Many mammals seasonally reduce body fat due to inherent periods of fasting, which is associated with decreased leptin concentrations. However, no data exist on the correlation between fat mass (FM) and circulating leptin in marine mammals, which have evolved large fat stores as part of their adaptation to periods of prolonged fasting. Therefore, FM was estimated (by tritiated water dilution), and serum leptin and cortisol were measured in 40 northern elephant seal ( Mirounga angustirostris) pups early (<1 wk postweaning) and late (6–8 wk postweaning) during their natural, postweaning fast. Body mass (BM) and FM were reduced late; however, percent FM (early: 43.9 ± 0.5, late: 45.5 ± 0.5%) and leptin [early: 2.9 ± 0.1 ng/ml human equivalents (HE), late: 3.0 ± 0.1 ng/ml HE] did not change. Cortisol increased between early (9.2 ± 0.5 μg/dl) and late (16.3 ± 0.9 μg/dl) periods and was significantly and negatively correlated with BM ( r = 0.426; P < 0.0001) and FM ( r = 0.328; P = 0.003). FM and percent FM were not correlated ( P > 0.10) with leptin at either period. The present study suggests that these naturally obese mammals appear to possess a novel cascade for regulating body fat that includes cortisol. The lack of a correlation between leptin and FM may reflect the different functions of fat between terrestrial and marine mammals.

scholarly journals Diet and mitochondrial DNA haplotype of a sperm whale (Physeter macrocephalus) found dead off Jurong Island, Singapore

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6705
Author(s):  
Marcus A.H. Chua ◽  
David J.W. Lane ◽  
Seng Keat Ooi ◽  
Serene H.X. Tay ◽  
Tsunemi Kubodera
Keyword(s):  
Mitochondrial Dna ◽  
Southeast Asia ◽  
Marine Mammals ◽  
Geographic Origin ◽  
Stomach Contents ◽  
Sperm Whale ◽  
Hydrodynamic Modelling ◽  
Physeter Macrocephalus ◽  
History Of ◽  
Mitochondrial Dna Haplotype

Despite numerous studies across the large geographic range of the sperm whale (Physeter macrocephalus), little is known about the diet and mitochondrial DNA haplotypes of this strongly female philopatric species in waters off Southeast Asia. A female sperm whale found dead in Singapore waters provided the opportunity to study her diet and mitochondrial DNA haplotype. Here we report on the identification of stomach contents and mitochondrial DNA haplotype of this individual, and we include coastal hydrodynamic modelling to determine the possible geographic origin of the whale. At least 28 species of prey were eaten by this adult female whale, most of which were cephalopods. The mesopelagic squids Taonius pavo, Histioteuthis pacifica, Chiroteuthis imperator,and Ancistrocheirus lesueurii made up over 65% of the whale’s stomach contents. Plastic debris was also found in the whale’s stomach. Based on the diet, genetics, and coastal hydrodynamic modelling that suggest an easterly drift of the whale carcass over several days, the dead sperm whale in Singapore probably originated from a pod in the Southern Indian Ocean. This study provides an increase in the understanding the diet and natural history of the sperm whale in Southeast Asia. The combined analyses of stomach contents, DNA, and hydrodynamic modeling could provide a context to future studies on the sperm whale strandings, and have broader applicability for other marine mammals in the region.

scholarly journals A Baseline Model For Estimating the Risk of Gas Embolism in Sea Turtles During Routine Dives

2021 ◽  
Vol 12 ◽  
Author(s):  
Nathan J. Robinson ◽  
Daniel García-Párraga ◽  
Brian A. Stacy ◽  
Alexander M. Costidis ◽  
Gabriela S. Blanco ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Marine Mammals ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Dermochelys Coriacea ◽  
Diving Behavior ◽  
Gas Embolism ◽  
Baseline Model ◽  
Leatherback Turtles

Sea turtles, like other air-breathing diving vertebrates, commonly experience significant gas embolism (GE) when incidentally caught at depth in fishing gear and brought to the surface. To better understand why sea turtles develop GE, we built a mathematical model to estimate partial pressures of N2 (PN2), O2 (PO2), and CO2 (PCO2) in the major body-compartments of diving loggerheads (Caretta caretta), leatherbacks (Dermochelys coriacea), and green turtles (Chelonia mydas). This model was adapted from a published model for estimating gas dynamics in marine mammals and penguins. To parameterize the sea turtle model, we used values gleaned from previously published literature and 22 necropsies. Next, we applied this model to data collected from free-roaming individuals of the three study species. Finally, we varied body-condition and cardiac output within the model to see how these factors affected the risk of GE. Our model suggests that cardiac output likely plays a significant role in the modulation of GE, especially in the deeper diving leatherback turtles. This baseline model also indicates that even during routine diving behavior, sea turtles are at high risk of GE. This likely means that turtles have additional behavioral, anatomical, and/or physiologic adaptions that serve to reduce the probability of GE but were not incorporated in this model. Identifying these adaptations and incorporating them into future iterations of this model will further reveal the factors driving GE in sea turtles.

scholarly journals An unfamiliar physeteroid periotic (Cetacea: Odontoceti) from the German middle–late Miocene North Sea basin at Groß Pampau

Fossil Record ◽  
2020 ◽  
Vol 23 (2) ◽  
pp. 151-168
Author(s):  
Irene Montañez-Rivera ◽  
Oliver Hampe
Keyword(s):  
North Sea ◽  
Marine Mammals ◽  
Sperm Whale ◽  
Morphological Characters ◽  
Systematic Position ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Anterior Process ◽  
General Arrangement ◽  
Accessory Ossicle

Abstract. The Miocene mica clay locality of Groß Pampau, known for numerous and partly spectacular finds of marine mammals is becoming more and more a prominent site that bears the potential to resolve questions regarding taphonomic relationships and to interpret life communities of the ancient North Sea because of its rich faunal assemblage including invertebrates and other remains of various vertebrate organisms. In the present work we describe a right periotic of Physeteroidea with morphological characters so far unknown from other sperm whales. The periotics of the middle Miocene Aulophyseter morricei demonstrate the closest resemblance to the Groß Pampau specimen in their overall appearance and in the general arrangement and proportions of single structures, particularly of the anterior process and pars cochlearis. A great similarity is also documented with periotics of the living sperm whale, Physeter macrocephalus, especially regarding the shape and disposition of the anterior process and the bony element located dorsally to the accessory ossicle. Kogiid periotics differ strongly from that of the Groß Pampau specimen by having an inflated and short anterior process and, typically, three well-defined spines on it. A new taxonomic naming of the Groß Pampau periotic is not appropriate at this stage, although it might demonstrate the existence of a so-far undescribed physeteroid species. Additionally, its systematic position remains yet unclear and it is unknown at this point if it could belong to Hoplocetus ritzi, another physeterid, whose fragments were discovered in the same locality, or to another, already-described taxon, of which the periotic is still unknown.

Sperm whale, Physeter macrocephalus, stranding on the Pakistani coast

2007 ◽  
Vol 87 (1) ◽  
pp. 363-364 ◽  
Author(s):  
M.A. Gore ◽  
E. Ahmad ◽  
Q.M. Ali ◽  
R.M. Culloch ◽  
S. Hameed ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Action Plan ◽  
Sperm Whale ◽  
Conservation Strategy ◽  
Physeter Macrocephalus ◽  
Sperm Whales

Sperm whales (Physeter macrocephalus) occur frequently in stranding records worldwide. However, none have been reported along the Pakistani coastline to date. This paper documents the first reported stranding of a sperm whale on the Pakistani coast. Ultimately, this finding is important in the planning of Pakistan's Biodiversity Action Plan and its National Conservation Strategy for marine mammals.

Phocid and cetacean blueprints of muscle metabolism

1993 ◽  
Vol 71 (10) ◽  
pp. 2089-2098 ◽  
Author(s):  
P. W. Hochachka ◽  
R. A. Foreman III
Keyword(s):  
Hypobaric Hypoxia ◽  
High Efficiency ◽  
Current Knowledge ◽  
Harbor Seal ◽  
Weddell Seal ◽  
Elephant Seal ◽  
Great Depth ◽  
Dive Duration ◽  
Southern Elephant Seal ◽  
Northern Elephant Seal

Large seals, such as northern and southern elephant seals and Weddell seals, are able to dive for unexpected lengths of time and to enormous depth. The current dive-duration record is 120 min (recorded for the southern elephant seal); the current depth record is 1.5 km (recorded for the northern elephant seal). Equally striking is the widespread observation that these seals, when at sea, spend close to 90% of the time submerged and often at great depth. For practical purposes, these species can be viewed as true mesopelagic animals when they are at sea. Analysis of current knowledge indicates that enzyme adaptations in chronic hypobaric hypoxia are directed mainly towards up-regulation of metabolic efficiencies. Evidence that similar metabolic adjustments are utilized by seals was obtained by profiling the maximum enzyme activities of four phocid species (harbor seal, Weddell seal, crabeater seal, leopard seal) and one cetacean (fin whale). In the seals, the patterns obtained were strikingly similar to those of hypobaric hypoxia adaptations. The extensive enzyme data obtained on seals, however, showed notably different patterns from those found in whale muscles. The data from the large seals were consistent with the concept that low power output but high-efficiency metabolic functions of skeletal muscles coupled with inherently low (and potentially further suppressible) metabolic rates constitute strategic biochemical components in the design of a mesopelagic mammal.

scholarly journals Adipose transcriptome analysis provides novel insights into molecular regulation of prolonged fasting in northern elephant seal pups

2018 ◽  
Vol 50 (7) ◽  
pp. 495-503 ◽  
Author(s):  
Bridget Martinez ◽  
Jane Khudyakov ◽  
Kim Rutherford ◽  
Daniel E. Crocker ◽  
Neil Gemmell ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Energy Homeostasis ◽  
De Novo ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Global Gene Expression ◽  
Elephant Seal ◽  
Prolonged Fasting ◽  
Northern Elephant Seal ◽  
Data Set

The physiological and cellular adaptations to extreme fasting in northern elephant seals ( Mirounga angustirostris, NES) are remarkable and may help to elucidate endocrine mechanisms that regulate lipid metabolism and energy homeostasis in mammals. Recent studies have highlighted the importance of thyroid hormones in the maintenance of a lipid-based metabolism during prolonged fasting in weaned NES pups. To identify additional molecular regulators of fasting, we used a transcriptomics approach to examine changes in global gene expression profiles before and after 6–8 wk of fasting in weaned NES pups. We produced a de novo assembly and identified 98 unique protein-coding genes that were differentially expressed between early and late fasting. Most of the downregulated genes were associated with lipid, carbohydrate, and protein metabolism. A number of downregulated genes were also associated with maintenance of the extracellular matrix, consistent with tissue remodeling during weight loss and the multifunctional nature of blubber tissue, which plays both metabolic and structural roles in marine mammals. Using this data set, we predict potential mechanisms by which NES pups sustain metabolism and regulate adipose stores throughout the fast, and provide a valuable resource for additional studies of extreme metabolic adaptations in mammals.

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