Lagenorhynchus Acutus Research Articles

Meals on Wheels? A Decade of Megafaunal Visual and Acoustic Observations from Offshore Oil & Gas Rigs and Platforms in the North and Irish Seas.

A decade of visual and acoustic detections of marine megafauna around offshore Oil & Gas (O&G) installations in the North and Irish Seas are presented. Marine megafauna activity was monitored visually and acoustically by Joint Nature Conservation Committee (JNCC) qualified and experienced Marine Mammal Observers (MMO) and Passive Acoustic Monitoring (PAM) Operators respectively, with real-time towed PAM in combination with industry standard software, PAMGuard. Monitoring was performed during routine O&G industrial operations for underwater noise mitigation purposes, and to ensure adherence to regulatory guidelines. Incidental sightings by off-effort MMOs and installation crew were also reported. Visual and acoustic monitoring spanned 55 non-consecutive days between 2004 and 2014. A total of 47 marine mammal sightings were recorded by MMOs on dedicated watch, and 10 incidental sightings of marine megafauna were reported over 10 years. Species included: harbour porpoise (Phocoena phocoena), Atlantic white-sided dolphin (Lagenorhynchus acutus), white beaked dolphin (Lagenorhynchus albirostris), common dolphin (Delphinus delphis), minke whale (Balaenoptera acutorostrata), common seal (Phoca vitulina), grey seal (Halichoerus grypus) and, basking shark (Cetorhinus maximus). Passive Acoustic Monitoring was conducted on two occasions in 2014; 160 PAM hours over 12 days recorded a total of 308 individual clicks identified as harbour porpoises. These appear to be the first such acoustic detections obtained from a North Sea drilling rig whilst using a typically configured hydrophone array designed for towing in combination with real-time PAMGuard software. This study provides evidence that marine megafauna are present around mobile and stationary offshore O&G installations during routine operational activities. On this basis, Environmental Impact Assessments (EIAs) for decommissioning O&G platforms should be carried-out on a case-by-case basis, and must include provisions for hitherto overlooked marine megafauna.

Insights into the diet of Atlantic white‐sided dolphins (Lagenorhynchus acutus) in the Northeast Atlantic

Insights into the diet of Atlantic white‐sided dolphins (<i>Lagenorhynchus acutus</i>) in the Northeast Atlantic

A genomewide catalogue of single nucleotide polymorphisms in white-beaked and Atlantic white-sided dolphins.

The field of population genetics is rapidly moving into population genomics as the quantity of data generated by high-throughput sequencing platforms increases. In this study, we used restriction-site-associated DNA sequencing (RADSeq) to recover genomewide genotypes from 70 white-beaked (Lagenorhynchus albirostris) and 43 Atlantic white-sided dolphins (L. acutus) gathered throughout their north-east Atlantic distribution range. Both species are at a high risk of being negatively affected by climate change. Here, we provide a resource of 38,240 RAD-tags and 52,981 nuclear SNPs shared between both species. We have estimated overall higher levels of nucleotide diversity in white-sided (π = 0.0492 ± 0.0006%) than in white-beaked dolphins (π = 0.0300 ± 0.0004%). White-sided dolphins sampled in the Faroe Islands, belonging to two pods (N = 7 and N = 11), showed similar levels of diversity (π = 0.0317 ± 0.0007% and 0.0267 ± 0.0006%, respectively) compared to unrelated individuals of the same species sampled elsewhere (e.g. π = 0.0285 ± 0.0007% for 11 Scottish individuals). No evidence of higher levels of kinship within pods can be derived from our analyses. When identifying the most likely number of genetic clusters among our sample set, we obtained an estimate of two to four clusters, corresponding to both species and possibly, two further clusters within each species. A higher diversity and lower population structuring was encountered in white-sided dolphins from the north-east Atlantic, in line with their preference for pelagic waters, as opposed to white-beaked dolphins that have a more patchy distribution, mainly across continental shelves.

Application of the LUminometric Methylation Assay to ecological species: tissue quality requirements and a survey of DNA methylation levels in animals

The LUminometric Methylation Assay (LUMA) measures global DNA methylation. LUMA depends on digestion of DNA with methyl-sensitive and methyl-insensitive restriction enzymes, followed by pyrosequencing. Until recently, LUMA has been principally used for biomedical research. Here, we use chickens as a model to investigate sample quality issues relating to LUMA and then apply the method to ecological species. First, we assessed the effect of tissue storage conditions on DNA methylation values. This is an important consideration for ecological species because samples are not always ideally preserved and LUMA is sensitive to poor DNA quality. We found that good quality LUMA data could be obtained from chicken liver and brain tissues stored at 21°C for at least 2 and 12h, respectively. Longer storage times introduced nonspecific peaks to pyrograms which were associated with reduced DNA methylation. Repeatedly, freezing and thawing the tissues did not affect LUMA data. Second, we measured DNA methylation in 12 species representing five animal classes: amphibians (African and Western clawed frog), reptiles (green anole lizard), fish (yellow perch, goldfish, lake trout), mammals (American mink, polar bear, short-beaked common dolphin, Atlantic white-sided dolphin) and birds (chicken, Japanese quail). We saw a pattern of high DNA methylation in fish (84-87%), and intermediate levels in mammals (68-72%) and birds (52-71%). This pattern corresponds well with previous measures of DNA methylation generated by HPLC. Our data represent the first CpG methylation values to be reported in several species and provide a basis for studying patterns of epigenetic inheritance in an ecological context.

Phylogeography and population dynamics of the white-sided dolphin (Lagenorhynchus acutus) in the North Atlantic

Highly mobile species in the marine environment may be expected to show little differentiation at the population level, but this is often not the case. Instead cryptic population structure is common, and effective conservation will require an understanding of how these patterns evolve. Here we present an assessment from both sides of the North Atlantic of differentiation among populations of a dolphin species that inhabits mainly pelagic waters, the Atlantic white-sided dolphin. We compare eleven putative populations in the western and eastern North Atlantic at mtDNA and microsatellite DNA loci and find reduced nucleotide diversity and signals for historical bottlenecks and post-bottleneck expansions in all regions. We calculate expansion times to have occurred during the early Holocene, following the last glacial maximum (LGM). We find evidence for connectivity among populations from either side of the North Atlantic, and differentiation between putative populations in the far northeast compared with all other areas sampled. Some data suggest the possibility of separate refugia during the LGM explaining this pattern, although ongoing ecological processes may also be a factor. We discuss the implications for developing effective programs of conservation and management in the context of ongoing anthropogenic impact.

Hemoglobin as a major binding protein for methylmercury in white-sided dolphin liver

As methylmercury (MeHg) can be bioaccumulated and biomagnified in the trophic web, its toxicity for marine mammals is of major concern. Mercury speciation in marine biota has been widely studied, mainly focused on the discrimination and quantification of inorganic Hg and MeHg. Less attention has been paid to the interactions of Hg with biomolecules and the characterization of its specific binding, which play a key role in metabolic pathways controlling its uptake, transformation, and toxicity. In the studied white-sided dolphin (Lagenorhynchus acutus) liver homogenate (QC04LH4) sample, approximately 60% of the total MeHg was found in the water soluble fraction, specifically associated with high molecular weight biomolecules. The identity of the involved proteins was investigated (after tryptic digestion of the fraction) by μRPLC with parallel detection by ICP-MS and ESI-MS/MS. Molecular mass spectrometry experiments were carried out at high resolution (100000) to ensure accurate protein identification and determination of the MeHg binding sites. Cysteine residue on the dolphin hemoglobin β chain was found to be the main MeHg binding site, suggesting that hemoglobin is a major MeHg binding protein in this marine mammal and could be a potential carrier of this MeHg from blood to liver prior to its degradation in this organ. In parallel, a significant proportion of selenium was found to be present as selenoneine and a potential role for this compound in Hg detoxification is discussed.

Entry and Elimination of Marine Mammal Brucella spp. by Hooded Seal (Cystophora cristata) Alveolar Macrophages In Vitro

A high prevalence of Brucella pinnipedialis serology and bacteriology positive animals has been found in the Northeast Atlantic stock of hooded seal ( Cystophora cristata ); however no associated gross pathological changes have been identified. Marine mammal brucellae have previously displayed different infection patterns in human and murine macrophages. To investigate if marine mammal Brucella spp. are able to invade and multiply in cells originating from a presumed host species, we infected alveolar macrophages from hooded seal with a B . pinnipedialis hooded seal isolate. Hooded seal alveolar macrophages were also challenged with B . pinnipedialis reference strain (NCTC 12890) from harbor seal ( Phoca vitulina ), B . ceti reference strain (NCTC 12891) from harbor porpoise ( Phocoena phocoena ) and a B . ceti Atlantic white-sided dolphin ( Lagenorhynchus acutus ) isolate (M83/07/1), to evaluate possible species-specific differences. Brucella suis 1330 was included as a positive control. Alveolar macrophages were obtained by post mortem bronchoalveolar lavage of euthanized hooded seals. Phenotyping of cells in the lavage fluid was executed by flow cytometry using the surface markers CD14 and CD18. Cultured lavage cells were identified as alveolar macrophages based on morphology, expression of surface markers and phagocytic ability. Alveolar macrophages were challenged with Brucella spp. in a gentamicin protection assay. Following infection, cell lysates from different time points were plated and evaluated quantitatively for colony forming units. Intracellular presence of B . pinnipedialis hooded seal isolate was verified by immunocytochemistry. Our results show that the marine mammal brucellae were able to enter hooded seal alveolar macrophages; however, they did not multiply intracellularly and were eliminated within 48 hours, to the contrary of B. suis that showed the classical pattern of a pathogenic strain. In conclusion, none of the four marine mammal strains tested were able to establish a persistent infection in primary alveolar macrophages from hooded seal.

Meningoencephalitis and Arthritis Associated with Brucella ceti in a Short-beaked Common Dolphin (Delphinus delphis)

Brucella species infection in marine mammal species has been reported to have a global distribution. In 2007, the description of Brucella ceti was published and formally adopted for those isolates originating from cetaceans and pathologic lesions similar to those seen in terrestrial mammals infected with Brucella spp. have been associated with its isolation. Brucella ceti infection specific to the central nervous system has been described in two species of cetacean: striped dolphins (Stenella coeruleoalba) in Europe and Costa Rica and an Atlantic white-sided dolphin (Lagenorhynchus acutus) in the UK. We describe the first report, to our knowledge, of B. ceti-associated meningitis and arthritis in a third species, the short-beaked common dolphin (Delphinus delphis), in an animal that stranded in the UK.

THREE-DIMENSIONAL IN VIVO MONITORING OF BONE RESPONSE TO IMPLANT INSERTION

Marine mammal by-catch in 11 pelagic trawl fisheries operated by four different countries in the northeast Atlantic was studied. Observers accompanied commercial fishing vessels and monitored 374 tows totalling 1771 h of towing during 377 days fishing. Three species of marine mammal were identified in by-catches (white-sided dolphin, Lagenorhynchus acutus, common dolphin, Delphinus delphis and grey seal Halichoerus grypus) and a fourth, bottlenose dolphin Tursiops truncatus, was probably present. Dolphins were caught in four of the 11 fisheries and seal in one. In those fisheries with cetacean by-catch, rates varied from 0.0606 to 0.1000 per tow and 0.0107 to 0.0137 per hour of towing and were highest in the French sea bass fishery and lowest in the French tuna fishery. Grey seals were caught in the Irish Celtic Sea herring fishery at a rate of 0.0513 per tow or 0.0396 per hour of towing. The mean ±SD dolphin catch rate for all fisheries combined was 0.048±0.013 per tow (one dolphin per 20.7 tows), or 0.0185±0.0019 per hour of towing (one dolphin per 98 h of towing) and, for all marine mammals, 0.059±0.019 (1 per 17.0 tows) or 0.0124±0.0121 (1 per 80.6 h of towing). 95% confidence intervals, calculated on untransformed data, for all fisheries combined were 0.4–1.6 dolphins per 100 h of towing.No operational factors were correlated with by-catch rates but the haul-back procedure was identified as a potentially important factor. All dolphin by-catches occurred during the night which may be a due to an association between cetaceans and trawlers at night. White-sided dolphins and grey seals were observed feeding around the net during towing and this behaviour may make them more vulnerable to capture. Operational difficulties in observing by-catch and potentially significant annual fluctuation in catch rates warrant further observer studies of these and other trawl fisheries.

First Records of the Melon-Headed Whale (Peponocephala electra) and the Atlantic White-Sided Dolphin (Lagenorhynchus acutus) in South Carolina

From January to May 2008, the first historical strandings of Peponocephala electra Gray (Melon-headed Whale) and Lagenorhynchus acutus Gray (Atlantic White-sided Dolphin) were recorded in South Carolina. A mass stranding of three Melon-headed Whales (2 males, 1 female) was recorded on 11 January 2008 along the Horry County coast in the cities of Myrtle Beach and North Myrtle Beach. Three additional Melon-headed Whales (1 male, 1 female, and 1 unknown sex) stranded as single individuals over the next two months at locations along the South Carolina coast. Lengths of the animals ranged from 161 to 250 cm, and the ages ranged from 1 to 24 years. On 4 May 2008, a single 263cm, 17-year-old, male Atlantic White-sided Dolphin stranded in Horry County. The most striking commonalities observed during the Melon-headed Whale and Atlantic White-sided Dolphin necropsies were severe pulmonary distress and reactive lymphadenopathy. The strandings reported herein are the first records of Melon-headed Whales and Atlantic White-sided Dolphins in South Carolina.

Clinical assessment and postrelease monitoring of 11 mass stranded dolphins on Cape Cod, Massachusetts

AbstractThe health, postrelease movements, and behavior of mass stranded Atlantic white‐sided dolphins (Lagenorhynchus acutus) and short‐beaked common dolphins (Delphinus delphis) from Cape Cod, Massachusetts, were evaluated. Health was assessed through physical examination and blood analysis. Eleven dolphins (eight white‐sided dolphins and three common dolphins) were relocated, outfitted with satellite transmitters, and released during seven mass stranding events. Five transmitters recorded only location, and six also included a time‐depth recorder. Transmission duration ranged from 8 h to 218 d, with a mean of 117 d (median = 118 d, SD = 82 d), after release. All dolphins demonstrated extensive movement throughout the Gulf of Maine. The distribution of tagged dolphins was considered normal based on comparisons with published data for these species. Excluding the dolphin that transmitted for only 8 h, mean minimum speeds for individual dolphins ranged from 3.4 to 6.6 km/h; overall mean for all dolphins was 5.4 km/h (SD = 0.9 km/h). The five dolphins with time‐depth recorders had mean dive depths of 8.6–40.3 m and mean dive durations of 46–296 s. Hematologic and biochemical data revealed only minor abnormalities. Data suggest that at least 10 of the 11 dolphins were likely successfully reintroduced into the wild.

Short Note: Rake Marks on a Harbor Porpoise (Phocoena phocoena) Calf Suggestive of a Fatal Interaction with an Atlantic White-Sided Dolphin (Lagenorhynchus acutus)

Short Note: Rake Marks on a Harbor Porpoise (Phocoena phocoena) Calf Suggestive of a Fatal Interaction with an Atlantic White-Sided Dolphin (Lagenorhynchus acutus)

Polychlorinated naphthalenes (PCNs) in sub-Arctic and Arctic marine mammals, 1986–2009

A selection of PCN congeners was analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), fin whale (Balaenoptera physalus), harbour porpoise (Phocoena phocoena), hooded seal (Cystophora cristata) and Atlantic white-sided dolphin (Lagenorhynchus acutus), covering a time period of more than 20 years (1986–2009). A large geographical area of the North Atlantic and Arctic areas was covered. PCN congeners 48, 52, 53, 66 and 69 were found in the blubber samples between 0.03 and 5.9 ng/g lw. Also PCBs were analyzed in minke whales and fin whales from Iceland and the total PCN content accounted for 0.2% or less of the total non-planar PCB content. No statistically significant trend in contaminant levels could be established for the studied areas. However, in all species except minke whales caught off Norway the lowest ∑PCN concentrations were found in samples from the latest sampling period.

Methoxylated polybrominated diphenyl ethers (MeO-PBDEs) are major contributors to the persistent organobromine load in sub-Arctic and Arctic marine mammals, 1986–2009

A selection of MeO-BDE and BDE congeners were analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), fin whale (Balaenoptera physalus), harbor porpoise (Phocoena phocoena), hooded seal (Cystophora cristata), and Atlantic white-sided dolphin (Lagenorhynchus acutus), covering a time period of more than 20years (1986–2009). The analytes were extracted and cleaned-up using open column extraction and multi-layer silica gel column chromatography. The analysis was performed using both low resolution and high resolution GC-MS. MeO-PBDE concentrations relative to total PBDE concentrations varied greatly between sampling periods and species. The highest MeO-PBDE levels were found in the toothed whale species pilot whale and white-sided dolphin, often exceeding the concentration of the most abundant PBDE, BDE-47. The lowest MeO-PBDE levels were found in fin whales and ringed seals. The main MeO-BDE congeners were 6-MeO-BDE47 and 2′-MeO-BDE68. A weak correlation only between BDE47 and its methoxylated analog 6-MeO-BDE47 was found and is indicative of a natural source for MeO-PBDEs.

Increasing levels of long-chain perfluorocarboxylic acids (PFCAs) in Arctic and North Atlantic marine mammals, 1984–2009

Temporal variations in concentrations of perfluorinated carboxylic acids (PFCAs) and sulfonic acids (PFSAs), including perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) structural isomers, were examined in livers of pilot whale ( Globicephala melas), ringed seal ( Phoca hisida), minke whale ( Balaenoptera acutorostrata), harbor porpoise ( Phocoena phocoena), hooded seal ( Cystophora cristata), Atlantic white-sided dolphin ( Lagenorhynchus acutus) and in muscle tissue of fin whales ( Balaenoptera physalus). The sampling spanned over 20 years (1984–2009) and covered a large geographical area of the North Atlantic and West Greenland. Liver and muscle samples were homogenized, extracted with acetonitrile, cleaned up using hexane and solid phase extraction (SPE), and analyzed by liquid chromatography with negative electrospray tandem mass spectrometry (LC-MS/MS). In general, the levels of the long-chained PFCAs (C9–C12) increased whereas the levels of PFOS remained steady over the studied period. The PFOS isomer pattern in pilot whale liver was relatively constant over the sampling years. However, in ringed seals there seemed to be a decrease in linear PFOS (L-PFOS) with time, going from 91% in 1984 to 83% in 2006.

Static inflation and deflation pressure–volume curves from excised lungs of marine mammals

Excised lungs from eight marine mammal species [harp seal (Pagophilus groenlandicus), harbor seal (Phoca vitulina), gray seal (Halichoerus grypush), Atlantic white-sided dolphin (Lagenorhynchus acutus), common dolphin (Delphinus delphis), Risso's dolphin (Grampus griseus), long-finned pilot whale (Globicephala melas) and harbor porpoise (Phocoena phocoena)] were used to determine the minimum air volume of the relaxed lung (MAV, N=15), the elastic properties (pressure-volume curves, N=24) of the respiratory system and the total lung capacity (TLC). Our data indicate that mass-specific TLC (sTLC, l kg(-1)) does not differ between species or groups (odontocete vs phocid) and agree with that estimated (TLC(est)) from body mass (M(b)) by applying the equation: TLC(est)=0.135 M(b)(0.92). Measured MAV was on average 7% of TLC, with a range from 0 to 16%. The pressure-volume curves were similar among species on inflation but diverged during deflation in phocids in comparison with odontocetes. These differences provide a structural basis for observed species differences in the depth at which lungs collapse and gas exchange ceases.

Polybrominated diphenyl ethers (PBDEs) in marine mammals from Arctic and North Atlantic regions, 1986–2009

A selection of PBDE congeners was analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), fin whale (Balaenoptera physalus), harbor porpoise (Phocoena phocoena), hooded seal (Cystophora cristata) and Atlantic white-sided dolphin (Lagenorhynchus acutus), covering a time period of more than 20years (1986–2009). The analytes were extracted and cleaned-up using open column extraction and multi-layer silica gel column chromatography, and the analysis was performed on a GC-MS system operating in the NCI mode. The highest PBDE levels were found in the toothed whale species pilot whale and white-sided dolphin, and the lowest levels in fin whales and ringed seals. One-sided analyses of variance (ANOVA) followed by Tukey comparisons of means were applied to test for differences between years and sampling areas. Due to inter-year sampling variability, only general comparisons of PBDE concentrations between different sampling areas could be made. Differences in PBDE concentrations between three sampling periods, from 1986 to 2007, were evaluated in samples of pilot whales, ringed seals, white-sided dolphins and hooded seals. The highest PBDE levels were found in samples from the late 1990s or beginning of 2000, possibly reflecting the increase in the global production of technical PBDE mixtures in the 1990s. The levels of BDE #153 and #154 increased relative to the total PBDE concentration in some of the species in recent years, which may indicate an increased relative exposure to higher brominated congeners. In order to assess the effect of measures taken in legally binding international agreements, it is important to continuously monitor POPs such as PBDEs in sub-Arctic and Arctic environments.

Using bycatch data to understand habitat use of small cetaceans: lessons from an experimental driftnet fishery

AbstractStenson, G. B., Benjamins, S., and Reddin, D. G. 2011. Using bycatch data to understand habitat use of small cetaceans: lessons from an experimental driftnet fishery. – ICES Journal of Marine Science, 68: 937–946. Many marine mammals inhabit offshore areas where it is difficult to determine distribution and abundance. Historical bycatch data of marine mammals in the Northwest Atlantic obtained from the Canadian experimental Atlantic salmon (Salmo salar) driftnet fishery were examined to obtain information on seasonal distribution and relative abundance. From 1965 to 2001, 47 cruises were undertaken totalling 12 566.5 km-h of fishing effort; four species of small cetacean and two species of pinniped were caught. Harbour porpoises (Phocoena phocoena) were the most frequently caught species in all areas except the Labrador Sea, where Atlantic white-sided dolphins (Lagenorhynchus acutus) were more common. Long-finned pilot whales (Globicephala melas), common dolphins (Delphinus delphis), harp seals (Pagophilus groenlandicus), and harbour seals (Phoca vitulina) were also taken occasionally. Although typically considered an inshore species, harbour porpoises were regularly reported in deep water (&gt;2000 m), in the Newfoundland Basin and Labrador Sea. Atlantic white-sided dolphins were often caught along the edge of the continental shelf and appeared to prefer relatively warm water. Finally, catch records indicate that waters of the Newfoundland Basin and Southern Grand Banks may contain important winter habitat for several small species of cetacean.

Investigation of Hg species binding biomolecules in dolphin liver combining GC and LC-ICP-MS with isotopic tracers

Hg stable isotopically labeled species were used to assist the investigation of Hg species (i.e. IHg and MeHg) binding biomolecules in the aqueous soluble fraction of white-sided dolphin (Lagenorhynchus acutus) liver homogenate (QC04LH4). By using stable enriched isotopic tracers (199IHg and 201MeHg), the transformation yields of both mercury species (i.e. methylation and demethylation) were evaluated during the different sample preparation steps, such as the tissue lyophilization and the extraction by ultrasonication. Hg species partitioning after fractionation of the sample (cytosolic fraction and residual fraction) was also studied and showed that MeHg is mainly present in the cytosol (60%), while IHg is preferentially associated to the solid residue (88%). The analysis of the water-soluble fraction by size exclusion chromatography-ICP MS revealed the association of Hg species with biomolecules in a wide molecular weight range. The ratio of IHg and MeHg was successively determined in each SEC fraction by GC-ICP-MS. Furthermore the use of isotopic tracers allowed demonstration of specific Hg species affinity with different biomolecule molecular weight fractions. The results indicate a specific affinity of the IHg with a biomolecule at an elution time corresponding to a metallothionein whereas MeHg is associated to a biomolecule of larger molecular weight.

Modular organizations of novel cetacean papillomaviruses

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.