Kingston Sarah E
Full Text Available Abstract Background Many molecular phylogenetic analyses rely on DNA sequence data obtained from single or multiple loci, particularly mitochondrial DNA loci. However, phylogenies for taxa that have undergone recent, rapid radiation events often remain unresolved. Alternative methodologies for discerning evolutionary relationships under these conditions are desirable. The dolphin subfamily Delphininae is a group that has likely resulted from a recent and rapid radiation. Despite several efforts, the evolutionary relationships among the species in the subfamily remain unclear. Results Here, we compare a phylogeny estimated using mitochondrial DNA (mtDNA control region sequences to a multi-locus phylogeny inferred from 418 polymorphic genomic markers obtained from amplified fragment length polymorphism (AFLP analysis. The two sets of phylogenies are largely incongruent, primarily because the mtDNA tree provides very poor resolving power; very few species' nodes in the tree are supported by bootstrap resampling. The AFLP phylogeny is considerably better resolved and more congruent with relationships inferred from morphological data. Both phylogenies support paraphyly for the genera Stenella and Tursiops. The AFLP data indicate a close relationship between the two spotted dolphin species and recent ancestry between Stenella clymene and S. longirostris. The placement of the Lagenodelphis hosei lineage is ambiguous: phenetic analysis of the AFLP data is consistent with morphological expectations but the phylogenetic analysis is not. Conclusion For closely related, recently diverged taxa, a multi-locus genome-wide survey is likely the most comprehensive approach currently available for phylogenetic inference.
Full Text Available Background The family Pontoporiidae (Cetacea, Odontoceti, Inioidea is currently represented in our oceans by just one species of diminutive dolphin (Pontoporia blainvillei, franciscana. Although P. blainvillei is limited to coastal waters of the South Atlantic along Brazil, Uruguay and Argentina, multiple Miocene and Pliocene fossils indicate the past presence of members of the family in the South Atlantic, South Paciifc and North Atlantic oceans. Our comprehension of the origin and diversity of this clade and of the relationships of its members with other inioids is hampered by the fact that part of the described fossil specimens, especially from the North Atlantic realm, are cranial fragments often associated to limited stratigraphic information. Methods Based on an almost complete fossil cranium of pontoporiid from the Westerschelde estuary, The Netherlands, whose preservation allows for detailed morphological observations, we describe a new genus and species. The latter is compared to other pontoporiids, as well as a few non-pontoporiid inioids. A phylogenetic analysis is performed to investigate the relationship of S. vandokkumi with the best-known extinct and extant inioids. Palynological analysis of the sediment associated to the holotype is used to assess its geological age. Results and discussion The new genus and species Scaldiporia vandokkumi is characterized among others by greatly thickened premaxillary eminences reaching the level of the antorbital notch. Palynologically dated from the late Tortonian—earliest Zanclean (7.6–5 Ma, Late Miocene—earliest Pliocene, this new pontoporiid confirms the surprising past diversity of marine inioids in the North Atlantic area. Finally the content of the pontoporiid subfamily Brachydelphininae is briefly discussed.
Full Text Available The transition from terrestrial ancestry to a fully pelagic life profoundly altered the body systems of cetaceans, with extreme morphological changes in the skull and feeding apparatus. The Oligocene Epoch was a crucial time in the evolution of cetaceans when the ancestors of modern whales and dolphins (Neoceti underwent major diversification, but details of dental structure and evolution are poorly known for the archaeocete-neocete transition. We report the morphology of teeth and ultrastructure of enamel in archaeocetes, and fossil platanistoids and delphinoids, ranging from late Oligocene (Waitaki Valley, New Zealand to Pliocene (Caldera, Chile. Teeth were embedded in epoxy resin, sectioned in cross and longitudinal planes, polished, etched, and coated with gold palladium for scanning electron microscopy (SEM observation. SEM images showed that in archaeocetes, squalodontids and Prosqualodon (taxa with heterodont and nonpolydont/limited polydont teeth, the inner enamel was organized in Hunter-Schreger bands (HSB with an outer layer of radial enamel. This is a common pattern in most large-bodied mammals and it is regarded as a biomechanical adaptation related to food processing and crack resistance. Fossil Otekaikea sp. and delphinoids, which were polydont and homodont, showed a simpler structure, with inner radial and outer prismless enamel. Radial enamel is regarded as more wear-resistant and has been retained in several mammalian taxa in which opposing tooth surfaces slide over each other. These observations suggest that the transition from a heterodont and nonpolydont/limited polydont dentition in archaeocetes and early odontocetes, to homodont and polydont teeth in crownward odontocetes, was also linked to a marked simplification in the enamel Schmelzmuster. These patterns probably reflect functional shifts in food processing from shear-and-mastication in archaeocetes and early odontocetes, to pierce-and-grasp occlusion in crownward odontocetes, with the implication of less demanding feeding biomechanics as seen in most extant odontocetes.
Loch, Carolina; Kieser, Jules A; Fordyce, R Ewan
The transition from terrestrial ancestry to a fully pelagic life profoundly altered the body systems of cetaceans, with extreme morphological changes in the skull and feeding apparatus. The Oligocene Epoch was a crucial time in the evolution of cetaceans when the ancestors of modern whales and dolphins (Neoceti) underwent major diversification, but details of dental structure and evolution are poorly known for the archaeocete-neocete transition. We report the morphology of teeth and ultrastructure of enamel in archaeocetes, and fossil platanistoids and delphinoids, ranging from late Oligocene (Waitaki Valley, New Zealand) to Pliocene (Caldera, Chile). Teeth were embedded in epoxy resin, sectioned in cross and longitudinal planes, polished, etched, and coated with gold palladium for scanning electron microscopy (SEM) observation. SEM images showed that in archaeocetes, squalodontids and Prosqualodon (taxa with heterodont and nonpolydont/limited polydont teeth), the inner enamel was organized in Hunter-Schreger bands (HSB) with an outer layer of radial enamel. This is a common pattern in most large-bodied mammals and it is regarded as a biomechanical adaptation related to food processing and crack resistance. Fossil Otekaikea sp. and delphinoids, which were polydont and homodont, showed a simpler structure, with inner radial and outer prismless enamel. Radial enamel is regarded as more wear-resistant and has been retained in several mammalian taxa in which opposing tooth surfaces slide over each other. These observations suggest that the transition from a heterodont and nonpolydont/limited polydont dentition in archaeocetes and early odontocetes, to homodont and polydont teeth in crownward odontocetes, was also linked to a marked simplification in the enamel Schmelzmuster. These patterns probably reflect functional shifts in food processing from shear-and-mastication in archaeocetes and early odontocetes, to pierce-and-grasp occlusion in crownward odontocetes, with the implication of less demanding feeding biomechanics as seen in most extant odontocetes.
Luiz Cláudio Pinto de Sá Alves
Full Text Available Dolphin interactions with fishermen have increased significantly and pose potential risks to the boto, Inia geoffrensis (Blainville, 1817, and the tucuxi, Sotalia fluviatilis (Gervais & Deville, 1853. The main objective of the present paper was to describe the existing conflicts between river dolphins and fishermen in the municipality of Manacapuru region. Sixteen fishermen were interviewed in Manacapuru, state of Amazonas, Brazil who described a situation of ongoing conflict that may be unsustainable. Two merchants from Manacapuru made unconfirmed reports on a boto carcass trade. Data collection for this study occurred between April 20th and April 25th, 2009, but the first author had been conducting research on river dolphins and fisheries in Manacapuru and nearby cities since the beginning of 2008, in order to gain the trust of the fishermen interviewed. The hunting and deliberate killing of the species is probably more threatening to botos than their incidental capture in fishing gears in the Manacapuru region. This practice may result from the fact that dolphins are prone to damaging fishing equipment, and stealing (and possibly damaging fish from the nets. They are portrayed negatively in numerous myths and superstitions of traditional Amazonian folklore, making them extremely undesired or even hated, seen as pests, and used in the piracatinga, Calophysus macropterus (Lichtenstein, 1819 fishery as bait. For tucuxis, incidental capture still represents the major threat to their conservation in the region evaluated here.
Full Text Available The leptin gene has received intensive attention and scientific investigation for its importance in energy homeostasis and reproductive regulation in mammals. Furthermore, study of the leptin gene is of crucial importance for public health, particularly for its role in obesity, as well as for other numerous physiological roles that it plays in mammals. In the present work, we report the identification of novel leptin genes in 4 species of Cetacea, and a comparison with 55 publicly available leptin sequences from mammalian genome assemblies and previous studies. Our study provides evidence for positive selection in the suborder Odontoceti (toothed whales of the Cetacea and the family Phocidae (earless seals of the Pinnipedia. We also detected positive selection in several leptin gene residues in these two lineages. To test whether leptin and its receptor evolved in a coordinated manner, we analyzed 24 leptin receptor gene (LPR sequences from available mammalian genome assemblies and other published data. Unlike the case of leptin, our analyses did not find evidence of positive selection for LPR across the Cetacea and Pinnipedia lineages. In line with this, positively selected sites identified in the leptin genes of these two lineages were located outside of leptin receptor binding sites, which at least partially explains why co-evolution of leptin and its receptor was not observed in the present study. Our study provides interesting insights into current understanding of the evolution of mammalian leptin genes in response to selective pressures from life in an aquatic environment, and leads to a hypothesis that new tissue specificity or novel physiologic functions of leptin genes may have arisen in both odontocetes and phocids. Additional data from other species encompassing varying life histories and functional tests of the adaptive role of the amino acid changes identified in this study will help determine the factors that promote the adaptive
Thaís dos S. Vianna
Full Text Available ABSTRACT Marine mammal strandings provide valuable insights into local biodiversity. Strandings can be caused by both natural and anthropogenic factors. In the state of Santa Catarina, Southern Brazil, organized marine mammal collections started in the 1980s through opportunistic and non-systematic collection efforts, representing a record of over 30 years of marine biodiversity. This study aimed to perform a preliminary review of 32 years of stranding records within this region. The secondary aim was to elucidate the stranding dynamics of the three most commonly recorded species. A total of 460 records were obtained, representing 17 species of odontocetes. The species registered most frequently were the franciscana, Pontoporia blainvillei (Gervais & d' Orbigny, 1844 (n = 173, bottlenose dolphin, Tursiops truncatus (Montagu, 1821 (n = 100, and Guiana dolphin Sotalia guianensis (Van Bénéden, 1864 (n = 97. Most of the stranding records were observed in the second half of the year during the austral winter and spring. The apparent causes of death could not be determined for most of the specimens due to carcass decomposition. For the specimens in which the apparent cause of death could be determined, 27% of the strandings were compatible with anthropogenic interactions. While the focus of this study was a preliminary assessment of stranding data obtained through opportunistic collection, it is evident that future systematic monitoring efforts and stable networks of collaborators will generate more reliable coastal biodiversity inventories and will allow the knowledge of population dynamics of marine mammal species. In particular, for threatened and vulnerable species, or species with poor natural history data, strandings are a fundamental tool for the understanding of marine biodiversity. Ideally, future more refined analyses of stranding data should be used to inform conservation and management policies and to elucidate the biology and ecology of marine and coastal ecosystems within this region.
Full Text Available Among odontocetes, members of the family Kogiidae (pygmy and dwarf sperm whales are known as small-sized and in many respects enigmatic relatives of the great sperm whale Physeter macrocephalus. Most of the still scanty fossil record of Kogiidae is represented by isolated skulls and ear bones from Neogene deposits of the Northern Hemisphere, with the significant exception of Scaphokogia, a highly autapomorphic genus from late Miocene deposits of the Pisco Formation exposed along the southern coast of Peru. Here we report on a new fossil kogiid from Aguada de Lomas, a site where the late Miocene beds of the Pisco Formation are exposed. This specimen consists of an almost complete cranium representing a new taxon of Kogiidae: Koristocetus pescei gen. et sp. nov. Koristocetus mainly differs from extant Kogia spp. by displaying a larger temporal fossa and well-individualized dental alveoli on the upper jaws. Coupled with a relatively elongated rostrum, these characters suggest that Koristocetus retained some degree of raptorial feeding abilities, contrasting with the strong suction feeding specialization seen in Recent kogiids. Our phylogenetic analysis recognizes Koristocetus as the earliest branching member of the subfamily Kogiinae. Interestingly, Koristocetus shared the southern coast of present-day Peru with members of the genus Scaphokogia, whose unique convex rostrum and unusual neurocranial morphology seemingly indicate a peculiar foraging specialization that has still to be understood. In conclusion, Koristocetus evokes a long history of high diversity, morphological disparity, and sympatric habits in fossil kogiids, thus suggesting that our comprehension of the evolutionary history of pygmy and dwarf sperm whales is still far from being exhaustive.
Bianucci, Giovanni; Bosio, Giulia; Malinverno, Elisa; de Muizon, Christian; Villa, Igor M.; Urbina, Mario; Lambert, Olivier
The South Asian river dolphin (Platanista gangetica) is the only extant survivor of the large clade Platanistoidea, having a well-diversified fossil record from the Late Oligocene to the Middle Miocene. Based on a partial skeleton collected from the Chilcatay Formation (Chilcatay Fm; southern coast of Peru), we report here a new squalodelphinid genus and species, Macrosqualodelphis ukupachai. A volcanic ash layer, sampled near the fossil, yielded the 40Ar/39Ar age of 18.78 ± 0.08 Ma (Burdigalian, Early Miocene). The phylogenetic analysis places Macrosqualodelphis as the earliest branching squalodelphinid. Combined with several cranial and dental features, the large body size (estimated body length of 3.5 m) of this odontocete suggests that it consumed larger prey than the other members of its family. Together with Huaridelphis raimondii and Notocetus vanbenedeni, both also found in the Chilcatay Fm, this new squalodelphinid further demonstrates the peculiar local diversity of the family along the southeastern Pacific coast, possibly related to their partition into different dietary niches. At a wider geographical scale, the morphological and ecological diversity of squalodelphinids confirms the major role played by platanistoids during the Early Miocene radiation of crown odontocetes.
Bosio, Giulia; Malinverno, Elisa; Villa, Igor M.; Urbina, Mario
The South Asian river dolphin (Platanista gangetica) is the only extant survivor of the large clade Platanistoidea, having a well-diversified fossil record from the Late Oligocene to the Middle Miocene. Based on a partial skeleton collected from the Chilcatay Formation (Chilcatay Fm; southern coast of Peru), we report here a new squalodelphinid genus and species, Macrosqualodelphis ukupachai. A volcanic ash layer, sampled near the fossil, yielded the 40Ar/39Ar age of 18.78 ± 0.08 Ma (Burdigalian, Early Miocene). The phylogenetic analysis places Macrosqualodelphis as the earliest branching squalodelphinid. Combined with several cranial and dental features, the large body size (estimated body length of 3.5 m) of this odontocete suggests that it consumed larger prey than the other members of its family. Together with Huaridelphis raimondii and Notocetus vanbenedeni, both also found in the Chilcatay Fm, this new squalodelphinid further demonstrates the peculiar local diversity of the family along the southeastern Pacific coast, possibly related to their partition into different dietary niches. At a wider geographical scale, the morphological and ecological diversity of squalodelphinids confirms the major role played by platanistoids during the Early Miocene radiation of crown odontocetes.
Full Text Available Abstract Background Cetacea (dolphins, porpoises, and whales is a clade of aquatic species that includes the most massive, deepest diving, and largest brained mammals. Understanding the temporal pattern of diversification in the group as well as the evolution of cetacean anatomy and behavior requires a robust and well-resolved phylogenetic hypothesis. Although a large body of molecular data has accumulated over the past 20 years, DNA sequences of cetaceans have not been directly integrated with the rich, cetacean fossil record to reconcile discrepancies among molecular and morphological characters. Results We combined new nuclear DNA sequences, including segments of six genes (~2800 basepairs from the functionally extinct Yangtze River dolphin, with an expanded morphological matrix and published genomic data. Diverse analyses of these data resolved the relationships of 74 taxa that represent all extant families and 11 extinct families of Cetacea. The resulting supermatrix (61,155 characters and its sub-partitions were analyzed using parsimony methods. Bayesian and maximum likelihood (ML searches were conducted on the molecular partition, and a molecular scaffold obtained from these searches was used to constrain a parsimony search of the morphological partition. Based on analysis of the supermatrix and model-based analyses of the molecular partition, we found overwhelming support for 15 extant clades. When extinct taxa are included, we recovered trees that are significantly correlated with the fossil record. These trees were used to reconstruct the timing of cetacean diversification and the evolution of characters shared by "river dolphins," a non-monophyletic set of species according to all of our phylogenetic analyses. Conclusions The parsimony analysis of the supermatrix and the analysis of morphology constrained to fit the ML/Bayesian molecular tree yielded broadly congruent phylogenetic hypotheses. In trees from both analyses, all Oligocene
Background Cetacea (dolphins, porpoises, and whales) is a clade of aquatic species that includes the most massive, deepest diving, and largest brained mammals. Understanding the temporal pattern of diversification in the group as well as the evolution of cetacean anatomy and behavior requires a robust and well-resolved phylogenetic hypothesis. Although a large body of molecular data has accumulated over the past 20 years, DNA sequences of cetaceans have not been directly integrated with the rich, cetacean fossil record to reconcile discrepancies among molecular and morphological characters. Results We combined new nuclear DNA sequences, including segments of six genes (~2800 basepairs) from the functionally extinct Yangtze River dolphin, with an expanded morphological matrix and published genomic data. Diverse analyses of these data resolved the relationships of 74 taxa that represent all extant families and 11 extinct families of Cetacea. The resulting supermatrix (61,155 characters) and its sub-partitions were analyzed using parsimony methods. Bayesian and maximum likelihood (ML) searches were conducted on the molecular partition, and a molecular scaffold obtained from these searches was used to constrain a parsimony search of the morphological partition. Based on analysis of the supermatrix and model-based analyses of the molecular partition, we found overwhelming support for 15 extant clades. When extinct taxa are included, we recovered trees that are significantly correlated with the fossil record. These trees were used to reconstruct the timing of cetacean diversification and the evolution of characters shared by "river dolphins," a non-monophyletic set of species according to all of our phylogenetic analyses. Conclusions The parsimony analysis of the supermatrix and the analysis of morphology constrained to fit the ML/Bayesian molecular tree yielded broadly congruent phylogenetic hypotheses. In trees from both analyses, all Oligocene taxa included in our
Full Text Available A new partial fossil skeleton of Messapicetus longirostris (Cetacea: Odontoceti: Ziphiidae collected in Cisterna quarry (Lecce from Tortonian (upper Miocene sediments of the "Pietra leccese" is described. It comprises the fragmentary skull (including most of the rostrum, parts of the mandibles, five teeth, the fragmentary right scapula, and one vertebral centrum. This new record, here referred to a juvenile individual, expands our knowledge about the skeletal anatomy of M. longirostris; this species was until now only known by the holotype, an almost complete skull from the same Cisterna quarry. Moreover, the new specimen confirms the distinction between M. longirostris and M. gregarius (late Miocene, Pisco Formation, Peru based on several osteological characters (e.g., the presence of a distinct maxillary tubercle and prominential notch in the latter species. New dating of layers in Cerro Colorado, the type locality of M. gregarius, suggests that M. longirostris and M. gregarius were contemporaneous sister-species with an antitropical distribution (a biogeographical pattern currently shown by two extant ziphiid genera. Unlike extant ziphiids, feeding predominantly on squid and benthopelagic fish in deep waters, the stem ziphiid M. gregarius was recently proposed to have been a raptorial piscivore who may have fed mainly on schools of epipelagic fish. Similarities at the level of the morphology and proportions of the oral apparatus suggest that the two species of Messapicetus may have occupied roughly identical ecological and trophic niches, a hypothesis supported by the characterization of the Pietra leccese environment as neritic.
1. A review is given of some phenomena concerning pregnancy and parturition of the Cetacea, depending on data in literature and on observations made in Antarctic Blue and Fin Whales on board the f.f. “Willem Barendsz” (1946—1947). 2. In Mystacoceti the frequency of twins appears to be less than in
Maria Carla de Francesco
Full Text Available Feeding adaptation, social behaviour, and interspecific interactions related to sexual dimorphism and allometric growth are particularly challenging to be investigated in the high sexual monomorphic Delphinidae. We used geometric morphometrics to extensively explore sexual dimorphism and ontogenetic allometry of different projections of the skull and the mandible of the bottlenose dolphin Tursiops truncatus. Two-dimensional landmarks were recorded on the dorsal, ventral, lateral, and occipital views of the skull, and on the lateral view of the left and the right mandible of 104 specimens from the Mediterranean and the North Seas, differing environmental condition and degree of interspecific associations. Landmark configurations were transformed, standardized and superimposed through a Generalized Procrustes Analysis. Size and shape differences between adult males and females were respectively evaluated through ANOVA on centroid size, Procrustes ANOVA on Procrustes distances, and MANOVA on Procrustes coordinates. Ontogenetic allometry was investigated by multivariate regression of shape coordinates on centroid size in the largest homogenous sample from the North Sea. Results evidenced sexual dimorphic asymmetric traits only detected in the adults of the North Sea bottlenose dolphins living in monospecific associations, with females bearing a marked incision of the cavity hosting the left tympanic bulla. These differences were related to a more refined echolocalization system that likely enhances the exploitation of local resources by philopatric females. Distinct shape in immature versus mature stages and asymmetric changes in postnatal allometry of dorsal and occipital traits, suggest that differences between males and females are established early during growth. Allometric growth trajectories differed between males and females for the ventral view of the skull. Allometric trajectories differed among projections of skull and mandible, and were related to dietary shifts experienced by subadults and adults.
Full Text Available The Ziphiidae (beaked whales represent a large group of open-ocean odontocetes (toothed cetaceans, whose elusive and deep diving behavior prevents direct observation in their natural habitat. Despite their generally large body size, broad geographical distribution, and high species number, ziphiids thus remain poorly known. Furthermore, the evolutionary processes that have led to their extreme adaptations and impressive extant diversity are still poorly understood. Here we report new fossil beaked whales from the late Miocene of the Pisco Formation (southern Peru. The best preserved remains here described are referred to two new genera and species, the Messinian Chavinziphius maxillocristatus and the Tortonian Chimuziphius coloradensis, based on skull remains from two marine vertebrate-rich localities: Cerro Los Quesos and Cerro Colorado, respectively. C. maxillocristatus is medium sized retains a complete set of functional lower teeth, and bears robust rostral maxillary crests similar to those of the extant Berardius. By contrast, C. coloradensis is small and characterized by large triangular nasals and moderately thickened premaxillae that dorsally close the mesorostral groove. Both species confirm the high past diversity of Ziphiidae, the richest cetacean family in terms of the number of genera and species. Our new phylogenetic and biogeographical analyses depart markedly from earlier studies in dividing beaked whales into two major clades: the Messapicetus clade, which, along with other stem ziphiids, once dominated the southeastern Pacific and North Atlantic; and crown Ziphiidae, the majority of which are found in deep-water regions of the Southern Ocean, with possible subsequent dispersal both globally (Mesoplodon and Ziphius and to the cooler waters of the northern oceans (Berardius and Hyperoodon. Despite this relatively clear separation, both lineages seem to follow similar evolutionary trends, including (1 a progressive reduction of dentition; (2 an increase in the compactness and thickness of the rostral bones; (3 similar changes in facial morphology (e.g., elevation of the vertex; and (4 an increase of body size. We suggest that these trends may be linked to a convergent ecological shift to deep diving and suction feeding.
Sightings of Delphinus delphis (Cetacea, Odontoceti in the Otranto Channel (Southern Adriatic Sea and Northern Ionian Sea / Avvistamenti di Delphinus delphis (Cetacea, Odontoceti nel Canale d'Otranto (Mar Adriatico Meridionale e Mar Ionio Settentrionale
Francesco Maria Angelici
Full Text Available Abstract Two sightings of Common dolphin Delphinus delphis in the Channel of Otranto are reported, and the status of this species in the Mediterranean Sea is briefly discussed. Riassunto Sono riportati due avvistamenti di Delfino comune Delphinus delphis nel Canale d'Otranto, lungo la costa greca e quella italiana. Viene inoltre brevemente commentata la frequenza degli avvistamenti e degli spiaggiamenti di tale specie nel Mar Mediterraneo.
Bianucci, G.; Landini, W.
An incomplete odontocete (Mammalia, Cetacea) skull from Middle Miocene Miste Bed (near Winterswijk in the eastern part of The Netherlands) is described as Vanbreenia trigonia, a new genus and species. The skull exhibits a short rostrum with only two maxillary teeth for each toothrow and with narrow
Kulemzina, Anastasia I; Proskuryakova, Anastasia A; Beklemisheva, Violetta R; Lemskaya, Natalia A; Perelman, Polina L; Graphodatsky, Alexander S
Cetacean karyotypes possess exceptionally stable diploid numbers and highly conserved chromosomes. To date, only toothed whales (Odontoceti) have been analyzed by comparative chromosome painting. Here, we studied the karyotype of a representative of baleen whales, the gray whale (Eschrichtius robustus, Mysticeti), by Zoo-FISH with dromedary camel and human chromosome-specific probes. We confirmed a high degree of karyotype conservation and found an identical order of syntenic segments in both branches of cetaceans. Yet, whale chromosomes harbor variable heterochromatic regions constituting up to a third of the genome due to the presence of several types of repeats. To investigate the cause of this variability, several classes of repeated DNA sequences were mapped onto chromosomes of whale species from both Mysticeti and Odontoceti. We uncovered extensive intrapopulation variability in the size of heterochromatic blocks present in homologous chromosomes among 3 individuals of the gray whale by 2-step differential chromosome staining. We show that some of the heteromorphisms observed in the gray whale karyotype are due to distinct amplification of a complex of common cetacean repeat and heavy satellite repeat on homologous autosomes. Furthermore, we demonstrate localization of the telomeric repeat in the heterochromatin of both gray and pilot whale (Globicephala melas, Odontoceti). Heterochromatic blocks in the pilot whale represent a composite of telomeric and common repeats, while heavy satellite repeat is lacking in the toothed whale consistent with previous studies. © 2016 S. Karger AG, Basel.
Fitzgerald, Erich M.G
Extant baleen whales (Cetacea, Mysticeti) are all large filter-feeding marine mammals that lack teeth as adults, instead possessing baleen, and feed on small marine animals in bulk. The early evolution of these superlative mammals, and their unique feeding method, has hitherto remained enigmatic. Here, I report a new toothed mysticete from the Late Oligocene of Australia that is more archaic than any previously described. Unlike all other mysticetes, this new whale was small, had enormous eye...
Monteiro-Neto, C.; Itavo, R.V.; Souza de Moraes, Luiz Eduardo
As a top predator, Sotalia fluviatilis may be at risk from pollutants from outfalls. - Lead (Pb), cadmium (Cd) and mercury (Hg) concentrations on liver and kidney of Sotalia fluviatilis (Cetacea: Delphinidae) stranded in the coast of Ceara, Brazil, were studied from 1996 to 1999. Pb levels were usually lower than the detection limit (0.1 μg/g). Concentrations of Cd were significantly higher in kidney than liver, averaging 0.8 μg/g. Mercury accumulation took place mainly in liver with an average concentration of 4.6 μg/g. Both metals were significantly higher in larger mature individuals, but differences between sexes were not significant. The detection of Cd, Hg and Pb in tissue samples of S. fluviatilis off the coast of Ceara indicated that heavy metals are locally available in the water, and bioaccumulation may be occurring through the food web. Contamination levels were not considered critical, but could be related to Ceara's growing industrial development. The associated risks of pollution outfalls may pose a threat to marine organisms in a near future, especially for top predators such as S. fluviatilis
The maximum lifespans in captivity for terrestrial mammalian species can be estimated by means of a multiple linear regression of logarithm of lifespan (L) on the logarithm of adult brain weight (E) and body weight (S). This paper describes the application of regression formulas based on data from terrestrial mammals to the estimation of odontocete and mysticete lifespans. The regression formulas predict cetacean lifespans that are in accord with the data on maximum cetacean lifespans obtained in recent years by objective age determination procedures. More remarkable is the correct prediction by the regression formulas that the odontocete species have nearly constant lifespans, almost independent of body weight over a 300:1 body weight range. This prediction is a consequence of the fact, remarkable in itself, that over this body weight range the Odontoceti have a brain:body allometric slope of 1/3, as compared to a slope of 2/3 for the Mammalia as a whole.
New records of the dolphin Albertocetus meffordorum (Odontoceti: Xenorophidae from the lower Oligocene of South Carolina: Encephalization, sensory anatomy, postcranial morphology, and ontogeny of early odontocetes.
Robert W Boessenecker
Full Text Available We report five new specimens of xenorophid dolphins from North and South Carolina. Four of the specimens represent the xenorophid Albertocetus meffordorum, previously only known from the holotype skull. The other is a fragmentary petrosal from the upper Oligocene Belgrade Formation that we refer to Echovenator sp, indicating at least two xenorophids from that unit. Two of the Albertocetus meffordorum specimens are from the lower Oligocene Ashley Formation: 1 a partial skeleton with neurocranium, fragmentary mandible, ribs, vertebrae, and chevrons, and 2 an isolated braincase. The partial vertebral column indicates that Albertocetus retained the ancestral morphology and locomotory capabilities of basilosaurid archaeocetes, toothed mysticetes, and physeteroids, and caudal vertebrae that are as wide as tall suggest that the caudal peduncle, which occurs in all extant Cetacea, was either wide or lacking. CT data from the isolated braincase were used to generate a digital endocast of the cranial cavity. The estimated EQ of this specimen is relatively high for an Oligocene odontocete, and other aspects of the brain, such as its anteroposterior length and relative size of the temporal lobe, are intermediate in morphology between those of extant cetaceans and terrestrial artiodactyls. Ethmoturbinals are also preserved, and are similar in morphology and number to those described for the Miocene odontocete Squalodon. These fossils extend the temporal range of Albertocetus meffordorum into the early Oligocene, its geographic range into South Carolina, and expand our paleobiological understanding of the Xenorophidae.
Alexandra T. Boersma
Full Text Available The diversification of crown cetacean lineages (i.e., crown Odontoceti and crown Mysticeti occurred throughout the Oligocene, but it remains an ongoing challenge to resolve the phylogenetic pattern of their origins, especially with respect to stem lineages. One extant monotypic lineage, Platanista gangetica (the Ganges and Indus river dolphin, is the sole surviving member of the broader group Platanistoidea, with many fossil relatives that range from Oligocene to Miocene in age. Curiously, the highly threatened Platanista is restricted today to freshwater river systems of South Asia, yet nearly all fossil platanistoids are known globally from marine rocks, suggesting a marine ancestry for this group. In recent years, studies on the phylogenetic relationships in Platanistoidea have reached a general consensus about the membership of different sub-clades and putative extinct groups, although the position of some platanistoid groups (e.g., Waipatiidae has been contested. Here we describe a new genus and species of fossil platanistoid, Arktocara yakataga, gen. et sp. nov. from the Oligocene of Alaska, USA. The type and only known specimen was collected from the marine Poul Creek Formation, a unit known to include Oligocene strata, exposed in the Yakutat City and Borough of Southeast Alaska. In our phylogenetic analysis of stem and node-based Platanistoidea, Arktocara falls within the node-based sub-clade Allodelphinidae as the sister taxon to Allodelphis pratti. With a geochronologic age between ∼29–24 million years old, Arktocara is among the oldest crown Odontoceti, reinforcing the long-standing view that the diversification for crown lineages must have occurred no later than the early Oligocene.
Boersma, Alexandra T.; McCurry, Matthew R.; Pyenson, Nicholas D.
Many odontocete groups have developed enlarged facial crests, although these crests differ in topography, composition and function. The most elaborate crests occur in the South Asian river dolphin (Platanista gangetica), in which they rise dorsally as delicate, pneumatized wings anterior of the facial bones. Their position wrapping around the melon suggests their involvement in sound propagation for echolocation. To better understand the origin of crests in this lineage, we examined facial crests among fossil and living Platanistoidea, including a new taxon, Dilophodelphis fordycei, nov. gen. and sp., described herein, from the Early Miocene Astoria Formation of Oregon, USA. We measured the physical extent and thickness of platanistoid crests, categorized their relative position and used computed tomography scans to examine their internal morphology and relative bone density. Integrating these traits in a phylogenetic context, we determined that the onset of crest elaboration or enlargement and the evolution of crest pneumatization among the platanistoids were separate events, with crest enlargement beginning in the Oligocene. However, we find no evidence for pneumatization until possibly the Early Miocene, although certainly by the Middle Miocene. Such an evolutionary context, including data from the fossil record, should inform modelling efforts that seek to understand the diversity of sound generation morphology in Odontoceti.
Buono, Mónica Romina
Los Balaenidae (Cetacea: Neoceti) son un grupo de misticetos caracterizados por presentar, en el cráneo y de la mandíbula, una serie de especializaciones vinculadas al sistema de alimentación por filtración, tales como un rostro muy arqueado y angosto, huesos rostrales sin interdigitación con los huesos occipitales, mandíbula con un proceso coronoides y angular reducido y barbas largas. El patrón corporal de los balénidos actuales, especialmente su anatomía esqueletaria, es muy conservador y ...
Dalebout, Merel L; Steel, Debbie; Baker, C Scott
With 14 species currently recognized, the beaked whale genus Mesoplodon (family Ziphiidae) is the most speciose in the order Cetacea. Beaked whales are widely distributed but are rarely seen at sea due to their oceanic distribution, deep-diving capacity, and apparent low abundance. Morphological differentiation among Mesoplodon species is relatively limited, with the exception of tooth form in adult males. Based on scarring patterns, males appear to use their tusk-like teeth as weapons in aggressive encounters with other males. Females are effectively toothless. We used sequences from seven nuclear introns (3348 base pairs) to construct a robust and highly resolved phylogeny, which was then used as a framework to test predictions from four hypotheses seeking to explain patterns of Mesoplodon tusk morphology and/or the processes that have driven the diversification of this genus: (1) linear progression of tusk form; (2) allopatric speciation through isolation in adjacent deep-sea canyons; (3) sympatric speciation through sexual selection on tusks; and (4) selection for species-recognition cues. Maximum-likelihood and Bayesian reconstructions confirmed the monophyly of the genus and revealed that what were considered ancestral and derived tusk forms have in fact arisen independently on several occasions, contrary to predictions from the linear-progression hypothesis. Further, none of the three well-supported species clades was confined to a single ocean basin, as might have been expected from the deep-sea canyon-isolation or sexual-selection hypotheses, and some species with similar tusks have overlapping distributions, contrary to predictions from the species-recognition hypothesis. However, the divergent tusk forms and sympatric distributions of three of the four sister-species pairs identified suggest that sexual selection on male tusks has likely played an important role in this unique radiation, although other forces are clearly also involved. To our knowledge
Paulo de Tarso da C. Chaves
Full Text Available Os esôfagos e estômagos de seis botos tucuxi, Sotalia fluviatilis (Cetacea: Delphinidae foram examinados anatômica e microscopicamente e comparados com os de botos marinhos do mesmo gênero. O esôfago é um simples tubo distensível e macroscopicamente uniforme até sua junção com o estômago. Este boto tem um estômago tricompartimentado: uma parte anterior ou muscular; uma principal, glandular; e uma pilórica. As características anatomo-funcionais de cada compartimento são descritas. Não se achou esfíncter entre o esôfago e o estômago. Em comparação com os delfinídeos marinhos, não há adaptações, por parte de Sotalia, à invasão relativamente recente do ambiente de água doce.The oesophagus and stomachs of six tucuxi dolphins, Sotalia fluviatilis (Cetacea: Delphinidae were examined anatomically and microscopically and compared with marine dolphins of the same genus. The oesophagus is a simple distendable tube and is macroscopically uniform to its junctureh with te stomach. This dolphin has a three-compartmented stomach: an anterior or muscular compartment; a principal one, which is glandular; and the pyloric part. The anatomical and functional characteristics of each compartment is described. No sphincter was found between the oesophagus and the stomach. In comparison with marine delphinids there are no adaptations specific to the relatively recent invasion of the fresh-water environment by Sotalia.
Fisher, Robert D.; Ludwig, Craig A.
The type collection of Recent mammals in the Division of Mammals, National Museum of Natural History, Smithsonian Institution, contains 612 specimens bearing names of 604 species-group taxa of Carnivora, Perissodactyla, Artiodactyla, and Cetacea as of May 2016. This catalog presents an annotated list of these holdings comprising 582 holotypes; 16 lectotypes, two of which are newly designated herein; 7 syntypes (15 specimens); and 1 neotype. Included are several specimens that should be in the collection but cannot be found or are now known to be in other collections and therefore are not in the database. Thirty-seven of the names are new since the last type catalog covering these orders, Arthur J. Poole and Viola S. Schantz’s 1942 “Catalog of the Type Specimens of Mammals in the United States National Museum, Including the Biological Surveys Collection” (Bulletin of the United States National Museum, 178). One of these, Lutra iowa Goldman, 1941, was transferred to the National Museum’s Paleobiology Department collection and is mentioned only briefly in this work. Orders and families are arranged systematically following D. E. Wilson and D. M. Reeder’s 2005 Mammal Species of the World: A Taxonomic and Geographic Reference, third edition, volume 1; within families, currently recognized genera are arranged alphabetically, and within each currently recognized genus, species and subspecies accounts are arranged alphabetically by original published name. Information in each account includes original name and abbreviated citation thereto, current name if other than original, citation for first use of current name combination for the taxon, type designation, U.S. National Museum catalog number(s), preparation, age and sex, date of collection and collector, original collector number, type locality, and remarks as appropriate. Digital photographs of each specimen will serve as a condition report and will be attached to each electronic specimen record. An addendum
Full Text Available Los delfines se caracterizan por una increíble versatilidad, la cual les ha permitido responder a los cambios estacionales de su ambiente. Dicha variación estacional en los patrones de comportamiento se considera poco conocida en delfines que habitan aguas tropicales. El delfín manchado (forma costera Stenella attenuata graffmani, parece ser la única especie de cetáceo residente en el Golfo de Papagayo, área que se caracteriza por una estacionalidad muy bien definida. El objetivo de este trabajo es determinar si esta estacionalidad influencia el tamaño del grupo, la presencia y patrones de comportamiento de esta especie de delfín en el golfo. Usando transectos en banda se recorrieron dos localidades del Golfo de Papagayo. El tamaño del grupo varío de uno a 50 individuos, con una media de 10.16 (DS =9.61. Las actividades alimentarias fueron más intensas que las interacciones sociales y de desplazamiento, las cuales siguieron un ordenamiento diario y estacional. Se describieron dos técnicas principales de forrajeo las cuales parecen estar asociadas con el tamaño del grupo y localidad dentro del golfo. La variación diaria en los patrones de comportamiento parecen estar relacionados con la disponibilidad, distribución, y arreglo espacial de las presas. De igual manera, la variación estacional de estas actividades probablemente esta asociada por la disponibilidad de alimento, tal como ha sido observado en un mayor número de grupos y una mayor inversión de tiempo en actividades de alimentación durante la época seca y finales de las lluviasOccurrence and behavioral patterns of the spotted coastal dolphin Stenella attenuata (Cetacea: Delphinidae in the Gulf of Papagayo, Costa Rica. Dolphins are characterized by a significant behavioral versatility, which allows them to respond to environmental seasonality. Seasonal variation in dolphin behavior in tropical waters is not well known. Stenella attenuata graffmani is a resident dolphin
van Beurden, Steven J; IJsseldijk, Lonneke L; Ordonez, Soledad R; Förster, Christine; de Vrieze, Geert; Gröne, Andrea; Verheije, M Hélène; Kik, Marja
Herpesviruses infect a wide range of vertebrates, including toothed whales of the order Cetacea. One of the smallest toothed whales is the harbour porpoise (Phocoena phocoena), which is widespread in the coastal waters of the northern hemisphere, including the North Sea. Here, we describe the detection and phylogenetic analysis of a novel gammaherpesvirus associated with mucocutaneous and skin lesions in stranded harbour porpoises along the Dutch coast, tentatively designated phocoenid herpesvirus 1 (PhoHV1). Phylogenetically, PhoHV1 forms a monophyletic clade with all other gammaherpesviruses described in toothed whales (Odontoceti) to date, suggesting a common evolutionary origin.
Gatesy, John; Geisler, Jonathan H; Chang, Joseph; Buell, Carl; Berta, Annalisa; Meredith, Robert W; Springer, Mark S; McGowen, Michael R
The emergence of Cetacea in the Paleogene represents one of the most profound macroevolutionary transitions within Mammalia. The move from a terrestrial habitat to a committed aquatic lifestyle engendered wholesale changes in anatomy, physiology, and behavior. The results of this remarkable transformation are extant whales that include the largest, biggest brained, fastest swimming, loudest, deepest diving mammals, some of which can detect prey with a sophisticated echolocation system (Odontoceti - toothed whales), and others that batch feed using racks of baleen (Mysticeti - baleen whales). A broad-scale reconstruction of the evolutionary remodeling that culminated in extant cetaceans has not yet been based on integration of genomic and paleontological information. Here, we first place Cetacea relative to extant mammalian diversity, and assess the distribution of support among molecular datasets for relationships within Artiodactyla (even-toed ungulates, including Cetacea). We then merge trees derived from three large concatenations of molecular and fossil data to yield a composite hypothesis that encompasses many critical events in the evolutionary history of Cetacea. By combining diverse evidence, we infer a phylogenetic blueprint that outlines the stepwise evolutionary development of modern whales. This hypothesis represents a starting point for more detailed, comprehensive phylogenetic reconstructions in the future, and also highlights the synergistic interaction between modern (genomic) and traditional (morphological+paleontological) approaches that ultimately must be exploited to provide a rich understanding of evolutionary history across the entire tree of Life. Copyright © 2012 Elsevier Inc. All rights reserved.
variables ambientales particulares, sin embargo, los resultados mostraron información valiosa sobre tendencias muy interesantes. La falta de significancia, en relación con los aspectos ambientales, fue atribuida a tres aspectos: (a las transiciones entre actividades se dieron generalmente dentro de un área poco variable, (b fue común que los delfines se desplazaran cubriendo grandes áreas sin cambiar de actividad y (c las condiciones ambientales en el Golfo son bastante homogéneas. En ambas especies el mayor promedio en el número de individuos por grupo correspondió a la categoría de socialización activa, seguido en forma decreciente por el desplazamiento, la socialización pasiva y la alimentación. En el caso del bufeo, el menor tamaño promedio de grupo estuvo asociado a las actividades de alimentación (ANDEVA, F= 2.624, p=0.037, gl= 4, mientras que en el manchado correspondió a los momentos de merodeo (ANDEvA, F= 3.817, p=0.009, gl= 4.Distribution and environmental conditions related to the behavior in the bottlenose dolphin (Tursiops truncatus and the spotted dolphin (Stenella attenuata (Cetacea: Delphinidae in Golfo Dulce, Costa Rica. Habitat characteristics influencing behavior in animal species vary locally. The influence that a particular environmental characteristic can have on a species depends not only on other variables, but on morphological, physiological and social conditions of that species. in this study, developed from June 1996 to July 1997, I studied whether specific behaviors are related to particular distribution areas and environmental factors in the bottlenose (Tursiops truncatus and the spotted dolphin (Stenella attenuata. The study area was covered along oblicuous linear transects, and the behavior of single groups was observed from 15 min to 5 h. Environmental factors such as depth, temperature, salinity and distance from shore, among others, were considered. For the bottlenose dolphin, foraging/feeding activities showed exclusive
Robert W Meredith
Full Text Available Cetaceans have a long history of commitment to a fully aquatic lifestyle that extends back to the Eocene. Extant species have evolved a spectacular array of adaptations in conjunction with their deployment into a diverse array of aquatic habitats. Sensory systems are among those that have experienced radical transformations in the evolutionary history of this clade. In the case of vision, previous studies have demonstrated important changes in the genes encoding rod opsin (RH1, short-wavelength sensitive opsin 1 (SWS1, and long-wavelength sensitive opsin (LWS in selected cetaceans, but have not examined the full complement of opsin genes across the complete range of cetacean families. Here, we report protein-coding sequences for RH1 and both color opsin genes (SWS1, LWS from representatives of all extant cetacean families. We examine competing hypotheses pertaining to the timing of blue shifts in RH1 relative to SWS1 inactivation in the early history of Cetacea, and we test the hypothesis that some cetaceans are rod monochomats. Molecular evolutionary analyses contradict the "coastal" hypothesis, wherein SWS1 was pseudogenized in the common ancestor of Cetacea, and instead suggest that RH1 was blue-shifted in the common ancestor of Cetacea before SWS1 was independently knocked out in baleen whales (Mysticeti and in toothed whales (Odontoceti. Further, molecular evidence implies that LWS was inactivated convergently on at least five occasions in Cetacea: (1 Balaenidae (bowhead and right whales, (2 Balaenopteroidea (rorquals plus gray whale, (3 Mesoplodon bidens (Sowerby's beaked whale, (4 Physeter macrocephalus (giant sperm whale, and (5 Kogia breviceps (pygmy sperm whale. All of these cetaceans are known to dive to depths of at least 100 m where the underwater light field is dim and dominated by blue light. The knockout of both SWS1 and LWS in multiple cetacean lineages renders these taxa rod monochromats, a condition previously unknown among
Bree, van P.J.H.; Nijssen, H.
Recently the Zoological Museum in Amsterdam came into possession of three specimens of the White-beaked Dolphin, Lagenorhynchus albirostris. As data on this species are rather scarce, it may be useful to publish a few notes on these animals. The first dolphin, a female, was caught in the North Sea
Ogden, J.A.; Conlogue, G.J.; Rhodin, A.G.J.; Yale Univ., New Haven, CT
A new roentgenographic classification (grading) scheme is presented for utilization in studies of skeletal development and maturation in marine mammals, particularly cetaceans. This is based on adequate description of the extent of development and maturation of the various secondary ossification centers, their eventual patterns of fusion, and subsequent remodeling with the metaphysis. The six stages are illustrated schematically and roentgenographically. This scheme may be applied to any cetacean longitudinal bone developing proximal and distal epiphyseal ossification centers. (orig.)
Drake, Summer E; Crish, Samuel D; George, John C; Stimmelmayr, Raphaella; Thewissen, J G M
We studied the histology and morphometrics of the hairs of bowhead whales (Balaena mysticetus). These whales are hairless except for two patches of more than 300 hairs on the rostral tip of the lower lip and chin, the rostral tip of the upper lip, and a bilateral row of approximately ten hairs caudal to the blowhole. Histological data indicate that hairs in all three of these areas are vibrissae: they show an outermost connective tissue capsule, a circumferential blood sinus system surrounding the hair shaft, and dense innervation to the follicle. Morphometric data were collected on hair diameters, epidermal recess diameters, hair follicle length, and external hair lengths. The main difference between the hairs in the different regions is that blowhole hairs have larger diameters than the hairs in the chin and rostrum regions. We speculate that the hair shaft thickness patterns in bowheads reflect functional specializations. © 2015 Wiley Periodicals, Inc.
Nardy, Olavo [UNESP
A macroecologia é uma linha de pesquisa que surgiu com o intuito de realizar uma ponte entre algumas ciências como a macroevolução, biogeografia e ecologia, buscando padrões em escalas amplas, mas variadas, como gradientes latitudinais de riqueza de espécies, utilizando propriedades emergentes do sistema natural para evidenciar fenômenos ou processos que regulem a distribuição e ocorrência das espécies entre outras características ecológicas. Muitos trabalhos buscam padrões desse tipo para ma...
Godfrey, Stephen J; Geisler, Jonathan; Fitzgerald, Erich M G
The structure of the olfactory apparatus is not well known in both archaic and extant whales; the result of poor preservation in most fossils and locational isolation deep within the skulls in both fossil and Recent taxa. Several specimens now shed additional light on the subject. A partial skull of an archaic cetacean is reported from the Pamunkey River, Virginia, USA. The specimen probably derives from the upper middle Eocene (Piney Point Formation) and is tentatively assigned to the Protocetidae. Uncrushed cranial cavities associated with the olfactory apparatus were devoid of sediment. CT scans clearly reveal the dorsal nasal meatus, ethmoturbinates within the olfactory recess, the cribriform plate, the area occupied by the olfactory bulbs, and the olfactory nerve tract. Several sectioned skulls of the minke whale (Balaenoptera acutorostrata) were also examined, and olfactory structures are remarkably similar to those observed in the fossil skull from the Pamunkey River. One important difference between the two is that the fossil specimen has an elongate olfactory nerve tract. The more forward position of the external nares in extant balaenopterids when compared with those of extant odontocetes is interpreted to be the result of the need to retain a functional olfactory apparatus and the forward position of the supraoccipital/cranial vertex. An increase in the distance between the occipital condyles and the vertex in balaenopterids enhances the mechanical advantage of the epaxial musculature that inserts on the occiput, a specialization that likely stabilizes the head of these enormous mammals during lunge feeding. Copyright © 2012 Wiley Periodicals, Inc.
Full Text Available Teeth are important elements in studies of modern and fossil Cetacea (whales, dolphins, providing information on feeding habits, estimations of age and phylogenetic relationships. The growth layer groups (GLGs recorded in dentine have demonstrated application for aging studies, but also have the potential to elucidate life history phenomena such as metabolic or physiologic events. Micro-Computed Tomography (Micro-CT is a non-invasive and non-destructive technique that allows 3-dimensional study of mineralized tissues, such as human teeth, and their physical properties. Teeth from extant dolphins (Cetacea: Odontoceti and some fossil odontocetes were scanned in a Skyscan 1172 Micro-CT desktop system. X-rays were generated at 100 kV and 100 µA for extant samples, and at 80kV and 124 µA for fossils. 0.5 mm thick aluminum and copper filters were used in the beam. Reconstructed images were informative for most extant species, showing a good resolution of the enamel layer, dentine and pulp cavity. Greyscale changes in the dentinal layers were not resolved enough to show GLGs. Visualization of the internal structure in fossil cetacean teeth depended on the degree of diagenetic alteration in the specimen; undifferentiated enamel and dentine regions probably reflect secondary mineralization. However, internal details were finely resolved for one fossil specimen, showing the enamel, internal layers of dentine and the pulp cavity. Micro-CT has been proven to be a useful tool for resolving the internal morphology of fossil and extant teeth of cetaceans before they are sectioned for other morphological analyses; however some methodological refinements are still necessary to allow better resolution of dentine for potential application in non-destructive age determination studies.
Full Text Available Abstract Background The phylogeny of Cetacea (whales is not fully resolved with substantial support. The ambiguous and conflicting results of multiple phylogenetic studies may be the result of the use of too little data, phylogenetic methods that do not adequately capture the complex nature of DNA evolution, or both. In addition, there is also evidence that the generic taxonomy of Delphinidae (dolphins underestimates its diversity. To remedy these problems, we sequenced the complete mitochondrial genomes of seven dolphins and analyzed these data with partitioned Bayesian analyses. Moreover, we incorporate a newly-developed "relaxed" molecular clock to model heterogenous rates of evolution among cetacean lineages. Results The "deep" phylogenetic relationships are well supported including the monophyly of Cetacea and Odontoceti. However, there is ambiguity in the phylogenetic affinities of two of the river dolphin clades Platanistidae (Indian River dolphins and Lipotidae (Yangtze River dolphins. The phylogenetic analyses support a sister relationship between Delphinidae and Monodontidae + Phocoenidae. Additionally, there is statistically significant support for the paraphyly of Tursiops (bottlenose dolphins and Stenella (spotted dolphins. Conclusion Our phylogenetic analysis of complete mitochondrial genomes using recently developed models of rate autocorrelation resolved the phylogenetic relationships of the major Cetacean lineages with a high degree of confidence. Our results indicate that a rapid radiation of lineages explains the lack of support the placement of Platanistidae and Lipotidae. Moreover, our estimation of molecular divergence dates indicates that these radiations occurred in the Middle to Late Oligocene and Middle Miocene, respectively. Furthermore, by collecting and analyzing seven new mitochondrial genomes, we provide strong evidence that the delphinid genera Tursiops and Stenella are not monophyletic, and the current taxonomy
Marta J. Cremer
Full Text Available The present study provides information about the diet of sympatric populations of small cetaceans in the Babitonga Bay estuary. This is the first study on the diet of these species in direct sympatry. The stomach contents of seven Guiana dolphins Sotalia guianensis and eight franciscanas Pontoporia blainvillei were analyzed. The prey of both cetaceans was mostly teleost fishes, followed by cephalopods. We identified 13 teleost fishes as part of the diet of the franciscanas, and 20 as part of the diet of Guiana dolphins. Lolliguncula brevis was the only cephalopod recorded, and was the most important prey for both cetaceans. Stellifer rastrifer and Gobionellus oceanicus were also important for franciscana, so as Mugil curema and Micropogonias furnieri were important for Guiana dolphins. Stellifer rastrifer and Cetengraulis edentulus were the fishes with the highest frequency of occurrence for franciscana (50%, while Achirus lineatus, C. edentulus, S. brasiliensis, Cynoscion leiarchus, M. furnieri, M. curema, Diapterus rhombeus, Eugerres brasilianus and G. oceanicus showed 28.6% of frequency of occurrence for Guiana dolphins. Franciscanas captured greater cephalopods than the Guiana dolphins in both total length (z= -3.38; n= 40; p< 0.05 and biomass (z = -2.46; n = 40; p<0.05. All of the prey species identified occur inside the estuary, which represents a safe habitat against predators and food availability, reinforcing the importance of the Babitonga Bay for these cetacean populations.
Eric G Ekdale
Full Text Available Anatomical comparisons of the ear region of baleen whales (Mysticeti are provided through detailed osteological descriptions and high-resolution photographs of the petrotympanic complex (tympanic bulla and petrosal bone of all extant species of mysticete cetaceans. Salient morphological features are illustrated and identified, including overall shape of the bulla, size of the conical process of the bulla, morphology of the promontorium, and the size and shape of the anterior process of the petrosal. We place our comparative osteological observations into a phylogenetic context in order to initiate an exploration into petrotympanic evolution within Mysticeti.The morphology of the petrotympanic complex is diagnostic for individual species of baleen whale (e.g., sigmoid and conical processes positioned at midline of bulla in Balaenoptera musculus; confluence of fenestra cochleae and perilymphatic foramen in Eschrichtius robustus, and several mysticete clades are united by derived characteristics. Balaenids and neobalaenids share derived features of the bulla, such as a rhomboid shape and a reduced anterior lobe (swelling in ventral aspect, and eschrichtiids share derived morphologies of the petrosal with balaenopterids, including loss of a medial promontory groove and dorsomedial elongation of the promontorium. Monophyly of Balaenoidea (Balaenidae and Neobalaenidae and Balaenopteroidea (Balaenopteridae and Eschrichtiidae was recovered in phylogenetic analyses utilizing data exclusively from the petrotympanic complex.This study fills a major gap in our knowledge of the complex structures of the mysticete petrotympanic complex, which is an important anatomical region for the interpretation of the evolutionary history of mammals. In addition, we introduce a novel body of phylogenetically informative characters from the ear region of mysticetes. Our detailed anatomical descriptions, illustrations, and comparisons provide valuable data for current and future studies on the phylogenetic relationships, evolution, and auditory physiology of mysticetes and other cetaceans throughout Earth's history.
Antonio José Tonello Júnior
Full Text Available The present paper constitutes the second record of epimeletic behavior for the toninha, Pontoporia blainvillei. A toninha calf carcass was recovered at Enseada Beach, São Francisco do Sul, southern Brazil (26o13’S - 48o31’W on October 9, 2001. Its total length indicated that it was a neonate or a premature calf. The calf had many parallel scratches on it, which were freshly made and produced by adult teeth. There were scratches on the fin, flukes and flippers, and the position and size of the marks demonstrated the intention of the adult to rescue the calf. The anterior region of the body showed net marks, suggesting that the calf had been accidentally entangled. The epimeletic behavior evidenced by the tooth marks could have occurred during the entanglement and/or after its liberation, and we suggest that the causa mortis of the calf was drowning.
Eschrichtius robustus (code ABIA ), two records on feeding in both E. robustus and Megaptera novaeanQliae (AC2A), and one record on intelligence (code 545...This field is indexed. For example, an entry for a gray whale sighting on 10 Oct 1910: OBSDATE/1 10-Oct-1910 ABIA OBSDATE/2 OctABIA 1910ABlA -- 13
Rudolph, P.; Smeenk, C.; Leatherwood, S.
Records of 29 species of cetaceans from the Indonesian Archipelago have been gleaned from published and unpublished sources, representing five families: Phocoenidae (1 species), Delphinidae (16), Ziphiidae (3), Physeteridae (3), and Balaenopteridae (6). The presence of 26 species could be confirmed
The early origin of birds is a hotly disputed debate and may be broadly framed as a conflict between paleontologists and ornithologists. The paleontological emphasis has shifted from Archaeopteryx and its origins to recent finds of Cretaceous birds and "feathered" dinosaurs from China. The identification of alleged feathers has, however, relied principally on the visual image. Some workers have interpreted these integumentary structures as collagen fibers. To test the latter hypothesis, using light microscopy, collagen from the hypodermis (blubber) and subdermal connective tissue sheath was examined from a dolphin that had been buried for a year as part of an experiment. Within the blubber, toward the central thicker parts of the material, the collagen fibers had compacted and the three-dimensional latticework of normal blubber had more or less collapsed. Chromatographic analysis of the blubber revealed pronounced oxidation of the unsaturated lipids, probably accounting for the collapse of the latticework. Fibers normally bound together in bundles became separated into individual fibers or smaller bundles by degradation of the glue-like substance binding them together. These degraded collagen fibers show, in many instances, feather-like patterns, strikingly reminiscent of many of those identified as either "protofeathers" or "modern" feathers in dromaeosaurid dinosaurs. The findings throw serious doubt on the virtually complete reliance on visual image by supporters of the feathered dinosaur thesis and emphasize the need for more rigorous methods of identification using modern feathers as a frame of reference. Since collagen is the main fiber type found in most supporting tissues, the results have wide implications regarding the degradation and fossilization of vertebrate integument, such as that of the ichthyosaurs, dinosaurs and birds.
Kienle, Sarah S; Ekdale, Eric G; Reidenberg, Joy S; Deméré, Tom A
Little is known about the anatomy and musculature of the gray whale (Eschrichtius robustus), especially related to the anatomy of the tongue and hyoid region. The recovery of an extremely fresh head of a neonatal female gray whale provided an opportunity to conduct the first in-depth investigation of the musculoskeletal features of the tongue and hyoid apparatus. Unlike other mysticetes, the gray whale tongue is strong, muscular, and freely mobile inside the buccal cavity. In particular, the genioglossus and hyoglossus muscles are extremely large and robust making up the majority of the body of the tongue. In addition, the genioglossus had a unique position and fiber orientation in the tongue compared to other mammals. The structure of the hyoid apparatus differs between E. robustus and other mysticete species, although there are similarities among individual elements. We provide the first documentation of fungiform papillae that may be associated with taste buds in Mysticeti. The highly mobile, robust tongue and the presence of well-defined tongue and hyoid musculature are in keeping with observations of gray whale feeding that suggest this group of whales utilize oral suction to draw benthic prey into the buccal cavity. © 2015 Wiley Periodicals, Inc.
Full Text Available Population density in cetaceans can be estimated through photo-identification, mark-recapture, land-based observations and visual estimative. We the aim to contribute with conservation strategies, we used line transects (distance method to estimate the population density of the river dolphin, S. guianensis, in the estuarine region of Cananéia, Southeastern Brazil. The study, developed from May 2003 until April 2004, during dry and rainy seasons and different times of the day, included a sampling area divided into three sectors according to their proximity to the open sea: Sector I (the closest to the open sea; Sector II (with a large flow of fresh water and a salient declivity; and Sector III (with a large flow of fresh water and non salient declivity. Onboard random sampling was carried out in all three sectors, and dolphins seen from the bow to 90° on both port and starboard sides, were registered along with their position and distance from the boat. The total density found was 12.41ind/km² (CV=25.53% with an average of 2.2 individuals per group for both periods of the day, morning and afternoon. Densities also varied between dry and rainy seasons, being lower in the first with 5.77ind/km² (CV=27.87% than in the second 20.28ind/km² (CV=31.95%, respectively. Regarding the three sectors, a non-causal heterogeneous distribution was found: Sector I was the most populated (D=33.10ind/km², CV=13.34%, followed by Sector II (D=7.8ind/km², CV=21.07% and Sector III (D=3.04ind/km², CV=34.04%. The aforementioned area, due to its proximity to the open sea, has the highest salinity level and therefore has the greatest chance of holding most of the marine fish schools which can be cornered by dolphins on high declivity areas during fishing activities. This suggests that food availability may be the most important factor on the river dolphin’s distribution in the estuary. Similar studies will contribute to a better understanding of these populations and are essential for future conservation strategies. Rev. Biol. Trop. 59 (3: 1275-1284. Epub 2011 September 01.El delfín estuarino S. guianensis, habita en aguas tropicales costeras y estuarinas. A pesar de su amplia distribución no se conoce suficiente, por lo tanto, recientemente se han intensificado sus estudios poblacionales. Transectos de línea (Método Distancia fueron utilizados para estimar la densidad de población de S. guianensis en la Bahía Trapandé, región de estuario de Cananéia, Sudeste de Brasil. El muestreo aleatorio se realizó en tres sectores de la bahía desde mayo 2003 hasta abril 2004. La densidad total fue de 12.41ind/km2. Considerando los tres sectores de forma individual, se observó una distribución heterogénea no ocasional: Sector I (más cerca del mar abierto D=33.10ind/km2; Sector II (que recibe un gran flujo de agua dulce, con un declive más destacado D=7.80ind/km2; Sector III (que recibe un gran flujo de agua dulce, sin declives salientes D=3.04ind/km2. Las condiciones ambientales como la estación de lluvias y la estacionalidad diaria, también se observaron en esta bahía. Los resultados mostraron un uso heterogéneo de la zona por los delfines
Full Text Available Population density in cetaceans can be estimated through photo-identification, mark-recapture, land-based observations and visual estimative. We the aim to contribute with conservation strategies, we used line transects (distance method to estimate the population density of the river dolphin, S. guianensis, in the estuarine region of Cananéia, Southeastern Brazil. The study, developed from May 2003 until April 2004, during dry and rainy seasons and different times of the day, included a sampling area divided into three sectors according to their proximity to the open sea: Sector I (the closest to the open sea; Sector II (with a large flow of fresh water and a salient declivity; and Sector III (with a large flow of fresh water and non salient declivity. Onboard random sampling was carried out in all three sectors, and dolphins seen from the bow to 90° on both port and starboard sides, were registered along with their position and distance from the boat. The total density found was 12.41ind/km² (CV=25.53% with an average of 2.2 individuals per group for both periods of the day, morning and afternoon. Densities also varied between dry and rainy seasons, being lower in the first with 5.77ind/km² (CV=27.87% than in the second 20.28ind/km² (CV=31.95%, respectively. Regarding the three sectors, a non-causal heterogeneous distribution was found: Sector I was the most populated (D=33.10ind/km², CV=13.34%, followed by Sector II (D=7.8ind/km², CV=21.07% and Sector III (D=3.04ind/km², CV=34.04%. The aforementioned area, due to its proximity to the open sea, has the highest salinity level and therefore has the greatest chance of holding most of the marine fish schools which can be cornered by dolphins on high declivity areas during fishing activities. This suggests that food availability may be the most important factor on the river dolphin’s distribution in the estuary. Similar studies will contribute to a better understanding of these populations and are essential for future conservation strategies. Rev. Biol. Trop. 59 (3: 1275-1284. Epub 2011 September 01.
Paulo César Simões-Lopes
Full Text Available We present a description of the backbone of the marine tucuzi (Sotalia guianensis vertebrae (n= 34, including the variations in the vertebral formula (n= 32(UFSC- Universidade Federal de Santa catarina: Ce7, T12,L10-12,Ca23-25= 52-56. Species diagnostic characters and intraspecific variations are presented. Cervical ribs occur in 22.5% of the samples. The metapophyses start from the fourth thoracic vertebra, and the zigapophyses start at the cervical level, being observed up to T11. The inclination of the transverse processes and neurapophyses is most reduced around L5 or L6. Transverse processes on caudal vertebrae disappear between Ca9 and Ca13. The neurapophyses, neural arches and metapophyses are observed up to Ca13 or Ca15. Caudal foramina appear between Ca3 and Ca6. The height of the vertebral body increases up to Ca13, then starts to decrease. The maximum width is found around Ca6, where the vertebral body becomes laterally compressed. The length of the vertebral body increases from the last cervical to T7 and then remains constant up to Ca13, decreasing from then on. This is the first study to take into account intraspecific shape and count variations, representing an improvement over the traditional typologic approach.
Full Text Available Acoustic communication is common in dolphins and encompasses a variety of sounds, either vocal or not. Among vocalizations, whistles are continuous narrow-band and frequency-modulated sounds, with a frequency range between 2-24 kHz. The aim of this study was to characterize the whistles of a resident group of bottlenose dolphins Tursiops truncatus in the coast of Aragua state (Venezuela and to determine their association with surface behavior. On average, whistle frequency ranged from 7 to 16 kHz. Six types of whistles, according to the contour of frequency modulation, were found: constant, ascending, descending, ascending-descending, descending-ascending and multiple. Only two behavioral states were observed: traveling and socialization. There was significant association between the type of whistle and behavior: whistles of medium complexity (ascending-descending were preferred during traveling and significantly avoided during socialization. Furthermore, whistles emitted during socialization were longer, of broader bandwidth, and spanning over lower frequencies than those emitted during traveling. The variation of whistles according to surface behavior confirms that they have a communicational value. Future research should focus on the causes and consequences of whistle emission to elucidate their referential function.
Loch, Carolina; Grando, Liliane J; Kieser, Jules A; Simões-Lopes, Paulo C
Pathological processes observed in the stomatognathic systems of mammalian species are a useful source of information about the habits, evolution and general health of such animals. Studies of pathological conditions on teeth are common in humans and other primates, but rare in wild animals in general and marine mammals in particular. For cetaceans, previous studies provided scanty records of dental anomalies in a few species. This is the first broad and systematic inventory of dental pathology in dolphins. Specimens stored at scientific collections from the southern coast of Brazil were visually inspected under a stereoscopic microscope using a dental explorer. Diagnosis of lesions and anomalies followed literature descriptions. Abnormalities such as caries-like lesions, mineralized calculus deposits, dental erosion, enamel anomalies (hypoplasia and exogenous pigmentation), root resorption, germination and other shape anomalies, were diagnosed in the delphinids Sotalia guianensis, Delphinus capensis, Stenella frontalis, Stenella coeruleoalba, Lagenodelphis hosei, Pseudorca crassidens, Orcinus orca, Steno bredanensis and Tursiops truncatus. Endogenous causes may be related to the occurrence of certain conditions, but the aetiology of caries-like lesions and calculus accumulation is still unknown for cetaceans. The diagnosis of alveolar anomalies and other bone lesions in specimens with dental pathology lead us to believe these lesions modify the integrity of the periodontal ligament and bony tissues, adding to the burden of morbidity of affected animals.
Buono, Mónica R; Fernández, Marta S; Fordyce, R Ewan; Reidenberg, Joy S
The nasal region of the skull has undergone dramatic changes during the course of cetacean evolution. In particular, mysticetes (baleen whales) conserve the nasal mammalian pattern associated with the secondary function of olfaction, and lack the sound-producing specializations present in odontocetes (toothed whales, dolphins and porpoises). To improve our understanding of the morphology of the nasal region of mysticetes, we investigate the nasal anatomy, osteology and myology of the southern right whale, Eubalaena australis, and make comparisons with other mysticetes. In E. australis external deflection surfaces around the blowholes appear to divert water off the head, and differ in appearance from those observed in balaenopterids, eschrichtiids and cetotherids. In E. australis the blowholes are placed above hypertrophied nasal soft tissues formed by fat and nasal muscles, a pattern also observed in balaenopterids (rorqual mysticetes) and a cetotherid (pygmy right whale, Caperea marginata). Blowhole movements are due to the action of five nasofacial muscles: dilator naris superficialis, dilator naris profundus, depressor alae nasi, constrictor naris, and retractor alae nasi. The dilator naris profundus found in E. australis has not been previously reported in balaenopterids. The other nasofacial muscles have a similar arrangement in balaenopterids, with minor differences. A novel structure, not reported previously in any mysticete, is the presence of a vascular tissue (rete mirabile) covering the lower nasal passage. This vascular tissue could play a role in warming inspired air, or may engorge to accommodate loss of respiratory space volume due to gas compression from increased pressure during diving. © 2014 Anatomical Society.
Frants H Jensen
Full Text Available Toothed whales (Cetacea, odontoceti use biosonar to navigate their environment and to find and catch prey. All studied toothed whale species have evolved highly directional, high-amplitude ultrasonic clicks suited for long-range echolocation of prey in open water. Little is known about the biosonar signals of toothed whale species inhabiting freshwater habitats such as endangered river dolphins. To address the evolutionary pressures shaping the echolocation signal parameters of non-marine toothed whales, we investigated the biosonar source parameters of Ganges river dolphins (Platanista gangetica gangetica and Irrawaddy dolphins (Orcaella brevirostris within the river systems of the Sundarban mangrove forest. Both Ganges and Irrawaddy dolphins produced echolocation clicks with a high repetition rate and low source level compared to marine species. Irrawaddy dolphins, inhabiting coastal and riverine habitats, produced a mean source level of 195 dB (max 203 dB re 1 µPapp whereas Ganges river dolphins, living exclusively upriver, produced a mean source level of 184 dB (max 191 re 1 µPapp. These source levels are 1-2 orders of magnitude lower than those of similar sized marine delphinids and may reflect an adaptation to a shallow, acoustically complex freshwater habitat with high reverberation and acoustic clutter. The centroid frequency of Ganges river dolphin clicks are an octave lower than predicted from scaling, but with an estimated beamwidth comparable to that of porpoises. The unique bony maxillary crests found in the Platanista forehead may help achieve a higher directionality than expected using clicks nearly an octave lower than similar sized odontocetes.
Rodrigo H. O. Tardin
Full Text Available Parental care is any form of parental behavior that increases offspring fitness. To the authors' knowledge, this study is the first to analyze the intensity of parental care in the Guiana dolphin, Sotalia guianensis (van Bénéden, 1864. The objectives of this study are as follows: 1 to quantify the degree of parental care in S. guianensis in Ilha Grande Bay, Rio de Janeiro; 2 to investigate the influence of behavioral state and group size on the degree of parental care; and 3 to evaluate the differences between the intensity of parental care provided to calves and juveniles. Our results indicate that the intensity of parental care is high in S. guianensis and that care is more intense in larger groups. It is possible that these differences serve to maximize hydrodynamic gains and to minimize risks. Our results suggest that parental care is more intense during travel. A possible reason for this greater intensity is that the feeding dynamics show a more random pattern than other behavioral states. Moreover, the results indicate that calves receive more intense care than juveniles. These results suggest that parent-offspring conflict is possible in the study population.
Ana Paula M. Di Beneditto
Full Text Available Pontoporia blainvillei (Gervais & D' Orbigny, 1844 and Sotalia fluviatilis (Gervais, 1853 have typically coastal habits and are sympatric in South-eastern Brazil. The purpose of this work was to record sightings and describe aspects concerning the behaviour of both species in this region, between 1993 and 1998. The sightings were accomplished by cruises and from a fixed point. Information provided by fishermen were also considered. In general, P. blainvillei was observed in all seasons of the year, up to five nautical miles away from the coast, up to 15 m deep and the groups comprised up to five specimens. The most part of the groups of S. fluviatilis, were observed in autumm and winter times and comprised up to 10 specimens. In about half of the sightings, the presence of calves and/or juveniles was noted. The cooperative (group fishing was the foranging behaviour most frequently noted for S. fluviatilis.Pontoporia blainvillei (Gervais & D’Orgigny, 1844 e Sotalia fluviatilis (Gervais, 1853 possuem hábitos tipicamente costeiros e são simpátricas no Sudeste do Brasil. O objetivo deste trabalho foi registrar avistagens e descrever aspectos relacionados ao comportamento de ambas as espécies na região, entre 1993 e 1998. As avistagens foram realizadas através de cruzeiros e ponto fixo. Informações fornecidas por pescadores também foram consideradas. Em geral, P. blainvillei foi observada em todas as estações do ano, a até cinco milhas náuticas de distância da linha da costa e 15 m de profundidade e, os grupos eram formados por até cinco espécimens. A maior parte dos grupos de S. fluviatilis foi observada no período de outono e inverno e, era formada por até 10 espécimens. Em metade das avistagens, a presença de filhotes e/ou juvenis foi verificada. A pesca cooperativa (em grupo foi o comportamento alimentar observado com maior freqüência para S. fluviatilis.
Full Text Available This work analyses, from an ethnoecological perspective, traditional knowledge about the ecology of the dolphin species of Babitonga bay, Pontoporia blainvillei and Sotalia guianensis, and their incidentalkilling by the local artisanal fishery. Set gillnetting is the most dangerous practice to dolphins. On the other hand, the traditional interaction between man and animal is fundamentally conservationist. Fishermen know about dolphin food chain relations, fishing and feeding strategies, pod size, uses of habitat, and behavior of dolphins. This knowledge can support future research and conservation measures for local dolphin species, considering that P. blainville is threatened of extinction and, with S. guianensis, not enough known.
May-Collado, Laura; Ramírez, Alvaro Morales
Dolphins are characterized by a significant behavioral versatility, which allows them to respond to environmental seasonality. Seasonal variation in dolphin behavior in tropical waters is not well known. Stenella attenuata graffmani is a resident dolphin in the clearly defined seasonal Gulf of Papagayo, Costa Rica, and we studied if dolphin group size, occurrence and behavioral patterns were associated with season and time of day in the gulf. Using strip transects we surveyed two locations for three consecutive years. School size ranged from 1 to 50 individuals, mean group size was 10.16 (SD = 9.61) individuals. Overall, foraging activities were the most frequent, followed by social interactions and travel. From 6:00 AM to 9:00 AM we mostly observed social interactions, followed by feeding-socializing (9:00 AM-12:00 PM) and feeding exclusively (12:00 PM-3:00 PM). Social activities intensified afterwards (3:00 PM-6:00 PM). Behavior and gulf seasonality were associated (chi2 = 90.52, gl = 6, psocializing was more frequent in the early rainy season (May-July). Larger groups (mean 12 dolphins) forage actively; smaller groups (mean 6 dolphins 6.51 +/- 5.12) foraged more passively. Seasonal variation in dolphin activities are likely to be associated with food availability, as observed in the high number of groups involved in foraging behaviors, and a high investment in foraging activities during the dry season.
Berta, Annalisa; Ekdale, Eric G; Zellmer, Nicholas T; Deméré, Thomas A; Kienle, Sarah S; Smallcomb, Meghan
Information is scarce on gray whale (Eschrichtius robustus) anatomy and that of mysticetes in general. Dissection of the head of a neonatal gray whale revealed novel anatomical details of the eye, blowhole, incisive papilla with associated nasopalatine ducts, sensory hairs, and throat grooves. Compared to a similar sized right whale calf, the gray whale eyeball is nearly twice as long. The nasal cartilages of the gray whale, located between the blowholes, differ from the bowhead in having accessory cartilages. A small, fleshy incisive papilla bordered by two blind nasopalatine pits near the palate's rostral tip, previously undescribed in gray whales, may be associated with the vomeronasal organ, although histological evidence is needed for definitive identification. Less well known among mysticetes are the numerous elongated, stiff sensory hairs (vibrissae) observed on the gray whale rostrum from the ventral tip to the blowhole and on the mandible. These hairs are concentrated on the chin, and those on the lower jaw are arranged in a V-shaped pattern. We confirm the presence of two primary, anteriorly converging throat grooves, confined to the throat region similar to those of ziphiid and physeteroid odontocetes. A third, shorter groove occurs lateral to the left primary groove. The throat grooves in the gray whale have been implicated in gular expansion during suction feeding. © 2015 Wiley Periodicals, Inc.
Full Text Available http://dx.doi.org/10.5007/2175-7925.2011v24n2p109 Baleias-francas (Eubalaena australis sofrem diferentes pressões antrópicas como poluição, tráfego de embarcações e emalhe em redes de pesca. Casos de enredamentos em baleias-francas são crescentes no litoral sul de Santa Catarina, podendo levar a encalhes e morte. Durante a temporada reprodutiva de 2010, foram registrados seis casos de emalhes em indivíduos juvenis e adultos. É necessária a criação de medidas de regulamentação da pesca durante a temporada reprodutiva de baleias-francas em Santa Catarina, considerando as peculiaridades da pesca na região com o objetivo de minimizar as injúrias causadas às baleias e evitar prejuízos às comunidades pesqueiras locais.
Purves, P.E.; Bree, van P.J.H.
Cadenat (1959) and Rancurel (1964) produced strong indirect evidence that off the west coast of Africa, the Bottle-nosed Dolphin, Tursiops truncatus, is in the habit of diving very deeply, possibly down to 600 m. Examination of the skulls of fully adult specimens of Tursiops taken off Dakar and St.
Meij, van der S.E.T.; Camphuysen, C.J.
Between 1970 and 2005 sightings data of cetaceans in the southern North Sea were collected as part of the Marine Mammal Database of the Dutch Seabird Group. The data include incidental sightings and reports as well as results from systematic surveys and seawatching data. They are therefore difficult
The aspects of the “connecting sac” are studied in Lagenorhynchus albirostris, Lagenorhynchus obliquidens, Lagenorhynchus acutus, Tursiops truncatus, Delphinus delphis, Phocoena phocoena, Sotalia guianensis, Stenella coeruleoalba and Stenella frontalis. Comparing the development of the connecting
Loch, Carolina; Swain, Michael V; Fraser, Sara J; Gordon, Keith C; Kieser, Jules A; Fordyce, R Ewan
Dolphins show increased tooth number and simplified tooth shape compared to most mammals, together with a simpler ultrastructural organization and less demanding biomechanical function. However, it is unknown if these factors are also reflected in the chemical composition of their teeth. Here, the bulk chemical composition and elemental distribution in enamel and dentine of extant dolphins were characterized and interpreted using X-ray and spectroscopy techniques. Teeth of 10 species of Delphinida were analyzed by WDX, EDX and Raman spectroscopy. For most of the species sampled, the mineral content was higher in enamel than in dentine, increasing from inner towards outer enamel. The transition from dentine to enamel was marked by an increase in concentration of the major components Ca and P, but also in Na and Cl. Mg decreased from dentine to enamel. Concentrations of Sr and F were often low and below detection limits, but F peaked at the outer enamel region for some species. Raman spectroscopy analyzes showed characteristics similar to carbonated hydroxyapatite, with the strongest peak for the phosphate PO4(3-) stretching mode at 960-961cm(-1). Dentine samples revealed a higher diversity of peaks representative of organic components and proteins than enamel. The similar distribution pattern and small variation in average concentration of major and minor elements in dentine and enamel of dolphins suggest that they are subject to strong physiological control. A clear trend of the elemental variations for all dolphin species sampled suggests that the general pattern of tooth chemistry is conserved among the Mammalia. Copyright © 2013 Elsevier Inc. All rights reserved.
Pedro F Fruet
Full Text Available A new mark-recapture abundance estimate and a photographic census were carried out to investigate the possible decline in the abundance of the bottlenose dolphins, Tursiops truncatus (Montagu, 1821, in the Patos Lagoon estuary due to the high levels of bycatch mortality which occurred between 2002 and 2006 in oceanic coastal areas close to the estuary. Fourteen systematic boat surveys were conducted between August and early December 2005 to photo-identify the bottlenose dolphins. The estimated number of animals, with long-lasting marks, in the population obtained from Chapman's and Mth models were 51 (95% CI = 49-53 and 52 (95% CI = 51-60, respectively. Taking into account the proportion of dolphins with long-lasting marks in the population, the total estimated population size ranged between 84 (95% CI = 76-93 and 86 (95% CI = 78-95 individuals, respectively, which was very similar to the 84 individuals revealed by the population census. Our results did not differ from the abundance estimate carried out in 1998, prior to the high fishing-related mortality event, suggesting that the population is stable. Plausible argument to explain the stability of the population is that some carcasses found on the oceanic coastal beaches near Patos Lagoon estuary come from animals that do not belong to the estuary community. Future studies should investigate fine-scale habitat partition between estuarine and adjacent coastal dolphins. If the existence of different communities living in close proximity (estuarine and coastal areas near to the estuary is confirmed, a new abundance estimate is needed to access the conservation status of bottlenose dolphins in this region.
Paulo César Simões-Lopes
Full Text Available The resident population of estuarine dolphins (Sotalia guianensis in the North Bay, Santa Catarina Island, southern Brazil, was studied from September 2001 until July 2003 through periodical boat surveys. Using focal-group and sequential sampling, information such as geographical position and behavioral patterns were registered at 5-minute intervals. All the information collected was insert in a GIS database of the study area. Since patterns of seasonal variation concerning home range and behavior had been established in previous work, we aimed at evaluating the existence of seasonal intensity of movements, therefore strengthening the proposed hypothesis of higher spatial requirements when food resources are low. The daily mean speed of the dolphin’s group was used as an index of the intensity of movements, and its seasonal variation throughout the study period was analyzed. We found a statistically significant seasonal variation in the intensity of movement. The dolphins tended to move more in the cold seasons, in contrast with the hot seasons when the dolphins tended to move less. Thus, previous studies are corroborated, supporting the hypothesis og higher spatial requirements when there are fewer food resources.
Vanessa T. Bittar
Full Text Available This study describes the diet and assesses potential overlap in the feeding habits of Trichiurus lepturus Linnaeus, 1758 and Pontoporia blainvilleiGervais & D'Orbigny, 1844 in northern Rio de Janeiro, southeastern Brazil. Fishes were numerically dominant in both diets, followed by cephalopods for P. blainvillei and crustaceans for T. lepturus. Both predators move along similar coastal feeding areas in northern Rio de Janeiro, but our results indicate differences in their resource exploitation, what allows for their coexistence.
Marta Jussara Cremer
Full Text Available The occupation pattern of Sotalia guianensis in São Francisco do Sul harbor inlet, in Babitonga bay, southern Brazil, was studied between September 1996 and June 1998. A total of 200 h of naturalistic observations and 141.2 h of estuarine dolphin systematic observations were made using binoculars 7 x 50. At each three minutes interval, data about number of individuals and behavior were registered. The population used the harbor inlet intensively, mainly for fishing activities. Ebb tide was responsible for a higher occupation index. Considering the months analyzed, the higher occupation index occurred in May, and in January the lower occurrence was observed. The mean group size was four individuals.Os padrões de ocupação da enseada do porto de cargas de São Francisco do Sul, no interior da Baía da Babitonga, sul do Brasil, pela população de botos cinza Sotalia guianensis foi estudada entre setembro/1996 e junho/1998. Totalizou-se 200 horas de observações naturalísticas e 141.2 horas de observação sistemática na área, utilizando-se binoculares 7 x 50. Foram registrados a cada intervalo de 3 minutos dados sobre o número de indivíduos presentes e comportamento. A população utilizou intensamente a enseada do porto, principalmente para atividades de pesca. A maré enchente foi responsável por maiores taxas de ocupação. Dentre os meses analisados, maio foi o mês com maior média nas taxas de ocupação, e janeiro o mês de menor ocorrência. O tamanho de grupo médio na área foi de quatro indivíduos.
Costa Martha Eloy
Full Text Available Abstract Artisanal fishermen, because of their direct and frequent contact with the aquatic environment, possess a wealth of knowledge about the natural history of the fauna of the region in which they live. This knowledge, both practical and theoretical, has been frequently utilized and integrated into academic research. Taking this into consideration, this study discusses the ethnoecological knowledge of artisanal fishermen from a community in Canavieiras, state of Bahia, Brazil regarding the Guiana dolphin (Sotalia guianensis, a typically costal member of the family Delphinidae that is little studied in this region. To this end, the behaviour of S. guianensis in Canavieiras was recorded over one year and the data obtained were compared with fishermen’s reports. A total of 609 hours of behavioural observations of S. guianensis was conducted from a fixed point in alternate morning and afternoon sessions between October 2009 and September 2010. Observations were conducted from a pier (15°40’59”S and 38°56’38”W situated on the banks of the Pardo River estuary - the region’s main river - at 5.5 m above water level. For ethnoecological data collection, semi-structured interviews were carried out with 26 fishermen in May, June and September 2010 and January 2011 in the fishing community of Atalaia. Occasional boat expeditions were made with the fishermen to compare their reports with direct observations of the behaviour of S. guianensis. The results demonstrate that fishermen possess a body of knowledge about S. guianensis that describes in detail the main behavioural aspects of the species. They reported the presence of S. guianensis in the Pardo River estuary throughout the year and its gregarious behaviour. They cited a relationship between the movement of dolphins and tidal cycles, and their presence in the estuary associated with the search for food. In addition, the fishermen reported that numbers of infants in groups were proportional to group size. Behaviours described were compatible with the observations made in situ and with data found in the scientific literature, confirming the importance of traditional knowledge in complementing scientific data. One behaviour mentioned by the fishermen that had no equivalence in the scientific literature was confirmed in situ and, therefore, constitutes the first record for this species.
Karina Rodríguez Sáenz
Full Text Available Paralelo a un estudio de zooplancton (1999-2000, se hicieron observaciones a bordo de un bote inflable, sobre la presencia o ausencia de delfines a lo largo de un transecto (~8 km long en la parte central de Bahía Culebra (24 km² , Golfo de Papagayo. Se realizaron 34 muestreos en total y hubo avistamientos de delfines en 20 de ellos. La única especie de cetáceo observado en la Bahía fue el delfín manchado (Stenella attenuata. Estos avistamientos fueron más frecuentes durante la época lluviosa, en particular durante el mes de mayo de ambos años. La presencia de S. attenuata en Bahía Culebra podría estar asociada a la abundancia de presas potenciales como peces y moluscos (calamares, como se evidencia por las estadísticas pesqueras disponibles para la zona Pacífica de Costa RicaParallel to a zooplankton study (1999-2000 observations were made (from an inflatable boat, on the presence of dolphins along a transect (~8 km long on the axis of Culebra Bay (24 km² , Gulf of Papagayo, Pacific coast of Costa Rica. Dolphins were found during 20 of the 31 boat surveys conducted. The only species of cetacean found in the bay was Stenella attenuata, the spotted dolphin. These sightings were more frequent during the rainy season, particularly during the month of May of both years. The presence of S. attenuata in Culebra Bay might be associated to the abundances of fish and mollusks (their presumed prey: for example, squids, as evidenced by fishery statistics available for this zone of the Pacific coast of Costa Rica
[Distribution and environmental conditions related to the behavior in the bottlenose dolphin (Tursiops truncatus) and the spotted dolphin (Stenella attenuata) (Cetacea: Delphinidae) in Golfo Dulce, Costa Rica].
Habitat characteristics influencing behavior in animal species vary locally. The influence that a particular environmental characteristic can have on a species depends not only on other variables, but on morphological, physiological and social conditions of that species. In this study, developed from June 1996 to July 1997, I studied whether specific behaviors are related to particular distribution areas and environmental factors in the bottlenose (Tursiops truncatus) and the spotted dolphin (Stenella attenuata). The study area was covered along oblicuous linear transects, and the behavior of single groups was observed from 15 min to 5 h. Environmental factors such as depth, temperature, salinity and distance from shore, among others, were considered. For the bottlenose dolphin, foraging/feeding activities showed exclusive coincidence with river mouths, coral reef and mangrove areas, while social and milling activities where seen close to feeding areas. Traveling occurred along different points parallel to the coast, with a low percentage of cases across the gulf (16.56 %), suggesting that the bottlenose rarely crosses from one side to the other. In the spotted dolphin, several behaviors were observed simultaneously in the schools and it was not possible to associate areas with particular behaviors. The lack of significant relationships among activities and particular environmental variables (ANOVA tests) is attributed to three aspects: (a) transitions among activities generally occurred into a low variable area, (b) dolphins often traveled along large areas without changing activities and (c) environmental conditions in Golfo Dulce are homogeneous. In the two species the highest average in the number of individuals per group corresponded to the category of active socializing, followed by traveling, passive socializing and feeding. In the case of the bottlenose dolphin, the smallest group size was associated with feeding activities (ANOVA, F= 2.624, p=0.037, n=156, df=4), while in the spotted dolphin the smallest group size corresponded to milling activities (ANOVA, F=3.817, p=0.009, n=51, df=4).
Bosselaers, Mark; Collareta, Alberto
An isolated compartment of a whale barnacle is herein described from Recent beach deposits in Zoutelande (Walcheren, The Netherlands). This specimen is identified as belonging to the extant coronulid species Cryptolepas rhachianecti, currently known as an epizoic symbiont of the grey whale Eschrichtius robustus. This find represents the first occurrence of C. rhachianecti outside the North Pacific, and the first one as a (sub)fossil. In view of the fact that E. robustus, which is currently confined to the North Pacific, is known as a subfossil from the northeastern Atlantic between late Late Pleistocene (c. 45,000 years ago) and historical (c. 1700 AD) times, we propose a similar (late Quaternary) age for the isolated compartment. The find indicates that the extinct late Quaternary northeastern Atlantic population of E. robustus was infected by Cryptolepas rhachianecti. Our find is, therefore, compatible with the hypothesis of an ancient grey whale migration route running between the subtropical/temperate waters of the northeast Atlantic (or Mediterranean Basin), and the cold waters of the Baltic Sea (or southern Arctic Ocean), through the southern North Sea. Finally, we discuss the systematic placement of the fossil barnacle species Cryptolepas murata and propose the possibility of its removal from the genus Cryptolepas pending further investigations.
Ekdale, Eric G; Deméré, Thomas A; Berta, Annalisa
The origin of baleen in mysticetes heralded a major transition during cetacean evolution. Extant mysticetes are edentulous in adulthood, but rudimentary teeth develop in utero within open maxillary and mandibular alveolar grooves. The teeth are resorbed prenatally and the alveolar grooves close as baleen germ develops. Arteries supplying blood to highly vascularized epithelial tissue from which baleen develops pass through lateral nutrient foramina in the area of the embryonic alveolar grooves and rudimentary teeth. Those vessels are hypothesized to be branches of the superior alveolar artery, but branches of the greater palatine arteries may play a role in the baleen vascularization. Through a combination of latex injection, CT, and traditional dissection of the palate of a neonatal gray whale (Eschrichtius robustus), we confirm that the baleen receives blood from vessels within the superior alveolar canal via the lateral foramina. The greater palatine artery is restricted to its own passage with no connections to the baleen. This study has implications for the presence of baleen in extinct taxa by identifying the vessels and bony canals that supply blood to the epithelium from which baleen develops. The results indicate that the lateral foramina in edentulous mysticete fossils are bony correlates for the presence of baleen, and the results can be used to help identify bony canals and foramina that have been used to reconstruct baleen in extinct mysticetes that retained teeth in adulthood. Further comparisons are made with mammals that also possess oral keratin structures, including ruminants, ornithorhynchid monotremes, and sirenians. © 2015 Wiley Periodicals, Inc.
Ekdale, Eric G; Kienle, Sarah S
Retia mirabilia play broad roles in cetacean physiology, including thermoregulation during feeding and pressure regulations during diving. Vascular bundles of lingual retia are described within the base of the tongue of a neonatal female gray whale (Eschrichtius robustus). Each rete consists of a central artery surrounded by four to six smaller veins. The retia and constituent vessels decrease in diameter as they extend anteriorly within the hyoglossus muscle from a position anterior to the basihyal cartilage toward the apex of the tongue. The position of the retia embedded in the hyoglossus and the anterior constriction of the vessels differs from reports of similar vascular bundles that were previously identified in gray whales. The retia likely serve as a counter-current heat exchange system to control body temperature during feeding. Cold blood flowing toward the body center within the periarterial veins would accept heat from warm blood in the central artery flowing toward the anterior end of the tongue. Although thermoregulatory systems have been identified within the mouths of a few mysticete species, the distribution of such vascular structures likely is more widespread among baleen whales than has previously been described. © 2015 Wiley Periodicals, Inc.
Fordyce, R. Ewan
The Eocene history of cetacean evolution is now represented by the expansive fossil record of archaeocetes elucidating major morphofunctional shifts relating to the land to sea transition, but the change from archaeocetes to modern cetaceans is poorly established. New fossil material of the recently recognized family Eomysticetidae from the upper Oligocene Otekaike Limestone includes a new genus and species, Waharoa ruwhenua, represented by skulls and partial skeletons of an adult, juvenile, and a smaller juvenile. Ontogenetic status is confirmed by osteohistology of ribs. Waharoa ruwhenua is characterized by an elongate and narrow rostrum which retains vestigial alveoli and alveolar grooves. Palatal foramina and sulci are present only on the posterior half of the palate. The nasals are elongate, and the bony nares are positioned far anteriorly. Enormous temporal fossae are present adjacent to an elongate and narrow intertemporal region with a sharp sagittal crest. The earbones are characterized by retaining inner and outer posterior pedicles, lacking fused posterior processes, and retaining a separate accessory ossicle. Phylogenetic analysis supports inclusion of Waharoa ruwhenua within a monophyletic Eomysticetidae as the earliest diverging clade of toothless mysticetes. This eomysticetid clade also included Eomysticetus whitmorei, Micromysticetus rothauseni, Tohoraata raekohao, Tokarahia kauaeroa, Tokarahia lophocephalus, and Yamatocetus canaliculatus. Detailed study of ontogenetic change demonstrates postnatal elaboration of the sagittal and nuchal crests, elongation of the intertemporal region, inflation of the zygomatic processes, and an extreme proportional increase in rostral length. Tympanic bullae are nearly full sized during early postnatal ontogeny indicating precocial development of auditory structures, but do increase slightly in size. Positive allometry of the rostrum suggests an ontogenetic change in feeding ecology, from neonatal suckling to a more specialized adult feeding behaviour. Possible absence of baleen anteriorly, a delicate temporomandibular joint with probable synovial capsule, non-laterally deflected coronoid process, and anteroposteriorly expanded palate suggests skim feeding as likely mode of adult feeding for zooplankton. Isotopic data in concert with preservation of young juveniles suggests the continental shelf of Zealandia was an important calving ground for latitudinally migrating Oligocene baleen whales. PMID:26380800
Hazevoet, Cornelis J.; Wenzel, Frederick W.
Observations of whales and dolphins in the Cape Verde Islands obtained in 1995 and 1996 are reported and data on the occurrence of 14 taxa are given, including four not previously reported from the region, viz. Bryde’s Whale Balaenoptera edeni, Killer Whale Orcinus orca, Rough-toothed Dolphin Steno
Gladilina E. V.
Full Text Available The first assessment of abundance of a local population of bottlenose dolphins in the Black Sea (near the Sudak coast in 2011–2012 has been conducted: the results of a mark-recapture study of photo identified animals were complemented by a vessel line transect survey. The overall abundance of a population was estimated at between 621 ± 198 and 715 ± 267 animals (Chapman and Petersen estimates, and the majority of members of the population were recorded in the surveyed area. The summer range covered the area of a few hundred square kilometers, similar to migrating coastal stocks in other world regions. The greatest density of distribution was observed in August in sea 45–60 m deep; in addition, frequent approaches to the coastline are usual for dolphins of this stock. These trends in distribution may be partly explained by distribution of prey. Interaction with sprat trawling fisheries can be a factor shaping the local population structure. Coastal waters of Sudak and adjoining sea areas are an important habitat for bottlenose dolphins in the northern Black Sea, significant for their conservation.
Full Text Available Bite marks suggest that the late Eocence archaeocete whale Basilosaurus isis (Birket Qarun Formation, Egypt fed upon juveniles of the contemporary basilosaurid Dorudon atrox. Finite element analysis (FEA of a nearly complete adult cranium of B. isis enables estimates of its bite force and tests the animal's capabilities for crushing bone. Two loadcases reflect different biting scenarios: 1 an intitial closing phase, with all adductors active and a full condylar reaction force; and 2 a shearing phase, with the posterior temporalis active and minimized condylar force. The latter is considered probable when the jaws were nearly closed because the preserved jaws do not articulate as the molariform teeth come into occulusion. Reaction forces with all muscles active indicate that B. isis maintained relatively greater bite force anteriorly than seen in large crocodilians, and exerted a maximum bite force of at least 16,400 N at its upper P3. Under the shearing scenario with minimized condylar forces, tooth reaction forces could exceed 20,000 N despite lower magnitudes of muscle force. These bite forces at the teeth are consistent with bone indentations on Dorudon crania, reatract-and-shear hypotheses of Basilosaurus bite function, and seizure of prey by anterior teeth as proposed for other archaeocetes. The whale's bite forces match those estimated for pliosaurus when skull lengths are equalized, suggesting similar tradeoffs of bite function and hydrodynamics. Reaction forces in B. isis were lower than maxima estimated for large crocodylians and carnivorous dinosaurs. However, comparison of force estimates from FEA and regression data indicate that B. isis exerted the largest bite forces yet estimated for any mammal, and greater force than expected from its skull width. Cephalic feeding biomechanics of Basilosaurus isis are thus consistent with habitual predation.
The occurrence of Pontoporia blainvillei (Gervais & d'Orbigny (Cetacea, Pontoporiidae in an estuarine area in southern Brazil Ocorrência de Pontoporia blainvillei (Gervais & d'Orbigny (Cetacea, Pontoporiidae em uma região estuarina no sul do Brasil
Marta J. Cremer
Full Text Available The toninha, or franciscana, Pontoporia blainvillei (Gervais & D'Orbigny, 1844, is an endemic species of cetacean of the southwestern Atlantic Ocean. There is little information on the occurrence of this species in its natural environment due to the great difficulty in sighting it. Systematized and non-systematized observations of franciscanas were made from December 1996 through November 2001 at Babitonga Bay, on the northern coast of Santa Catarina State, southern Brazil. The observations were made from small motorboats. A total of 79 observations were made, totaling 561 individuals. Up to 59.5% of the groups consisted of over four individuals and the average group size was seven. Calves were present in 30.4% of the observations. The species was found throughout the year within the bay and preferential areas were identified. Calves were registered during all seasons. Data are presented on the behavior (feeding, traveling, aerial behavior and behavior relating to the boats and on inter-specific interactions with terns, cormorants [Phalacrocorax brasilianus (Gmelin, 1789] and brown boobies [Sula leucogaster (Boddaert, 1783]. The species is sympatric with the estuarine dolphin Sotalia guianensis (P. J. Van Bénéden, 1864 in the bay, but there was no record of interaction between them. The area of the bay represents an important refuge for the franciscana species.A toninha, ou franciscana, Pontoporia blainvillei (Gervais & D'Orbigny, 1844, é uma espécie endêmica de cetáceos que ocorre no Oceano Atlântico sul ocidental. Existem poucas informações sobre a ocorrência da espécie em seu ambiente natural em função da grande dificuldade em avistá-la. Observações sistematizadas e não-sistematizadas de franciscanas foram realizadas no período entre dezembro de 1996 e novembro de 2001 na Baía da Babitonga, no litoral norte do estado de Santa Catarina, sul do Brasil. As observações foram realizadas a partir de pequenas embarcações a motor. Um total de 79 observações foram efetuadas, totalizando 561 indivíduos. Acima de 59.5% dos grupos eram compostos por mais de quatro indivíduos e a média de tamanho de grupo foi de sete. Filhotes estiveram presentes em 30.4% das observações. A espécie foi encontrada na baía ao longo de todo o ano e foram identificadas áreas de uso preferencial. Filhotes foram registrados em todas as estações. São apresentadas informações sobre o comportamento (alimentação, deslocamento, comportamentos aéreos e relativos a embarcações assim como sobre interações interespecíficas com trinta-réis, biguás [Phalacrocorax brasilianus (Gmelin, 1789] e atobás marrons [Sula leucogaster (Boddaert, 1783]. A espécie é simpátrica do golfinho estuarino Sotalia guianensis (P. J. Van Bénéden, 1864 na baía, mas não foram efetuados registros de interação entre ambas as espécies. A área da baía representa um importante refúgio para a franciscana.
Distribution, abundance and density estimates of franciscanas, Pontoporia blainvillei (Cetacea: Pontoporiidae, in Babitonga bay, southern Brazil Distribuição e estimativas de abundância e densidade de franciscanas, Pontoporia blainvillei (Cetacea: Pontoporiidae, na baía da Babitonga, sul do Brasil
Marta J. Cremer
Full Text Available Pontoporia blainvillei (Gervais & d'Orbigny, 1844 is threatened throughout its distribution. The species can be found year-round in the Babitonga bay estuary (26º 02'-26º 28'S and 48º28'-48º50'W, in the north coast of the state of Santa Catarina, Brazil. Boat surveys were conducted in order to evaluate its abundance and density between 2000 and 2003. Sampling was random and stratified, with 46 transects in five sub-areas, comprising a total area of 160 km². Data collection was conducted following the linear transect method with distance sampling. A total of 1174.7 km was scanned and 38 groups were observed. Franciscanas were not uniformly distributed in Babitonga bay. Group size ranged from one to 13 animals (mean ± SD = 5.02 ± 3.62. Model 1 (Half-Normal showed the best fit to the data. The estimated population size was 50 animals and the density was 0.32 individuals km-2. Density estimates evaluated in the sub-areas where franciscanas occurred resulted in a density of 0.46 individuals km-2. Monitoring this population is of considerable importance due to the constant threats that this species faces in this bay.Pontoporia blainvillei (Gervais & d'Orbigny, 1844 ocorre ao longo de todo o ano no estuário da baía da Babitonga, no litoral norte de Santa Catarina, sul do Brasil. Foram realizadas amostragens com o objetivo de obter informações sobre sua abundância e densidade populacional nesta área entre os anos de 2000 e 2003. A amostragem foi aleatória e estratificada, com 46 transecções estabelecidas em cinco grandes sub-áreas, compreendendo 160 km². A coleta de dados foi conduzida utilizando o método de transecções lineares com amostragem de distância. Foram percorridos 1174,7 km e 38 grupos foram registrados. As franciscanas não apresentaram uma distribuição uniforme na baía da Babitonga. O tamanho de grupo variou de um a 13 animais (5,02 ± 3,62. O Modelo 1 (Meio-Normal promoveu o melhor ajustamento dos parâmetros. A população foi estimada em 50 animais e a densidade foi de 0,32 indivíduos km-2. A estimação de densidade calculadas apenas para as sub-áreas de ocorrência (áreas 2, 3 e 5; total de 101 km2 resultou em uma densidade de 0,46 indivíduos km-2. O monitoramento desta população é de grande importância devido às constantes ameaças que a espécie está sujeita na baía.
Anomalias ósseas congênitas em Sotalia guianensis (Mammalia, Cetacea, Delphinidae da costa centro-norte do Estado do Rio de Janeiro Congenital bone defects in Guiana dolphin, Sotalia guianensis (Mammalia, Cetacea, Delphinidae in the northcentral coast of Rio de Janeiro State, Brazil
Full Text Available Carcaças de botos-cinza Sotalia guianensis (van Bénéden, 1864 foram recuperadas entre 20 de agosto de 2001 e 13 de fevereiro de 2006, na costa centro-norte fluminense. A maior parte delas (85% entre Barra de São João (22º35'S 41º59'W e Quissamã (22º06'S 41º28'W. Foram estudadas as colunas vertebrais dos 20 exemplares que apresentavam mais de 60% das vértebras presentes. A coleção é formada por 75% de animais imaturos, e todos os esqueletos mostram alterações tafonômicas mínimas. Duas categorias de anomalias congênitas foram diagnosticadas, ambas relacionadas ao desenvolvimento do mesoderma paraxial. A sétima vértebra cervical (C7 foi a única afetada, as costelas cervicais e o não fechamento do arco neural atingiram 15 (75% dos indivíduos analisados, dos quais três (15% apresentam ambas as anomalias. Nove (45% indivíduos apresentaram costelas cervicais uni ou bilateral, e nove (45% indivíduos apresentaram não fechamento do arco neural; em todos os casos as vértebras contíguas eram normais. A ocorrência de anomalias nesta série do Rio de Janeiro é maior do que as referidas na literatura brasileira para outras séries de Sotalia do Amazonas, Ceará e Santa Catarina. A série de Sotalia descrita vem de uma região do litoral muito limitada e provavelmente representa uma população local. As costelas cervicais são geneticamente determinadas e podem estar concentradas por uma condição de grande proximidade biológica entre os animais; o não fechamento do arco pode ter também um componente ambiental, a ser investigado futuramente.Carcasses of Guiana dolphins, Sotalia guianensis (van Bénéden, 1864 were recovered from August 20, 2001 to February 13, 2006 along the north-central coast of Rio de Janeiro state. Most of the animals (85% were found between Barra de São João (22º35'S 41º59'W and Quissamã (22º06'S 41º28'W. We studied the vertebral columns of all the 20 specimens that had more than 60% of the vertebrae preserved. The series has 75% of immature animals and all skeletons displayed a minimum of taphonomic changes. Two categories of congenital anomalies were diagnosed, both related to the development of the paraxial mesoderm. The seventh cervical vertebra (C7 was the only affected; the cervical ribs and the cleft neural arches were present in 15 (75% of the individuals, three (15% of which had both anomalies. Nine (45% individuals had unilateral or bilateral cervical ribs, and nine (45% individuals had cleft neural arches; the contiguous vertebrae were normal in every case. The frequency of these anomalies was higher in that Rio de Janeiro series than in other Sotalia series previously reported in the Brazilian literature for Amazonas, Ceará and Santa Catarina States. The present Sotalia series here described comes from a very limited coastal region probably representing a local population. The cervical ribs are genetically defined and may be concentrated because of a condition of close biological proximity among the animals; the cleft arch could also be determined by environmental factors, to be investigated in the future.
Full Text Available NC_004310 gi|23502485 >1bxwA 4 170 45 261 5e-15 ... gb|AAN30527.1| outer membrane protein Omp3...1 [Brucella suis 1330] gb|AAS84575.1| ... Omp31b [Brucella cetaceae] gb|AAS84574.1| Omp31b ... ... ... [Brucella cetaceae] gb|AAS84573.1| Omp31b [Brucella ... cetaceae] gb|AAS84572.1| Omp31b [Br...ucella pinnipediae] ... gb|AAS84571.1| Omp31b [Brucella melitensis biovar ... ... Neotomae] ref|NP_698612.1| outer membrane protein Omp31 ... [Brucella suis 1330] ...
A review is presented of various parasitic helminths found in marine animals, particularly Cetacea and Pinnipedia. The parasites are discussed in terms of their taxonomy, life cycle, geographic distribution, and ecology.
Briscoe, A.G.; Bray, R. A.; Brabec, Jan; Littlewood, D. T. J.
Roč. 65, č. 3 (2016), s. 271-275 ISSN 1383-5769 Institutional support: RVO:60077344 Keywords : Digenea * Balaenoptera acutorostrata * Cetacea * Hologenophore * NGS Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.744, year: 2016
Comportamento do boto-cinza, Sotalia guianensis (Van Bénédén (Cetacea, Delphinidae na presença de barcos de turismo na Praia de Pipa, Rio Grande do Norte, Brasil Behavior of estuarine dolphin, Sotalia guianensis (Van Bénédén (Cetacea, Delphinidae in the presence of tourist boats in Pipa Beach, Rio Grande do Norte, Brazil
Full Text Available A crescente indústria do turismo tem se estendido ao ambiente aquático, deste modo tornando os mamíferos aquáticos suscetíveis a interações com humanos. O turismo de observação de golfinhos na praia de Pipa litoral sul do Rio Grande do Norte, tem se desenvolvido aumentando o número de barcos de observação de golfinhos operando nesta área. No presente estudo alterações comportamentais do Sotalia guianensis (Van Bénédén, 1864 causado pela presença destes barcos foi verificada. Registros comportamentais de S. guianensis foram compilados de um ponto fixo do alto de uma falésia próxima à área de estudo. As observações foram realizadas quando não havia barcos, na presença de barcos e após a saída dos barcos. Os resultados mostraram que o tipo de aproximação praticado pelos barcos de observação de golfinhos tinha maior influência no comportamento dos animais, especialmente em grupos com filhotes. Os impactos de curto prazo foram mais discretos, no entanto, novos métodos devem ser aplicados no sentido de verificar impactos de longo prazo no comportamento dos golfinhos.The ever-increasing tourist industry has extended to the aquatic environments, thus making the aquatic mammals susceptible to interactions with humans. Dolphin watching tourism has developed to a great extent in the Pipa Beach, Rio Grande do Norte, consequently the number of dolphin-watching boats operating in this area has increased. In the present study the behavioral alterations of Sotalia guianensis (Van Bénédén, 1864 caused by the presence of these boats were verified. Behavioral registers of S. guianensis were compiled from a fixed point on the cliffs close to the study area. The observations were effected when there were no boats, in the presence of boats and after the departure of boats. The results show that type of approach by the dolphin watching boats had a major influence on the behavior of the dolphins, especially so in the groups with calves. The short term impacts were rather discrete, however, new methods should be applied in order to verify the long term impacts on the dolphins.
Seasonal and daily patterns of group size, cohesion and activity of the estuarine dolphin, Sotalia guianensis (P.J. van Bénéden (Cetacea, Delphinidae, in southern Brazil Padrões sazonais e diários do tamanho de grupo, coesão e atividade do boto-cinza, Sotalia guianensis (P.J. van Bénéden (Cetacea, Delphinidae, no sul do Brasil
Fábio G. Daura-Jorge
Full Text Available The resident population of estuarine dolphin, Sotalia guianensis (P.J. van Bénéden, 1864, in Norte Bay, Santa Catarina, southern Brazil, was studied from 2000 to 2003. Systematic one-day cruises were undertaken aboard a 5 m sail boat equipped with an outboard motor. Applying the focal-group method, information such as geographical position, predominant behavioural patterns, group size, cohesion index and the presence of calves, were registered at every five-minute interval, totalling 198 hours of direct observation of the dolphins. The estuarine dolphin used preferential areas for each behavioural pattern. The mean group size was approximately 29 individuals, and the presence of calves occurred throughout the entire year, but with a significant increase in the warm seasons. The frequency of behavioural patterns and group size varied according to season and time of day, and were strongly associated. The frequency of moving behaviours increased in the cold seasons and along the day. The seasonal variation in the moving behaviours suggest the requirement of a larger area in the cold seasons, probably related to seasonal fluctuations in the abundance of dominant prey items. Higher group sizes were observed while dolphins were foraging. The cohesion index also varied according to the behaviour. Our results showed that group organization and behavioural patterns of this estuarine dolphin population are probably linked to daily and seasonal environment cycles, and also possibly to the condition of being at the furthest southern limit of distribution of the species.A população residente de boto-cinza, Sotalia guianensis (P.J. van Bénéden, 1864, da Baía Norte, Santa Catarina, sul do Brasil, foi estudada de 2000 a 2003. Foram realizados cruzeiros sistemáticos de um dia, a bordo de um veleiro de 5 m equipado com motor de popa. Utilizando o método de grupo-focal, informações como posição geográfica, padrão comportamental predominante, tamanho de grupo, índice de coesão e presença de filhotes, foram registradas a cada intervalo de cinco minutos, totalizando 198 horas de observação direta dos botos. O boto-cinza utilizou áreas preferenciais para cada padrão comportamental. O tamanho médio de grupo foi aproximadamente de 29 indivíduos, e a presença de filhotes ocorreu ao longo de todo o ano, porém com aumento significante nas estações quentes. A freqüência dos padrões comportamentais e o tamanho de grupo apresentaram forte correlação, e variaram em relação à estação do ano e hora do dia. Os comportamentos de movimento foram mais freqüentes nas estações frias e ao longo do dia. A variação sazonal destes comportamentos sugere o requerimento de maiores áreas nas estações frias, provavelmente relacionado com as flutuações sazonais de abundância e dominância de presas. Os maiores tamanhos de grupo ocorreram em comportamentos de forrageio. O índice de coesão também variou com o comportamento. Nossos resultados demonstram que a organização de grupo e os padrões comportamentais desta população de boto-cinza são provavelmente influenciados por ciclos ambientais diários e sazonais, e pela condição de limite sul de distribuição para a espécie.
de Stephanis Renaud
Full Text Available Abstract Background Previous DNA-based phylogenetic studies of the Delphinidae family suggest it has undergone rapid diversification, as characterised by unresolved and poorly supported taxonomic relationships (polytomies for some of the species within this group. Using an increased amount of sequence data we test between alternative hypotheses of soft polytomies caused by rapid speciation, slow evolutionary rate and/or insufficient sequence data, and hard polytomies caused by simultaneous speciation within this family. Combining the mitogenome sequences of five new and 12 previously published species within the Delphinidae, we used Bayesian and maximum-likelihood methods to estimate the phylogeny from partitioned and unpartitioned mitogenome sequences. Further ad hoc tests were then conducted to estimate the support for alternative topologies. Results We found high support for all the relationships within our reconstructed phylogenies, and topologies were consistent between the Bayesian and maximum-likelihood trees inferred from partitioned and unpartitioned data. Resolved relationships included the placement of the killer whale (Orcinus orca as sister taxon to the rest of the Globicephalinae subfamily, placement of the Risso's dolphin (Grampus griseus within the Globicephalinae subfamily, removal of the white-beaked dolphin (Lagenorhynchus albirostris from the Delphininae subfamily and the placement of the rough-toothed dolphin (Steno bredanensis as sister taxon to the rest of the Delphininae subfamily rather than within the Globicephalinae subfamily. The additional testing of alternative topologies allowed us to reject all other putative relationships, with the exception that we were unable to reject the hypothesis that the relationship between L. albirostris and the Globicephalinae and Delphininae subfamilies was polytomic. Conclusion Despite their rapid diversification, the increased sequence data yielded by mitogenomes enables the
Rice, Dale W.
This National Oceanic and Atmospheric Administration publication lists 116 species of living and recently extinct marine mammals of the world. Included are 36 species of Order Carnivora (polar bear, sea otter, and 34 pinnipeds); 5 species of Order Sirenia; 10 of Order Mysticeti (baleen whales); and 65 species of Order Odontoceti (tooth whales).…
Full Text Available NC_003318 gi|17989189 >1bxwA 4 170 40 240 2e-16 ... gb|AAN33618.1| outer membrane protein Omp3...1 [Brucella suis 1330] gb|AAS84567.1| ... Omp31 [Brucella cetaceae] gb|AAS84566.1| Omp31 [Br...ucella ... cetaceae] gb|AAS84565.1| Omp31 [Brucella pinnipediae] ... gb|AAS84564.1| Omp31 [Bru...nsis] ... gb|AAL27297.1| outer membrane protein Omp31 [Brucella ... melitensis biovar Neotomae...] gb|AAL27290.1| outer ... membrane protein Omp31 [Brucella melitensis biovar Suis] ... gb|AAL
Hernández-Orts, J.S.; Viola, M.N.P.; García, N.A.; Crespo, E.A.; González, R.; García-Varela, M.; Kuchta, Roman
Roč. 3936, č. 3 (2015), s. 301-334 ISSN 1175-5326 R&D Projects: GA ČR GAP506/12/1632 Institutional support: RVO:60077344 Keywords : Acanthocephala * Nematoda * Cestoda * Trematoda * Carnivora * Cetacea * South West Atlantic Subject RIV: EG - Zoology Impact factor: 0.994, year: 2015
... of marine mammal parts (hard and soft parts) from up to 200 animals per year within the order Cetacea... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XW11 Marine Mammals; File No. 14514 AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric...
Spoel, van der S.
After a few years of serious illness Dr. W. L. van Utrecht, born 13 December 1926 in Tiel, died still very unexpected at the age of 67 year on 10 August 1994. After a study of chemistry and biology he joined from 1952 till 1963 the working group for Cetacea of the Netherlands Organisation of Applied
Stejskalová, K.; Bayerova, Z.; Futas, J.; Hrazdilová, K.; Klumplerova, M.; Oppelt, J.; Šplíchalová, P.; Di Guardo, G.; Mazzariol, S.; Di Francesco, C. E.; Di Francesco, G.; Terracciano, G.; Paiu, R.M.; Ursache, T. D.; Modrý, David; Horin, P.
Roč. 90, č. 6 (2017), s. 343-353 ISSN 2059-2302 Institutional support: RVO:60077344 Keywords : Cetacea * haplotype * immunity * innate * mhc-dqb * Phocoena phocoena * polymorphism * single nucleotide * Stenella coeruleoalba Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology
Mogensen, Line; Kinze, Carl Christian; Werge, Thomas
A large number of mammalian species harbor a tandem repeat in exon III of the gene encoding dopamine receptor D4 (DRD4), a receptor associated with cognitive functions. In this study, a DRD4 gene exon III tandem repeat from the order Cetacea was identified and characterized. Included in our study...
... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Scope of regulations. 18.2 Section 18.2 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED... with respect to cetacea (whales and porpoises), pinnipedia, other than walrus (seals and sea lions...
Metales pesados en el riñón del delfín franciscana, Pontoporia blainvillei (Cetácea: Pontoporiidae y su relación con parámetros biológicos Heavy metals in kidney tissues of Franciscana dolphin, Pontoporia blainvillei (Cetacea: Pontoporiidae, and their relationship with biological parameters
María V Panebianco
Full Text Available En este estudio se determinó los niveles de metales pesados (Cd, Pb, Zn, Cu, Cr y Ni en el tejido renal del delfín franciscana, Pontoporia blainvillei, y se estableció la influencia de los parámetros ecológicos y biológicos sobre la bioacumulación de estos elementos. Se analizaron muestras de 38 ejemplares colectados entre 2004 y 2010 en el sur de Buenos Aires, Argentina. La edad de los animales y el estado de madurez sexual se determinaron por métodos histológicos, y los niveles de metales pesados por Espectrofotometría de Absorción Atómica. No se determinaron diferencias significativas para las concentraciones de Zn, Cu y Cd entre ambos sexos. Los niveles de Cd presentaron diferencias según el estado de madurez sexual y se relacionaron positivamente con la longitud, peso corporal y edad. Los niveles de Cd, Cu y Zn resultaron menores a los informados en estudios previos realizados en el norte de Buenos Aires y Uruguay.Heavy metal (Cd, Pb, Zn, Cu, Cr,Ni concentrations were determined in the kidney tissue of the Franciscana dolphin, Pontoporia blainvillei, and the influence of ecological and biological parameters on the bioaccumulation of these elements was established. Samples from 38 specimens, collected between 2004 and 2010 off southern Buenos Aires, Argentina, were analyzed. Histological methods were used to determine both the age and sexual maturity of the animals. Heavy metal concentrations were measured by atomic absorption spectrophotometry. No significant differences were found by sex for Zn, Cu, and Cd. However, Cd levels differed between maturity stages and were positively related to length, body weight, and age. The Cd, Cu, and Zn levels reported here in were lower than those included in previous studies done off northern Buenos Aires and Uruguay.
Gnanadesikan, Gitanjali E.; Pearse, William; Shaw, Allison K.
Abstract Many organisms migrate between distinct habitats, exploiting variable resources while profoundly affecting ecosystem services, disease spread, and human welfare. However, the very characteristics that make migration captivating and significant also make it difficult to study, and we lack a comprehensive understanding of which species migrate and why. Here we show that, among mammals, migration is concentrated within Cetacea and Artiodactyla but also diffusely spread throughout the cl...
Montgomery Stephen H
Full Text Available Abstract Background Representatives of Cetacea have the greatest absolute brain size among animals, and the largest relative brain size aside from humans. Despite this, genes implicated in the evolution of large brain size in primates have yet to be surveyed in cetaceans. Results We sequenced ~1240 basepairs of the brain development gene microcephalin (MCPH1 in 38 cetacean species. Alignments of these data and a published complete sequence from Tursiops truncatus with primate MCPH1 were utilized in phylogenetic analyses and to estimate ω (rate of nonsynonymous substitution/rate of synonymous substitution using site and branch models of molecular evolution. We also tested the hypothesis that selection on MCPH1 was correlated with brain size in cetaceans using a continuous regression analysis that accounted for phylogenetic history. Our analyses revealed widespread signals of adaptive evolution in the MCPH1 of Cetacea and in other subclades of Mammalia, however, there was not a significant positive association between ω and brain size within Cetacea. Conclusion In conjunction with a recent study of Primates, we find no evidence to support an association between MCPH1 evolution and the evolution of brain size in highly encephalized mammalian species. Our finding of significant positive selection in MCPH1 may be linked to other functions of the gene.
Full Text Available sperm whale Physeter macrocephalus Chordata/Vertebrata/Mammalia/Theria/Eutheria/Cetacea Physeter_macrocephal...us_L.png Physeter_macrocephalus_NL.png Physeter_macrocephalus_S.png Physeter_macrocephal...us_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Physeter+macrocephalus&t=L http://bioscience...dbc.jp/taxonomy_icon/icon.cgi?i=Physeter+macrocephalus&t=NL http://biosciencedbc....jp/taxonomy_icon/icon.cgi?i=Physeter+macrocephalus&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Physeter+macrocephalus&t=NS ...
Tsai, Cheng-Hsiu; Fordyce, R. Ewan
Ancestor–descendant relationships (ADRs), involving descent with modification, are the fundamental concept in evolution, but are usually difficult to recognize. We examined the cladistic relationship between the only reported fossil pygmy right whale, †Miocaperea pulchra, and its sole living relative, the enigmatic pygmy right whale Caperea marginata, the latter represented by both adult and juvenile specimens. †Miocaperea is phylogenetically bracketed between juvenile and adult Caperea marginata in morphologically based analyses, thus suggesting a possible ADR—the first so far identified within baleen whales (Cetacea: Mysticeti). The †Miocaperea–Caperea lineage may show long-term morphological stasis and, in turn, punctuated equilibrium. PMID:25589485
Full Text Available North Pacific right whale Eubalaena japonica Chordata/Vertebrata/Mammalia/Theria/Eu...theria/Cetacea Eubalaena_japonica_L.png Eubalaena_japonica_NL.png Eubalaena_japonica_S.png Eubalaena_japonic...a_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Eubalaena+japonica&t=L http://biosciencedbc.jp/tax...onomy_icon/icon.cgi?i=Eubalaena+japonica&t=NL http://biosciencedbc.jp/taxonomy_ic...on/icon.cgi?i=Eubalaena+japonica&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Eubalaena+japonica&t=NS ...
Full Text Available The distribution and density of pelagic megafauna (marine mammals, seabirds, elasmobranches, and sea turtles are important indicators of marine biodiversity, reflecting the condition of the underlying ecosystems. A dedicated aerial survey was conducted in the tropical Southwest Indian Ocean to map their distribution, the taxonomic diversity, and to estimate their densities to serve as a baseline for the area. This large survey across three ecological sub-regions revealed contrasting spatial distributions: maps of taxonomic richness of marine mammals and seabirds revealed different “hotspots” in the area. Densities were estimated for eight cetacean taxa with small and large Delphininae, or small Globicephalinae dominating, and for seven seabird taxa, with terns and noddies dominating. At the community level, the Southwest Indian Ocean megafauna was structured by the marine environment with strong differences between the Mozambique Channel and the Mascarene Islands, or between shelf and slope/oceanic habitats. Our results illustrate how multi-taxa aerial surveys are relevant and cost-effective monitoring tools for marine megafauna, allowing a community-wide approach.
Banguera Hinestroza, Eulalia
The six species currently classified within the genus Lagenorhynchus exhibit a pattern of antitropical distribution common among marine taxa. In spite of their morphological similarities they are now considered an artificial grouping, and include both recent and the oldest representatives of the Delphinidae radiation. They are, therefore, a good model for studying questions about the evolutionary processes that have driven dolphin speciation, dispersion and distribution. Here we used two different approaches. First we constructed a multigenic phylogeny with a minimum amount of missing data (based on 9 genes, 11,030 bp, using the 6 species of the genus and their closest relatives) to infer their relationships. Second, we built a supermatrix phylogeny (based on 33 species and 27 genes) to test the effect of taxon sampling on the phylogeny of the genus, to provide inference on biogeographic history, and provide inference on the main events shaping the dispersion and radiation of delphinids. Our analyses suggested an early evolutionary history of marine dolphins in the North Atlantic Ocean and revealed multiple pathways of migration and radiation, probably guided by paleoceanographic changes during the Miocene and Pliocene. L. acutus and L albirostris likely shared a common ancestor that arose in the North Atlantic around the Middle Miocene, predating the radiation of subfamilies Delphininae, Globicephalinae and Lissodelphininae. (C) 2014 Elsevier Inc. All rights reserved.
Morin, Phillip A.
Little is known about global patterns of genetic connectivity in pelagic dolphins, including how circumtropical pelagic dolphins spread globally following the rapid and recent radiation of the subfamily delphininae. In this study, we tested phylogeographic hypotheses for two circumtropical species, the spinner dolphin (Stenella longirostris) and the pantropical spotted dolphin (Stenella attenuata), using more than 3000 nuclear DNA single nucleotide polymorphisms (SNPs) in each species. Analyses for population structure indicated significant genetic differentiation between almost all subspecies and populations in both species. Bayesian phylogeographic analyses of spinner dolphins showed deep divergence between Indo-Pacific, Atlantic and eastern tropical Pacific Ocean (ETP) lineages. Despite high morphological variation, our results show very close relationships between endemic ETP spinner subspecies in relation to global diversity. The dwarf spinner dolphin is a monophyletic subspecies nested within a major clade of pantropical spinner dolphins from the Indian and western Pacific Ocean populations. Population-level division among the dwarf spinner dolphins was detected—with the northern Australia population being very different from that in Indonesia. In contrast to spinner dolphins, the major boundary for spotted dolphins is between offshore and coastal habitats in the ETP, supporting the current subspecies-level taxonomy. Comparing these species underscores the different scale at which population structure can arise, even in species that are similar in habitat (i.e. pelagic) and distribution. PMID:29765639
Cetaceans occurrence visual monitoring during seismic survey in the North of Campos Basin; Monitoramento visual de ocorrencia de cetaceos durante o levantamento de dados sismicos no norte da Bacia de Campos
Flor, Karina C.A.; Amaro, Thays P.C.; Carloni, Giuliano G. [Ecologus Engenharia Consultiva, Rio de Janeiro, RJ (Brazil); Uller, George A. [CGGVeritas, Rio de Janeiro, RJ (Brazil)
The objective of this research is to present the results of the marine biota visual monitoring developed during the seismic survey in the north area of Campos Basin. The monitoring lasted five months, between 14 February and 14 July 2007, reaching, on average, eleven hours and fifty one minutes of sign effort per day. It was conducted by fourteen marine biota catch sign, three for each period of boarding, that took over during all period of the activity. Sixty two cetaceans were registered, eight belonging to suborder Odontoceti and four belonging to suborder Mysticeti. Tursiops truncatus was the predominant species in number of registers, followed by Megaptera novaeangliae. It's important to report that during all seismic activity period there wasn't any cetacean register presenting any behavior disturbance. (author)
Douzery, E; Catzeflis, F M
The complete 12S rRNA gene has been sequenced in 4 Ungulata (hoofed eutherians) and 1 marsupial and compared to 38 available mammalian sequences in order to investigate the molecular evolution of the mitochondrial small-subunit ribosomal RNA molecule. Ungulata were represented by one artiodactyl (the collared peccary, Tayassu tajacu, suborder Suiformes), two perissodactyls (the Grevy's zebra, Equus grevyi, suborder Hippomorpha; the white rhinoceros, Ceratotherium simum, suborder Ceratomorpha), and one hyracoid (the tree hyrax, Dendrohyrax dorsalis). The fifth species was a marsupial, the eastern gray kangaroo (Macropus giganteus). Several transition/transversion biases characterized the pattern of changes between mammalian 12S rRNA molecules. A bias toward transitions was found among 12S rRNA sequences of Ungulata, illustrating the general bias exhibited by ribosomal and protein-encoding genes of the mitochondrial genome. The derivation of a mammalian 12S rRNA secondary structure model from the comparison of 43 eutherian and marsupial sequences evidenced a pronounced bias against transversions in stems. Moreover, transversional compensatory changes were rare events within double-stranded regions of the ribosomal RNA. Evolutionary characteristics of the 12S rRNA were compared with those of the nuclear 18S and 28S rRNAs. From a phylogenetic point of view, transitions, transversions and indels in stems as well as transversional and indels events in loops gave congruent results for comparisons within orders. Some compensatory changes in double-stranded regions and some indels in single-stranded regions also constituted diagnostic events. The 12S rRNA molecule confirmed the monophyly of infraorder Pecora and order Cetacea and demonstrated the monophyly of the suborder Ruminantia was not supported and the branching pattern between Cetacea and the artiodacytyl suborders Ruminantia and Suiformes was not established. The monophyly of the order Perissodactyla was evidenced
Full Text Available Abstract Some 63 species have been recorded in Albania from 1950 to 1994, with the exclusion of Cetacea. Another 15 species, including 5 found on the eastern border between Albania and Greece, are considered probably present. Hence 78 species could occur in Albania. According to IUCN red list of threatened animals, 8 species are defined as vulnerable, 15 as lower risk and one (the Mediterranean monk seal as critically endangered. In Albania, the legal protection of mammals includes all bat species, carnivores (except the stone marten, the red fox and the wolf, the chamois, the roe deer and the Mediterranean monk seal. General information on the distributional pattern and the population size is reported for some species, mainly carnivores.
Gnanadesikan, Gitanjali E; Pearse, William D; Shaw, Allison K
Many organisms migrate between distinct habitats, exploiting variable resources while profoundly affecting ecosystem services, disease spread, and human welfare. However, the very characteristics that make migration captivating and significant also make it difficult to study, and we lack a comprehensive understanding of which species migrate and why. Here we show that, among mammals, migration is concentrated within Cetacea and Artiodactyla but also diffusely spread throughout the class (found in 12 of 27 orders). We synthesize the many ecological drivers of round-trip migration into three types of movement-between breeding and foraging sites, between breeding and refuge sites, and continuous tracking of forage/prey-each associated with different traits (body mass, diet, locomotion, and conservation status). Our results provide only partial support for the hypothesis that migration occurs without phylogenetic constraint. Furthermore, our findings suggest that categorizing migration into these three types may aid predictions of migrants' responses to environmental changes.
Fitzgerald, Erich M. G.
The titanic baleen whales (Cetacea, Mysticeti) have a bizarre skull morphology, including an elastic mandibular symphysis, which permits dynamic oral cavity expansion during bulk feeding. How this key innovation evolved from the sutured symphysis of archaeocetes has remained unclear. Now, mandibles of the Oligocene toothed mysticete Janjucetus hunderi show that basal mysticetes had an archaeocete-like sutured symphysis. This archaic morphology was paired with a wide rostrum typical of later-diverging baleen whales. This demonstrates that increased oral capacity via rostral widening preceded the evolution of mandibular innovations for filter feeding. Thus, the initial evolution of the mysticetes' unique cranial form and huge mouths was perhaps not linked to filtering plankton, but to enhancing suction feeding on individual prey. PMID:21849306
Tsai, Cheng-Hsiu; Fordyce, R Ewan
Ancestor-descendant relationships (ADRs), involving descent with modification, are the fundamental concept in evolution, but are usually difficult to recognize. We examined the cladistic relationship between the only reported fossil pygmy right whale, †Miocaperea pulchra, and its sole living relative, the enigmatic pygmy right whale Caperea marginata, the latter represented by both adult and juvenile specimens. †Miocaperea is phylogenetically bracketed between juvenile and adult Caperea marginata in morphologically based analyses, thus suggesting a possible ADR-the first so far identified within baleen whales (Cetacea: Mysticeti). The †Miocaperea-Caperea lineage may show long-term morphological stasis and, in turn, punctuated equilibrium. © 2015 The Author(s) Published by the Royal Society. All rights reserved.
Tsai, Cheng-Hsiu; Fordyce, R Ewan
Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living baleen whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in baleen whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.
Lopes-Marques, Mónica; Ruivo, Raquel; Fonseca, Elza; Teixeira, Ana; Castro, L Filipe C
Gene duplication and loss are powerful drivers of evolutionary change. The role of loss in phenotypic diversification is notably illustrated by the variable enzymatic repertoire involved in vertebrate protein digestion. Among these we find the pepsin family of aspartic proteinases, including chymosin (Cmy). Previous studies demonstrated that Cmy, a neo-natal digestive pepsin, is inactivated in some primates, including humans. This pseudogenization event was hypothesized to result from the acquisition of maternal immune immunoglobulin G (IgG) transfer. By investigating 94 mammalian subgenomes we reveal an unprecedented level of Cmy erosion in placental mammals, with numerous independent events of gene loss taking place in Primates, Dermoptera, Rodentia, Cetacea and Perissodactyla. Our findings strongly suggest that the recurrent inactivation of Cmy correlates with the evolution of the passive transfer of IgG and uncovers a noteworthy case of evolutionary cross-talk between the digestive and the immune system, modulated by gene loss. Copyright © 2017 Elsevier Inc. All rights reserved.
Full Text Available Abstract Background A diversity of hypotheses have been proposed based on both morphological and molecular data to reveal phylogenetic relationships within the order Cetacea (dolphins, porpoises, and whales, and great progress has been made in the past two decades. However, there is still some controversy concerning relationships among certain cetacean taxa such as river dolphins and delphinoid species, which needs to be further addressed with more markers in an effort to address unresolved portions of the phylogeny. Results An analysis of additional SINE insertions and SINE-flanking sequences supported the monophyly of the order Cetacea as well as Odontocete, Delphinoidea (Delphinidae + Phocoenidae + Mondontidae, and Delphinidae. A sister relationship between Delphinidae and Phocoenidae + Mondontidae was supported, and members of classical river dolphins and the genera Tursiops and Stenella were found to be paraphyletic. Estimates of divergence times revealed rapid divergences of basal Odontocete lineages in the Oligocene and Early Miocene, and a recent rapid diversification of Delphinidae in the Middle-Late Miocene and Pliocene within a narrow time frame. Conclusions Several novel SINEs were found to differentiate Delphinidae from the other two families (Monodontidae and Phocoenidae, whereas the sister grouping of the latter two families with exclusion of Delphinidae was further revealed using the SINE-flanking sequences. Interestingly, some anomalous PCR amplification patterns of SINE insertions were detected, which can be explained as the result of potential ancestral SINE polymorphisms and incomplete lineage sorting. Although a few loci were potentially anomalous, this study demonstrated that the SINE-based approach is a powerful tool in phylogenetic studies. Identifying additional SINE elements that resolve the relationships in the superfamily Delphinoidea and family Delphinidae will be important steps forward in completely resolving
Chen, Zhuo; Xu, Shixia; Zhou, Kaiya; Yang, Guang
A diversity of hypotheses have been proposed based on both morphological and molecular data to reveal phylogenetic relationships within the order Cetacea (dolphins, porpoises, and whales), and great progress has been made in the past two decades. However, there is still some controversy concerning relationships among certain cetacean taxa such as river dolphins and delphinoid species, which needs to be further addressed with more markers in an effort to address unresolved portions of the phylogeny. An analysis of additional SINE insertions and SINE-flanking sequences supported the monophyly of the order Cetacea as well as Odontocete, Delphinoidea (Delphinidae + Phocoenidae + Mondontidae), and Delphinidae. A sister relationship between Delphinidae and Phocoenidae + Mondontidae was supported, and members of classical river dolphins and the genera Tursiops and Stenella were found to be paraphyletic. Estimates of divergence times revealed rapid divergences of basal Odontocete lineages in the Oligocene and Early Miocene, and a recent rapid diversification of Delphinidae in the Middle-Late Miocene and Pliocene within a narrow time frame. Several novel SINEs were found to differentiate Delphinidae from the other two families (Monodontidae and Phocoenidae), whereas the sister grouping of the latter two families with exclusion of Delphinidae was further revealed using the SINE-flanking sequences. Interestingly, some anomalous PCR amplification patterns of SINE insertions were detected, which can be explained as the result of potential ancestral SINE polymorphisms and incomplete lineage sorting. Although a few loci were potentially anomalous, this study demonstrated that the SINE-based approach is a powerful tool in phylogenetic studies. Identifying additional SINE elements that resolve the relationships in the superfamily Delphinoidea and family Delphinidae will be important steps forward in completely resolving cetacean phylogenetic relationships in the future.
Ekdale, Eric G.
Background Variation is a naturally occurring phenomenon that is observable at all levels of morphology, from anatomical variations of DNA molecules to gross variations between whole organisms. The structure of the otic region is no exception. The present paper documents the broad morphological diversity exhibited by the inner ear region of placental mammals using digital endocasts constructed from high-resolution X-ray computed tomography (CT). Descriptions cover the major placental clades, and linear, angular, and volumetric dimensions are reported. Principal Findings The size of the labyrinth is correlated to the overall body mass of individuals, such that large bodied mammals have absolutely larger labyrinths. The ratio between the average arc radius of curvature of the three semicircular canals and body mass of aquatic species is substantially lower than the ratios of related terrestrial taxa, and the volume percentage of the vestibular apparatus of aquatic mammals tends to be less than that calculated for terrestrial species. Aspects of the bony labyrinth are phylogenetically informative, including vestibular reduction in Cetacea, a tall cochlear spiral in caviomorph rodents, a low position of the plane of the lateral semicircular canal compared to the posterior canal in Cetacea and Carnivora, and a low cochlear aspect ratio in Primatomorpha. Significance The morphological descriptions that are presented add a broad baseline of anatomy of the inner ear across many placental mammal clades, for many of which the structure of the bony labyrinth is largely unknown. The data included here complement the growing body of literature on the physiological and phylogenetic significance of bony labyrinth structures in mammals, and they serve as a source of data for future studies on the evolution and function of the vertebrate ear. PMID:23805251
Charlotte E. Page
Full Text Available Convergent evolution can provide insights into the predictability of, and constraints on, the evolution of biodiversity. One striking example of convergence is seen in the ‘river dolphins’. The four dolphin genera that make up the ‘river dolphins’ (Inia geoffrensis, Pontoporia blainvillei, Platanista gangetica and Lipotes vexillifer do not represent a single monophyletic group, despite being very similar in morphology. This has led many to using the ‘river dolphins’ as an example of convergent evolution. We investigate whether the skulls of the four ‘river dolphin’ genera are convergent when compared to other toothed dolphin taxa in addition to identifying convergent cranial and mandibular features. We use geometric morphometrics to uncover shape variation in the skulls of the ‘river dolphins’ and then apply a number of phylogenetic techniques to test for convergence. We find significant convergence in the skull morphology of the ‘river dolphins’. The four genera seem to have evolved similar skull shapes, leading to a convergent morphotype characterised by elongation of skull features. The cause of this morphological convergence remains unclear. However, the features we uncover as convergent, in particular elongation of the rostrum, support hypotheses of shared feeding mode or diet and thus provide the foundation for future work into convergence within the Odontoceti.
McCurry, Matthew R; Evans, Alistair R; Fitzgerald, Erich M G; Adams, Justin W; Clausen, Philip D; McHenry, Colin R
The striking resemblance of long-snouted aquatic mammals and reptiles has long been considered an example of morphological convergence, yet the true cause of this similarity remains untested. We addressed this deficit through three-dimensional morphometric analysis of the full diversity of crocodilian and toothed whale (Odontoceti) skull shapes. Our focus on biomechanically important aspects of shape allowed us to overcome difficulties involved in comparing mammals and reptiles, which have fundamental differences in the number and position of skull bones. We examined whether diet, habitat and prey size correlated with skull shape using phylogenetically informed statistical procedures. Crocodilians and toothed whales have a similar range of skull shapes, varying from extremely short and broad to extremely elongate. This spectrum of shapes represented more of the total variation in our dataset than between phylogenetic groups. The most elongate species (river dolphins and gharials) are extremely convergent in skull shape, clustering outside of the range of the other taxa. Our results suggest the remarkable convergence between long-snouted river dolphins and gharials is driven by diet rather than physical factors intrinsic to riverine environments. Despite diverging approximately 288 million years ago, crocodilians and odontocetes have evolved a remarkably similar morphological solution to feeding on similar prey. © 2017 The Author(s).
Oliveira Sarah G
Full Text Available Abstract Background Active transposable elements (TEs can be passed between genomes of different species by horizontal transfer (HT. This may help them to avoid vertical extinction due to elimination by natural selection or silencing. HT is relatively frequent within eukaryotic taxa, but rare between distant species. Findings Closely related Mariner-type DNA transposon families, collectively named as Mariner-1_Tbel families, are present in the genomes of two ants and two mammalian genomes. Consensus sequences of the four families show pairwise identities greater than 95%. In addition, mammalian Mariner1_BT family shows a close evolutionary relationship with some insect Mariner families. Mammalian Mariner1_BT type sequences are present only in species from three groups including ruminants, tooth whales (Odontoceti, and New World leaf-nosed bats (Phyllostomidae. Conclusions Horizontal transfer accounts for the presence of Mariner_Tbel and Mariner1_BT families in mammals. Mariner_Tbel family was introduced into hedgehog and tree shrew genomes approximately 100 to 69 million years ago (MYA. Most likely, these TE families were transferred from insects to mammals, but details of the transfer remain unknown.
Oliveira, Sarah G; Bao, Weidong; Martins, Cesar; Jurka, Jerzy
Active transposable elements (TEs) can be passed between genomes of different species by horizontal transfer (HT). This may help them to avoid vertical extinction due to elimination by natural selection or silencing. HT is relatively frequent within eukaryotic taxa, but rare between distant species. Closely related Mariner-type DNA transposon families, collectively named as Mariner-1_Tbel families, are present in the genomes of two ants and two mammalian genomes. Consensus sequences of the four families show pairwise identities greater than 95%. In addition, mammalian Mariner1_BT family shows a close evolutionary relationship with some insect Mariner families. Mammalian Mariner1_BT type sequences are present only in species from three groups including ruminants, tooth whales (Odontoceti), and New World leaf-nosed bats (Phyllostomidae). Horizontal transfer accounts for the presence of Mariner_Tbel and Mariner1_BT families in mammals. Mariner_Tbel family was introduced into hedgehog and tree shrew genomes approximately 100 to 69 million years ago (MYA). Most likely, these TE families were transferred from insects to mammals, but details of the transfer remain unknown.
Paul R. Wade
Full Text Available Many severely depleted populations of baleen whales (Mysticeti have exhibited clear signs of recovery whereas there are few examples in toothed whales (Odontoceti. We hypothesize that this difference is due, at least in part, to social and behavioural factors. Clearly, a part of the lack of resilience to exploitation is explained by odontocete life history. However, an additional factor may be the highly social nature of many odontocetes in which survival and reproductive success may depend on: (a social cohesion and organization, (b mutual defence against predators and possible alloparental care, (c inter-generational transfer of “knowledge”, and (d leadership by older individuals. We found little evidence of strong recovery in any of the depleted populations examined. Their relatively low potential rates of increase mean that odontocete populations can be over-exploited with take rates of only a few percent per year. Exploitation can have effects beyond the dynamics of individual removals. Four species showed evidence of a decrease in birth rates following exploitation; potential mechanisms include a deficit of adult females, a deficit of adult males, and disruption of mating systems. The evidence for a lack of strong recovery in heavily exploited odontocete populations indicates that management should be more precautionary.
Hocking, David P; Marx, Felix G; Fitzgerald, Erich M G; Evans, Alistair R
The origin of baleen whales (Mysticeti), the largest animals on Earth, is closely tied to their signature filter-feeding strategy. Unlike their modern relatives, archaic whales possessed a well-developed, heterodont adult dentition. How these teeth were used, and what role their function and subsequent loss played in the emergence of filter feeding, is an enduring mystery. In particular, it has been suggested that elaborate tooth crowns may have enabled stem mysticetes to filter with their postcanine teeth in a manner analogous to living crabeater and leopard seals, thereby facilitating the transition to baleen-assisted filtering. Here we show that the teeth of archaic mysticetes are as sharp as those of terrestrial carnivorans, raptorial pinnipeds and archaeocetes, and thus were capable of capturing and processing prey. By contrast, the postcanine teeth of leopard and crabeater seals are markedly blunter, and clearly unsuited to raptorial feeding. Our results suggest that mysticetes never passed through a tooth-based filtration phase, and that the use of teeth and baleen in early whales was not functionally connected. Continued selection for tooth sharpness in archaic mysticetes is best explained by a feeding strategy that included both biting and suction, similar to that of most living pinnipeds and, probably, early toothed whales (Odontoceti). © 2017 The Authors.
Umezu, Takeshi; Minamisako, Yoko; Ebihara, Hiroshi; Watanabe, Hiroshi.
Sperm whales are notable squid-eaters. They feed mainly on medium to large-sized cephalopods at midwater levels and defecate near the surface. This suggests the existence of an upward transport of 60 Co by sperm whales from the mesopelagic zone (150-1,200m). To elucidate this squid-whale route for this artificial radionuclide, 60 Co content was determined in squid and in predator whales captured by commercial whaling. In the Cephalopoda livers 60 Co levels of 30-500 mBq kg -1 wet were found and in the viscera of Odontoceti (toothed whales) 15-40 mBq kg -1 wet. About 0.3% of 60 Co ingested was estimated to be retained in a 23-year-old male sperm whale. In the livers of Bryde's whales, 60 Co levels of 40-80 mBq kg -1 wet were detected, but not in euphausiids and sardines, their possible prey. The level of Co in sperm whales was nearly the same as in Bryde's whales. Specific radioactivity 60 Co/ 59 Co in mBq μg -1 was several times higher in sperm whale (1.1-1.6) than in cephalopods (0.19-0.77). Eating prey with a high content of 60 Co in the 1960's may have contributed to the present body burden in sperm whales with a long-life span. However, the origin of 60 Co in Bryde's whales is unknown. (author)
Buhl, E H; Oelschläger, H A
For the first time in cetaceans, the development of the terminalis system and its continuity between the olfactory placode and the telencephalon has been demonstrated by light microscopy. In the early development of toothed whales (Odontoceti) this system is partially incorporated within the fila olfactoria which grow out from the olfactory placode. As the peripheral olfactory system is reduced in later stages, a strongly developed ganglionlike structure (terminalis ganglion) remains within the primitive meninx. Peripherally it is connected via the cribriform plate with ganglionic cell clusters near the septal mucosa. Centrally it is attached to the telencephalon (olfactory tubercle, septal region) by several nerve fibre bundles. In contrast to all other mammalian groups, toothed whales and dolphins are anosmatic while being totally adapted to aquatic life. Therefore the remaining ganglion and plexus must have non-olfactory properties. They may be responsible for the autonomic innervation of intracranial arteries and of the large mucous epithelia in the accessory nasal air sacs. The morphology, evolution and functional implications of the terminalis system in odontocetes and other mammals are discussed.
Guzmán-Verri, Caterina; González-Barrientos, Rocío; Hernández-Mora, Gabriela; Morales, Juan-Alberto; Baquero-Calvo, Elías; Chaves-Olarte, Esteban; Moreno, Edgardo
Since the first case of brucellosis detected in a dolphin aborted fetus, an increasing number of Brucella ceti isolates has been reported in members of the two suborders of cetaceans: Mysticeti and Odontoceti. Serological surveys have shown that cetacean brucellosis may be distributed worldwide in the oceans. Although all B. ceti isolates have been included within the same species, three different groups have been recognized according to their preferred host, bacteriological properties, and distinct genetic traits: B. ceti dolphin type, B. ceti porpoise type, and B. ceti human type. It seems that B. ceti porpoise type is more closely related to B. ceti human isolates and B. pinnipedialis group, while B. ceti dolphin type seems ancestral to them. Based on comparative phylogenetic analysis, it is feasible that the B. ceti ancestor radiated in a terrestrial artiodactyl host close to the Raoellidae family about 58 million years ago. The more likely mode of transmission of B. ceti seems to be through sexual intercourse, maternal feeding, aborted fetuses, placental tissues, vertical transmission from mother to the fetus or through fish or helminth reservoirs. The B. ceti dolphin and porpoise types seem to display variable virulence in land animal models and low infectivity for humans. However, brucellosis in some dolphins and porpoises has been demonstrated to be a severe chronic disease, displaying significant clinical and pathological signs related to abortions, male infertility, neurobrucellosis, cardiopathies, bone and skin lesions, strandings, and death. PMID:22919595
Yamato, Maya; Ketten, Darlene R; Arruda, Julie; Cramer, Scott; Moore, Kathleen
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. Copyright © 2012 Wiley Periodicals, Inc.
Payne, S.F.; Hartwig, E.O.
Twenty-two marine mammal species including 2 baleen whales, 20 toothed whales, and one pinniped occur in Hawaiian waters. Among these are two endangered species, the migratory humpback whale (Megaptera novaengliae) around the main islands, and the non-migratory Hawaiian monk seal (Monachus schauinslandi) in the extreme northwestern island chain. The endangered species are among those most commonly sighted, while spinner dolphins (Stenella spp.), bottle-nosed dolphins (Tursiops sp.), and false killer whales (Pseudorca crassidens) are sighted less frequently. Most Hawaiian cetacean species are Odontoceti, or toothed whales, and feed on fish and squid. The Mysteceti or baleen whales feed on plankton, however the endangered humpback whale, which migrates to Hawaii to breed and calve, presumably does not feed there. The endangered monk seal feeds on cephalopods and fish. The impact of OTEC on endangered and non-endangered marine mammals results from several direct and indirect effects and is discussed in the text. Careful siting of OTEC plants away from humpback breeding areas and monk seal breeding and feeding areas will avoid adverse effects on these populations.
Begeman, L; St Leger, J A; Blyde, D J; Jauniaux, T P; Lair, S; Lovewell, G; Raverty, S; Seibel, H; Siebert, U; Staggs, S L; Martelli, P; Keesler, R I
Intestinal volvulus was recognized as the cause of death in 18 cetaceans, including 8 species of toothed whales (suborder Odontoceti). Cases originated from 11 institutions from around the world and included both captive (n = 9) and free-ranging (n = 9) animals. When the clinical history was available (n = 9), animals consistently demonstrated acute dullness 1 to 5 days prior to death. In 3 of these animals (33%), there was a history of chronic gastrointestinal illness. The pathological findings were similar to those described in other animal species and humans, and consisted of intestinal volvulus and a well-demarcated segment of distended, congested, and edematous intestine with gas and bloody fluid contents. Associated lesions included congested and edematous mesentery and mesenteric lymph nodes, and often serofibrinous or hemorrhagic abdominal effusion. The volvulus involved the cranial part of the intestines in 85% (11 of 13). Potential predisposing causes were recognized in most cases (13 of 18, 72%) but were variable. Further studies investigating predisposing factors are necessary to help prevent occurrence and enhance early clinical diagnosis and management of the condition.
Lambert, Olivier; Martínez-Cáceres, Manuel; Bianucci, Giovanni; Di Celma, Claudio; Salas-Gismondi, Rodolfo; Steurbaut, Etienne; Urbina, Mario; de Muizon, Christian
Although combined molecular and morphological analyses point to a late middle Eocene (38-39 million years ago) origin for the clade Neoceti (Odontoceti, echolocating toothed whales plus Mysticeti, baleen whales, and relatives), the oldest known mysticete fossil dates from the latest Eocene (about 34 million years ago) of Antarctica [1, 2]. Considering that the latter is not the most stemward mysticete in recent phylogenies and that Oligocene toothed mysticetes display a broad morphological disparity most likely corresponding to contrasted ecological niches, the origin of mysticetes from a basilosaurid ancestor and its drivers are currently poorly understood [1, 3-8]. Based on an articulated cetacean skeleton from the early late Eocene (Priabonian, around 36.4 million years ago) of the Pisco Basin, Peru, we describe a new archaic tooth-bearing mysticete, Mystacodon selenensis gen. et sp. nov. Being the geologically oldest neocete (crown group cetacean) and the earliest mysticete to branch off described so far, the new taxon is interpreted as morphologically intermediate between basilosaurids and later toothed mysticetes, providing thus crucial information about the anatomy of the skull, forelimb, and innominate at these critical initial stages of mysticete evolution. Major changes in the morphology of the oral apparatus (including tooth wear) and flipper compared to basilosaurids suggest that suction and possibly benthic feeding represented key, early ecological traits accompanying the emergence of modern filter-feeding baleen whales' ancestors. Copyright © 2017 Elsevier Ltd. All rights reserved.
Bininda-Emonds Olaf RP
Full Text Available Abstract Background The higher-level phylogeny of placental mammals has long been a phylogenetic Gordian knot, with disagreement about both the precise contents of, and relationships between, the extant orders. A recent MRP supertree that favoured 'outdated' hypotheses (notably, monophyly of both Artiodactyla and Lipotyphla has been heavily criticised for including low-quality and redundant data. We apply a stringent data selection protocol designed to minimise these problems to a much-expanded data set of morphological, molecular and combined source trees, to produce a supertree that includes every family of extant placental mammals. Results The supertree is well-resolved and supports both polyphyly of Lipotyphla and paraphyly of Artiodactyla with respect to Cetacea. The existence of four 'superorders' – Afrotheria, Xenarthra, Laurasiatheria and Euarchontoglires – is also supported. The topology is highly congruent with recent (molecular phylogenetic analyses of placental mammals, but is considerably more comprehensive, being the first phylogeny to include all 113 extant families without making a priori assumptions of suprafamilial monophyly. Subsidiary analyses reveal that the data selection protocol played a key role in the major changes relative to a previously published higher-level supertree of placentals. Conclusion The supertree should provide a useful framework for hypothesis testing in phylogenetic comparative biology, and supports the idea that biogeography has played a crucial role in the evolution of placental mammals. Our results demonstrate the importance of minimising poor and redundant data when constructing supertrees.
Gearty, William; McClain, Craig R.; Payne, Jonathan L.
Four extant lineages of mammals have invaded and diversified in the water: Sirenia, Cetacea, Pinnipedia, and Lutrinae. Most of these aquatic clades are larger bodied, on average, than their closest land-dwelling relatives, but the extent to which potential ecological, biomechanical, and physiological controls contributed to this pattern remains untested quantitatively. Here, we use previously published data on the body masses of 3,859 living and 2,999 fossil mammal species to examine the evolutionary trajectories of body size in aquatic mammals through both comparative phylogenetic analysis and examination of the fossil record. Both methods indicate that the evolution of an aquatic lifestyle is driving three of the four extant aquatic mammal clades toward a size attractor at ˜500 kg. The existence of this body size attractor and the relatively rapid selection toward, and limited deviation from, this attractor rule out most hypothesized drivers of size increase. These three independent body size increases and a shared aquatic optimum size are consistent with control by differences in the scaling of energetic intake and cost functions with body size between the terrestrial and aquatic realms. Under this energetic model, thermoregulatory costs constrain minimum size, whereas limitations on feeding efficiency constrain maximum size. The optimum size occurs at an intermediate value where thermoregulatory costs are low but feeding efficiency remains high. Rather than being released from size pressures, water-dwelling mammals are driven and confined to larger body sizes by the strict energetic demands of the aquatic medium.
Full Text Available Due to the permanent influences of different factors (habitat degradation and fragmentation, deforestation, infrastructure and urbanization, natural extension or decreasing of some species’ distribution, increasing number of alien species etc., from time to time the faunistic structure of a certain area is changing. As a result of the permanent and increasing anthropic and invasive species’ pressure, our previous checklist of recent mammals from Romania (since 1984 became out of date. A number of 108 taxa are mentioned in this checklist, representing 7 orders of mammals: Insectivora (10 species, Chiroptera (30 sp., Lagomorpha (2 sp., Rodentia (35 sp., Cetacea (3 sp., Carnivora (19 sp., Artiodactyla (8 sp.. In this list are mentioned the scientific and vernacular names (in Romanian and English languages, species distribution and conservation status, according to the Romanian regulations. Thus, only 21 species have stable populations while 76 have populations in decline or in drastic decline. Other categories are not evaluated or even present an increase in their population.
Full Text Available The evolution of the cetacean skeleton followed a path that differentiated this group from other terrestrial mammals about 50 million years ago , and debate is still going on about the relationships between Cetacea and Artiodactyla , , . Some skeletal traits of the basilosaurids (the more advanced forms of Archaeocetes, such as the expansion of the peribullary air sinuses, dental modification and vertebral size uniformity  are maintained and further emphasized also in contemporary odontocetes and mysticetes. Using Dual-Energy X-Ray Absorptiometry here we report that the deposition of bone mineral in fetal and newborn specimens of the fin whale Balaenoptera physalus is remarkably higher in the bulla tympanica than in the adjacent basal skull or in the rest of the skeleton. Ossification of the tympanic bulla in fetal Artiodactyla (bovine, hippopotamus is minimal, becomes sensible after birth and then progresses during growth, contrarily to the precocious mineralization that we observed in fin whales. Given the importance of the ear bones for the precise identification of phylogenetic relationship in therian evolution , this feature may indicate a specific evolutionary trait of fin whales and possibly other cetacean species or families. Early mineralization of the tympanic bulla allows immediate sound conduction in the aquatic medium and consequently holds potential importance for mother-calf relationship and postnatal survival.
Gottschling, Marc; Bravo, Ignacio G; Schulz, Eric; Bracho, Maria A; Deaville, Rob; Jepson, Paul D; Van Bressem, Marie-Françoise; Stockfleth, Eggert; Nindl, Ingo
The phylogenetic position of cetacean papillomaviruses (PVs: Omikron-PVs and Upsilon-PVs) varies depending on the region of the genome analysed. They cluster together with Alpha-PVs when analysing early genes and with Xi-PVs and Phi-PVs when analysing late genes. We cloned and sequenced the complete genomes of five novel PVs, sampled from genital and oesophageal lesions of free-ranging cetaceans: Delphinus delphis (DdPV1), Lagenorhynchus acutus (TtPV3 variant), and Phocoena phocoena (PphPV1, PphPV2, and PphPV3). Using Maximum Likelihood and Bayesian approaches, all cetacean PVs constituted a monophyletic group with Alpha-, Omega-, and Dyodelta-PVs as inferred from E1-E2 early genes analyses, thus matching the shared phenotype of mucosal tropism. However, cetacean PVs, with the exception of PphPV3, were the closest relatives of Xi-PVs and Phi-PVs in L2-L1 late genes analyses, isolated from cow and goat, thus reflecting the close relationship between Cetacea and Artiodactyla. Our results are compatible with a recombination between ancestral PVs infecting the Cetartiodactyla lineage. Our study supports a complex evolutionary scenario with multiple driving forces for PV diversification, possibly including recombination and also interspecies transmission. Copyright © 2010 Elsevier Inc. All rights reserved.
Moskalev, Alexey А; Kudryavtseva, Anna V; Graphodatsky, Alexander S; Beklemisheva, Violetta R; Serdyukova, Natalya A; Krutovsky, Konstantin V; Sharov, Vadim V; Kulakovskiy, Ivan V; Lando, Andrey S; Kasianov, Artem S; Kuzmin, Dmitry A; Putintseva, Yuliya A; Feranchuk, Sergey I; Shaposhnikov, Mikhail V; Fraifeld, Vadim E; Toren, Dmitri; Snezhkina, Anastasia V; Sitnik, Vasily V
Gray whale, Eschrichtius robustus (E. robustus), is a single member of the family Eschrichtiidae, which is considered to be the most primitive in the class Cetacea. Gray whale is often described as a "living fossil". It is adapted to extreme marine conditions and has a high life expectancy (77 years). The assembly of a gray whale genome and transcriptome will allow to carry out further studies of whale evolution, longevity, and resistance to extreme environment. In this work, we report the first de novo assembly and primary analysis of the E. robustus genome and transcriptome based on kidney and liver samples. The presented draft genome assembly is complete by 55% in terms of a total genome length, but only by 24% in terms of the BUSCO complete gene groups, although 10,895 genes were identified. Transcriptome annotation and comparison with other whale species revealed robust expression of DNA repair and hypoxia-response genes, which is expected for whales. This preliminary study of the gray whale genome and transcriptome provides new data to better understand the whale evolution and the mechanisms of their adaptation to the hypoxic conditions.
Park, Travis; Marx, Felix G; Fitzgerald, Erich M G; Evans, Alistair R
The pygmy right whale, Caperea marginata, is the least understood extant baleen whale (Cetacea, Mysticeti). Knowledge on its basic anatomy, ecology, and fossil record is limited, even though its singular position outside both balaenids (right whales) and balaenopteroids (rorquals + grey whales) gives Caperea a pivotal role in mysticete evolution. Recent investigations of the cetacean cochlea have provided new insights into sensory capabilities and phylogeny. Here, we extend this advance to Caperea by describing, for the first time, the inner ear of this enigmatic species. The cochlea is large and appears to be sensitive to low-frequency sounds, but its hearing limit is relatively high. The presence of a well-developed tympanal recess links Caperea with cetotheriids and balaenopteroids, rather than balaenids, contrary to the traditional morphological view of a close Caperea-balaenid relationship. Nevertheless, a broader sample of the cetotheriid Herpetocetus demonstrates that the presence of a tympanal recess can be variable at the specific and possibly even the intraspecific level. © 2017 Wiley Periodicals, Inc.
Full Text Available There was a fauna of baleen whales (Cetacea: Mysticeti in the Central Paratethys, a Miocene water body which covered the area of present-day Central Europe. Most of the fossil baleen whales from the Central Paratethys have been found in strata assigned to the regional Badenian age and comprise endemic forms, known only from this region. Here a new description is provided for a fragmentary skeleton of a whale found in Belgrade, Serbia, and its age context and biological aspects are discussed. This specimen, consisting of a fragmentary horizontal ramus of the mandible and eight caudal vertebrae, is tentatively identified as ?Parietobalaena sp., a globally known Miocene taxon, with related forms having been recorded earlier from the Eastern Paratethys. An early Sarmatian age (i.e., about 12.7-12.4 Ma is proposed for the specimen. Based on epiphyseal fusion of caudal vertebrae, the specimen’s age is identified as a subadult, with a body length of around 2.5 m and an estimated adult body length around 3-3.5 m, which is extremely small for baleen whales. This find represents one of the latest records of baleen whales in the Central Paratethys and one of the latest published records of Parietobalaena-like taxa in the world.
Robert W Meredith
Full Text Available Vestigial structures occur at both the anatomical and molecular levels, but studies documenting the co-occurrence of morphological degeneration in the fossil record and molecular decay in the genome are rare. Here, we use morphology, the fossil record, and phylogenetics to predict the occurrence of "molecular fossils" of the enamelin (ENAM gene in four different orders of placental mammals (Tubulidentata, Pholidota, Cetacea, Xenarthra with toothless and/or enamelless taxa. Our results support the "molecular fossil" hypothesis and demonstrate the occurrence of frameshift mutations and/or stop codons in all toothless and enamelless taxa. We then use a novel method based on selection intensity estimates for codons (omega to calculate the timing of iterated enamel loss in the fossil record of aardvarks and pangolins, and further show that the molecular evolutionary history of ENAM predicts the occurrence of enamel in basal representatives of Xenarthra (sloths, anteaters, armadillos even though frameshift mutations are ubiquitous in ENAM sequences of living xenarthrans. The molecular decay of ENAM parallels the morphological degeneration of enamel in the fossil record of placental mammals and provides manifest evidence for the predictive power of Darwin's theory.
Deméré, Thomas A; McGowen, Michael R; Berta, Annalisa; Gatesy, John
The origin of baleen in mysticete whales represents a major transition in the phylogenetic history of Cetacea. This key specialization, a keratinous sieve that enables filter-feeding, permitted exploitation of a new ecological niche and heralded the evolution of modern baleen-bearing whales, the largest animals on Earth. To date, all formally described mysticete fossils conform to two types: toothed species from Oligocene-age rocks ( approximately 24 to 34 million years old) and toothless species that presumably utilized baleen to feed (Recent to approximately 30 million years old). Here, we show that several Oligocene toothed mysticetes have nutrient foramina and associated sulci on the lateral portions of their palates, homologous structures in extant mysticetes house vessels that nourish baleen. The simultaneous occurrence of teeth and nutrient foramina implies that both teeth and baleen were present in these early mysticetes. Phylogenetic analyses of a supermatrix that includes extinct taxa and new data for 11 nuclear genes consistently resolve relationships at the base of Mysticeti. The combined data set of 27,340 characters supports a stepwise transition from a toothed ancestor, to a mosaic intermediate with both teeth and baleen, to modern baleen whales that lack an adult dentition but retain developmental and genetic evidence of their ancestral toothed heritage. Comparative sequence data for ENAM (enamelin) and AMBN (ameloblastin) indicate that enamel-specific loci are present in Mysticeti but have degraded to pseudogenes in this group. The dramatic transformation in mysticete feeding anatomy documents an apparently rare, stepwise mode of evolution in which a composite phenotype bridged the gap between primitive and derived morphologies; a combination of fossil and molecular evidence provides a multifaceted record of this macroevolutionary pattern.
Marcos César de Oliveira Santos
Full Text Available The São Paulo state (SP coast (23º18'S, 44º42'W; 25º14'S, 48º01'W is of approximately 600 km in length, bordering the Western Atlantic Ocean, in southeastern Brazil. Cetacean sightings and strandings have long been observed throughout this area. Scattered data from scientific publications, skeletal remains in museums, photographs and articles from newspaper files, universities and aquaria have been organised and updated since 1993. Field investigations on strandings and sightings have also been conducted. A total of 29 cetacean species have been recorded, including 7 baleen whales (Mysticeti and 22 toothed whales (Odontoceti, as follows: Balaenoptera physalus, B. borealis, B. edeni, B. acutorostrata, B. bonaerensis, Megaptera novaeangliae, Eubalaena australis, Physeter macrocephalus, Kogia breviceps, K. sima, Berardius arnuxii, Mesoplodon europaeus, M. mirus, Ziphius cavirostris, Orcinus orca, Feresa attenuata, Globicephala melas, G. macrorhynchus, Pseudorca crassidens, Delphinus capensis, Lagenodelphis hosei, Steno bredanensis, Tursiops truncatus, Stenella frontalis, S. longirostris, S. coeruleoalba, Lissodelphis peronii, Sotalia guianensis and Pontoporia blainvillei. Several species have been observed only once and include strays from their areas of common distribution, as well as species with known preferences for offshore distribution. Others, such as P. blainvillei and S. guianensis, are common coastal dwellers year-round. Z. cavirostris, P. crassidens and L. hosei are reported for the first time on the SP coast.A costa do Estado de São Paulo (SP (23º18'S, 44º42'O; 25º14'S, 48º01'O apresenta aproximadamente 600 km de extensão voltada para o Oceano Atlântico Ocidental no sudeste do Brasil. Registros de encalhes e de avistamentos de cetáceos vêm sendo realizados ao longo desse litoral. Desde 1993, dados obtidos em literatura científica, material osteológico encontrado em museus, fotografias e artigos de arquivos de jornais
Full Text Available Abstract Papers on mammalogy published on the main Italian journals from 1980 to 2003: trends and analysis We analysed articles on mammalogy published from 1980 to 2003 in the main journals published in Italy: Italian Journal of Zoology (IJZ, Ethology Ecology & Evolution (EEE and Hystrix. The number of articles increased throughout the study period as well as the average number of authors. The observed frequency of paper on Carnivora Rodentia and Arctiodactyla is higher than expected on the basis of their richness, here assumed as a index of their availability for researchers. This data could be interpreted as the effect of an increased availability of funds provided by Local Administration for game management (Arctiodactyla, the attractiveness of predators and the possibility to do research at community level with small grants (Rodentia. The hypothesis is supported by a very low research effort devoted to Cetacea and Chiroptera. We observed a decreasing trend in frequency of paper concerning "traditional" approaches, a stabilisation of paper concerning mammal zoogeography and eco-ethology and a linear increase in emerging subject such as game management, conservation biology and ecotoxicology. From a quantitative point of view, Hystrix is comparable to IJZ and EEE; however, printing punctuality must be considerably improved. Riassunto È stata analizzata, sotto il profilo quali-quantitativo, la produzione di articoli teriologici pubblicata su Italian Journal of Zoology, Ethology Ecology & Evolution e Hystrix fra il 1980 e il 2003. La quantità di articoli tende ad aumentare nel tempo, al pari del numero medio di autori per articolo. La frequenza di articoli inerenti Carnivori, Roditori e Artiodattili è maggiore di quanto atteso sulla base della ricchezza di specie in Italia, assunta come indice della disponibilità di specie nella
Full Text Available The archipelago of the Azores is like an oasis in the middle of the Atlantic Ocean. Surrounded by deep waters, those islands are a “must stop” place for every traveler, including, of course, cetaceans. Around the archipelago more than 24 different species of whales and dolphins can be seen. Some of them are resident such as the common dolphin or the emblematic sperm whale. But others are seasonal or sporadic, such as the spotted dolphin or the big baleen whales. The aim of this study is to assess the temporal distribution of the baleen whales sighted off Azores. We analyzed data gathered off the south coast of São Miguel (Azores from 2006 to 2013 from whale watching vessels. The whale watching company is located in Ponta Delgada and it works all throughout the year, always when the weather, the sea state and the number of tourists allow doing it. In Azores, whale watching companies use to locate cetaceans from land, with specialized lookouts spotting the animals from strategic points on the shore (as whalers did. These lookouts use powerful binoculars to locate the animals, and then give instructions to the boats to get to them. Once there, the boat registers date, hour, sea state, visibility, position (GPS, species, number of individuals, number of adults, juveniles and calves, behavior, association with other species and if there are other boats in the area. Photos are taken whenever it is possible and they are analyzed when the quality is good enough to distinguish natural marks and shapes. Most of the photos used in this study were taken in the last 5 years. Photo-Id catalogues were created for blue whales, fin whales and humpback whales. Data collected are more complete and frequent since 2009. In this case we have analyzed a total of 7691 sightings, belonging to 20 different species of cetaceans, 14 Odontoceti and 6 Mysticeti. In the latter group we recorded 491 sightings. The three most sighted Mysticeti species were the three great
Adams, Josh; Felis, Jonathan J.; Mason, John W.; Takekawa, John Y.
(-2) and similar during winter (37.4 ± 4.6 birds km-2) and summer (37.5 ± 6.4 birds km-2). Within the outer-shelf domain (100 – 200-m depth), average densities for all marine birds combined were greatest during winter (34.6 ± 4.2 birds km-2), lesser during fall (16.2 ± 1.7 birds km-2), and least during summer (6.9 ± 1.1 birds km-2). Within the farthest offshore waters over the continental slope domain (200 – 2000-m depth) average densities for all marine birds combined were greatest during fall (10.0 ± 2.2 birds km-2) and winter (9.3 ± 1.5 birds km-2), and lesser during summer (6.2 ± 1.4 birds km-2). We observed 16 cetacean species and five pinniped species. Among the Mysticeti (baleen whales), humpback whales (Megaptera novaeangliae) were most frequently observed (114 sightings of 264 individuals) during summer and fall mostly over the outer-shelf and slope waters, however, individuals were also seen within the Siltcoos, Nehalem, Fort Bragg, and Eureka Focal Areas. We recorded 11 Odontoceti (toothed whale) species. Harbor porpoises (Phocoena phocoena) were the most frequently sighted (164 sightings of 270 individuals). Harbor porpoises were present year-round and most frequently sighted within the inner-shelf domain throughout the entire study area in all seasons. Harbor porpoises occurred in all six Focal Areas, with noteworthy aggregations within the Eureka, Siltcoos, and Grays Harbor Focal Areas. We recorded 246 sightings of 375 individual pinnipeds (5 species). California sea lions (Zalophus californianus) were the most frequently sighted and were present year-round with slightly more sightings recorded during the fall. California sea lions showed a decreasing frequency of sightings and relative abundance with distance from shore across the bathymetric domains surveyed, being most frequently observed over the inner-shelf. Northern elephant seals (Mirounga angustirostris), harbor seals (Phoca vitulina), and northern fur seals (Callorhinus ursinus) were