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1.
Sci Rep ; 12(1): 19468, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376385

RESUMO

The sperm whale lives in most deep ice-free waters of the globe. It was targeted during two periods of whaling peaking in the 1840's and 1960's. Using a habitat suitability model, we extrapolated estimates of abundance from visual and acoustic surveys to give a global estimate of 736,053 sperm whales (CV = 0.218) in 1993. Estimates of trends in the post-whaling era suggest that: whaling, by affecting the sex ratio and/or the social cohesion of females, reduced recovery rates well after whaling ceased; preferentially-targeted adult males show the best evidence of recovery, presumably due to recruitment from breeding populations; several decades post-whaling, sperm whale populations not facing much human impact are recovering slowly, but populations may be declining in areas with substantial anthropogenic footprint. A theta-logistic population model enhanced to simulate spatial structure and the non-removal impacts of whaling indicated a pre-whaling population of 1,949,698 (CV = 0.178) in 1710 being reduced by whaling, and then then recovering a little to about 844,761 (CV = 0.209) in 2022. There is much uncertainty about these numbers and trends. A larger population estimate than produced by a similar analysis in 2002 is principally due to a better assessment of ascertainment bias.


Assuntos
Cachalote , Baleias , Animais , Feminino , Masculino , Humanos , Densidade Demográfica , Ecossistema
2.
Sci Rep ; 12(1): 16821, 2022 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-36207450

RESUMO

Sperm whales are an ideal species to study using passive acoustic technology because they spend the majority of their time underwater and produce echolocation clicks almost continuously while foraging. Passive acoustic line transect data collected between June and August 2016 were used to estimate a depth-corrected acoustic abundance and study the dive behaviour of foraging sperm whales in the western North Atlantic Ocean. 2D localizations (n = 699) were truncated at a slant range of 6500 m and combined with the multipath arrivals of surface reflected echoes to calculate 3D localizations (n = 274). Distance sampling using depth-corrected perpendicular distances resulted in a 10.5% change in the acoustic abundance estimate (2199 whales, CV = 14.6%) compared to uncorrected slant ranges (1969 whales, CV = 14.1%), and a detection function that was a better fit for the data. Sperm whales exhibited multiple foraging strategies, with bottom phases occurring at depths of 400-800, 800-1200, or > 1200 m, accounting for an average 39.2, 49.5, or 44.9% of the total recorded dive time, respectively. These results suggest that estimating 3D localizations using acoustic line transect data improves acoustic abundance estimation and can be used to answer population level questions about foraging ecology.


Assuntos
Ecolocação , Cachalote , Acústica , Animais , Humanos , Vocalização Animal , Baleias
3.
Vet Res Commun ; 46(4): 1303-1309, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36149569

RESUMO

On 25 August 2021, a single female sperm whale (Physeter macrocephalus) was found stranded dead in Playa Tuxpan, Veracruz, Mexico. Skin biopsies were obtained and screened for the detection of various potentially pathogenic bacterial genera, using conventional polymerase chain reaction and sequencing of the positive amplicons. We recorded, for the first time, the presence of Vibrio paraheamolyticus in skin samples from P. macrocephalus in the Gulf of Mexico. Additionally, we discuss 29 records reporting strandings of sperm whales from six states of the Mexican Republic. Most of the records are concentrated in the Pacific Ocean. Our findings increase the inventory of bacteria reported in P. macrocephalus worldwide, summarising the knowledge of stranding events in sperm whale populations in Mexico.


Assuntos
Cachalote , Vibrio , Feminino , Animais , Cachalote/microbiologia , México , Meio Ambiente
4.
Chemosphere ; 308(Pt 3): 136448, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36115469

RESUMO

Although lipophilic compounds have been the focus of numerous studies in marine mammals, their association with lipids is widely accepted, but rarely scrutinized. This pilot study aimed to investigate potential relationships between individual lipids from different lipid classes identified through a non-targeted Nuclear Magnetic Resonance (NMR) based lipidomics approach and legacy POPs in the blubber of long-finned pilot whales, sperm whales, common bottlenose dolphins, and Indo-Pacific bottlenose dolphins. Concentrations of selected POPs such as HCB and HCHs in sperm whales from Tasmania were found to differ from those in long-finned pilot whales and common bottlenose dolphins from the same location. Profiles of NMR spectra measured in blubber of sperm whales were also distinctly different compared to the pilot whales and common bottlenose dolphins. Two groups of Indo-Pacific bottlenose dolphins from South Australia that were 20 years apart showed highly comparable profiles of NMR signals despite having higher concentrations of several POP classes in the more recent group. More specific correlations were investigated between selected POPs (n = 12) and all detected NMR signals (n = 63) in all species. Outcomes were species-specific, but difficult to interpret due to the lack of available literature for marine mammals and the small sample sizes per species. Because of the key role of lipids in the bioaccumulation of POPs and in the incidence of diseases, more attention should be given to the identification and characterization of lipid species in future toxicological studies. However, future studies should focus on one marine mammal species to increase sample sizes and limit the number of confounding factors, such as diet, that can influence POP and lipid levels and profiles.


Assuntos
Golfinho Nariz-de-Garrafa , Caniformia , Baleia Comum , Poluentes Químicos da Água , Baleias Piloto , Tecido Adiposo/química , Animais , Monitoramento Ambiental , Éteres Difenil Halogenados/análise , Hexaclorobenzeno/análise , Lipídeos/análise , Poluentes Orgânicos Persistentes , Projetos Piloto , Cachalote , Poluentes Químicos da Água/análise
5.
Proc Natl Acad Sci U S A ; 119(37): e2201692119, 2022 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-36074817

RESUMO

Culture, a pillar of the remarkable ecological success of humans, is increasingly recognized as a powerful force structuring nonhuman animal populations. A key gap between these two types of culture is quantitative evidence of symbolic markers-seemingly arbitrary traits that function as reliable indicators of cultural group membership to conspecifics. Using acoustic data collected from 23 Pacific Ocean locations, we provide quantitative evidence that certain sperm whale acoustic signals exhibit spatial patterns consistent with a symbolic marker function. Culture segments sperm whale populations into behaviorally distinct clans, which are defined based on dialects of stereotyped click patterns (codas). We classified 23,429 codas into types using contaminated mixture models and hierarchically clustered coda repertoires into seven clans based on similarities in coda usage; then we evaluated whether coda usage varied with geographic distance within clans or with spatial overlap between clans. Similarities in within-clan usage of both "identity codas" (coda types diagnostic of clan identity) and "nonidentity codas" (coda types used by multiple clans) decrease as space between repertoire recording locations increases. However, between-clan similarity in identity, but not nonidentity, coda usage decreases as clan spatial overlap increases. This matches expectations if sympatry is related to a measurable pressure to diversify to make cultural divisions sharper, thereby providing evidence that identity codas function as symbolic markers of clan identity. Our study provides quantitative evidence of arbitrary traits, resembling human ethnic markers, conveying cultural identity outside of humans, and highlights remarkable similarities in the distributions of human ethnolinguistic groups and sperm whale clans.


Assuntos
Identificação Social , Cachalote , Acústica , Animais , Cultura , Oceano Pacífico , Vocalização Animal
6.
J Comp Physiol B ; 192(6): 789-804, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35939091

RESUMO

We examined the differential deposition of lipids according to layer, sex and ontogeny in the blubber of 31 adult sperm whales (n = 22 females, 9 males) and two calves that stranded off the Tasmanian coast from 2002 to 2004. Total lipid (TL) content varied widely across the blubber layers of adults (27-77%). Overall, females had higher TL content than males possibly representing higher energy needs due to reproduction. Higher TL content in the middle layer of adults (69%) suggests this layer may act as an energy reserve. Wax esters (WE) dominated the blubber and were highest in the outer layer of adults and calves, likely providing insulative qualities for this deep-diving odontocete. Triacyclglycerols, an easily mobilized energy source, were highest in the inner layer of females (37.3 ± 13.5%) and calves (32.1 ± 1.8%) compared to males (17.1 ± 8.2%). Monounsaturated fatty acids (MUFA) also dominated the blubber. An increasing gradient from the inner to outer layer reflected an increasing source of endogenously synthesized lipids, whereas an increasing gradient of saturated fatty acids and polyunsaturated fatty acids (PUFA) toward the inner layer reflected an increasing source of dietary lipids. Although body site did not affect lipid profiles, stratification between the outer and more metabolically active inner layers suggests that only using the outer layer may result in an incomplete lipid profile for sperm whales.


Assuntos
Ácidos Graxos , Cachalote , Tecido Adiposo , Animais , Ácidos Graxos Monoinsaturados , Ácidos Graxos Insaturados , Feminino , Masculino
7.
Sci Rep ; 12(1): 12918, 2022 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-35902622

RESUMO

Deep-habitat cetaceans are generally difficult to study, leading to a limited knowledge of their population. This paper assesses the differential distribution patterns of three deep-habitat cetaceans (Sperm whale-Physeter macrocephalus, Risso's dolphin-Grampus griseus & Cuvier's beaked whale-Ziphius cavirostris). We used data of 842 opportunistic sightings of cetaceans in the western Mediterranean sea. We inferred environmental and spatio-temporal factors that affect their distribution. Binary logistic regression models were generated to compare the presence of deep-habitat cetaceans with the presence of other cetacean species in the dataset. Then, the favourability function was applied, allowing for comparison between all the models. Sperm whale and Risso's dolphin presence was differentially favoured by the distance to towns in the eastern part of the western Mediterranean sea. The differential distribution of sperm whale was also influenced by the stability of SST, and that of the Risso's dolphin by lower mean salinity and higher mean Chlorophyll A concentration. When modelling the three deep-habitat cetaceans (including Cuvier's beaked whale), the variable distance to towns had a negative influence on the presence of any of them more than it did to other cetaceans, being more favourable far from towns, so this issue should be further investigated.


Assuntos
Golfinhos , Animais , Clorofila A , Ecossistema , Mar Mediterrâneo , Cachalote , Baleias
8.
Sci Rep ; 12(1): 10639, 2022 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-35739207

RESUMO

The Humboldt Current Ecosystem (HCE) is one of the most productive marine ecosystems, sustaining one of the largest fishing industries in the world. Although several species of cetaceans are known to inhabit these productive waters, quantitative assessments of their abundance and distribution patterns are scarce and patchy. Here, we present the first abundance and distribution estimates for fin whale (Balaenoptera physalus), southeast Pacific blue whales (Balaenoptera musculus), sperm whale (Physeter macrocephalus), dusky dolphin (Lagenorhynchus obscurus), and common dolphin (Delphinus spp.) in the entire Chilean portion of the HCE. Line transect surveys were conducted during 2016-2021 between 18° S and 41° S and up to ~ 200 km offshore, and data were analyzed using distance sampling methods. Group counts were modelled as a function of environmental variables using single step Bayesian Binomial N-mixture model (BNMM), which allows full uncertainty propagation between model components. By using spatially explicit predictions of cetacean densities and observed vessel densities in the HCE, we provide quantitative assessments on the relative probability of cetaceans encountering vessels (RPCEV). Dusky dolphin and fin whale showed the largest distribution overlap with industrial and artisanal fishery fleets. Our results highlight areas where effort should be prioritized to address the extant but unquantified negative interactions between vessels and cetaceans in Chilean HCE.


Assuntos
Balaenoptera , Golfinhos , Baleia Comum , Animais , Teorema de Bayes , Cetáceos , Chile , Ecossistema , Cachalote
9.
Sci Rep ; 12(1): 9620, 2022 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-35688859

RESUMO

Species Distribution Models are commonly used with surface dynamic environmental variables as proxies for prey distribution to characterise marine top predator habitats. For oceanic species that spend lot of time at depth, surface variables might not be relevant to predict deep-dwelling prey distributions. We hypothesised that descriptors of deep-water layers would better predict the deep-diving cetacean distributions than surface variables. We combined static variables and dynamic variables integrated over different depth classes of the water column into Generalised Additive Models to predict the distribution of sperm whales Physeter macrocephalus and beaked whales Ziphiidae in the Bay of Biscay, eastern North Atlantic. We identified which variables best predicted their distribution. Although the highest densities of both taxa were predicted near the continental slope and canyons, the most important variables for beaked whales appeared to be static variables and surface to subsurface dynamic variables, while for sperm whales only surface and deep-water variables were selected. This could suggest differences in foraging strategies and in the prey targeted between the two taxa. Increasing the use of variables describing the deep-water layers would provide a better understanding of the oceanic species distribution and better assist in the planning of human activities in these habitats.


Assuntos
Cachalote , Baleias , Animais , Baías , Ecossistema , Oceanos e Mares , Água
10.
Proc Biol Sci ; 289(1977): 20220774, 2022 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-35765834

RESUMO

Shark-cetacean trophic interactions, preserved as bite marks in the fossil record, mostly correspond to isolated or fragmentary findings that bear limited information about major trophic patterns or roles. Here, we provide evidence of focalized foraging by sharks in the form of tooth bite marks over physeteroids fossil bones from the late Miocene of Peru. These findings indicate that sharks were targeting the forehead of coeval physeteroids to actively feed on their lipid-rich nasal complexes. Miocene physeteroids displayed a broad diversity, including giant predatorial forms, small benthic foragers and suction feeders. Like their extant relatives, these animals exhibited enlarged fatty forehead organs responsible for their sound production capabilities, thus evolving taxon-specific cranial architecture. Bite marks are found on the cranial bones where these structures were attached, indicating that sharks actively targeted this region; but also, in areas that would only be accessible following the consumption of the surrounding soft tissues. The shape of the bite marks and their distribution suggests a series of consecutive scavenging events by individuals of different shark species. Similar bite patterns can be recognized on other Miocene physeteroids fossils from across the globe, suggesting that sharks actively exploited physeteroid carcasses as fat sources.


Assuntos
Tubarões , Cachalote , Animais , Fósseis , Peru , Crânio
11.
PLoS One ; 17(3): e0264988, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35324943

RESUMO

A combination of machine learning and expert analyst review was used to detect odontocete echolocation clicks, identify dominant click types, and classify clicks in 32 years of acoustic data collected at 11 autonomous monitoring sites in the western North Atlantic between 2016 and 2019. Previously-described click types for eight known odontocete species or genera were identified in this data set: Blainville's beaked whales (Mesoplodon densirostris), Cuvier's beaked whales (Ziphius cavirostris), Gervais' beaked whales (Mesoplodon europaeus), Sowerby's beaked whales (Mesoplodon bidens), and True's beaked whales (Mesoplodon mirus), Kogia spp., Risso's dolphin (Grampus griseus), and sperm whales (Physeter macrocephalus). Six novel delphinid echolocation click types were identified and named according to their median peak frequencies. Consideration of the spatiotemporal distribution of these unidentified click types, and comparison to historical sighting data, enabled assignment of the probable species identity to three of the six types, and group identity to a fourth type. UD36, UD26, and UD28 were attributed to Risso's dolphin (G. griseus), short-finned pilot whale (G. macrorhynchus), and short-beaked common dolphin (D. delphis), respectively, based on similar regional distributions and seasonal presence patterns. UD19 was attributed to one or more species in the subfamily Globicephalinae based on spectral content and signal timing. UD47 and UD38 represent distinct types for which no clear spatiotemporal match was apparent. This approach leveraged the power of big acoustic and big visual data to add to the catalog of known species-specific acoustic signals and yield new inferences about odontocete spatiotemporal distribution patterns. The tools and call types described here can be used for efficient analysis of other existing and future passive acoustic data sets from this region.


Assuntos
Golfinhos , Ecolocação , Acústica , Animais , Aprendizado de Máquina , Cachalote , Vocalização Animal , Baleias
12.
Glob Chang Biol ; 28(12): 3860-3870, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35302678

RESUMO

Sperm whales (Physeter macrocephalus) are a cosmopolitan species but are only found in ice-free regions of the ocean. It is unknown how their distribution might change in regions undergoing rapid loss of sea ice and ocean warming like Baffin Bay in the eastern Canadian Arctic. In 2014 and 2018, sperm whales were sighted near Eclipse Sound, Baffin Bay: the first recorded uses of this region by sperm whales. In this study, we investigate the spatiotemporal distribution of sperm whales near Eclipse Sound using visual and acoustic data. We combine several published open-source, data sets to create a map of historical sperm whale presence in the region. We use passive acoustic data from two recording sites between 2015 and 2019 to investigate more recent presence in the region. We also analyze regional trends in sea ice concentration (SIC) dating back to 1901 and relate acoustic presence of sperm whales to the mean SIC near the recording sites. We found no records of sperm whale sightings near Eclipse Sound outside of the 2014/2018 observations. Our acoustic data told a different story, with sperm whales recorded yearly from 2015 to 2019 with presence in the late summer and fall months. Sperm whale acoustic presence increased over the 5-year study duration and was closely related to the minimum SIC each year. Sperm whales, like other cetaceans, are ecosystem sentinels, or indicators of ecosystem change. Increasing number of days with sperm whale presence in the Eclipse Sound region could indicate range expansion of sperm whales as a result of changes in sea ice. Monitoring climate change-induced range expansion in this region is important to understand how increasing presence of a top-predator might impact the Arctic food web.


Assuntos
Camada de Gelo , Cachalote , Animais , Baías , Canadá , Ecossistema
13.
Biochem Biophys Res Commun ; 598: 26-31, 2022 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-35151200

RESUMO

Globins are heme proteins such as hemoglobin (Hb), myoglobin (Mb) and neuroglobin (Ngb), playing important roles in biological system. In addition to normal functions, zebrafish Ngb was able to penetrate cell membranes, whereas less was known for other globin members. In this study, to improve the cell-membrane-penetrating activity of globins, we used sperm whale Mb as a model protein and constructed a quadruple mutant of G5K/Q8K/A19K/V21K Mb (termed 4K Mb), by introduction of four positive charges on the protein surface, which was designed according to the amino acid alignment with that of zebrafish Ngb. Spectroscopic and crystallographic studies showed that the four positively charged Lys residues did not affect the protein structure. Cell-membrane-penetrating essay further showed that 4K Mb exhibited enhanced activity compared to that of native Mb. This study provides valuable information for the effect of distribution of charged residues on the protein structure and the cell-membrane-penetrating activity of globins. Therefore, it will guide the design of protein-based biomaterials for biological applications.


Assuntos
Membrana Celular/metabolismo , Mioglobina/química , Mioglobina/metabolismo , Animais , Membrana Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dicroísmo Circular , Cristalografia por Raios X , Fluoresceína-5-Isotiocianato/química , Humanos , Lisina/química , Células MCF-7 , Mutação , Mioglobina/genética , Mioglobina/farmacocinética , Espectrofotometria Ultravioleta , Cachalote
14.
Folia Parasitol (Praha) ; 692022 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-35145047

RESUMO

Data mining animal of genomes has been used before to identify endoparasites, and may be a particularly useful tool to surpass some difficulties faced by studies in the marine environment. We detected a species of Sarcocystis Lankester, 1882, contamination in the sperm whale (Physeter catodon Linnaeus) reference genome available in the GenBank database. We identified and extracted multiple gene fragments and placed the sequences in a phylogenetic framework. Our results indicate that the sequences of Sarcocystis sp. found in the genome do not correspond to any currently described species, despite a few other similar sequences having been identified in fur seals (Pinnipedia) and another sperm whale. Including data from previous studies, we suggest there is enough evidence to support the occurrence of at least four species of Sarcocystis in marine mammals. We also demonstrate that the term "S. canis-like" has been used for samples not closely related to Sarcocystis canis Dubey et Speer, 1991.


Assuntos
Artiodáctilos , Sarcocystidae , Sarcocystis , Sarcocistose , Animais , Filogenia , Sarcocystis/genética , Sarcocistose/epidemiologia , Sarcocistose/veterinária , Cachalote
15.
Sci Rep ; 12(1): 2007, 2022 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-35132115

RESUMO

A total of 147 days spread over 4 years were recorded by a stereophonic sonobuoy set up in the Mediterranean sea, near the coast of Toulon, south of France. These recordings were analyzed in the scope of studying sperm whales (Physeter macrocephalus) and the impact anthropic noises may have on this species. With the use of a novel approach, which combines the use of a stereophonic antenna with a neural network, 226 sperm whales' passages have been automatically detected in an effective range of 32 km. This dataset was then used to analyze the sperm whales' abundance, the background noise, the influence of the background noise on the acoustic presence, and the animals' size. The results show that sperm whales are present all year round in groups of 1-9 individuals, especially during the daytime. The estimated density is 1.69 whales/1000 km[Formula: see text]. Animals were also less frequent during periods with an increased background noise due to ferries. The animal size distribution revealed the recorded sperm whales were distributed in length from about 7 to 15.5 m, and lonely whales are larger, while groups of two are composed of juvenile and mid-sized animals.


Assuntos
Comportamento Animal , Tamanho Corporal , Ruído dos Transportes , Comportamento Social , Cachalote/fisiologia , Cachalote/psicologia , Animais , Conjuntos de Dados como Assunto , França , Mar Mediterrâneo , Navios
16.
Sci Rep ; 12(1): 1973, 2022 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-35132140

RESUMO

Experimental research has shown that beaked whales exhibit strong avoidance reactions to naval active sonars used during antisubmarine warfare training exercises, including cessation of echolocation and foraging activity. Behavioural responses to sonar have also been linked to strandings and mortality. Much of the research on the responses of beaked whales and other cetaceans to naval active sonar has occurred on or near U.S. naval training ranges, and the impacts of sonar in other regions remain poorly understood, particularly as these impacts, including mortality, are likely to go unobserved in offshore areas. In September 2016 the multinational naval exercise 'CUTLASS FURY 2016' (CF16) was conducted off eastern Canada. We used passive acoustic recordings collected in the region to quantify the occurrence and characteristics of sonar signals, measure ambient noise levels, and assess changes in the acoustic activity of beaked and sperm whales. The number of hours per day with echolocation clicks from Cuvier's beaked whales and sperm whales were significantly reduced during CF16, compared to the pre-exercise period in 2016 (sperm whales) and to control data from 2015 (both species). Clicks from an unidentified Mesoplodont beaked whale species, sporadically detected prior to CF16, were absent during the exercise and for 7 days afterward. These results suggest that beaked and sperm whales ceased foraging in the vicinity of CF16 and likely avoided the affected area. Such disturbance may have energetic, health, and fitness consequences.


Assuntos
Ecolocação , Som/efeitos adversos , Cachalote/fisiologia , Cachalote/psicologia , Guerra , Baleias/fisiologia , Baleias/psicologia , Animais , Aprendizagem da Esquiva , Canadá , Mergulho , Comportamento Alimentar
17.
Microb Ecol ; 83(1): 18-33, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33745062

RESUMO

Large baleen and toothed whales play crucial ecological roles in oceans; nonetheless, very little is known about their intestinal microbiomes. Based on striking differences in natural history and thus in feeding behaviours, it can be expected that intestinal microbiomes of large baleen whales and toothed whales are different. To test this hypothesis, the phylogenetic composition of faecal microbiomes was investigated by a 16S rRNA gene amplicon sequence-based approach for Bacteria and Archaea. Faecal samples from free-ranging large whales collected off the Azores Archipelago (Portugal) were used, comprising 13 individual baleen whales (one sei, two blue and ten fin whales) and four sperm whales. The phylogenetic composition of the Bacteria faecal microbiomes of baleen and toothed whales showed no significant differences at the phylum level. However, significant differences were detected at the family and genus levels. Most abundant phyla were Firmicutes, Bacteroidetes, Proteobacteria, Tenericutes and Spirochaeta. Few highly abundant bacterial genera were identified as key taxa with a high contribution to differences among baleen and toothed whales microbiomes. Only few archaeal sequences were detected, primarily Methanomassiliicoccales representing potential methanogenic Archaea. This is the first study that directly compares the faecal bacterial and archaeal microbiomes of free-ranging baleen and toothed whales which represent the two parvorders of Cetacea which members are fully aquatic large mammals which were evolutionary split millions of years ago.


Assuntos
Balaenoptera , Microbiota , Animais , Filogenia , RNA Ribossômico 16S/genética , Cachalote/microbiologia
18.
J Anat ; 240(4): 669-677, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34761390

RESUMO

In 2016, two adult male sperm whales beached off of Yangkou Port in Nantong City, Jiangsu Province, China. The local government planned to preserve them as specimens, one was entrusted to Dalian Hoffen Biological Co., Ltd., and thus became the first sperm whale to be preserved by plastination. The other sperm whale was preserved in Nantong by the traditional stripping method (The skin was preserved, and then the prosthesis was filled into the skin to preserve the specimens. The material of the prosthesis was polyurethane. The outline of the animal was sculpted by suturing the skin like a bag and filling it with polyurethane). Plastination of such a large marine mammal allowed us to view the mutual adaptations of its internal structure to its specific living environment and daily habits. This sperm whale is the largest specimen in the world and this is the first time a sperm whale has been preserved using the plastination method. The plastination process also provides a method for studying the anatomy of large marine mammals for humans to understand deep-sea organisms at close contact and visual level. The plastination of this sperm whale promises to be a world class resource holding tremendous scientific, educational, and artistic value.


Assuntos
Plastinação , Cachalote , Animais , China , Masculino , Poliuretanos
19.
J Genet ; 1002021.
Artigo em Inglês | MEDLINE | ID: mdl-34787113

RESUMO

Marine mammals are exposed to the oxidative stress induced by hypoxia/reoxygenation cycles yet resist cellular damage. The availability of high-quality genomes promises to provide insights on how this is achieved. In this study, we considered the ubiquitinconjugating enzymes (E2) gene family, UBE2 genes, which encodes enzymes with critical roles in cellular physiology, including the oxidative stress response. The sperm whale was the first marine mammal with a chromosome-level genome, allowing the study of gene family repertories, phylogenetic relationships, chromosome gene organization, and other evolutionary patterns on a genomewide basis. Here, 39 UBE2 genes (similar to human, including 32 intact genes, one partial gene, six pseudogenes) were identified in sperm whale genome. These genes were found on 17 chromosomes and were assigned into 23 subfamilies, 16 subgroups, and four classes based on structural characteristics and functions, phylogeny and conserved domains, respectively. Although the gene structure and motif distribution of sperm whale UBE2 genes are conserved in each subfamily, motif variation and intron gain/loss may contribute to functional divergence. Segmental duplications were detected in six gene pairs, which could drive UBE2 gene innovation in the sperm whale. Contrasting seven cetaceans and five terrestrial taxa, we found that cetaceans have experienced shifts in selective constraint on UBE2 genes, which may contribute to oxidative stress tolerance during the adaptation to aquatic life. Our results provide the first comprehensive survey of cetacean UBE2 genes.


Assuntos
Cachalote/genética , Enzimas de Conjugação de Ubiquitina/genética , Motivos de Aminoácidos/genética , Animais , Mapeamento Cromossômico , Evolução Molecular , Duplicação Gênica , Genoma , Filogenia
20.
PLoS One ; 16(8): e0255667, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34347854

RESUMO

In habitat modelling, environmental variables are assumed to be proxies of lower trophic levels distribution and by extension, of marine top predator distributions. More proximal variables, such as potential prey fields, could refine relationships between top predator distributions and their environment. In situ data on prey distributions are not available over large spatial scales but, a numerical model, the Spatial Ecosystem And POpulation DYnamics Model (SEAPODYM), provides simulations of the biomass and production of zooplankton and six functional groups of micronekton at the global scale. Here, we explored whether generalised additive models fitted to simulated prey distribution data better predicted deep-diver densities (here beaked whales Ziphiidae and sperm whales Physeter macrocephalus) than models fitted to environmental variables. We assessed whether the combination of environmental and prey distribution data would further improve model fit by comparing their explanatory power. For both taxa, results were suggestive of a preference for habitats associated with topographic features and thermal fronts but also for habitats with an extended euphotic zone and with large prey of the lower mesopelagic layer. For beaked whales, no SEAPODYM variable was selected in the best model that combined the two types of variables, possibly because SEAPODYM does not accurately simulate the organisms on which beaked whales feed on. For sperm whales, the increase model performance was only marginal. SEAPODYM outputs were at best weakly correlated with sightings of deep-diving cetaceans, suggesting SEAPODYM may not accurately predict the prey fields of these taxa. This study was a first investigation and mostly highlighted the importance of the physiographic variables to understand mechanisms that influence the distribution of deep-diving cetaceans. A more systematic use of SEAPODYM could allow to better define the limits of its use and a development of the model that would simulate larger prey beyond 1,000 m would probably better characterise the prey of deep-diving cetaceans.


Assuntos
Distribuição Animal/fisiologia , Mergulho/fisiologia , Comportamento Alimentar/fisiologia , Comportamento Predatório/fisiologia , Cachalote/fisiologia , Animais , Biomassa , Ecossistema , Oceanos e Mares , Zooplâncton/fisiologia
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