Arimidelphis sorbinii is a new genus and a new species of Delphinidae (Cetacea, Odontoceti) based on an incomplete skull with right ear bones, mandible, teeth and left forelimb, all from one animal, from the Late Pliocene sediments of Marecchia river (Central Eastern Italy). This specimen had previously been wrongly referred to the fossil species Tursiops osennae. Arimidelphis shows some affinities with killer whale (Orcinus), as the short rostrum, the very strong preorbital process with circ...
Luis Felipe Silva Pereira Mayorga
Full Text Available This study presents the first stranding records of Ziphius cavirostris (Ziphius cavirostris Cuvier, 1823 (Cetacea, Odontoceti in the state of Espírito Santo, Brazil. The first occurrence was recorded in the second half of 2007 on Trindade Island (20°30’46,82”S, 29°18’26,32”O, a volcanic island located 1.167km away from the mainland, where morphometric data were not collected. The other occurrence was recorded in the second half of 2009 in the city of Vila Velha (20º22’570”S, 40º18’292”O, where morphometric data were collected.
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.
Gutstein, Carolina Simon; Cozzuol, Mario Alberto; Pyenson, Nicholas D
"River dolphins" are a paraphyletic group of toothed whales (Odontoceti) that represent independent secondary invasions of freshwater habitats. Different "river dolphin" lineages display suites of convergent morphological specializations that commonly reflect adaptations to riverine and freshwater environments, such as longirostry, reduced orbits, and wide, paddle-like flippers. One lineage, the Iniidae, is presently endemic to South America, and includes several extinct Neogene taxa along with their sole extant genus, Inia (the Amazon River dolphin). We report here a humerus recovered from the late Miocene deposits of the Ituzaingó Formation in the Paraná Basin of Argentina. The specimen exhibits diagnostic features of the family Iniidae, including a scapular-sternal joint of the humerus, which is a unique anatomical connection among mammals. This joint permits enhanced parasagittal adduction of the flipper as a control surface, relative to other odontocetes, providing Inia with a high degree of maneuverability in its structurally complex and heterogenous riverine habitat. This unique anatomical connection, here documented from the late Miocene (∼9 million years-6.5 million years old), not only provides the oldest diagnostic record for Iniidae, but it also indicates a similar habitat use for this lineage, a finding coincident with the current paleoenvironmental interpretation for the Ituzaingó Formation.
Morfologia do sincrânio do boto-cinza, Sotalia guianensis (P.J. van Bénéden (Cetacea, Delphinidae Syncranial morphology of the estuarine dolphin Sotalia guianensis (P.J. van Bénéden (Cetacea, Delphinidae
Paulo C. Simões-Lopes
Full Text Available Apresenta-se uma descrição da morfologia comparada do sincrânio de Sotalia guianensis (P.J. van Bénéden, 1864, incluindo suas variações ontogenéticas e intra-específicas. As descrições foram baseadas em 51 crânios completos ou parciais depositados na coleção do laboratório de Mamíferos Aquáticos, do Departamento de Ecologia e Zoologia, CCB, Universidade Federal de Santa Catarina. O sincrânio é bastante homogêneo e manifesta sua assimetria na morfologia dos ossos, passagens nasais e forames. O rostro é proporcionalmente estreito em relação aos outros Delphinidae do mesmo porte. A região temporal é circular em indivíduos jovens, mas se torna oval nos adultos onde se forma uma crista temporal evidente. O forame elíptico do periótico está presente tanto em indivíduos jovens quanto adultos. Os nasais são bipartidos e podem ocorrer ossos suturais entre os frontais. O processo hamular dos pterigóides é bastante inflado e fenestrado. A sínfise mandibular alcança de 19 de 19-23% do comprimento do dentário. Cada pré-maxilar e maxilar possui de 30-35 dentes e cada dentário de 30-38 dentes.Morphological and comparative description of the syncranium of Sotalia guianensis (P.J. van Bénéden, 1864, including ontogenic aspects and intraspecific variations are presented. The descriptions were based on the examination of 51 complete or partial skulls, kept at the Marine Mammals Lab. Collection from the Departamento de Ecologia e Zoologia, CCB, at the Federal University of Santa Catarina. The sincranium is very homogeneous and manifests its asymmetry in the morphology of the bones, nasal passages and foramina. The rostrum is proportionally narrow in relation to other Delphinidae of the same size. The temporal region is circular in young specimens, but it becomes oval in the adults were it forms a well marked temporal crest. The elliptical foramen of the periotic bone is present both in young and adult individuals. The nasals
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 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.
Cerioni, S; Mariniello, L
The striped dolphin represents the most common species of cetacean stranded along the Italian coasts. A parasitological survey on 17 specimens of Stenella coerulecaiba stranded along coasts of Latium from 1985 to 1991, has been carried out. The morphological study enabled the identification of the following parasites. The sites are reported in brackets. DIGENEA: Campula rochebruni (liver), Campula palliata (liver), Pholeter gastrophilus (pyloric stomach). CESTODA: Tetrabothrium forsteri (intestine), Strobilocephalus triangularis (intestine), Monorygma grimaldii, larvae (abdominal cavity, mesentery, testes), Phyliobothrium delphini, larvae (subcutaneous fat). NEMATODA: Skrjabinalius sp. (lungs). COPEPODA: Pennella sp. (skin). ISOPODA: Ceratothoa parallela (mouth, stomach). AMPHIPODA: Syncyamus aequus (blowhole).
Figueroa, L; Puga, S
The finding of Corynosoma cetaceum Johnston and Best 1942, as a parasite of Cephalorhynchus eutropia Gray, 1846, is reported. This constitutes the first record of this acanthocephala in a new host, as well a new geographic distribution.
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.
SIMON GUTSTEIN, CAROLINA
La evolucion de la ecolocalizacion en los odontocetos ha sido ampliamente estudiada y consiste en la emision de un haz de sonido de alta recuencia, recepcion de ecos del sonido emitido y su procesamiento neurologico. La ecolocalizacion, comun a todos los odontocetos actuales, se diferencia en las propiedades acusticas entre los taxones y tal vez en la preferencia de habitat. Se ha estudiado la emision de sonidos de alta frecuencia y la formación del haz de sonido, tanto con modelos computacio...
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.
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.
Site fidelity of Sotalia guianensis (Cetacea: Delphinidae in Sepetiba Bay, Rio de Janeiro, Brazil Fidelidade de área de Sotalia guianensis (Cetacea: Delphinidae na Baía de Sepetiba, Rio de Janeiro, Brasil
Mariana F. Nery
Full Text Available Estuarine dolphins, Sotalia guianensis (Van Bénéden, 1864, were identified in Sepetiba Bay (22º35'S, 44º03'W, state of Rio de Janeiro, Brazil, between February 1994 and July 2006 using the photo-identification method. A total of 72 surveys resulted in the identification and cataloguing of 217 individual dolphins. Seventy-nine (36% were resighted at least once during the study period. The average interval between resightings was 40,6 ± 31,1 months. Large numbers of mother-and-calf pairs were recorded during the 12 years and new individuals were frequently encountered in the photographic records. These results suggest that part of the dolphin population is more consistently found in Sepetiba Bay, probably for feeding and reproduction, while other individuals use the Bay only sporadically.Indivíduos da população dos golfinhos estuarinos, Sotalia guianensis (Van Bénéden, 1864, da Baía de Sepetiba (22º35'S, 44º03'W Estado do Rio de Janeiro, sudeste do Brasil, foram catalogados pelo método de foto-identificação durante o período de fevereiro de 1994 a julho de 2006. Foram conduzidas 72 expedições de barco, resultando na identificação e catalogação de 217 botos. Destes 79 (36,4% foram recapturados pelo menos uma vez durante o período de estudo; o intervalo médio entre as recapturas foi de 40,6 ± 31,1 meses. A presença de pares de mães-filhotes foi numerosa ao longo dos 12 anos de estudo e novos indivíduos foram constantemente identificados na área. Os resultados sugerem que parte desta população depende substancialmente do habitat fornecido pela Baía de Sepetiba, tanto para alimentação quanto para fins de reprodução, apesar de haver indivíduos que pouco se utilizam desta área.
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.
Full Text Available Cetaceans present a group structure of great complexity and display a wide behavioral plasticity. Many efforts have been made to understand the group structures of the various species, however, this type of information is still lacking for some species. Therefore, our objectives were to 1 characterize the structure of the Sotalia guianensis groups in Ilha Grande Bay, Rio de Janeiro, Brazil, and 2 investigate how both behavior and season influence the group structure of this population. This species is considered "data deficient" by the IUCN. We conducted 28 boat trips using group focal procedures, and a total of 1,314 groups were observed. Of these groups, 1,268 (94.4% contained calves, the largest percentage ever reported for the species. Groups with calves were larger than those without them, suggesting a strategy to protect these individuals with underdeveloped physiology. The mean group sizes reached 17.6 ± 18.3 individuals. Within these groups, we observed that both behavior (H = 112.5, d.f. = 2, P < 0.05 and season (number of simulations: 10,000; sample size of fall-winter = 544; sample size of spring-summer = 684; P < 0.05, demonstrated a statistically significant influence. The most common degree of cohesion was mixed, and cohesion also varied with behavior (χ2 = 10.1, P < 0.05 and season (χ2 = 31.0, P < 0.05. This paper contributes towards understanding the highly variable nature of S. guianensis group dynamics. These data may be important in understanding the structure of groups in a site that is being increasingly impacted by different human activities. Moreover, this area contains the largest aggregation ever observed for this species and may therefore represent an important source of genetic diversity for the species as a whole.
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.
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.
McGowen, Michael R; Gatesy, John; Wildman, Derek E
Cetacea (whales, dolphins, and porpoises) is a model group for investigating the molecular signature of macroevolutionary transitions. Recent research has begun to reveal the molecular underpinnings of the remarkable anatomical and behavioral transformation in this clade. This shift from terrestrial to aquatic environments is arguably the best-understood major morphological transition in vertebrate evolution. The ancestral body plan and physiology were extensively modified and, in many cases, these crucial changes are recorded in cetacean genomes. Recent studies have highlighted cetaceans as central to understanding adaptive molecular convergence and pseudogene formation. Here, we review current research in cetacean molecular evolution and the potential of Cetacea as a model for the study of other macroevolutionary transitions from a genomic perspective.
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
Cleaned skeletons of 658 specimen of 47 species of Odontoceti and 44 skeletons of 10 species of Mysticeti were examined for evidence of pathological changes, especially of the vertebrae. Beside the examination of the cleaned skeletons, 132 spinal columns of seven species of Odontoceti were studied d
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 m
Bianucci, Giovanni; Di Celma, Claudio; Urbina, Mario; Lambert, Olivier
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.
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.
Fernanda Menezes de Oliveira e Silva
Os linfócitos, principais células do sistema imune, podem ser encontrados em órgãos e tecidos de dois grandes sistemas do corpo: o sistema linfático, composto por uma extensa rede de vasos linfáticos e linfonodos; e o sistema linfoide, mais abrangente e que, além de englobar o sistema linfático, abrange todas as células, tecidos e órgãos do corpo que contêm agregados linfocitários, tais como o timo, baço e linfonodos. Embora esteja amplamente descrito para animais domésticos e alguns animais ...
Urbina, Mario; Lambert, Olivier
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. PMID:27688973
Mário César Sedrez
Full Text Available This article reports the necropsy of a specimen of striped dolphin Stenella coeruleoalba found stranded in the north coast of Terceira Island, Azores, Portugal. Here, the importance of standard protocols in post-mortem examinations and the need to adequately proceed were discussed. Stranded marine mammals are valuable specimens for several studies of pathology and other veterinary medical aspects. Although the causa mortis was not determined, the full access to stranded specimens was crucial, not only for pathology studies but also for a proper training to veterinary medicine students whenever possible.
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.
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.
Marcos C. de O. Santos
Full Text Available The aim of the present study was to provide a preliminary description of habitat use by Guiana dolphins, Sotalia guianensis (Van Bénéden, 1864 in the Paranaguá Estuarine Complex (PEC, state of Paraná, Brazil. Approximately 124 km² were surveyed by small boat from April 2006 to July 2008 in the following subsets of the PEC: Canal do Superagui (~28 km²; Pinheiros Bay (~34 km²; part of Laranjeiras Bay, which included the Guaraqueçaba sub-estuary (~38 km²; and part of the Mixture Section of the PEC (~24 km². Our efforts were unevenly distributed in the study area. During 55 survey days covering seven distinct seasons, we spent 165 hours observing 323 groups of S. guianensis. Group size varied from two individuals to aggregations as large as approximately 100 dolphins. A total of 49,921 photographs were analyzed; 15,038 (30% were considered useful for identification purposes. A total of 182 individuals were catalogued, from which 122 (67% were cataloged in the last three seasons, when the surveyed area was expanded. The number of individual sightings in distinct days varied from one to 16. A total of 94 individuals (51.6% were re-sighted at least once. From the 37 individuals cataloged in the first season, 18 (48.6% were re-sighted in the last season. Eleven individuals with 5+ sightings were always observed in the same subset of the estuary, including an individual with 13 sightings. Sixteen individuals with three to 16 sightings were observed in three of the four estuary subsets surveyed. An individual cataloged in May 2002 in a pilot study was re-sighted up to August 2006. Our preliminary results correspond to the first evidence of site fidelity for several monitored individuals; it also revealed, for the first time, the flexibility of movements throughout the entire estuarine complex by several other individuals
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.
[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).
Fettuccia, Daniela de Castro
Apesar da existência de importantes trabalhos morfológicos para as duas espécies do gênero Sotalia, é limitado o conhecimento do esqueleto como um todo, considerando a variação ontogenética inter e intraespecífica, geográfica e sexual. Com o intuito de contribuir para um melhor conhecimento osteológico e fornecer subsídios para a conservação foram avaliados 536 sincrânios e 257 pós-crânios parciais e completos de S. guianensis (boto-cinza) de várias localidades da América do...
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
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.
Luana Caroline Souza Barroso
Full Text Available A espécie Sotalia fluviatilis é pouco conhecida na região amazônica, principalmente no estado do Amapá, onde estudos são bastante escassos. O presente estudo tem por objetivo contribuir para o aumento do conhecimento sobre o padrão comportamental e percepção dos barqueiros sobre S. fluviatilis no porto do açaí. Este trabalho foi realizado em um ponto fixo localizado no Porto do Açaí. As observações foram feitas mensalmente no período de julho de 2013 a dezembro de 2013 em período matutino, junto às entrevistas com os barqueiros presentes no porto com a aplicação de um questionário de pesquisa com TCLE. Os padrões comportamentais mais frequentes observados pelo tucuxi foram deslocamento lento, deslocamento rápido e forrageio. Com relação a percepção dos barqueiros quando perguntados a maior parte dos barqueiros afirmou ver o boto tucuxi com frequência no porto, em grupos de dois a três indivíduos, realizando atividade de alimentação/forrageio. A presença maior da espécie no período de maré alta foi afirmada pelos entrevistados, corroborando com os dados de observação in loco. Segundo os entrevistados o tucuxi quando avistado localiza-se as margens do rio e que a presença da espécie é atribuída à alimentação descartada pelos vendedores de peixe do local e que hoje há menos animais em relação à 5 anos. Nesse sentido, espera-se o presente estudo contribua para informações sobre áreas de ocorrência de S. fluviatilis e futuramente subsidiar medidas de conservação para a espécie, tendo em vista a iminência da construção de um porto de escoamento de soja nas proximidades da área. Palavras-chave: Conhecimento popular, Etologia, região norte, cetáceos. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v5n4p119-124
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.
The influence of seasonality, tide and time of activities on the behavior of Sotalia guianensis (Van Bénéden (Cetacea, Delphinidae in Pernambuco, Brazil Influência da sazonalidade, maré e horário de atividades sobre o comportamento de Sotalia guianensis (Van Bénéden (Cetacea, Delphinidae em Pernambuco, Brasil
Janaina P. Araújo
Full Text Available Data on Sotalia guianensis Van Bénéden, 1864 occurrence on the beaches of Pernambuco (Northeastern Brazil is restricted to information on stranding and on printed material from local newspapers; actual observations of such animals have not been published. This study intends to determine the use of habitat, behavioral activities and assess the relationships between environmental factors and the recorded behavior. Observations were conducted on open sea coastal areas, on the beaches of Olinda and Piedade, as well as in sheltered areas, in the ports of Recife and Suape. Monitoring was carried out every month in each area, during two consecutive days, from September 2004 to August 2005. Results corroborate that this species prefers to occupy more protected environments, the port of Recife being the main concentration area for such species. Piedade is just an exploratory area, possibly due to shark occurrence. Olinda is only occasionally used. Concentration areas seem to be used for feeding, and incidence of caudal exhibition suggests that most of the estuarine dolphin prey items are demersal. Environmental conditions (seasonality, tide and time did not show to be significant when related to the estuarine dolphin behavior.Dados sobre a ocorrência de Sotalia guianensis Van Bénéden, 1864 nas praias pernambucanas (Nordeste do Brasil estão limitados a informações de encalhes e de matérias impressas nos jornais locais, sendo inéditas observações efetivas desses animais. Este estudo pretende determinar o uso do habitat, comportamento e avaliar as relações entre fatores ambientais e as condutas registradas. Observações foram realizadas tanto em áreas costeiras de mar aberto, nas praias de Olinda e Piedade, quanto em áreas abrigadas, nos Portos do Recife e Suape. O monitoramento foi realizado por dois dias consecutivos por mês em cada área, no período de setembro de 2004 a agosto de 2005. Os resultados corroboram a preferência da espécie em ocupar ambientes mais protegidos, sendo o porto do Recife o principal ponto de concentração da espécie. Piedade é apenas uma área exploratória, possivelmente pela ocorrência de tubarões. Olinda tem uso ocasional. As áreas de concentração parecem estar destinadas à alimentação, e a incidência de condutas caudais sugere que a maioria das presas dos botos-cinza é demersal. As condições ambientais (sazonalidade, maré e horário não se mostraram significativas quando relacionadas com as condutas realizadas pelos botos-cinza.
Behavioral patterns and movement intensity of Sotalia guianensis (P. J. van Bénéden (Cetacea, Delphinidae in two different areas on the Brazilian coast Padrões comportamentais e intensidade de movimentos de Sotalia guianensis (P. J. van Bénéden (Cetacea, Delphinidae em duas diferentes áreas da costa brasileira
Fábio G. Daura-Jorge
Full Text Available The behavioral patterns of the estuarine dolphin, Sotalia guianensis (P. J. van Bénéden, 1864, were compared between two populations along the Brazilian coast: Caravelas (Bahia, along the eastern coast, and Norte Bay (Santa Catarina, along the southern coast. Applying the focal-group sampling in both areas, information such as the geographic position (UTM of groups and predominant behavioral patterns were obtained. Geographic positions were used to calculate the total distance traveled by estuarine dolphin groups on each observation day. Since the distance traveled varies with time, the daily mean speed of the dolphin’s group was used as an index of movement intensity. Two comparable and easily recognizable behavioral patterns were considered: travelling and foraging. Overall movement intensity and behavioral pattern frequency were similar between both areas. However, a seasonal variation was observed in both parameters in Norte Bay, while in Caravelas these parameters were homogeneous throughout the year. Variation in the behavior of the estuarine dolphin was consistent with variations in environmental factors, such as water temperature.Os padrões comportamentais do botocinza, Sotalia guianensis (P. J. van Bénéden, 1864, foram comparados entre duas populações da costa brasileira: Caravelas (Bahia, na costa leste, e Baía Norte (Santa Catarina, na costa sul. Utilizando o método de grupo-focal em ambas as áreas, informações como posições geográficas (UTM do grupo e padrão comportamental predominante foram coletadas. A posição geográfica foi utilizada para o cálculo da distância total percorrida por um grupo de botos-cinza em cada área de observação. Como a distância é uma medida que varia com o tempo, a velocidade média diária do grupo de botos foi usada como um índice de intensidade de movimento. Dois padrões comportamentais comparáveis e facilmente reconhecíveis foram considerados: deslocamento e forrageamento. A intensidade de movimentos e a freqüência dos padrões comportamentais foram similares entre as duas áreas. No entanto, foi observada uma variação sazonal dos dois parâmetros para a Baía Norte, enquanto em Caravelas estes parâmetros foram homogêneos ao longo do ano. A variação no comportamento do boto-cinza acompanhou a variação de fatores ambientais como a temperatura.
Deinse, van A.B.
Bij de beschrijving en (of) de determinatie van Cetacea speelt de staart geen belangrijke rol. Toch is er een vertegenwoordiger dier orde te noemen, waarbij de staart er zoo karakteristiek uitziet, dat hierdoor alleen reeds geslacht en soort volkomen zijn bepaald. Ik bedoel Megaptera novaeangliae (M
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.
Full Text Available Perairan Indonesia merupakan daerah ruaya (migrationdari jenis-jenis mamalia laut (marine mammals seperti paus, lumba-lumba dan ikan duyung, terutama di wilayah Indonesia bagian timur.Cetacea dan berbagai jenis biota laut peruaya lainnya termasuk jenis penyu hingga saat ini keberadaannya semakin terancam.Pemerintah Indonesia, melalui Departemen Kelautan dan Perikanan melakukan upaya perlindungan spesies bagi mamalia laut dengan membentuk dan menetapkan kawasan konservasi Laut Sawu sebagai Kawasan Konservasi Perairan Nasional (KKNP.Penetapan suatu kawasan menjadi kawasan yang dilindungi tidak lepas dari kendala dan hambatan yang dihadapinya, tetapi hambatan dan kendala ini dapat dijadikan suatu tantangan dalam mengelola sumberdaya alam yang lebih efektif.Pengelolaan yang efektif bagi mamalia laut yakni dengan tetap melindungi ekosistem dan habitatnya, melakukan penelitian dan monitoring, pemantauan terhadap illegal fishing maupun destructive fishing.Kata Kunci :Cetacea, Konservasi, Tantangan, Pengelolaan efektif
Pankaj S. Bhatnagar
Full Text Available Whales are a group of marine creatures that have elicited scientifi c and layman’s curiosity since long. The present paper has a focus on elucidating fossils of two Odontoceti families viz. Physeteridae and Monodentidae. Extant Physeteridae is a monotypic family, while Monodentidae is restricted geographically to cold waters of the Arctic and adjoining seas. Physeteridae fossil data showed a total of 28 species, while Monodentidae had only half a dozen species. Warming of the climate in the past appears to have played a role in northward migration of Monodentids.
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.
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
Fahlke, Julia M.; Hampe, Oliver
Odontoceti and Mysticeti (toothed and baleen whales) originated from Eocene archaeocetes that had evolved from terrestrial artiodactyls. Cranial asymmetry is known in odontocetes that can hear ultrasound (>20,000 Hz) and has been linked to the split function of the nasal passage in breathing and vocalization. Recent results indicate that archaeocetes also had asymmetric crania. Their asymmetry has been linked to directional hearing in water, although hearing frequencies are still under debate. Mysticetes capable of low-frequency and infrasonic hearing (<20 Hz) are assumed to have symmetric crania. This study aims to resolve whether mysticete crania are indeed symmetric and whether mysticete cranial symmetry is plesiomorphic or secondary. Cranial shape was analyzed applying geometric morphometrics to three-dimensional (3D) cranial models of fossil and modern mysticetes, Eocene archaeocetes, modern artiodactyls, and modern odontocetes. Statistical tests include analysis of variance, principal components analysis, and discriminant function analysis. Results suggest that symmetric shape difference reflects general trends in cetacean evolution. Asymmetry includes significant fluctuating and directional asymmetry, the latter being very small. Mysticete crania are as symmetric as those of terrestrial artiodactyls and archaeocetes, without significant differences within Mysticeti. Odontocete crania are more asymmetric. These results indicate that (1) all mysticetes have symmetric crania, (2) archaeocete cranial asymmetry is not conspicuous in most of the skull but may yet be conspicuous in the rostrum, (3) directional cranial asymmetry is an odontocete specialization, and (4) directional cranial asymmetry is more likely related to echolocation than hearing.
Fahlke, Julia M; Hampe, Oliver
Odontoceti and Mysticeti (toothed and baleen whales) originated from Eocene archaeocetes that had evolved from terrestrial artiodactyls. Cranial asymmetry is known in odontocetes that can hear ultrasound (>20,000 Hz) and has been linked to the split function of the nasal passage in breathing and vocalization. Recent results indicate that archaeocetes also had asymmetric crania. Their asymmetry has been linked to directional hearing in water, although hearing frequencies are still under debate. Mysticetes capable of low-frequency and infrasonic hearing (evolution. Asymmetry includes significant fluctuating and directional asymmetry, the latter being very small. Mysticete crania are as symmetric as those of terrestrial artiodactyls and archaeocetes, without significant differences within Mysticeti. Odontocete crania are more asymmetric. These results indicate that (1) all mysticetes have symmetric crania, (2) archaeocete cranial asymmetry is not conspicuous in most of the skull but may yet be conspicuous in the rostrum, (3) directional cranial asymmetry is an odontocete specialization, and (4) directional cranial asymmetry is more likely related to echolocation than hearing.
Ekdale, Eric G
Living mysticetes (baleen whales) and odontocetes (toothed whales) differ significantly in auditory function in that toothed whales are sensitive to high-frequency and ultrasonic sound vibrations and mysticetes to low-frequency and infrasonic noises. Our knowledge of the evolution and phylogeny of cetaceans, and mysticetes in particular, is at a point at which we can explore morphological and physiological changes within the baleen whale inner ear. Traditional comparative anatomy and landmark-based 3D-geometric morphometric analyses were performed to investigate the anatomical diversity of the inner ears of extinct and extant mysticetes in comparison with other cetaceans. Principal component analyses (PCAs) show that the cochlear morphospace of odontocetes is tangential to that of mysticetes, but odontocetes are completely separated from mysticetes when semicircular canal landmarks are combined with the cochlear data. The cochlea of the archaeocete Zygorhiza kochii and early diverging extinct mysticetes plot within the morphospace of crown mysticetes, suggesting that mysticetes possess ancestral cochlear morphology and physiology. The PCA results indicate variation among mysticete species, although no major patterns are recovered to suggest separate hearing or locomotor regimes. Phylogenetic signal was detected for several clades, including crown Cetacea and crown Mysticeti, with the most clades expressing phylogenetic signal in the semicircular canal dataset. Brownian motion could not be excluded as an explanation for the signal, except for analyses combining cochlea and semicircular canal datasets for Balaenopteridae. J. Morphol. 277:1599-1615, 2016. © 2016 Wiley Periodicals, Inc.
Nicholas D Pyenson; Jorge Vélez-Juarbe; Gutstein, Carolina S.; Holly Little; Dioselina Vigil; Aaron O’Dea
In contrast to dominant mode of ecological transition in the evolution of marine mammals, different lineages of toothed whales (Odontoceti) have repeatedly invaded freshwater ecosystems during the Cenozoic era. The so-called ‘river dolphins’ are now recognized as independent lineages that converged on similar morphological specializations (e.g., longirostry). In South America, the two endemic ‘river dolphin’ lineages form a clade (Inioidea), with closely related fossil inioids from marine roc...
Gingerich, Philip D.; Zouhri, Samir
Six genera and species of archaic whales are present in a new fauna from the Aridal Formation at Gueran in the Sahara Desert of southwestern Morocco. Three of the archaeocete species represent semiaquatic Protocetidae and three species are fully aquatic Basilosauridae. Protocetids are characteristic of Lutetian lower middle Eocene strata, and basilosaurids are characteristic of Priabonian late Eocene beds. Similar representation of both families is restricted to intervening Bartonian strata and indicative of a late middle Eocene age. Archaeocetes from Gueran include (1) a small protocetid represented by a partial humerus, teeth, and vertebrae; (2) a middle-sized protocetid represented by a partial innominate and proximal femur; (3) the very large protocetid Pappocetus lugardi represented by teeth, a partial innominate, and two partial femora; (4) a new species of the small basilosaurid Chrysocetus represented by a dentary, teeth, humeri, and many vertebrae; (5) a new species of the larger basilosaurid Platyosphys (resurrected as a distinct genus) represented by a partial braincase, tympanic bulla, and many vertebrae; and (6) the large basilosaurid Eocetus schweinfurthi represented by teeth, a tympanic bulla, and lumbar vertebrae. The Gueran locality is important geologically because it constrains the age of a part of the Aridal Formation, and biologically because it includes a diversity of archaic whales represented by partial skeletons with vertebrae in sequence and by forelimb and hind limb remains. With further collecting, Gueran archaeocete skeletons promise to clarify the important evolutionary transition from foot-powered swimming in Protocetidae to the tail-powered swimming of Basilosauridae and all later Cetacea.
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.
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.
Nicolle V Sydney; Emygdio La Monteiro-Filho
Most techniques used for estimating the age of Sotalia guianensis (van Bénéden, 1864) (Cetacea; Delphinidae) are very expensive, and require sophisticated equipment for preparing histological sections of teeth. The objective of this study was to test a more affordable and much simpler method, involving of the manual wear of teeth followed by decalcification and observation under a stereomicroscope. This technique has been employed successfully with larger species of Odontoceti. Twenty-six specimens were selected, and one tooth of each specimen was worn and demineralized for growth layers reading. Growth layers were evidenced in all specimens; however, in 4 of the 26 teeth, not all the layers could be clearly observed. In these teeth, there was a significant decrease of growth layer group thickness, thus hindering the layers count. The juxtaposition of layers hindered the reading of larger numbers of layers by the wear and decalcification technique. Analysis of more than 17 layers in a single tooth proved inconclusive. The method applied here proved to be efficient in estimating the age of Sotalia guianensis individuals younger than 18 years. This method could simplify the study of the age structure of the overall population, and allows the use of the more expensive methodologies to be confined to more specific studies of older specimens. It also enables the classification of the calf, young and adult classes, which is important for general population studies.
Cláudio L. S. Sampaio
Full Text Available Few studies have registered signs of mutilation on cetaceans in Brazil, especially from shark attacks. This work describes interactions between cookiecutter sharks Isistius spp. and cetaceans through the analysis of bite records for cetacean carcasses washed ashore on the Bahia coast between 1996 and 2005. Twenty bite records were analyzed in 13 cetacean species, of which the Delphinidae family was the most frequent. After the analysis, Isistius plutodus was identified as the aggressor species on 80% of the records, followed by I. brasiliensis (20%, based on the characteristic shape of the mutilations. The areas most subject to attack in cetaceans were: flanks 40%; head and abdomen 20% each; dorsal 15%; and genital with 5%. The relatively high number of bites on the flanks was probably due to its larger area, which offered greater opportunities to the cookiecutter shark. At least three bite records were related to the possible causes of strandings in delphinids. We recommend further studies on interactions between sharks and cetaceans along the Brazilian coast.
Nicholas D. Pyenson
Full Text Available In contrast to dominant mode of ecological transition in the evolution of marine mammals, different lineages of toothed whales (Odontoceti have repeatedly invaded freshwater ecosystems during the Cenozoic era. The so-called ‘river dolphins’ are now recognized as independent lineages that converged on similar morphological specializations (e.g., longirostry. In South America, the two endemic ‘river dolphin’ lineages form a clade (Inioidea, with closely related fossil inioids from marine rock units in the South Pacific and North Atlantic oceans. Here we describe a new genus and species of fossil inioid, Isthminia panamensis, gen. et sp. nov. from the late Miocene of Panama. The type and only known specimen consists of a partial skull, mandibles, isolated teeth, a right scapula, and carpal elements recovered from the Piña Facies of the Chagres Formation, along the Caribbean coast of Panama. Sedimentological and associated fauna from the Piña Facies point to fully marine conditions with high planktonic productivity about 6.1–5.8 million years ago (Messinian, pre-dating the final closure of the Isthmus of Panama. Along with ecomorphological data, we propose that Isthminia was primarily a marine inhabitant, similar to modern oceanic delphinoids. Phylogenetic analysis of fossil and living inioids, including new codings for Ischyrorhynchus, an enigmatic taxon from the late Miocene of Argentina, places Isthminia as the sister taxon to Inia, in a broader clade that includes Ischyrorhynchus and Meherrinia, a North American fossil inioid. This phylogenetic hypothesis complicates the possible scenarios for the freshwater invasion of the Amazon River system by stem relatives of Inia, but it remains consistent with a broader marine ancestry for Inioidea. Based on the fossil record of this group, along with Isthminia, we propose that a marine ancestor of Inia invaded Amazonia during late Miocene eustatic sea-level highs.
Pyenson, Nicholas D; Vélez-Juarbe, Jorge; Gutstein, Carolina S; Little, Holly; Vigil, Dioselina; O'Dea, Aaron
In contrast to dominant mode of ecological transition in the evolution of marine mammals, different lineages of toothed whales (Odontoceti) have repeatedly invaded freshwater ecosystems during the Cenozoic era. The so-called 'river dolphins' are now recognized as independent lineages that converged on similar morphological specializations (e.g., longirostry). In South America, the two endemic 'river dolphin' lineages form a clade (Inioidea), with closely related fossil inioids from marine rock units in the South Pacific and North Atlantic oceans. Here we describe a new genus and species of fossil inioid, Isthminia panamensis, gen. et sp. nov. from the late Miocene of Panama. The type and only known specimen consists of a partial skull, mandibles, isolated teeth, a right scapula, and carpal elements recovered from the Piña Facies of the Chagres Formation, along the Caribbean coast of Panama. Sedimentological and associated fauna from the Piña Facies point to fully marine conditions with high planktonic productivity about 6.1-5.8 million years ago (Messinian), pre-dating the final closure of the Isthmus of Panama. Along with ecomorphological data, we propose that Isthminia was primarily a marine inhabitant, similar to modern oceanic delphinoids. Phylogenetic analysis of fossil and living inioids, including new codings for Ischyrorhynchus, an enigmatic taxon from the late Miocene of Argentina, places Isthminia as the sister taxon to Inia, in a broader clade that includes Ischyrorhynchus and Meherrinia, a North American fossil inioid. This phylogenetic hypothesis complicates the possible scenarios for the freshwater invasion of the Amazon River system by stem relatives of Inia, but it remains consistent with a broader marine ancestry for Inioidea. Based on the fossil record of this group, along with Isthminia, we propose that a marine ancestor of Inia invaded Amazonia during late Miocene eustatic sea-level highs.
the Bay of Fundy might support as much as 80% of the total summer population south of the Gulf of St . Lawrence . During the high abundance levels of...Suborder Odontoceti (Toothed Whales) Family Delphinidae Family Monodontidae Beluga ( Delphinapterus leucas ) Family Physeteridae Pygmy Sperm Whale (Kogia...in spring and summer extends from the Gulf of St . Lawrence /Nova Scotia region 249 northward (Sergeant 1966; Sutcliffe and Brodie 1977). In fall and
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
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
Arnason, Ulfur; Gullberg, Anette; Janke, Axel
The evolution of the order Cetacea (whales, dolphins, porpoises) has, for a long time, attracted the attention of evolutionary biologists. Here we examine cetacean phylogenetic relationships on the basis of analyses of complete mitochondrial genomes that represent all extant cetacean families. The results suggest that the ancestors of recent cetaceans had an explosive evolutionary radiation 30-35 million years before present. During this period, extant cetaceans divided into the two primary groups, Mysticeti (baleen whales) and Odontoceti (toothed whales). Soon after this basal split, the Odontoceti diverged into the four extant lineages, sperm whales, beaked whales, Indian river dolphins and delphinoids (iniid river dolphins, narwhals/belugas, porpoises and true dolphins). The current data set has allowed test of two recent morphological hypotheses on cetacean origin. One of these hypotheses posits that Artiodactyla and Cetacea originated from the extinct group Mesonychia, and the other that Mesonychia/Cetacea constitutes a sister group to Artiodactyla. The current results are inconsistent with both these hypotheses. The findings suggest that the claimed morphological similarities between Mesonychia and Cetacea are the result of evolutionary convergence rather than common ancestry.
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.
Springer, Mark S; Gatesy, John
Various toothed whales (Odontoceti) are unique among mammals in lacking olfactory bulbs as adults and are thought to be anosmic (lacking the olfactory sense). At the molecular level, toothed whales have high percentages of pseudogenic olfactory receptor genes, but species that have been investigated to date retain an intact copy of the olfactory marker protein gene (OMP), which is highly expressed in olfactory receptor neurons and may regulate the temporal resolution of olfactory responses. One hypothesis for the retention of intact OMP in diverse odontocete lineages is that this gene is pleiotropic with additional functions that are unrelated to olfaction. Recent expression studies provide some support for this hypothesis. Here, we report OMP sequences for representatives of all extant cetacean families and provide the first molecular evidence for inactivation of this gene in vertebrates. Specifically, OMP exhibits independent inactivating mutations in six different odontocete lineages: four river dolphin genera (Platanista, Lipotes, Pontoporia, Inia), sperm whale (Physeter), and harbor porpoise (Phocoena). These results suggest that the only essential role of OMP that is maintained by natural selection is in olfaction, although a non-olfactory role for OMP cannot be ruled out for lineages that retain an intact copy of this gene. Available genome sequences from cetaceans and close outgroups provide evidence of inactivating mutations in two additional genes (CNGA2, CNGA4), which imply further pseudogenization events in the olfactory cascade of odontocetes. Selection analyses demonstrate that evolutionary constraints on all three genes (OMP, CNGA2, CNGA4) have been greatly reduced in Odontoceti, but retain a signature of purifying selection on the stem Cetacea branch and in Mysticeti (baleen whales). This pattern is compatible with the 'echolocation-priority' hypothesis for the evolution of OMP, which posits that negative selection was maintained in the common
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
Meredith, Robert W; Gatesy, John; Emerling, Christopher A; York, Vincent M; Springer, Mark S
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
Full Text Available The historic collection of fossil odontocetes (Cetacea from Monte Voltraio, near Volterra (Tuscany, Italy has been examined and lithostratigraphical and biostratigraphical investigations on the find locality have been carried out. The Monte Voltraio outcrop is referred to the Middle Pliocene, in particular to Globorotalia aemiliana and Discoaster tamalis zones. The odontocete remains are assigned to the families Kogiidae (Kogia pusilla and Delphinidae (Globicephala? etruriae and two indeterminate specimens which might belong to Hemisyntrachelus and Stenella giulii. The Middle Pliocene cetacean fauna from the Mediterranean basin (Monte Voltraio and Rio Stramonte associations includes extinct taxa or extant taxa no longer represented in this basin. The disappearance of these taxa may be linked with the Pliocene and/or Quaternary climatic deteriorations (e.g. the climatic crisis at about 2.6-2.4 MA.
McGowen, Michael R; Spaulding, Michelle; Gatesy, John
Cetaceans are remarkable among mammals for their numerous adaptations to an entirely aquatic existence, yet many aspects of their phylogeny remain unresolved. Here we merged 37 new sequences from the nuclear genes RAG1 and PRM1 with most published molecular data for the group (45 nuclear loci, transposons, mitochondrial genomes), and generated a supermatrix consisting of 42,335 characters. The great majority of these data have never been combined. Model-based analyses of the supermatrix produced a solid, consistent phylogenetic hypothesis for 87 cetacean species. Bayesian analyses corroborated odontocete (toothed whale) monophyly, stabilized basal odontocete relationships, and completely resolved branching events within Mysticeti (baleen whales) as well as the problematic speciose clade Delphinidae (oceanic dolphins). Only limited conflicts relative to maximum likelihood results were recorded, and discrepancies found in parsimony trees were very weakly supported. We utilized the Bayesian supermatrix tree to estimate divergence dates among lineages using relaxed-clock methods. Divergence estimates revealed rapid branching of basal odontocete lineages near the Eocene-Oligocene boundary, the antiquity of river dolphin lineages, a Late Miocene radiation of balaenopteroid mysticetes, and a recent rapid radiation of Delphinidae beginning approximately 10 million years ago. Our comprehensive, time-calibrated tree provides a powerful evolutionary tool for broad-scale comparative studies of Cetacea.
Montgomery, Stephen H; Geisler, Jonathan H; McGowen, Michael R; Fox, Charlotte; Marino, Lori; Gatesy, John
Cetaceans rival primates in brain size relative to body size and include species with the largest brains and biggest bodies to have ever evolved. Cetaceans are remarkably diverse, varying in both phenotypes by several orders of magnitude, with notable differences between the two extant suborders, Mysticeti and Odontoceti. We analyzed the evolutionary history of brain and body mass, and relative brain size measured by the encephalization quotient (EQ), using a data set of extinct and extant taxa to capture temporal variation in the mode and direction of evolution. Our results suggest that cetacean brain and body mass evolved under strong directional trends to increase through time, but decreases in EQ were widespread. Mysticetes have significantly lower EQs than odontocetes due to a shift in brain:body allometry following the divergence of the suborders, caused by rapid increases in body mass in Mysticeti and a period of body mass reduction in Odontoceti. The pattern in Cetacea contrasts with that in primates, which experienced strong trends to increase brain mass and relative brain size, but not body mass. We discuss what these analyses reveal about the convergent evolution of large brains, and highlight that until recently the most encephalized mammals were odontocetes, not primates.
Dalebout, M L; Helden, A V; van Waerebeek, K; Baker, C S
To assist in the species-level identification of stranded and hunted beaked whales, we compiled a database of 'reference' sequences from the mitochondrial DNA control region for 15 of the 20 described ziphiid species. Reference samples for eight species were obtained from stranded animals in New Zealand and South Australia. Sequences for a further seven species were obtained from a previously published report. This database was used to identify 20 'test' samples obtained from incompletely documented strandings around New Zealand. Analyses showed that four of these 'test' specimens (20%) had initially been misidentified. These included two animals of particular interest: (i) a Blainville's beaked whale (Mesoplodon densirostris), the first record of this species in New Zealand waters; and, (ii) a juvenile Andrews' beaked whale (Mesoplodon bowdoini), a species known from just over 20 strandings worldwide. A published sequence from a beaked whale product purchased in the Republic of Korea was identified as a Cuvier's beaked whale (Ziphius cavirostris). Levels of intra- and interspecific variation were compared to determine the potential for misidentification when the database or taxonomy is incomplete. Intraspecific variation was generally 4.7%. Exceptions were within-species variation in Hyperoodon planifrons, southern bottlenosed whale (4.12%), which exceeded the variation between the two species of Berardius (3.78%), and variation between the two specimens assigned to M. hectori, Hector's beaked whale (7.14%). The latter case appears to be an error in species identification, and could represent the discovery of a new species of beaked whale.
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.
Rodrigo H. Tardin
Full Text Available Difficulties in quantifying behavioral events can cause loss of information about cetacean behavior, especially behaviors whose functions are still debated. The lack of knowledge is greater for South American species such as Sotalia guianensis (Van Benédén, 1864. Our objective was to contextualize the behavioral events inside behavioral states using a Permutational Multivariate Analysis of Variance (MANOVA. Three events occurred in the Feeding, Socio-Sexual and Travelling states (Porpoising, Side flop, Tail out dive, and five events occurred in the Feeding and Travelling states (Back flop, Horizontal jump, Lobtail, Spy-hop, Partial flop ahead. Three events (Belly exposure, Club, and Heading occurred exclusively in the Socio-sexual state. Partial Back flop and Head flop occurred exclusively in the Feeding state. For the events that occurred in multiple states, we observed that some events occurred more frequently in one of the states (p < 0.001, such as Lobtail, Tail out dive horizontal Jump, Partial flop ahead and Side flop. Our multivariate analysis, which separated Socio-sexual behavior from Feeding and Travelling, showed that the abundance of behavioral events differs between states. This differentiation indicates that some events are associated with specific behavioral states. Almost 40% of the events observed were exclusively performed in one state, which indicates a high specialization for some events. Proper discrimination and contextualization of behavioral events may be efficient tools to better understand dolphin behaviors. Similar studies in other habitats and with other species, will help build a broader scenario to aid our understanding of the functions of dolphin behavioral events.
McGowen, Michael R; Clark, Clay; Gatesy, John
The macroevolutionary transition of whales (cetaceans) from a terrestrial quadruped to an obligate aquatic form involved major changes in sensory abilities. Compared to terrestrial mammals, the olfactory system of baleen whales is dramatically reduced, and in toothed whales is completely absent. We sampled the olfactory receptor (OR) subgenomes of eight cetacean species from four families. A multigene tree of 115 newly characterized OR sequences from these eight species and published data for Bos taurus revealed a diverse array of class II OR paralogues in Cetacea. Evolution of the OR gene superfamily in toothed whales (Odontoceti) featured a multitude of independent pseudogenization events, supporting anatomical evidence that odontocetes have lost their olfactory sense. We explored the phylogenetic utility of OR pseudogenes in Cetacea, concentrating on delphinids (oceanic dolphins), the product of a rapid evolutionary radiation that has been difficult to resolve in previous studies of mitochondrial DNA sequences. Phylogenetic analyses of OR pseudogenes using both gene-tree reconciliation and supermatrix methods yielded fully resolved, consistently supported relationships among members of four delphinid subfamilies. Alternative minimizations of gene duplications, gene duplications plus gene losses, deep coalescence events, and nucleotide substitutions plus indels returned highly congruent phylogenetic hypotheses. Novel DNA sequence data for six single-copy nuclear loci and three mitochondrial genes (> 5000 aligned nucleotides) provided an independent test of the OR trees. Nucleotide substitutions and indels in OR pseudogenes showed a very low degree of homoplasy in comparison to mitochondrial DNA and, on average, provided more variation than single-copy nuclear DNA. Our results suggest that phylogenetic analysis of the large OR superfamily will be effective for resolving relationships within Cetacea whether supermatrix or gene-tree reconciliation procedures are
熊晔; 周旭明; 杨梅; 张盼; 杨云霞; 杨光
本文基于实验室筛选得到的13对内含子标记,在鲸偶蹄目的15个物种中进行有效扩增,并重建了这15个物种的系统发育关系.结果表明,抹香鲸总科(Physeteroidea)位于齿鲸亚目(Odontoceti)的基部,从而支持了传统的齿鲸亚目的单系性.在海豚总科(Delphinoidea)内部,贝斯分析结果支持了鼠海豚科(Phocoenidae)和一角鲸科(Monodontidae)的姐妹群关系,而后再与海豚科(Delphinidae)相聚.系统发育分析同时还强烈支持了海豚科的四个属(Sousa,Tursiops,Stenella,Delphinus)组成一个单系的"复合体".另外,我们的分析结果并不支持瓶鼻海豚属(Tursiops)和原海豚属(Stenella)的单系性.基于松散分子钟的分歧时间估算与以往文献中的结果没有明显差异.这些研究结果提示,核基因内含子序列有希望解决一些长期存在的鲸类系统发育问题.%Sequences of 13 introns from 15 Cetartiodactyla species were determined to reveal the phylogeny of cetaceans.Our results support the monophyly of the traditionally accepted suborder Odontoceti ( toothed whales ), placing the dwarf sperm whale ( Kogia sima), a representative species of superfamily Physeteroidea, as sister to other toothed whales. Within the superfamily Delphinoidea, phylogenetic analyses identified a sister relationship between Delphinidae and Monodontidae + Phocoenidae. A close relationship among four genera ( Sousa, Tursiops, Stenella, and Delphinus) is strongly supported,which suggested the monophyly of the Sousa-Stenella-Tursiops-Delphinus complex. Neither the two Tursiops species ( T.truncates and T. aduncus ) nor the two Stenella species (S. coeruleoalba and S. attenuata ) examined in present study clustered together, which strongly supported the paraphyly of these two genera as suggested in previous studies. Furthermore,the present Bayesian inference with a lognormal relaxed molecular clock provided divergence time for each clade, which is consistent with
Schenkkan, E.J.; Purves, P.E.
The nasal complex of Kogia has been compared with that of Physeter and shown to be homologous with that of less specialized ondotocetes. The nasal complex of the Physeterids is structurally related to that of the Platanistids and Ziphioids. The spermaceti organ unique to the Physeteridae forms a par
Milinkovitch, M C; Meyer, A; Powell, J R
Traditionally, living cetaceans (order Cetacea) are classified into two highly distinct suborders: the echolocating toothed whales, Odontoceti, and the filter-feeding baleen whales, Mysticeti. A molecular phylogeny based on 1,352 base pairs of two mitochondrial ribosomal gene segments and the mitochondrial cytochrome b gene for all major groups of cetaceans contradicts this long-accepted taxonomic subdivision. One group of toothed whales, the sperm whales, is more closely related to the morphologically highly divergent baleen whales than to other odontocetes. This finding suggests that the suborder Odontoceti constitutes an unnatural grouping and challenges the conventional scenario of a long, independent evolutionary history of odontocetes and mysticetes. The superfamily Delphinoidea (dolphins, porpoises, and white whales) appears to be monophyletic; the Amazon River dolphin, Inia geoffrensis, is its sister species. This river dolphin is genetically more divergent from the morphologically similar marine dolphins than the sperm whales are from the morphologically dissimilar baleen whales. The phylogenetic relationships among the three families of Delphinoidea remain uncertain, and we suggest that the two cladogenetic events that generated these three clades occurred within a very short period of time. Among the baleen whales, the bowhead is basal, and the gray whale is the sister species to the rorquals (family Balaenopteridae). The phylogenetic position of beaked whales (Ziphioidea) remains weakly supported by molecular data. Based on molecular clock assumptions, the mitochondrial-DNA data suggest a more recent origin of baleen whales (approximately 25 mya) than has been previously assumed (> 40 mya). This revised phylogeny has important implications for the rate and mode of evolution of morphological and physiological innovations in cetaceans.
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.
Kurichithara K. Sajikumar
Full Text Available We report the presence and behaviour of a pod of short-finned pilot whale Globicephala macrorhynchus in the southeastern Arabian Sea. The pod was observed in the southeastern side of Minicoy Island, in the Nine degree channel (09°219′23′′N;74°39′529′′E on 03.02.2013. Later, on 06.02.2013,the same pod of pilot whales were observed near Kalpeni Island (10°02′402′′N; 73°39′579′′E 130 km northwest of the previous location. The average length of the whales was estimated as 550 cm and weight as approximately 1200 kg. They were travelling in a northwesterly direction. The pod size of the whales sighted was twelve and several species specific behaviour such as side rolling, spyhopping, lobtailing, peduncle arching and movement patterns such as synchronous travelling and logging could be observed. The occurrence of scars and injuries on the body of four whales in the pod are also reported.
Bjerager, Poul; Heegaard, S.; Tougaard, J.
Ophthalmology, cetacea, odontocetes, vision, retraction, rete ophthalmica, retractor muscle, eye muscles, Physeter......Ophthalmology, cetacea, odontocetes, vision, retraction, rete ophthalmica, retractor muscle, eye muscles, Physeter...
In the study of phonation in odontocete cetaceans and particularly that of echolocation by means of sonar, a great number of conflicting hypotheses have been advanced regarding the correlation of sound production with the many anatomical features that are to be found in the upper respiratory tract.
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.
The anatomy of the nasal passage of three specimens of the Boutu has been studied. The various diverticula appear to be aberrant from those described for other Platanistidae. The vestibular airsac system has developed into one enormous diverticulum. Except for a narrow region caudal to the blowhole,
dimorphism 933 Sexual maturity 989 Weaning 742 Age estimation baleen 370 BT Baleen 129 Age estimation bone 390 BT Osteology 717 Age estimation corpora...bilateral anatomical asymmetry. RT Blow 153 Blowhole 157 Picrmentation 233 Osteology 717 Respiratory system 861 Skull 257 Attacking Agonistic behavior 570... Osteology 717 Paleontology 733 Skull 257 Vertebral formula 740 Bonnet Callosities 165 Dermal hardening 285 Field marks 413 Individual identification 529
Felix Georg Marx
Full Text Available The family Cetotheriidae has played a major role in recent discussions of baleen whale phylogenetics. Within this group, the enigmatic, monotypic Metopocetus durinasus has been interpreted as transitional between herpetocetines and other members of the family, but so far has been restricted to a single, fragmentary cranium of uncertain provenance and age. Here, we expand the genus and shed new light on its phylogenetic affinities and functional morphology by describing Metopocetus hunteri sp. nov. from the Late Miocene of the Netherlands. Unlike the holotype of M. durinasus, the material described here is confidently dated and preserves both the tympanic bulla and additional details of the basicranium. M. hunteri closely resembles M. durinasus, differing primarily in its somewhat less distally expanded compound posterior process of the tympanoperiotic. Both species are characterised by the development of an unusually large fossa on the ventral surface of the paroccipital process, which extends anteriorly on to the compound posterior process and completely floors the facial sulcus. In life, this enlarged fossa may have housed the posterior sinus and/or the articulation of the stylohyal. Like other cetotheriids, Metopocetus also bears a well-developed, posteriorly-pointing dorsal infraorbital foramen near the base of the ascending process of the maxilla, the precise function of which remains unclear.
Brown Gladden, J G; Ferguson, M M; Clayton, J W
The North American beluga whale Delphinapterus leucas population has been divided into a number of putative geographical stocks based upon migration routes and areas of summer concentration. Nucleotide sequences of the mitochondrial DNA (mtDNA) control region were used to assess whether these geographical stocks are genetically distinct. Beluga whale samples from 25 sites were collected primarily from aboriginal subsistence hunts across North America from 1984 to 1994. Thirty-nine mtDNA haplotypes were identified in 628 beluga samples. No differences were found in the distribution of haplotypes between male and female beluga whales at any sampling site. These haplotypes segregated into two distinct assemblages in both a haplotype network and a neighbour-joining tree. The haplotype assemblages and a geographically disjunct distribution that suggests postglacial recolonization of the North American Arctic from two different refugia. An analysis of molecular variance based on haplotype relationships and frequency indicated genetic heterogeneity among beluga whale summering groups (P St Lawrence River and the western or central Arctic. The results of this study show a high degree of philopatry to specific summering areas by this highly mobile animal.
The family Cetotheriidae has played a major role in recent discussions of baleen whale phylogenetics. Within this group, the enigmatic, monotypic Metopocetus durinasus has been interpreted as transitional between herpetocetines and other members of the family, but so far Ihas been restricted to a single, fragmentary cranium of uncertain provenance and age. Here, we expand the genus and shed new light on its phylogenetic affinities and functional morphology by describing Metopocetus hunteri sp...
Eric G Ekdale
Full Text Available BACKGROUND: 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. PRINCIPAL FINDINGS: 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. SIGNIFICANCE: 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.
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.
Endo, Tetsuya; Haraguchi, Koichi; Sakata, Masakatsu
Small cetaceans (toothed whales odontoceti and dolphins delphinidae) have been traditionally hunted along the coast of Japan and fresh red meat and blubber, as well as boiled internal organs such as liver, kidney, lung and small intestine, are still being sold for human consumption. We surveyed mercury contamination in boiled liver, kidney and lung products marketed in Japan between 1999-2001. The average +/- S.D. of total mercury (T-Hg) was 370 +/- 525 (range: 7.60 approximately 1980, n = 26) microg/g in liver, 40.5 +/- 48.5 (7.30-95.1, n = 15) microg/g in kidney and 42.8 +/- 43.8 (2.10-79.6, n = 23) microg/g in lung. A high correlation was observed between T-Hg and selenium (Se) concentrations in these organs, supporting the formation of a Hg-Se complex. The formation of a Hg-Se complex probably contribute to the detoxification of Hg for cetaceans and allows a very large accumulation of Hg in livers. The provisional permitted level of T-Hg in marine foods set by the Japanese Ministry of Health and Welfare is 0.4 microg/ g, and the provisional permitted weekly intake (PTWI) set by WHO is 5 microg/kg bw/week. The maximal T-Hg detected in boiled liver (1,980 microg/g) exceeds the permitted level by approximately 5,000 times and the consumption of only 0.15 g of liver exceeds the PTWI of 60 kg of body weight of the consumer, suggesting the possibility of an acute intoxication by T-Hg even after a single consumption of the product.
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.
Jensen, Frants H; Rocco, Alice; Mansur, Rubaiyat M; Smith, Brian D; Janik, Vincent M; Madsen, Peter T
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.
Bree, van P.J.H.; Purves, P.E.
The dimensions are given of three skulls of Lipotes vexillifer, the only specimens preserved in collections outside of China. At the same time drawings of the Lipotes vexillifer skull in the British Museum (Natural History) have been made and published with a photograph of the London specimen before
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.
Dornburg, Alex; Brandley, Matthew C; McGowen, Michael R; Near, Thomas J
Various nucleotide substitution models have been developed to accommodate among lineage rate heterogeneity, thereby relaxing the assumptions of the strict molecular clock. Recently developed "uncorrelated relaxed clock" and "random local clock" (RLC) models allow decoupling of nucleotide substitution rates between descendant lineages and are thus predicted to perform better in the presence of lineage-specific rate heterogeneity. However, it is uncertain how these models perform in the presence of punctuated shifts in substitution rate, especially between closely related clades. Using cetaceans (whales and dolphins) as a case study, we test the performance of these two substitution models in estimating both molecular rates and divergence times in the presence of substantial lineage-specific rate heterogeneity. Our RLC analyses of whole mitochondrial genome alignments find evidence for up to ten clade-specific nucleotide substitution rate shifts in cetaceans. We provide evidence that in the uncorrelated relaxed clock framework, a punctuated shift in the rate of molecular evolution within a subclade results in posterior rate estimates that are either misled or intermediate between the disparate rate classes present in baleen and toothed whales. Using simulations, we demonstrate abrupt changes in rate isolated to one or a few lineages in the phylogeny can mislead rate and age estimation, even when the node of interest is calibrated. We further demonstrate how increasing prior age uncertainty can bias rate and age estimates, even while the 95% highest posterior density around age estimates decreases; in other words, increased precision for an inaccurate estimate. We interpret the use of external calibrations in divergence time studies in light of these results, suggesting that rate shifts at deep time scales may mislead inferences of absolute molecular rates and ages.
Full Text Available Right whales (Eubalaena australis have been suffering with anthropogenic activities such as pollution, marine traffic and entanglement in fishing nets. The entanglement of right whales grows each breeding season on the southern coast of Santa Catarina state, and can cause strands and even death. During the 2010 breeding season, six entanglements among immature and adult whales were recorded. In most of the cases, the whales kept swimming slowly and didn’t want to approximate the whale watching boat. Fishing activities in the area during the right whale breeding season need to be regularized to avoid conflicts and injuries to the whales.
Bree, van P.J.H.; Sergeant, D.E.; Hoek, W.
A Harbour Porpoise, Phocoena phocoena, taken from near Shallow Bay, Mackenzie River Delta, Northwest Territories (68°48’ N 136°35’ W) in July 1973 represents a range extension 800 km eastwards from the previous extreme northeastern record on the north Alaskan coast. All 12 Harbour Porpoises so far e
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 Three whales washed ashore along Kerala coast of southwest India were identified as Bryde’s Whale Balaenoptera edeni Anderson based on sequencing of mitochondrial cytochrome c oxidase subunit 1 and cytochrome b genes. The results of mtDNA sequencing in the present study confirm the presence of B. edeni species of ‘Bryde’s Whale complex’ in the coastal waters of India.
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 family Cetotheriidae has played a major role in recent discussions of baleen whale phylogenetics. Within this group, the enigmatic, monotypic Metopocetus durinasus has been interpreted as transitional between herpetocetines and other members of the family, but so far has been restricted to a single, fragmentary cranium of uncertain provenance and age. Here, we expand the genus and shed new light on its phylogenetic affinities and functional morphology by describing Metopocetus hunteri sp....
On the feeding habit of the Guiana Dolphin Sotalia guianensis (van Bénedèn, 1864 (Mammalia: Cetartiodactyla: Delphinidae in southeastern Brazil (~220S: has there been any change in more than two decades?
Ana Paula Madeira Di Beneditto
Full Text Available Along the north and central coast of Rio de Janeiro State (22025’S–23000’S, southeastern Brazil, the Guiana Dolphin Sotalia guianensis forages on neritic prey, mainly fish. From the analysis of the dolphin’s stomach contents and the identification of partially digested prey, it was verified that the most frequent prey species were young specimens of Trichiurus lepturus. Comparing our results with previous studies on the feeding habits of Guiana Dolphin in the same region, we noticed the maintenance of its feeding preferences during more than two decades, indicating little or no change in the use of prey by this top predator.
Mrio Csar Sedrez; Joo de vila Barcelos; Joo Pedro Barreiros
This article reports the necropsy of a specimen of striped dolphinStenella coeruleoalba found stranded in the north coast of Terceira Island, Azores, Portugal. Here, the importance of standard protocols in post-mortem examinations and the need to adequately proceed were discussed. Stranded marine mammals are valuable specimens for several studies of pathology and other veterinary medical aspects. Although the causa mortis was not determined, the full access to stranded specimens was crucial, not only for pathology studies but also for a proper training to veterinary medicine students whenever possible.
Boersma, Alexandra T; Pyenson, Nicholas D
Living sperm whales are represented by only three species (Physeter macrocephalus, Kogia breviceps and Kogia sima), but their fossil record provides evidence of an ecologically diverse array of different forms, including morphologies and body sizes without analog among living physeteroids. Here we provide a redescription of Ontocetus oxymycterus, a large but incomplete fossil sperm whale specimen from the middle Miocene Monterey Formation of California, described by Remington Kellogg in 1925. The type specimen consists of a partial rostrum, both mandibles, an isolated upper rostrum fragment, and incomplete tooth fragments. Although incomplete, these remains exhibit characteristics that, when combined, set it apart morphologically from all other known physeteroids (e.g., a closed mesorostral groove, and the retention of enameled tooth crowns). Kellogg originally placed this species in the genus Ontocetus, a enigmatic tooth taxon reported from the 19th century, based on similarities between the type specimen Ontocetus emmonsi and the conspicuously large lower dentition of Ontocetus oxymycterus. However, the type of the genus Ontocetus is now known to represent a walrus tusk (belonging to fossil Odobenidae) instead of a cetacean tooth. Thus, we assign this species to the new genus Albicetus, creating the new combination of Albicetus oxymycterus, gen. nov. We provide new morphological observations of the type specimen, including a 3D model. We also calculate a total length of approximately 6 m in life, using cranial proxies of body size for physeteroids. Lastly, a phylogenetic analysis of Albicetus oxymycterus with other fossil and living Physeteroidea resolves its position as a stem physeteroid, implying that large body size and robust dentition in physeteroids evolved multiple times and in distantly related lineages.
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.
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.
Boessenecker, Robert W; 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.
Dumont, Maïtena; de Buffrénil, Vivian; Miján, Ismael; Lambert, Olivier
The rostrum of most ziphiids (beaked whales) displays bizarre swollen regions, accompanied with extreme hypermineralisation and an alteration of the collagenous mesh of the bone. The functional significance of this specialization remains obscure. With the voluminous and dense hemispheric excrescence protruding from the premaxillae, the recently described fossil ziphiid Globicetus hiberus is the most spectacular case. This study describes the histological structure and interprets the growth pattern of this unique feature. Histologically, the prominence in Globicetus is made up of an atypical fibro-lamellar complex displaying an irregular laminar organization and extreme compactness (osteosclerosis). Its development is suggested to have resulted from a protraction of periosteal accretion over the premaxillae, long after the end of somatic growth. Complex shifts in the geometry of this tissue are likely to have occurred during its accretion and no indication of Haversian remodeling could be found. X-ray diffraction and Raman spectroscopy indicate that the bone matrix in the premaxillary prominence of Globicetus closely resembles that of the rostrum of the extant beaked whale Mesoplodon densirostris: apatite crystals are of common size and strongly oriented, but the collagenous meshwork within bone matrix seems to be extremely sparse. These morphological and structural data are discussed in the light of functional interpretations proposed for the highly unusual and diverse ziphiid rostrum. J. Morphol. 277:1292-1308, 2016. © 2016 Wiley Periodicals, Inc.
Robert W. Boessenecker
Full Text Available 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.
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
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.
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.
Goldin P. E.
Full Text Available There are two porpoise stocks in the northern Black Sea: the north-western (Odessa Gulf and northeastern (Crimean and Caucasian waters; in addition, another stock is in the Sea of Azov. The Azov porpoises are distinct in their body size and biology. This research was conducted on the skulls of stranded sexually mature porpoises from the north-eastern Black Sea, north-western Black Sea and the Sea of Azov. In the north-eastern Black Sea samples, both present-day and old-time, the sexual dimorphism of the skull size was not significant, whereas in the Sea of Azov the females were significantly larger than males. The Azov skulls were strongly different from those from the Black Sea: they were larger, proportionally wider and had the wider rostra; also, there was no significant chronological variation within the Black Sea. The Azov and Black Sea samples were classified with the 100 % success with four variables. The northwestern Black Sea skulls were somewhat intermediate in their characteristics between the Azov and northeastern Black Sea samples, but they were classify ed together with other Black Sea specimens. The difference between the Azov and Black Sea skulls was greater than between many North Atlantic populations, despite the extreme geographical proximity of the two stocks. The low variation within the Black Sea supports the earlier conclusions on the lack of genetic variation: all the Black Sea stocks are expected to be genetically similar sub-populations, whereas the Azov and Marmara stocks possibly represent the genetically distant populations. The porpoises from the Black Sea and the Sea of Azov equally show the traits which characterize the subspecies Phocoena phocoena relicta, but the Black Sea porpoises appear to be more paedomorphic in terms of ontogenetic trajectories.
Alexandra T Boersma
Full Text Available Living sperm whales are represented by only three species (Physeter macrocephalus, Kogia breviceps and Kogia sima, but their fossil record provides evidence of an ecologically diverse array of different forms, including morphologies and body sizes without analog among living physeteroids. Here we provide a redescription of Ontocetus oxymycterus, a large but incomplete fossil sperm whale specimen from the middle Miocene Monterey Formation of California, described by Remington Kellogg in 1925. The type specimen consists of a partial rostrum, both mandibles, an isolated upper rostrum fragment, and incomplete tooth fragments. Although incomplete, these remains exhibit characteristics that, when combined, set it apart morphologically from all other known physeteroids (e.g., a closed mesorostral groove, and the retention of enameled tooth crowns. Kellogg originally placed this species in the genus Ontocetus, a enigmatic tooth taxon reported from the 19th century, based on similarities between the type specimen Ontocetus emmonsi and the conspicuously large lower dentition of Ontocetus oxymycterus. However, the type of the genus Ontocetus is now known to represent a walrus tusk (belonging to fossil Odobenidae instead of a cetacean tooth. Thus, we assign this species to the new genus Albicetus, creating the new combination of Albicetus oxymycterus, gen. nov. We provide new morphological observations of the type specimen, including a 3D model. We also calculate a total length of approximately 6 m in life, using cranial proxies of body size for physeteroids. Lastly, a phylogenetic analysis of Albicetus oxymycterus with other fossil and living Physeteroidea resolves its position as a stem physeteroid, implying that large body size and robust dentition in physeteroids evolved multiple times and in distantly related lineages.
Hardt, Fernando Augusto Sliva
Orientador : Paulo César de Azevedo Simőes-Lopes Dissertaçăo (mestrado) - Universidade Federal do Paraná, Setor de Cięncias Biológicas, Programa de Pós-Graduaçăo em Zoologia. Defesa: Curitiba, 2005 Inclui bibliografia Área de concentraçăo: Zoologia
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.
Estrutura populacional da Balaenoptera bonaerensis (Burmeister (Cetacea, Balaenopteridae nas áreas de reprodução do Oceano Atlântico Sul Minke whale Balaenoptera bonaerensis (Burmeister (Cetacea, Balaenopteridae population structure in the breeding grounds off South Atlantic Ocean
Full Text Available Um estudo da composição dos grupos de baleias minke, Balaenoptera bonaerensis (Burmeister, 1867, capturadas nas águas de Costinha, Paraíba, Brasil, na época da caça comercial, foi realizado com o objetivo de conhecer a dinâmica dos principais parâmetros biológicos, assim como aspectos do comportamento reprodutivo desta espécie. Foram analisados dados da caça coletados pela Superintendência para o Desenvolvimento da Pesca e Companhia de Pesca Norte do Brasil acerca do tamanho e composição dos grupos, proporções sexuais e grau de maturidade das baleias capturadas entre os anos de 1975 a 1985. Os grupos encontrados nas águas de Costinha foram em geral de pequeno tamanho e compostos de animais de ambos os sexos, com predominância de fêmeas e animais maturos sexualmente. Os filhotes, as fêmeas lactantes e prenhes foram raramente encontrados. Esta população de baleias encontrava-se em maior número na costa da Paraíba entre os meses de setembro e outubro, principal período de concepção para a espécie, devendo ocorrer grande número de fecundações nesta área e período. A ausência de fêmeas prenhes ou lactantes e filhotes nesta população demonstra que os nascimentos não ocorrem nesta área. O encalhe e a avistagem de filhotes da baleia minke na costa leste da América do Sul (entre 25ºS e 40ºS sugere o nascimento dos filhotes em médias latitudes desta região, onde a temperatura da água é inferior à encontrada na costa do nordeste brasileiro. Desta forma há indícios de que existam distintas áreas para o nascimento de filhotes e o acasalamento da baleia minke nas águas do Oceano Atlântico Sul Ocidental. A poligamia é um comportamento reprodutivo apresentado pela baleia minke, tendo sido observado através da proporção sexual das capturas e da composição dos grupos formados apenas por animais maturos sexualmente nesta área de acasalamento.A group composition study of the minke whale, Balaenoptera bonaerensis (Burmeister, 1867 captured in the waters of Costinha, Paraíba, Brazil, was conducted with the aim of better understand the reproductive behavior of this species as well as the ecological characteristics of that population. In this study, the information gathered by Superintendência para o Desenvolvimento da Pesca and Companhia de Pesca Norte do Brasil from 1975 to 1985 about the whale's group size and composition, sexual proportion, sexual maturity of the captured whales was analyzed. The groups found in the waters of Costinha were in general of small size and composed by animals of both sexes, with a greater proportion of sexual mature and female animals. Calves, lactating or pregnant females were rarely found. That population concentrated in higher number in the waters of Costinha between September to October, the most important period for the species conception. A great number of conceptions might occur at this time in the area. The absence of lactating females and calves in the population demonstrate that births do not occur in this area. Strandings and sightings of young minke whales in the South America east coast (between 25ºS e 40ºS suggests that births occur at medium latitudes of this region, where the water temperature is inferior to that one in the Northeast Brazilian Coast. In that way, the possibility of the existence of distinct areas to births and breeding activities of minke whales in the South Atlantic Ocean might be considered. The polygamy is a reproductive behavior of minke whale, observed by the composition and sexual proportion of groups composed by sexual mature animals in this breeding ground.
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.
Yukiko Yamamoto; Tomonari Akamatso; Vera Maria Ferreira da Silva; Yayoi Yoshida; Shiro Kohshima
Odontoceti emit broadband high-frequency clicks on echolocation for orientation or prey detection. In the Amazon Basin, two odontoceti species, boto (Amazon River dolphin, Inia geoffrensis) and tucuxi (Sotalia fluviatilis), live sympatrically. The acoustic characteristics of the echolocation clicks of free-ranging botos and tucuxis were measured with a hydrophone array consisting of a full-band and an acoustic event recorder (A-tag). The clicks of the two species were short-duration broadband...
Niskern, Diana, Comp.
The family Delphinidae is the largest family of toothed whales. It includes not only those mammals commonly referred to as dolphins, such as the bottlenosed dolphin often seen in captivity, but also the killer whale. This literature and resources guide is not intended to be a comprehensive bibliography on dolphins; the guide is designed--as the…
Susana Caballero; Sebastian Duchêne; Garavito, Manuel F.; Beth Slikas; C Scott Baker
A small number of cetaceans have adapted to an entirely freshwater environment, having colonized rivers in Asia and South America from an ancestral origin in the marine environment. This includes the ‘river dolphins’, early divergence from the odontocete lineage, and two species of true dolphins (Family Delphinidae). Successful adaptation to the freshwater environment may have required increased demands in energy involved in processes such as the mitochondrial osmotic balance. For this reason...
Rodríguez-Fonseca, Javier; Cubero-Pardo,Priscilla
Cetacean strandings in Costa Rica are reported for a period of 33 years, with a total of 35 strandings, 13 species and 247 individuals involved. The vast majority of documented strandings occurred on the Pacific coast and correspond to single individuals (32 and 28 strandings respectively). The highest stranding number was in the period from 1990 to 1999 (n=24). Physeter catodon (cachalot or sperm whale) is the species with the highest frequency of strandings (n=8) and the family Delphinidae ...
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.
Arbelo, Manuel; Los Monteros, Antonio Espinosa de; Herráez, Pedro; Andrada, Marisa; Sierra, Eva; Rodríguez, Francisco; Jepson, Paul D; Fernández, Antonio
Between 1999 and 2005, 233 stranded cetaceans (comprising 19 species) were reported in the waters of the Canary Islands. Of these, 138/233 (59.2%) were subjected to a complete or partial standardized necropsy, including 4 Balaenopteridae, 9 Physeteridae, 8 Kogiidae, 27 Ziphiidae and 90 Delphinidae. Of these, 46/138 (33.3%) cetaceans were diagnosed with anthropogenic pathological categories (i.e. the cause of death was anthropogenic). These included fishing interaction (bycatch) (19 individuals), 'atypical' mass stranding events linked to naval exercises (13), ship collisions (8) and other anthropogenic-related pathology (6). 'Natural' (i.e. non-anthropogenic) causes of death accounted for another 82/138 (59.4%) cases, including infectious and non-infectious diseases (63), neonatal pathology (8), intra- and interspecific interactions (6) and mass strandings (5). The cause(s) of death could not be determined in 10/138 (7.3%) necropsied animals. The most common causes of death were ship collisions in 6/9 (66.6%) Physeteridae, 'atypical' mass stranding linked to naval exercises in 13/27 (48.1%) Ziphiidae, and 'natural' infectious and non-infectious diseases in 55/90 (61.1%) Delphinidae. Interaction with fishing activities was established as cause of death in 15/90 (16.7%) Delphinidae. These data show that a range of anthropogenic and natural single and mass mortality events occur in multiple cetacean species stranded in the Canary Islands.
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
Demetrikopoulos, Melissa K.; Morris, Lee G.; Fobbs, Archibald J., Jr.; Johnson, John I.
Dolphins, manatees, and sea lions are all aquatic mammals but are not closely related taxonomically. All three species are marine mammals, meaning they spend part or all of their lives in the sea and contiguous bodies of water. Dolphins belong to the taxonomic order Cetacea, which includes whales, dolphins, and porpoises. Manatees (sea cows),…
conger R Hippocampus erectus** Lined seahorse C Hippocampus zosterae Dwarf seahorse U Histrio histrio Sargassumf ish R Hybognathus hayi Cypress minnow U...Odontoceti - Toothed whales Family Physeteridae - Sperm whales Koala breviceps - Pygmy sperm whale Kogia simus - Dwarf sperm whale Family Ziphiidae...Decapterus punctatus Round scad R Diplectcum bivittatum Dwarf sand perch R Dormitator maculatus Fat sleeper C Corosoma cepedianum Gizzard shad U Dorosona
Barbara A Blacklaws
Full Text Available There is increasing concern for the well-being of cetacean populations around the UK. Tattoo skin disease (characterised by irregular, grey, black or yellowish, stippled cutaneous lesions caused by poxvirus infection is a potential health indicatora potential health indicator for cetaceans. Limited sequence data indicates that cetacean poxviruses (CPVs belong to an unassigned genus of the Chordopoxvirinae. To obtain further insight into the phylogenetic relationships between CPV and other Chordopoxvirinae members we partially characterized viral DNA originating from tattoo lesions collected in Delphinidae and Phocoenidae stranded along the UK coastline in 1998-2008. We also evaluated the presence of CPV in skin lesions other than tattoos to examine specificity and sensitivity of visual diagnosis. After DNA extraction, regions of the DNA polymerase and DNA topoisomerase I genes were amplified by PCR, sequenced and compared with other isolates. The presence of CPV DNA was demonstrated in tattoos from one striped dolphin (Stenella coeruleoalba, eight harbour porpoises (Phocoena phocoena and one short-beaked common dolphin (Delphinus delphis and in one 'dubious tattoo' lesion detected in one other porpoise. Seventeen of the 18 PCR positive skin lesions had been visually identified as tattoos and one as a dubious tattoo. None of the other skin lesions were PCR positive. Thus, visual identification had a 94.4% sensitivity and 100% specificity. The DNA polymerase PCR was most effective in detecting CPV DNA. Limited sequence phylogeny grouped the UK samples within the odontocete poxviruses (CPV group 1 and indicated that two different poxvirus lineages infect the Phocoenidae and the Delphinidae. The phylogenetic tree had three major branches: one with the UK Phocoenidae viruses, one with the Delphinidae isolates and one for the mysticete poxvirus (CPV group 2. This implies a radiation of poxviruses according to the host suborder and the families within
Zhou Kaiya; Xu Shixia; Chen Zhuo; Yang Guang
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 ...
Rodríguez-Fonseca, J; Cubero-Pardo, P
Cetacean strandings in Costa Rica are reported for a period of 33 years, with a total of 35 strandings, 13 species and 247 individuals involved. The vast majority of documented strandings occurred on the Pacific coast and correspond to single individuals (32 and 28 strandings respectively). The highest stranding number was in the period from 1990 to 1999 (n = 24). Physeter catodon (cachalot or sperm whale) is the species with the highest frequency of strandings (n = 8) and the family Delphinidae has the majority of species (n = 8) and strandings (n = 22). No other general tendencies were determined with the existing data.
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.
Montelli, Stefano; Peruffo, Antonella; Patarnello, Tomaso; Cozzi, Bruno; Negrisolo, Enrico
The mitochondrion is the power plant of the eukaryotic cell, and tRNAs are the fundamental components of its translational machinery. In the present paper, the evolution of mitochondrial tRNAs was investigated in the Cetacea, a clade of Cetartiodactyla that retuned to water and thus had to adapt its metabolism to a different medium than that of its mainland ancestors. Our analysis focussed on identifying the factors that influenced the evolution of Cetacea tRNA double-helix elements, which play a pivotal role in the formation of the secondary and tertiary structures of each tRNA and consequently manipulate the whole translation machinery of the mitochondrion. Our analyses showed that the substitution pathways in the stems of different tRNAs were influenced by various factors, determining a molecular evolution that was unique to each of the 22 tRNAs. Our data suggested that the composition, AT-skew, and GC-skew of the tRNA stems were the main factors influencing the substitution process. In particular, the range of variation and the fluctuation of these parameters affected the fate of single tRNAs. Strong heterogeneity was observed among the different species of Cetacea. Finally, it appears that the evolution of mitochondrial tRNAs was also shaped by the environments in which the Cetacean taxa differentiated. This latter effect was particularly evident in toothed whales that either live in freshwater or are deep divers.
Braun, Benjamin A; Marcovitz, Amir; Camp, J Gray; Jia, Robin; Bejerano, Gill
Viral outbreaks in dolphins and other Delphinoidea family members warrant investigation into the integrity of the cetacean immune system. The dynamin-like GTPase genes Myxovirus 1 (Mx1) and Mx2 defend mammals against a broad range of viral infections. Loss of Mx1 function in human and mice enhances infectivity by multiple RNA and DNA viruses, including orthomyxoviruses (influenza A), paramyxoviruses (measles), and hepadnaviruses (hepatitis B), whereas loss of Mx2 function leads to decreased resistance to HIV-1 and other viruses. Here we show that both Mx1 and Mx2 have been rendered nonfunctional in Odontoceti cetaceans (toothed whales, including dolphins and orcas). We discovered multiple exon deletions, frameshift mutations, premature stop codons, and transcriptional evidence of decay in the coding sequence of both Mx1 and Mx2 in four species of Odontocetes. We trace the likely loss event for both proteins to soon after the divergence of Odontocetes and Mystocetes (baleen whales) ∼33-37 Mya. Our data raise intriguing questions as to what drove the loss of both Mx1 and Mx2 genes in the Odontoceti lineage, a double loss seen in none of 56 other mammalian genomes, and suggests a hitherto unappreciated fundamental genetic difference in the way these magnificent mammals respond to viral infections.
Tanaka, Yoshihiro; Fordyce, R Ewan
The Oligocene Epoch was a time of major radiation of the Odontoceti (echolocating toothed whales, dolphins). Fossils reveal many odontocete lineages and considerable structural diversity, but whether the clades include some crown taxa or only archaic groups is contentious. The New Zealand fossil dolphin "Prosqualodon" marplesi (latest Oligocene, ≥23.9 Ma) is here identified as a crown odontocete that represents a new genus, Otekaikea, and adds to the generic diversity of Oligocene odontocetes. Otekaikea marplesi is known only from the holotype, which comprises a partial skeleton from the marine Otekaike Limestone of the Waitaki Valley. Otekaikea marplesi was about 2.5 m long; it had procumbent anterior teeth, and a broad dished face for the nasofacial muscles implicated in production of echolocation sounds. The prominent condyles and unfused cervical vertebrae suggest a flexible neck. A phylogenetic analysis based on morphological features places Otekaikea marplesi in the extinct group Waipatiidae, within the clade Platanistoidea. The phylogeny implies an Oligocene origin for the lineage now represented by the endangered Ganges River dolphin (Platanista gangetica), supporting an Oligocene history for the crown Odontoceti.
Au, Whitlow W. L.; Lammers, Marc O.
The mammalian order cetacea consist of dolphins and whales, animals that are found in all the oceans and seas of the world. A few species even inhabit fresh water lakes and rivers. A list of 80 species of cetaceans in a convenient table is presented by Ridgway [20.1]. These mammals vary considerably in size, from the largest living mammal, the large blue whale (balaenoptera musculus), to the very small harbor porpoise (phocoena phocoena) and Commerson's dolphin (cephalorhynchus commersonnii), which are typically slightly over a meter in length.
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.
Klingshirn, M.A. [Ashland Univ., OH (United States); Luo, Z. [College of Charleston, SC (United States)
It has been suggested that the order Cetacea (whales and porpoises) are closely related to artiodactyls, even-hoofed ungulate mammals such as the pig and cow. Paleontological and molecular data strongly supports this concept of phylogenetic relationships. In a study of DNA sequences of two mitochondrial ribosomal gene segments of cetaceans, the artiodactyls were found to be closest related to Cetaceans. These well accepted studies on the phylogenetic affinities of artiodactyls and cetaceans cause us to conduct a comparative study of the bony structure of the inner ear of these two taxa.
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)
Park, Travis; Fitzgerald, Erich M G; Evans, Alistair R
The evolution of biosonar (production of high-frequency sound and reception of its echo) was a key innovation of toothed whales and dolphins (Odontoceti) that facilitated phylogenetic diversification and rise to ecological predominance. Yet exactly when high-frequency hearing first evolved in odontocete history remains a fundamental question in cetacean biology. Here, we show that archaic odontocetes had a cochlea specialized for sensing high-frequency sound, as exemplified by an Oligocene xenorophid, one of the earliest diverging stem groups. This specialization is not as extreme as that seen in the crown clade. Paired with anatomical correlates for high-frequency signal production in Xenorophidae, this is strong evidence that the most archaic toothed whales possessed a functional biosonar system, and that this signature adaptation of odontocetes was acquired at or soon after their origin.
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
Bajpai, S; Thewissen, J G M; Sahni, A
The origin of whales (order Cetacea) from a four-footed land animal is one of the best understood examples of macroevolutionary change. This evolutionary transition has been substantially elucidated by fossil finds from the Indian subcontinent in the past decade and a half. Here, we review the first steps of whale evolution, i.e. the transition from a land mammal to obligate marine predators, documented by the Eocene cetacean families of the Indian subcontinent: Pakicetidae, Ambulocetidae, Remingtonocetidae, Protocetidae, and Basilosauridae, as well as their artiodactyl sister group, the Raoellidae. We also discuss the influence that the excellent fossil record has on the study of the evolution of organ systems, in particular the locomotor and hearing systems.
Thewissen, J G M; Cooper, Lisa Noelle; Clementz, Mark T; Bajpai, Sunil; Tiwari, B N
Although the first ten million years of whale evolution are documented by a remarkable series of fossil skeletons, the link to the ancestor of cetaceans has been missing. It was known that whales are related to even-toed ungulates (artiodactyls), but until now no artiodactyls were morphologically close to early whales. Here we show that the Eocene south Asian raoellid artiodactyls are the sister group to whales. The raoellid Indohyus is similar to whales, and unlike other artiodactyls, in the structure of its ears and premolars, in the density of its limb bones and in the stable-oxygen-isotope composition of its teeth. We also show that a major dietary change occurred during the transition from artiodactyls to whales and that raoellids were aquatic waders. This indicates that aquatic life in this lineage occurred before the origin of the order Cetacea.
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.
da Silva, Vera M F; Carter, Anthony M; Ambrosio, Carlos E; Carvalho, Ana F; Bonatelli, Marina; Lima, Marcelo C; Miglino, Maria Angelica
A recent reassessment of the phylogenetic affinities of cetaceans makes it timely to compare their placentation with that of the artiodactyls. We studied the placentae of two sympatric species of dolphin from the Amazon River Basin, representing two distinct families. The umbilical cord branched to supply a bilobed allantoic sac. Small blood vessels and smooth muscle bundles were found within the stroma of the cord. Foci of squamous metaplasia occurred in the allanto-amnion and allantochorion. The interhemal membrane of the placenta was of the epitheliochorial type. Two different types of trophoblastic epithelium were seen. Most was of the simple columnar type and indented by fetal capillaries. However, there were also areolar regions with tall columnar trophoblast and these were more sparsely supplied with capillaries. The endometrium was well vascularised and richly supplied with actively secreting glands. These findings are consistent with the current view that Cetacea are nested within Artiodactyla as sister group to the hippopotamids.
Full Text Available Abstract A recent reassessment of the phylogenetic affinities of cetaceans makes it timely to compare their placentation with that of the artiodactyls. We studied the placentae of two sympatric species of dolphin from the Amazon River Basin, representing two distinct families. The umbilical cord branched to supply a bilobed allantoic sac. Small blood vessels and smooth muscle bundles were found within the stroma of the cord. Foci of squamous metaplasia occurred in the allanto-amnion and allantochorion. The interhemal membrane of the placenta was of the epitheliochorial type. Two different types of trophoblastic epithelium were seen. Most was of the simple columnar type and indented by fetal capillaries. However, there were also areolar regions with tall columnar trophoblast and these were more sparsely supplied with capillaries. The endometrium was well vascularised and richly supplied with actively secreting glands. These findings are consistent with the current view that Cetacea are nested within Artiodactyla as sister group to the hippopotamids.
S Bajpai; J G M Thewissen; A Sahni
The origin of whales (order Cetacea) from a four-footed land animal is one of the best understood examples of macroevolutionary change. This evolutionary transition has been substantially elucidated by fossil finds from the Indian subcontinent in the past decade and a half. Here, we review the first steps of whale evolution, i.e. the transition from a land mammal to obligate marine predators, documented by the Eocene cetacean families of the Indian subcontinent: Pakicetidae, Ambulocetidae, Remingtonocetidae, Protocetidae, and Basilosauridae, as well as their artiodactyl sister group, the Raoellidae. We also discuss the influence that the excellent fossil record has on the study of the evolution of organ systems, in particular the locomotor and hearing systems.
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.
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...... were samples from 10 white-beaked dolphins (Lagenorhynchus albirostris), 10 harbor porpoises (Phocoena phocoena), eight sperm whales (Physeter macrocephalus), and five minke whales (Balaenoptera acutorostrata). Using enzymatic amplification followed by sequencing of amplified fragments, a tandem repeat...... composed of 18-bp basic units was detected in all of these species. The tandem repeats in white-beaked dolphin and harbor porpoise were both monomorphic and consisted of 11 and 12 basic units, respectively. In contrast, the sperm whale harbored a polymorphic tandem repeat with size variants composed...
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.
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.
Eric G Ekdale
Full Text Available 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.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.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.
Marie-Françoise Van Bressem
Full Text Available We review the molecular and epidemiological characteristics of cetacean morbillivirus (CeMV and the diagnosis and pathogenesis of associated disease, with six different strains detected in cetaceans worldwide. CeMV has caused epidemics with high mortality in odontocetes in Europe, the USA and Australia. It represents a distinct species within the Morbillivirus genus. Although most CeMV strains are phylogenetically closely related, recent data indicate that morbilliviruses recovered from Indo-Pacific bottlenose dolphins (Tursiops aduncus, from Western Australia, and a Guiana dolphin (Sotalia guianensis, from Brazil, are divergent. The signaling lymphocyte activation molecule (SLAM cell receptor for CeMV has been characterized in cetaceans. It shares higher amino acid identity with the ruminant SLAM than with the receptors of carnivores or humans, reflecting the evolutionary history of these mammalian taxa. In Delphinidae, three amino acid substitutions may result in a higher affinity for the virus. Infection is diagnosed by histology, immunohistochemistry, virus isolation, RT-PCR, and serology. Classical CeMV-associated lesions include bronchointerstitial pneumonia, encephalitis, syncytia, and lymphoid depletion associated with immunosuppression. Cetaceans that survive the acute disease may develop fatal secondary infections and chronic encephalitis. Endemically infected, gregarious odontocetes probably serve as reservoirs and vectors. Transmission likely occurs through the inhalation of aerosolized virus but mother to fetus transmission was also reported.
Full Text Available The Chilean oceanic islands Easter Island (Rapa Nui and Salas y Gómez Island (Motu Motiro Hiva have received little attention with regards to basic marine mammal investigations. Here we review and update available information on the status of marine mammals in this area from different sources, including published accounts, local interviews and two recent expeditions. We also provide detailed accounts for each confirmed family or species, including historical data from published archaeological studies and whalers' logbooks from the 18th to the 20th centuries. Results indicate that a total of five marine mammal families (Balaenopteridae, Physeteridae, Ziphiidae, Delphinidae and Phocidae have been confirmed within the study area, representing two mammalian orders (Cetartiodactyla and Carnivora. Within these, twelve species are known to occur: blue whale (Balaenoptera musculus, unidentified minke whale (Balaenoptera bonaerensis or B. acutorostrata, humpback whale (Megaptera novaeangliae, sperm whale (Physeter macrocephalus, Cuvier's beaked whale (Ziphius cavirostris, Blainville's beaked whale (Mesoplodon densirostris, false killer whale (Pseudorca crassidens, unidentified pilot whale (Globicephala sp., bottlenose dolphin (Tursiops truncatus, common dolphin (Delphinus sp., southern elephant seal (Mirounga leonina and leopard seal (Hydrurga leptonyx. We discuss the implications of some of most noteworthy records and make a plea for further studies to improve our knowledge of these top predators in one of the most isolated places in the world.
Acutis, Pier Luigi; Peletto, Simone; Grego, Elena; Colussi, Silvia; Riina, Maria Vittoria; Rosati, Sergio; Mignone, Walter; Caramelli, Maria
The partial PrP gene sequence and the deduced protein of eight cetacean species, seven of which have never been reported so far, have been determined in order to extend knowledge of sequence variability of the PrP genes in different species and to aid in speculation on cetacean susceptibility to prions. Both the nucleotide and the deduced amino acid sequences have been analysed in comparison with some of the known mammalian PrPs. Cetacean PrPs present typical features of eutherian PrPs. The PrP gene from the species of the family Delphinidae gave identical nucleic acid sequences, while differences in the PrP gene were found in Balaenopteridae and Ziphidae. The phylogenetic tree resulting from analysis of the cetacean PrP gene sequences, together with reported sequences of some ungulates, carnivores and primates, showed that the PrP gene phylogenesis mirrors the species phylogenesis. The PrP gene of cetaceans is very close to species where natural forms of TSEs are known. From an analysis of the sequences and the phylogenesis of the PrP gene, susceptibility to or occurrence of prion diseases in cetaceans can not be excluded.
Van Bressem, Marie-Françoise; Duignan, Pádraig J; Banyard, Ashley; Barbieri, Michelle; Colegrove, Kathleen M; De Guise, Sylvain; Di Guardo, Giovanni; Dobson, Andrew; Domingo, Mariano; Fauquier, Deborah; Fernandez, Antonio; Goldstein, Tracey; Grenfell, Bryan; Groch, Kátia R; Gulland, Frances; Jensen, Brenda A; Jepson, Paul D; Hall, Ailsa; Kuiken, Thijs; Mazzariol, Sandro; Morris, Sinead E; Nielsen, Ole; Raga, Juan A; Rowles, Teresa K; Saliki, Jeremy; Sierra, Eva; Stephens, Nahiid; Stone, Brett; Tomo, Ikuko; Wang, Jianning; Waltzek, Thomas; Wellehan, James F X
We review the molecular and epidemiological characteristics of cetacean morbillivirus (CeMV) and the diagnosis and pathogenesis of associated disease, with six different strains detected in cetaceans worldwide. CeMV has caused epidemics with high mortality in odontocetes in Europe, the USA and Australia. It represents a distinct species within the Morbillivirus genus. Although most CeMV strains are phylogenetically closely related, recent data indicate that morbilliviruses recovered from Indo-Pacific bottlenose dolphins (Tursiops aduncus), from Western Australia, and a Guiana dolphin (Sotalia guianensis), from Brazil, are divergent. The signaling lymphocyte activation molecule (SLAM) cell receptor for CeMV has been characterized in cetaceans. It shares higher amino acid identity with the ruminant SLAM than with the receptors of carnivores or humans, reflecting the evolutionary history of these mammalian taxa. In Delphinidae, three amino acid substitutions may result in a higher affinity for the virus. Infection is diagnosed by histology, immunohistochemistry, virus isolation, RT-PCR, and serology. Classical CeMV-associated lesions include bronchointerstitial pneumonia, encephalitis, syncytia, and lymphoid depletion associated with immunosuppression. Cetaceans that survive the acute disease may develop fatal secondary infections and chronic encephalitis. Endemically infected, gregarious odontocetes probably serve as reservoirs and vectors. Transmission likely occurs through the inhalation of aerosolized virus but mother to fetus transmission was also reported.
Ackman, R G; Eaton, C A; Kinneman, J; Litchfield, C
The melon and jaw lipids of the freshwater dolphin Sotalia fluviatilis are composed mainly of isovaleroyl wax esters and diisovaleroyl triglycerides. The blubber fat contains only a trace of wax ester and is mostly tri-(long chain) and monoisovaleroyl triglycerides. Detailed gas liquid chromatographic analyses of the intact wax esters and triglycerides and of the derived fatty acids and fatty alcohols indicate common compositional patterns in the wax esters and triglycerides of the respective head lipids. Both odd and even long chain (C12-C16) isostructures are prominent in the melon and jaw lipids, but only higher odd chain length iso-acids are major components in the blubber. Sotalia fluviatilis (family Delphinidae) and Inia geoffrensis (family Platanistidae) share the same freshwater habitat in the upper Amazon River, and both utilize echolocation to navigate and to find food. Comparison of their respective bioacoustical lipid compositions show distinctive types of head fats, Sotalia being rich in iso-5:0 and Inia lacking iso-5:0. This indicates that iso-valeric acid per se has no obligatory role in dolphin echolocation.
Reif, John S; Schaefer, Adam M; Bossart, Gregory D
Lobomycosis, a fungal disease of the skin and subcutaneous tissues caused by Lacazia loboi, is sometimes referred to as a zoonotic disease because it affects only specific delphinidae and humans; however, the evidence that it can be transferred directly to humans from dolphins is weak. Dolphins have also been postulated to be responsible for an apparent geographic expansion of the disease in humans. Morphological and molecular differences between the human and dolphin organisms, differences in geographic distribution of the diseases between dolphins and humans, the existence of only a single documented case of presumed zoonotic transmission, and anecdotal evidence of lack of transmission to humans following accidental inoculation of tissue from infected dolphins do not support the hypothesis that dolphins infected with L. loboi represent a zoonotic hazard for humans. In addition, the lack of human cases in communities adjacent to coastal estuaries with a high prevalence of lobomycosis in dolphins, such as the Indian River Lagoon in Florida (IRL), suggests that direct or indirect transmission of L. loboi from dolphins to humans occurs rarely, if at all. Nonetheless, attention to personal hygiene and general principals of infection control are always appropriate when handling tissues from an animal with a presumptive diagnosis of a mycotic or fungal disease.
Guimarães, J P; Febronio, A M B; Vergara-Parente, J E; Werneck, M R
The parasitic fauna of cetaceans is an important tool for ecological studies, including analyses on the causes of death. Halocercus brasiliensis is a nematode frequently found in the bronchi and bronchioles of some cetaceans, and it is commonly associated with focal inflammation of the respiratory tract leading to bacterial pneumonia and septicemia and, sometimes, to death. The objective of this study was to report infections by H. brasiliensis in the respiratory tract of Delphinidae stranded on the northern seaside of Bahia, Sergipe, and south of Alagoas, all states in the northeast region of Brazil. A total of 30 individuals, 1 Feresa attenuate (pygmy killer whale), 9 Stenella clymene (Clymene dolphin), and 20 Sotalia guianensis (Guiana dolphin) were studied. In 16 of them, the presence of H. brasiliensis was observed with a mean intensity of 3.5 ± 0.6 (range 1-9) in the hosts. Macroscopically, parasitic calcified nodules, lung congestion, edema, and emphysema were observed. Histopathological examination showed interstitial and granulomatous pneumonia with multifocal infiltrates, discrete to moderate edema, congestion, diffuse hemorrhage, and foci of calcification. We conclude that parasitic pneumonia in the sampled individuals may have directly contributed to stranding and death of the animals.
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.
Alba, Patricia; Terracciano, Giuliana; Franco, Alessia; Lorenzetti, Serena; Cocumelli, Cristiano; Fichi, Gianluca; Eleni, Claudia; Zygmunt, Michel S; Cloeckaert, Axel; Battisti, Antonio
Brucella spp. was isolated from brain, lung and intestinal lymph nodes of a dead adult male striped dolphin (Stenella coeruleoalba) found stranded on the Tyrrhenian coast (Tuscany, Italy) of the Mediterranean Sea in February 2012. Brucella spp. was associated with moderate to severe lesions of meningoencephalitis. A co-infection by Toxoplasma gondii was also demonstrated at brain level by means of molecular and histopathologic methods. The Brucella isolate was further characterized based on a fragment-specific polymerase chain reaction (PCR) approach, consisting of a set of five specific PCRs, targeting specific chromosomal IS711 locations for marine mammal Brucellae, as described previously. The isolate was thus classified as Brucella ceti I; V fragment-positive (or B. ceti dolphin type), according to previous studies. Multi Locus Sequence Analysis demonstrated that the isolate belongs to Sequence Type 26, while omp2 (omp2a and omp2b genes) sequence analysis further confirmed the isolate belonged to this group of strains. This is the first report of Brucella spp. from marine mammals in the Mediterranean Sea, and represents a further observation that this strain group is associated with hosts of the Family Delphinidae, and particularly with the striped dolphins, also in the Mediterranean area, thus constituting a further biological hazard of concern for this vulnerable subpopulation.
Van Bressem, Marie-Françoise; Duignan, Pádraig J.; Banyard, Ashley; Barbieri, Michelle; Colegrove, Kathleen M; De Guise, Sylvain; Di Guardo, Giovanni; Dobson, Andrew; Domingo, Mariano; Fauquier, Deborah; Fernandez, Antonio; Goldstein, Tracey; Grenfell, Bryan; Groch, Kátia R.; Gulland, Frances; Jensen, Brenda A; Jepson, Paul D; Hall, Ailsa; Kuiken, Thijs; Mazzariol, Sandro; Morris, Sinead E; Nielsen, Ole; Raga, Juan A; Rowles, Teresa K; Saliki, Jeremy; Sierra, Eva; Stephens, Nahiid; Stone, Brett; Tomo, Ikuko; Wang, Jianning; Waltzek, Thomas; Wellehan, James FX
We review the molecular and epidemiological characteristics of cetacean morbillivirus (CeMV) and the diagnosis and pathogenesis of associated disease, with six different strains detected in cetaceans worldwide. CeMV has caused epidemics with high mortality in odontocetes in Europe, the USA and Australia. It represents a distinct species within the Morbillivirus genus. Although most CeMV strains are phylogenetically closely related, recent data indicate that morbilliviruses recovered from Indo-Pacific bottlenose dolphins (Tursiops aduncus), from Western Australia, and a Guiana dolphin (Sotalia guianensis), from Brazil, are divergent. The signaling lymphocyte activation molecule (SLAM) cell receptor for CeMV has been characterized in cetaceans. It shares higher amino acid identity with the ruminant SLAM than with the receptors of carnivores or humans, reflecting the evolutionary history of these mammalian taxa. In Delphinidae, three amino acid substitutions may result in a higher affinity for the virus. Infection is diagnosed by histology, immunohistochemistry, virus isolation, RT-PCR, and serology. Classical CeMV-associated lesions include bronchointerstitial pneumonia, encephalitis, syncytia, and lymphoid depletion associated with immunosuppression. Cetaceans that survive the acute disease may develop fatal secondary infections and chronic encephalitis. Endemically infected, gregarious odontocetes probably serve as reservoirs and vectors. Transmission likely occurs through the inhalation of aerosolized virus but mother to fetus transmission was also reported. PMID:25533660
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.
Xu, Shixia; Chen, Yuan; Cheng, Yuefeng; Yang, Dan; Zhou, Xuming; Xu, Junxiao; Zhou, Kaiya; Yang, Guang
The enlargement of cetacean brain size represents an enigmatic event in mammalian evolution, yet its genetic basis remains poorly explored. One candidate gene associated with brain size evolution is the abnormal spindle-like microcephaly associated (ASPM), as mutations in this gene cause severe reductions in the cortical size of humans. Here, we investigated the ASPM gene in representative cetacean lineages and previously published sequences from other mammals to test whether the expansion of the cetacean brain matched adaptive ASPM evolution patterns. Our analyses yielded significant evidence of positive selection on the ASPM gene during cetacean evolution, especially for the Odontoceti and Delphinoidea lineages. These molecular patterns were associated with two major events of relative brain size enlargement in odontocetes and delphinoids. It is of particular interest to find that positive selection was restricted to cetaceans and primates, two distant lineages both characterized by a massive expansion of brain size. This result is suggestive of convergent molecular evolution, although no site-specific convergence at the amino acid level was found.
Sacristán, Carlos; Carballo, Matilde; Muñoz, María Jesús; Bellière, Edwige Nina; Neves, Elena; Nogal, Verónica; Esperón, Fernando
Cetacean morbillivirus (CeMV) (family Paramyxoviridae, genus Morbillivirus) is considered the most pathogenic virus of cetaceans. It was first implicated in the bottlenose dolphin (Tursiops truncatus) mass stranding episode along the Northwestern Atlantic coast in the late 1980s, and in several more recent worldwide epizootics in different Odontoceti species. This study describes a new one step real-time reverse transcription fast polymerase chain reaction (real-time RT-fast PCR) method based on SYBR(®) Green to detect a fragment of the CeMV fusion protein gene. This primer set also works for conventional RT-PCR diagnosis. This method detected and identified all three well-characterized strains of CeMV: porpoise morbillivirus (PMV), dolphin morbillivirus (DMV) and pilot whale morbillivirus (PWMV). Relative sensitivity was measured by comparing the results obtained from 10-fold dilution series of PMV and DMV positive controls and a PWMV field sample, to those obtained by the previously described conventional phosphoprotein gene based RT-PCR method. Both the conventional and real-time RT-PCR methods involving the fusion protein gene were 100- to 1000-fold more sensitive than the previously described conventional RT-PCR method.
Full Text Available 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.
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.
Nikaido, M; Matsuno, F; Hamilton, H; Brownell, R L; Cao, Y; Ding, W; Zuoyan, Z; Shedlock, A M; Fordyce, R E; Hasegawa, M; Okada, N
SINE (short interspersed element) insertion analysis elucidates contentious aspects in the phylogeny of toothed whales and dolphins (Odontoceti), especially river dolphins. Here, we characterize 25 informative SINEs inserted into unique genomic loci during evolution of odontocetes to construct a cladogram, and determine a total of 2.8 kb per taxon of the flanking sequences of these SINE loci to estimate divergence times among lineages. We demonstrate that: (i) Odontocetes are monophyletic; (ii) Ganges River dolphins, beaked whales, and ocean dolphins diverged (in this order) after sperm whales; (iii) three other river dolphin taxa, namely the Amazon, La Plata, and Yangtze river dolphins, form a monophyletic group with Yangtze River dolphins being the most basal; and (iv) the rapid radiation of extant cetacean lineages occurred some 28-33 million years B.P., in strong accord with the fossil record. The combination of SINE and flanking sequence analysis suggests a topology and set of divergence times for odontocete relationships, offering alternative explanations for several long-standing problems in cetacean evolution.
Peichl, L; Behrmann, G; Kröger, R H
Most terrestrial mammals have colour vision based on two spectrally different visual pigments located in two types of retinal cone photoreceptors, i.e. they are cone dichromats with long-to-middle-wave-sensitive (commonly green) L-cones and short-wave-sensitive (commonly blue) S-cones. With visual pigment-specific antibodies, we here demonstrate an absence of S-cones in the retinae of all whales and seals studied. The sample includes seven species of toothed whales (Odontoceti) and five species of marine carnivores (eared and earless seals). These marine mammals have only L-cones (cone monochromacy) and hence are essentially colour-blind. For comparison, the study also includes the wolf, ferret and European river otter (Carnivora) as well as the mouflon and pygmy hippopotamus (Artiodactyla), close terrestrial relatives of the seals and whales, respectively. These have a normal complement of S-cones and L-cones. The S-cone loss in marine species from two distant mammalian orders strongly argues for convergent evolution and an adaptive advantage of that trait in the marine visual environment. To us this suggests that the S-cones may have been lost in all whales and seals. However, as the spectral composition of light in clear ocean waters is increasingly blue-shifted with depth, an S-cone loss would seem particularly disadvantageous. We discuss some hypotheses to explain this paradox.
Fahlke, Julia M; Gingerich, Philip D; Welsh, Robert C; Wood, Aaron R
Eocene archaeocete whales gave rise to all modern toothed and baleen whales (Odontoceti and Mysticeti) during or near the Eocene-Oligocene transition. Odontocetes have asymmetrical skulls, with asymmetry linked to high-frequency sound production and echolocation. Mysticetes are generally assumed to have symmetrical skulls and lack high-frequency hearing. Here we show that protocetid and basilosaurid archaeocete skulls are distinctly and directionally asymmetrical. Archaeocete asymmetry involves curvature and axial torsion of the cranium, but no telescoping. Cranial asymmetry evolved in Eocene archaeocetes as part of a complex of traits linked to directional hearing (such as pan-bone thinning of the lower jaws, mandibular fat pads, and isolation of the ear region), probably enabling them to hear the higher sonic frequencies of sound-producing fish on which they preyed. Ultrasonic echolocation evolved in Oligocene odontocetes, enabling them to find silent prey. Asymmetry and much of the sonic-frequency range of directional hearing were lost in Oligocene mysticetes during the shift to low-frequency hearing and bulk-straining predation.
Hassanin, Alexandre; Delsuc, Frédéric; Ropiquet, Anne; Hammer, Catrin; Jansen van Vuuren, Bettine; Matthee, Conrad; Ruiz-Garcia, Manuel; Catzeflis, François; Areskoug, Veronika; Nguyen, Trung Thanh; Couloux, Arnaud
of cetartiodactyls was punctuated by four main phases of rapid radiation during the Cenozoic era: the sudden occurrence of the three extant lineages within Cetartiodactyla (Cetruminantia, Suina and Tylopoda); the basal diversification of Cetacea during the Early Oligocene; and two radiations that involve Cetacea and Pecora, one at the Oligocene/Miocene boundary and the other in the Middle Miocene. In addition, we show that the high species diversity now observed in the families Bovidae and Cervidae accumulated mainly during the Late Miocene and Plio-Pleistocene.
Caballero, Susana; Duchêne, Sebastian; Garavito, Manuel F.; Slikas, Beth; Baker, C. Scott
A small number of cetaceans have adapted to an entirely freshwater environment, having colonized rivers in Asia and South America from an ancestral origin in the marine environment. This includes the ‘river dolphins’, early divergence from the odontocete lineage, and two species of true dolphins (Family Delphinidae). Successful adaptation to the freshwater environment may have required increased demands in energy involved in processes such as the mitochondrial osmotic balance. For this reason, riverine odontocetes provide a compelling natural experiment in adaptation of mammals from marine to freshwater habitats. Here we present initial evidence of positive selection in the NADH dehydrogenase subunit 2 of riverine odontocetes by analyses of full mitochondrial genomes, using tests of selection and protein structure modeling. The codon model with highest statistical support corresponds to three discrete categories for amino acid sites, those under positive, neutral, and purifying selection. With this model we found positive selection at site 297 of the NADH dehydrogenase subunit 2 (dN/dS>1.0,) leading to a substitution of an Ala or Val from the ancestral state of Thr. A phylogenetic reconstruction of 27 cetacean mitogenomes showed that an Ala substitution has evolved at least four times in cetaceans, once or more in the three ‘river dolphins’ (Families Pontoporidae, Lipotidae and Inidae), once in the riverine Sotalia fluviatilis (but not in its marine sister taxa), once in the riverine Orcaella brevirostris from the Mekong River (but not in its marine sister taxa) and once in two other related marine dolphins. We located the position of this amino acid substitution in an alpha-helix channel in the trans-membrane domain in both the E. coli structure and Sotalia fluviatilis model. In E. coli this position is located in a helix implicated in a proton translocation channel of respiratory complex 1 and may have a similar role in the NADH dehydrogenases of
Full Text Available A small number of cetaceans have adapted to an entirely freshwater environment, having colonized rivers in Asia and South America from an ancestral origin in the marine environment. This includes the 'river dolphins', early divergence from the odontocete lineage, and two species of true dolphins (Family Delphinidae. Successful adaptation to the freshwater environment may have required increased demands in energy involved in processes such as the mitochondrial osmotic balance. For this reason, riverine odontocetes provide a compelling natural experiment in adaptation of mammals from marine to freshwater habitats. Here we present initial evidence of positive selection in the NADH dehydrogenase subunit 2 of riverine odontocetes by analyses of full mitochondrial genomes, using tests of selection and protein structure modeling. The codon model with highest statistical support corresponds to three discrete categories for amino acid sites, those under positive, neutral, and purifying selection. With this model we found positive selection at site 297 of the NADH dehydrogenase subunit 2 (dN/dS>1.0, leading to a substitution of an Ala or Val from the ancestral state of Thr. A phylogenetic reconstruction of 27 cetacean mitogenomes showed that an Ala substitution has evolved at least four times in cetaceans, once or more in the three 'river dolphins' (Families Pontoporidae, Lipotidae and Inidae, once in the riverine Sotalia fluviatilis (but not in its marine sister taxa, once in the riverine Orcaella brevirostris from the Mekong River (but not in its marine sister taxa and once in two other related marine dolphins. We located the position of this amino acid substitution in an alpha-helix channel in the trans-membrane domain in both the E. coli structure and Sotalia fluviatilis model. In E. coli this position is located in a helix implicated in a proton translocation channel of respiratory complex 1 and may have a similar role in the NADH dehydrogenases of
Ranil P. Nanayakkara
Full Text Available In Sri Lanka thirty species of cetaceans have been recorded to date. The canyon at Trincomalee bay is a multiple submarine canyon complex and anecdotal reports suggest that the Trincomalee bay and its adjacent waters are utilised by a number of cetacean species. Though Cetaceans are known to be abundant in the waters off Trincomalee there is a dearth of research and data pertaining to the abundance and species frequenting the Trincomalee bay and its adjacent waters. As such the current study was initiated, to get a consensus of the abundance and occurrences of species in Trincomalee Bay and its adjacent waters. Field surveys were carried out for 19 months and the research platform was a 35-foot commercial fishing vessel. 177 cetacean encounters were recorded on 67 of the 75 field days. Remarkably a total of 11 species of cetaceans which composed of two species of Baleen Whales and nine species of Toothed Whales were recorded. Delphinidae was the most common family recorded, followed by Balaenopteridae, Ziphiidae, Physeteridae, and Kogiidae. Spinner Dolphins were the most abundant cetacean owing to the large pods observed and the regularity of the sightings. They were the only species seen feeding/traveling with birds and fish (tuna. Sperm Whales, Blue Whales, and Bryde’s Whales were also relatively common. Two records of interspecific association between cetaceans were recorded. The increase in the human population in the study area has resulted in the overexploitation of marine resources which has dire repercussions on the marine mammal communities found in these waters.
Chan, Kun-Wei; Lo, Chieh; Chu, Chi-Shih; Chin, Li-Te; Wang, Yu-Ting; Yang, Wei-Cheng
This protocol describes the development of a colloidal gold immunochromatographic test strip based on the sandwich format that can be used to differentiate the myoglobin (Mb) of cetaceans from that of seals and other animals. The strip provides rapid and on-the-spot screening for cetacean meat, thereby restraining its illegal trade and consumption. Two monoclonal antibodies (mAbs) with reactivity toward the Mb of cetaceans were developed. The amino acid sequences of Mb antigenic reactive regions from various animals were analyzed in order to design two synthetic peptides (a general peptide and a specific peptide) and thereafter raise the mAbs (subclass IgG1). The mAbs were selected from hybridomas screened by indirect ELISA, western blot and dot blot. CGF5H9 was specific to the Mbs of rabbits, dogs, pigs, cows, goats, and cetaceans while it showed weak to no affinity to the Mbs of chickens, tuna and seals. CSF1H13 can bind seals and cetaceans with strong affinity but showed no affinity to other animals. Cetacean samples from four families (Balaenopteridae, Delphinidae, Phocoenidae and Kogiidae) were used in this study, and the results indicated that these two mAbs have broad binding ability to Mbs from different cetaceans. These mAbs were applied on a sandwich-type colloidal gold immunochromatographic test strip. CGF5H9, which recognizes many species, was colloid gold-labeled and used as the detection antibody. CSF1H13, which was coated on the test zone, detected the presence of cetacean and seal Mbs. Muscle samples from tuna, chicken, seal, five species of terrestrial mammals and 15 species of cetaceans were tested in triplicate. All cetacean samples showed positive results and all the other samples showed negative results.
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.
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.
Dungan, Sarah Z; Chang, Belinda S W
Like many aquatic vertebrates, whales have blue-shifting spectral tuning substitutions in the dim-light visual pigment, rhodopsin, that are thought to increase photosensitivity in underwater environments. We have discovered that known spectral tuning substitutions also have surprising epistatic effects on another function of rhodopsin, the kinetic rates associated with light-activated intermediates. By using absorbance spectroscopy and fluorescence-based retinal release assays on heterologously expressed rhodopsin, we assessed both spectral and kinetic differences between cetaceans (killer whale) and terrestrial outgroups (hippo, bovine). Mutation experiments revealed that killer whale rhodopsin is unusually resilient to pleiotropic effects on retinal release from key blue-shifting substitutions (D83N and A292S), largely due to a surprisingly specific epistatic interaction between D83N and the background residue, S299. Ancestral sequence reconstruction indicated that S299 is an ancestral residue that predates the evolution of blue-shifting substitutions at the origins of Cetacea. Based on these results, we hypothesize that intramolecular epistasis helped to conserve rhodopsin's kinetic properties while enabling blue-shifting spectral tuning substitutions as cetaceans adapted to aquatic environments. Trade-offs between different aspects of molecular function are rarely considered in protein evolution, but in cetacean and other vertebrate rhodopsins, may underlie multiple evolutionary scenarios for the selection of specific amino acid substitutions.
Lyamin, Oleg I; Manger, Paul R; Ridgway, Sam H; Mukhametov, Lev M; Siegel, Jerome M
Our knowledge of the form of lateralized sleep behavior, known as unihemispheric slow wave sleep (USWS), seen in all members of the order Cetacea examined to date, is described. We trace the discovery of this phenotypically unusual form of mammalian sleep and highlight specific aspects that are different from sleep in terrestrial mammals. We find that for cetaceans sleep is characterized by USWS, a negligible amount or complete absence of rapid eye movement (REM) sleep, and a varying degree of movement during sleep associated with body size, and an asymmetrical eye state. We then compare the anatomy of the mammalian somnogenic system with what is known in cetaceans, highlighting areas where additional knowledge is needed to understand cetacean sleep. Three suggested functions of USWS (facilitation of movement, more efficient sensory processing and control of breathing) are discussed. Lastly, the possible selection pressures leading to this form of sleep are examined, leading us to the suggestion that the selection pressure necessitating the evolution of cetacean sleep was most likely the need to offset heat loss to the water from birth and throughout life. Aspects such as sentinel functions and breathing are likely to be proximate evolutionary phenomenon of this form of sleep.
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.
Arnason, U; Janke, A
Reasonably correct phylogenies are fundamental to the testing of evolutionary hypotheses. Here, we present phylogenetic findings based on analyses of 67 complete mammalian mitochondrial (mt) genomes. The analyses, irrespective of whether they were performed at the amino acid (aa) level or on nucleotides (nt) of first and second codon positions, placed Erinaceomorpha (hedgehogs and their kin) as the sister group of remaining eutherians. Thus, the analyses separated Erinaceomorpha from other traditional lipotyphlans (e.g., tenrecs, moles, and shrews), making traditional Lipotyphla polyphyletic. Both the aa and nt data sets identified the two order-rich eutherian clades, the Cetferungulata (comprising Pholidota, Carnivora, Perissodactyla, Artiodactyla, and Cetacea) and the African clade (Tenrecomorpha, Macroscelidea, Tubulidentata, Hyracoidea, Proboscidea, and Sirenia). The study corroborated recent findings that have identified a sister-group relationship between Anthropoidea and Dermoptera (flying lemurs), thereby making our own order, Primates, a paraphyletic assembly. Molecular estimates using paleontologically well-established calibration points, placed the origin of most eutherian orders in Cretaceous times, 70-100 million years before present (MYBP). The same estimates place all primate divergences much earlier than traditionally believed. For example, the divergence between Homo and Pan is estimated to have taken place approximately 10 MYBP, a dating consistent with recent findings in primate paleontology.
Siegal-Willott, Jessica; Estrada, Amara; Bonde, Robert; Wong, Arthur; Estrada, Daniel J; Harr, Kendal
Electrocardiographic (ECG) measurements were recorded in two subspecies of awake, apparently healthy, wild manatees (Trichechus manatus latirostris and T. m. manatus) undergoing routine field examinations in Florida and Belize. Six unsedated juveniles (dependent and independent calves) and 6 adults were restrained in ventral recumbency for ECG measurements. Six lead ECGs were recorded for all manatees and the following parameters were determined: heart rate and rhythm; P, QRS, and T wave morphology, amplitude, and duration; and mean electrical axis (MEA). Statistical differences using a t-test for equality of means were determined. No statistical difference was seen based on sex or subspecies of manatees in the above measured criteria. Statistical differences existed in heart rate (P = 0.047), P wave duration (P = 0.019), PR interval (P = 0.025), and MEA (P = 0.021) between adult manatees and calves. Our findings revealed normal sinus rhythms, no detectable arrhythmias, prolonged PR and QT intervals, prolonged P wave duration, and small R wave amplitude as compared with cetacea and other marine mammals. This paper documents the techniques for and baseline recordings of ECGs in juvenile and adult free-living manatees. It also demonstrates that continual assessment of cardiac electrical activity in the awake manatee can be completed and can be used to aid veterinarians and biologists in routine health assessment, during procedures, and in detecting the presence of cardiac disease or dysfunction.
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.
Xu, Yan-Yan; Tian, Xiao-Xiao; Chen, Lei-Lei; Pan, Hong-Chun
Juema pig is a kind of rare and special pig which is well adapted to high altitude, cold climate and harsh natural environment. The complete mitochondrial genome of Juema pig Sus scrofa is a circular molecule of 16 532 bp in length, containing 13 protein-coding genes, two ribosomal RNAs, 22 transfer RNAs, and a control region. The A + T content of the overall base composition of H-strand is 60.7% (T: 26.2%; C: 26.0%; A: 34.5%; G: 13.3%). ND4L gene begins with GTG as start codon, ND2, ND3, and ND5 genes begin with ATA as a start codon, and other nine protein-coding genes start with ATG. Cyt b gene is terminated with AGA as stop codon, ND1 and ND2 genes are terminated with TAG as stop codon, COII, COIII, ND3, and ND4 end with T, while ATP6, ATP8, COI, ND4L, ND5, and ND6 end with TAA. In addition, the phylogenetic relationships from neighbor-joining analyses based on the 13 concatenated PCGs indicated (Tylopoda (Suina (Ruminantia (Hippopotamidae, Cetacea)))).
Benoit, Julien; Adnet, Sylvain; El Mabrouk, Essid; Khayati, Hayet; Ben Haj Ali, Mustapha; Marivaux, Laurent; Merzeraud, Gilles; Merigeaud, Samuel; Vianey-Liaud, Monique; Tabuce, Rodolphe
Sea cows (manatees, dugongs) are the only living marine mammals to feed solely on aquatic plants. Unlike whales or dolphins (Cetacea), the earliest evolutionary history of sirenians is poorly documented, and limited to a few fossils including skulls and skeletons of two genera composing the stem family of Prorastomidae (Prorastomus and Pezosiren). Surprisingly, these fossils come from the Eocene of Jamaica, while stem Hyracoidea and Proboscidea - the putative sister-groups to Sirenia - are recorded in Africa as early as the Late Paleocene. So far, the historical biogeography of early Sirenia has remained obscure given this paradox between phylogeny and fossil record. Here we use X-ray microtomography to investigate a newly discovered sirenian petrosal from the Eocene of Tunisia. This fossil represents the oldest occurrence of sirenians in Africa. The morphology of this petrosal is more primitive than the Jamaican prorastomids’ one, which emphasizes the basal position of this new African taxon within the Sirenia clade. This discovery testifies to the great antiquity of Sirenia in Africa, and therefore supports their African origin. While isotopic analyses previously suggested sirenians had adapted directly to the marine environment, new paleoenvironmental evidence suggests that basal-most sea cows were likely restricted to fresh waters. PMID:23342128
Full Text Available Sea cows (manatees, dugongs are the only living marine mammals to feed solely on aquatic plants. Unlike whales or dolphins (Cetacea, the earliest evolutionary history of sirenians is poorly documented, and limited to a few fossils including skulls and skeletons of two genera composing the stem family of Prorastomidae (Prorastomus and Pezosiren. Surprisingly, these fossils come from the Eocene of Jamaica, while stem Hyracoidea and Proboscidea--the putative sister-groups to Sirenia--are recorded in Africa as early as the Late Paleocene. So far, the historical biogeography of early Sirenia has remained obscure given this paradox between phylogeny and fossil record. Here we use X-ray microtomography to investigate a newly discovered sirenian petrosal from the Eocene of Tunisia. This fossil represents the oldest occurrence of sirenians in Africa. The morphology of this petrosal is more primitive than the Jamaican prorastomids' one, which emphasizes the basal position of this new African taxon within the Sirenia clade. This discovery testifies to the great antiquity of Sirenia in Africa, and therefore supports their African origin. While isotopic analyses previously suggested sirenians had adapted directly to the marine environment, new paleoenvironmental evidence suggests that basal-most sea cows were likely restricted to fresh waters.
Chauvet, M T; Coffe, G; Chauvet, J; Acher, R
Neurohypophysial hormone-Neurophysin complexes have been prepared from posterior pituitary glands of Artiodactyla (ox, sheep, pig), Perissodactyla (horse) and Cetacea (whale), by fractionated salt precipitation. The components have been separated by molecular sieving in 0.2 M acetic acid and neurophysins have been purified by ion-exchange chromatography on DEAE-Sephadex A-50. Two types of neurophysins, MSEL-neurophysins and VLDV-neurophysins, can be distinguished according to the amino acid residues in positions 2, 3, 6 and 7. MSEL-neurophysins of sheep, ox and pig have been characterized by the amino acid sequence. Ovine and bovine MSEL-neurophysins are nearly identical (one substitution out of 95 residues) and porcine MSEL-neurophysin is very similar (four substitutions and an apparent 3-residue C-terminal deletion). The biological function of neurophysins might be the carriage of neurohypophysial hormones but in this respect, each type of neurophysin is not clearly specific for a given hormone. On the other hand, each neurophysin might share a common precursor with a neurohypophysial hormone, the two parts remaining associated after cleavage. However, in the sheep posterior pituitary gland, the molar proportions of the two types of neurophysins, oxytocin and arginine vasopressin, are not equal, MSEL-neurophysin being more abundant than the other components. If a common precursor exists, neurophysins and neurohypophysial hormones are not merely produced by a simple cleavage mechanism.
Johnson, Mark; Madsen, Peter T; Zimmer, Walter M X; de Soto, Natacha Aguilar; Tyack, Peter L
Beaked whales (Cetacea: Ziphiidea) of the genera Ziphius and Mesoplodon are so difficult to study that they are mostly known from strandings. How these elusive toothed whales use and react to sound is of concern because they mass strand during naval sonar exercises. A new non-invasive acoustic ording tag was attached to four beaked whales(two Mesoplodon densirostris and two Ziphius cavirostris) and recorded high-frequency clicks during deep dives. The tagged whales only clicked at depths below 200 m, down to a maximum depth of 1267 m. Both species produced a large number of short, directional, ultrasonic clicks with significant energy below 20 kHz. The tags recorded echoes from prey items; to our knowledge, a first for any animal echolocating in the wild. As far as we are aware, these echoes provide the first direct evidence on how free-ranging toothed whales use echolocation in foraging. The strength of these echoes suggests that the source level of Mesoplodon clicks is in the range of 200-220 dB re 1 microPa at 1 m. This paper presents conclusive data on the normal vocalizations of these beaked whale species, which may enable acoustic monitoring to mitigate exposure to sounds intense enough to harm them.
Lehman, L D; Jones, B N; Dwulet, F E; Bogardt, R A; Gurd, F R
The complete primary structure of the major component myoglobin from the goose-beaked whale, Ziphius cavirostris, was determined by specific cleavage of the protein to obtain large peptides which are readily degraded by the automatic sequencer. Over 80% of the amino acid sequence was established from the three peptides resulting from the cleavage of the apomyoglobin at its two methionine residues with cyanogen bromide along with the four peptides resulting from the cleavage with trypsin of the citraconylated apomyoglobin at its three arginine residues. Further digestion of the central cyanogen bromide peptide with S. aureus strain V8 protease and the 1,2-cyclohexanedione-treated central cyanogen bromide peptide with trypsin enabled the determination of the remainder of the covalent structure. This myoglobin differs from the cetacean myoglobins determined to date at 12 to 17 positions. These large sequence differences reflect the distant taxonomic relationships between the goose-beaked whale and the other species of Cetacea the myoglobin sequences of which have previously been determined.
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.
Kida, M Y
Molecular and statistical studies support the close phylogenetic relation between Cetacea and Artiodactyla. The presence of the tracheal bronchus has been pointed out as one of the common traits between only these groups. Nakakuki (1980) has investigated the mammalian tracheobronchial trees in 50 species based on his new nomenclature, and his study has consequently demonstrated the above-mentioned indication. Therefore, comparative anatomy of the tracheobronchial tree based on the nomenclature seems to be useful for investigations of the cetacean phylogeny. Three pairs of fetal lungs of the minke whale (Balaenoptera acutorostrata) were supplied from the Institute of Cetacean Research, Tokyo (1991) to observe their tracheobronchial trees and the ramification of the pulmonary artery. The fetal tracheobronchial tree consisted of one tracheal, four lateral, four dorsal and one medial secondary bronchi in the right lung, and five or six lateral and four or five dorsal secondary bronchi in the left, using the new nomenclature. The right pulmonary artery crossed the right axial bronchus from the ventral side to the dorsal over the third lateral bronchus. The tracheal bronchus in the fetal minke whale seems to belong to the type II of Nakakuki's nomenclature, and this type is seen in one species of the river dolphins. The other conspicuous traits of the fetal lungs are the defect of the second lateral broncus and the route of the pulmonary artery in the right side. This route is very different from that of many other mammals.
Cozzi, Bruno; Podestà, Michela; Mazzariol, Sandro; Zotti, Alessandro
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.
Hevner, Robert F
The dentate gyrus (DG), a part of the hippocampal formation, has important functions in learning, memory, and adult neurogenesis. Compared with homologous areas in sauropsids (birds and reptiles), the mammalian DG is larger and exhibits qualitatively different phenotypes: 1) folded (C- or V-shaped) granule neuron layer, concave toward the hilus and delimited by a hippocampal fissure; 2) nonperiventricular adult neurogenesis; and 3) prolonged ontogeny, involving extensive abventricular (basal) migration and proliferation of neural stem and progenitor cells (NSPCs). Although gaps remain, available data indicate that these DG traits are present in all orders of mammals, including monotremes and marsupials. The exception is Cetacea (whales, dolphins, and porpoises), in which DG size, convolution, and adult neurogenesis have undergone evolutionary regression. Parsimony suggests that increased growth and convolution of the DG arose in stem mammals concurrently with nonperiventricular adult hippocampal neurogenesis and basal migration of NSPCs during development. These traits could all result from an evolutionary change that enhanced radial migration of NSPCs out of the periventricular zones, possibly by epithelial-mesenchymal transition, to colonize and maintain nonperiventricular proliferative niches. In turn, increased NSPC migration and clonal expansion might be a consequence of growth in the cortical hem (medial patterning center), which produces morphogens such as Wnt3a, generates Cajal-Retzius neurons, and is regulated by Lhx2. Finally, correlations between DG convolution and neocortical gyrification (or capacity for gyrification) suggest that enhanced abventricular migration and proliferation of NSPCs played a transformative role in growth and folding of neocortex as well as archicortex.
Full Text Available Cetacea are secondarily aquatic amniotes that underwent their land-to-sea transition during the Eocene. Primitive forms, called archaeocetes, include five families with distinct degrees of adaptation to an aquatic life, swimming mode and abilities that remain difficult to estimate. The lifestyle of early cetaceans is investigated by analysis of microanatomical features in postcranial elements of archaeocetes. We document the internal structure of long bones, ribs and vertebrae in fifteen specimens belonging to the three more derived archaeocete families--Remingtonocetidae, Protocetidae, and Basilosauridae--using microtomography and virtual thin-sectioning. This enables us to discuss the osseous specializations observed in these taxa and to comment on their possible swimming behavior. All these taxa display bone mass increase (BMI in their ribs, which lack an open medullary cavity, and in their femora, whereas their vertebrae are essentially spongious. Humeri and femora show opposite trends in microanatomical specialization in the progressive independence of cetaceans from a terrestrial environment. Humeri change from very compact to spongious, which is in accordance with the progressive loss of propulsive role for the forelimbs, which were used instead for steering and stabilizing. Conversely, hind-limbs in basilosaurids became strongly reduced with no involvement in locomotion but display strong osteosclerosis in the femora. Our study confirms that Remingtonocetidae and Protocetidae were almost exclusively aquatic in locomotion for the taxa sampled, which probably were shallow water suspended swimmers. Basilosaurids display osseous specializations similar to those of modern cetaceans and are considered more active open-sea swimmers. This study highlights the strong need for homologous sections in comparative microanatomical studies, and the importance of combining information from several bones of the same taxon for improved functional
Houssaye, Alexandra; Tafforeau, Paul; de Muizon, Christian; Gingerich, Philip D
Cetacea are secondarily aquatic amniotes that underwent their land-to-sea transition during the Eocene. Primitive forms, called archaeocetes, include five families with distinct degrees of adaptation to an aquatic life, swimming mode and abilities that remain difficult to estimate. The lifestyle of early cetaceans is investigated by analysis of microanatomical features in postcranial elements of archaeocetes. We document the internal structure of long bones, ribs and vertebrae in fifteen specimens belonging to the three more derived archaeocete families--Remingtonocetidae, Protocetidae, and Basilosauridae--using microtomography and virtual thin-sectioning. This enables us to discuss the osseous specializations observed in these taxa and to comment on their possible swimming behavior. All these taxa display bone mass increase (BMI) in their ribs, which lack an open medullary cavity, and in their femora, whereas their vertebrae are essentially spongious. Humeri and femora show opposite trends in microanatomical specialization in the progressive independence of cetaceans from a terrestrial environment. Humeri change from very compact to spongious, which is in accordance with the progressive loss of propulsive role for the forelimbs, which were used instead for steering and stabilizing. Conversely, hind-limbs in basilosaurids became strongly reduced with no involvement in locomotion but display strong osteosclerosis in the femora. Our study confirms that Remingtonocetidae and Protocetidae were almost exclusively aquatic in locomotion for the taxa sampled, which probably were shallow water suspended swimmers. Basilosaurids display osseous specializations similar to those of modern cetaceans and are considered more active open-sea swimmers. This study highlights the strong need for homologous sections in comparative microanatomical studies, and the importance of combining information from several bones of the same taxon for improved functional interpretation.
Tucker, Marlee A; Rogers, Tracey L
Predator-prey body mass relationships are a vital part of food webs across ecosystems and provide key information for predicting the susceptibility of carnivore populations to extinction. Despite this, there has been limited research on the minimum and maximum prey size of mammalian carnivores. Without information on large-scale patterns of prey mass, we limit our understanding of predation pressure, trophic cascades and susceptibility of carnivores to decreasing prey populations. The majority of studies that examine predator-prey body mass relationships focus on either a single or a subset of mammalian species, which limits the strength of our models as well as their broader application. We examine the relationship between predator body mass and the minimum, maximum and range of their prey's body mass across 108 mammalian carnivores, from weasels to baleen whales (Carnivora and Cetacea). We test whether mammals show a positive relationship between prey and predator body mass, as in reptiles and birds, as well as examine how environment (aquatic and terrestrial) and phylogenetic relatedness play a role in this relationship. We found that phylogenetic relatedness is a strong driver of predator-prey mass patterns in carnivorous mammals and accounts for a higher proportion of variance compared with the biological drivers of body mass and environment. We show a positive predator-prey body mass pattern for terrestrial mammals as found in reptiles and birds, but no relationship for aquatic mammals. Our results will benefit our understanding of trophic interactions, the susceptibility of carnivores to population declines and the role of carnivores within ecosystems.
Andrea A. Cabrera Arreola
Full Text Available En Guatemala el estudio de los cetáceos inició en la década de los sesenta con los primeros registros de varamiento y captura incidental. Sin embargo, pocos trabajos científicos con datos de cetáceos han sido publicados. Con el objetivo de centralizar la información de cetáceos y obtener conocimiento biológico para el desarrollo de planes de manejo y conservación, se realizó una revisión bibliográfica de cetáceos en Guatemala que recaba información de los últimos 50 años. Se obtuvo un total de 1,014 registros de avistamiento (1979-2011, 62 registros de captura incidental (1961/85 y 16 registros de varamientos (1975, 2007-2012, los cuales se analizaron en mapas batimétricos y en mapas de presiones antropogénicas. Se identificaron diecinueve especies pertenecientes a cinco familias de cetáceos, incluyendo Balaenopteridae, Delphinidae, Ziphiidae, Kogiidae y Physeteridae. El esfuerzo y área de muestreo varió durante 1961-2012. Se identificaron diferentes patrones de distribución especie-específicos. La mayoría de avistamientos se registraron cerca de zonas con topografía compleja. Aunque los eventos de captura incidental se registraron únicamente en alta mar, los resultados sugieren que especies de distribución costera se encuentran en zonas con mayor riesgo antropogénico. Se reportaron ocho especies de cetáceos varados, eventos ocurridos principalmente en el departamento de Escuintla desde el año 2007. Debido a la gran diversidad en los patrones de distribución, comportamiento y uso de hábitat de los cetáceos, combinado con los riesgos antropogénicos de la zona, es necesario que se considere un enfoque integral cuando se implementen planes de manejo y conservación marina en Guatemala.
钟志军; 杜昕颖; 彭广能; 黄克和; 陈泽良; 于爽; 徐杰; 王玉飞; 白耀霞; 陈燕芬; 付思美; 王同坤; 汪舟佳
Brucellae are Gram-negative,facultative intracellular bacteria that can infect many species of animals and man.Six species are currently recognized within the genus Brucella：B.melitensis,B.abortus,B.suis,B.neotomae,B.ovis,and B.canis.This classification is mainly based on differences in pathogenicity and in host preferences.Although the six species can be differentiated by conventional phenotypic tests,these species display a high degree of DNA homology in DNA-DNA hybridization assays（90% identity）.Therefore it has been proposed that the Brucella genus should comprise only one species i.e.B.melitensis and that the other species should be considered as biovars.However,several molecular genotyping methods have shown of significant DNA polymorphism Brucella species allowing the species to be correctly differentiated.This is also true for the recent marine mammal Brucella isolates,which two new species names have been proposed,i.e.B.pinnipediae and B.cetaceae,according to the classical criteria of host preferentialism（pinnipeds and cetaceans respectively） and specific molecular markers.This article reviews the evolution and taxonomy of Brucella.%布鲁菌属革兰氏阴性兼性胞内寄生菌,能感染多种宿主动物和人。该属可分为6个典型种,包括羊种、牛种、猪种、沙林鼠种、绵羊附睾种以及犬种布鲁菌等。此分类是基于其致病性以及宿主偏好性的差异划分。尽管6个种通过传统表型试验能区分,但布鲁菌种内采用DNA-DNA杂交证明DNA同源性高度一致（相似性大于90%）。因此有人提议布鲁菌由单一种组成,即布鲁菌属中只有羊种布鲁菌,其他种都是羊种菌的生物亚型之一。然而基于其他分子技术的基因分型表明其DNA多态性表现明显,说明目前对这个种的分型还是比较准确。而最近分离的海洋种布鲁氏
Irie, Masahito; Koga, Akihiko; Kaneko-Ishino, Tomoko; Ishino, Fumitoshi
Amongst the 11 eutherian-specific genes acquired from a sushi-ichi retrotransposon is the CCHC type zinc-finger protein-encoding gene SIRH11/ZCCHC16. Its contribution to eutherian brain evolution is implied because of its involvement in cognitive function in mice, possibly via the noradrenergic system. Although, the possibility that Sirh11/Zcchc16 functions as a non-coding RNA still remains, dN/dS ratios in pairwise comparisons between its orthologs have provided supportive evidence that it acts as a protein. It became a pseudogene in armadillos (Cingulata) and sloths (Pilosa), the only two extant orders of xenarthra, which prompted us to examine the lineage-specific variations of SIRH11/ZCCHC16 in eutherians. We examined the predicted SIRH11/ZCCHC16 open reading frame (ORF) in 95 eutherian species based on the genomic DNA information in GenBank. A large variation in the SIRH11/ZCCHC16 ORF was detected in several lineages. These include a lack of a CCHC RNA-binding domain in its C-terminus, observed in gibbons (Hylobatidae: Primates) and megabats (Megachiroptera: Chiroptera). A lack of the N-terminal half, on the other hand, was observed in New World monkeys (Platyrrhini: Primates) and species belonging to New World and African Hystricognaths (Caviomorpha and Bathyergidae: Rodents) along with Cetacea and Ruminantia (Cetartiodactyla). Among the hominoids, interestingly, three out of four genera of gibbons have lost normal SIRH11/ZCCHC16 function by deletion or the lack of the CCHC RNA-binding domain. Our extensive dN/dS analysis suggests that such truncated SIRH11/ZCCHC16 ORFs are functionally diversified even within lineages. Combined, our results show that SIRH11/ZCCHC16 may contribute to the diversification of eutherians by lineage-specific structural changes after its domestication in the common eutherian ancestor, followed by putative species-specific functional changes that enhanced fitness and occurred as a consequence of complex natural selection events
and with phosphates and silica as important but secondary materials. The preservation of calcareous skeletons in deep time has resulted in providing interesting information: for example, the number of days in the Devonian year has been established on the basis of well-preserved lunar (annual) cycles, and isotope chemistry has led to an elaborate protocol for using O18/O16 stable isotopes for palaeotemperature measurements in the geological past. Stable isotopes of dental apatite have helped to establish ecological shifts (terrestrial to wholly marine) during the evolution of the Cetacea. Biomineralization as a field of specialization is still searching for its own independent identity, but gradually, its importance is being realized as a model for engineering applications especially at the nanometer scale.
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