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Kobayashi H, Whitehead H, Amano M. Long-term associations among male sperm whales (Physeter macrocephalus). PLoS One 2020; 15:e0244204. [PMID: 33362216 PMCID: PMC7757888 DOI: 10.1371/journal.pone.0244204] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 12/04/2020] [Indexed: 12/02/2022] Open
Abstract
Little is known about the social structure of male sperm whales (Physeter macrocephalus) after they leave their natal units. While previous studies found no evidence for preferred associations among males, the observation of mass-strandings consisting exclusively of males, suggest that they have strong social bonds. To investigate the social associations among male sperm whales, we used half weight index of association, permutation tests and standardized lagged association rate models on a large photo-identification database collected between 2006 and 2017 in Nemuro Strait, Japan. Our results suggest that while male sperm whales are not as social as females, they do form long term associations, have preferred companionship, and forage in social proximity to each other. The best-fitting model to the standardized lagged association rate showed that associations among males last for at least 2.7 years and as most males leave the area after 2 years, associations may last for longer. Twenty dyads were observed associating over more than 2 years, for a maximum 5 years. One dyad was observed associating on 19 different days and clustered on 7 different days. Male associations may function to enhance foraging or to fend off predators. Such relationships seem to be adapted to a pelagic habitat with uncertain resource availability and predation pressure.
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Affiliation(s)
- Hayao Kobayashi
- Graduate School of Fisheries and Environmental Science, Nagasaki University, Nagasaki, Japan
- * E-mail:
| | - Hal Whitehead
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | - Masao Amano
- Graduate School of Fisheries and Environmental Science, Nagasaki University, Nagasaki, Japan
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Autenrieth M, Hartmann S, Lah L, Roos A, Dennis AB, Tiedemann R. High-quality whole-genome sequence of an abundant Holarctic odontocete, the harbour porpoise (Phocoena phocoena). Mol Ecol Resour 2018; 18:1469-1481. [PMID: 30035363 DOI: 10.1111/1755-0998.12932] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 07/04/2018] [Accepted: 07/05/2018] [Indexed: 11/27/2022]
Abstract
The harbour porpoise (Phocoena phocoena) is a highly mobile cetacean found across the Northern hemisphere. It occurs in coastal waters and inhabits basins that vary broadly in salinity, temperature and food availability. These diverse habitats could drive subtle differentiation among populations, but examination of this would be best conducted with a robust reference genome. Here, we report the first harbour porpoise genome, assembled de novo from an individual originating in the Kattegat Sea (Sweden). The genome is one of the most complete cetacean genomes currently available, with a total size of 2.39 Gb and 50% of the total length found in just 34 scaffolds. Using 122 of the longest scaffolds, we were able to show high levels of synteny with the genome of the domestic cattle (Bos taurus). Our draft annotation comprises 22,154 predicted genes, which we further annotated through matches to the NCBI nucleotide database, GO categorization and motif prediction. Within the predicted genes, we have confirmed the presence of >20 genes or gene families that have been associated with adaptive evolution in other cetaceans. Overall, this genome assembly and draft annotation represent a crucial addition to the genomic resources currently available for the study of porpoises and Phocoenidae evolution, phylogeny and conservation.
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Affiliation(s)
- Marijke Autenrieth
- Institute of Biochemistry and Biology, Evolutionary Biology/Systematic Zoology, University of Potsdam, Potsdam, Germany
| | - Stefanie Hartmann
- Institute of Biochemistry and Biology, Evolutionary Adaptive Genomics, University of Potsdam, Potsdam, Germany
| | - Ljerka Lah
- Institute of Biochemistry and Biology, Evolutionary Biology/Systematic Zoology, University of Potsdam, Potsdam, Germany
| | - Anna Roos
- Swedish Museum of Natural History, Stockholm, Sweden
| | - Alice B Dennis
- Institute of Biochemistry and Biology, Evolutionary Biology/Systematic Zoology, University of Potsdam, Potsdam, Germany
| | - Ralph Tiedemann
- Institute of Biochemistry and Biology, Evolutionary Biology/Systematic Zoology, University of Potsdam, Potsdam, Germany
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Beached bachelors: An extensive study on the largest recorded sperm whale Physeter macrocephalus mortality event in the North Sea. PLoS One 2018; 13:e0201221. [PMID: 30086178 PMCID: PMC6080757 DOI: 10.1371/journal.pone.0201221] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 07/11/2018] [Indexed: 11/19/2022] Open
Abstract
Between the 8th January and the 25th February 2016, the largest sperm whale Physeter macrocephalus mortality event ever recorded in the North Sea occurred with 30 sperm whales stranding in five countries within six weeks. All sperm whales were immature males. Groups were stratified by size, with the smaller animals stranding in the Netherlands, and the largest in England. The majority (n = 27) of the stranded animals were necropsied and/or sampled, allowing for an international and comprehensive investigation into this mortality event. The animals were in fair to good nutritional condition and, aside from the pathologies caused by stranding, did not exhibit significant evidence of disease or trauma. Infectious agents were found, including various parasite species, several bacterial and fungal pathogens and a novel alphaherpesvirus. In nine of the sperm whales a variety of marine litter was found. However, none of these findings were considered to have been the primary cause of the stranding event. Potential anthropogenic and environmental factors that may have caused the sperm whales to enter the North Sea were assessed. Once sperm whales enter the North Sea and head south, the water becomes progressively shallower (<40 m), making this region a global hotspot for sperm whale strandings. We conclude that the reasons for sperm whales to enter the southern North Sea are the result of complex interactions of extrinsic environmental factors. As such, these large mortality events seldom have a single ultimate cause and it is only through multidisciplinary, collaborative approaches that potentially multifactorial large-scale stranding events can be effectively investigated.
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Schnitzler JG, Pinzone M, Autenrieth M, van Neer A, IJsseldijk LL, Barber JL, Deaville R, Jepson P, Brownlow A, Schaffeld T, Thomé JP, Tiedemann R, Das K, Siebert U. Inter-individual differences in contamination profiles as tracer of social group association in stranded sperm whales. Sci Rep 2018; 8:10958. [PMID: 30026609 PMCID: PMC6053436 DOI: 10.1038/s41598-018-29186-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 07/05/2018] [Indexed: 11/09/2022] Open
Abstract
Ecological and physiological factors lead to different contamination patterns in individual marine mammals. The objective of the present study was to assess whether variations in contamination profiles are indicative of social structures of young male sperm whales as they might reflect a variation in feeding preferences and/or in utilized feeding grounds. We used a total of 61 variables associated with organic compounds and trace element concentrations measured in muscle, liver, kidney and blubber gained from 24 sperm whales that stranded in the North Sea in January and February 2016. Combining contaminant and genetic data, there is evidence for at least two cohorts with different origin among these stranded sperm whales; one from the Canary Island region and one from the northern part of the Atlantic. While genetic data unravel relatedness and kinship, contamination data integrate over areas, where animals occured during their lifetime. Especially in long-lived animals with a large migratory potential, as sperm whales, contamination data may carry highly relevant information about aggregation through time and space.
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Affiliation(s)
- Joseph G Schnitzler
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, 25761, Büsum, Schleswig-Holstein, Germany.
| | - Marianna Pinzone
- Freshwater and Oceanic sciences Unit of reSearch - Oceanology, University of Liège, Allée du 6 Août, B6C, 4000, Liège, Belgium
| | - Marijke Autenrieth
- Unit of Evolutionary Biology/Systematic Zoology, Institute for Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany
| | - Abbo van Neer
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, 25761, Büsum, Schleswig-Holstein, Germany
| | - Lonneke L IJsseldijk
- Faculty of Veterinary Medicine, Department of Pathobiology, Utrecht University, Yalelaan 1, 3584CL, Utrecht, The Netherlands
| | - Jonathan L Barber
- Centre for the Environment, Fisheries and Aquaculture Science (Cefas) Lowestoft Laboratory, Pakefield Road, Lowestoft, Suffolk, NR33 0HT, UK
| | - Rob Deaville
- CSIP, Institute of Zoology, Regent's Park, London, NW1 4RY, UK
| | - Paul Jepson
- CSIP, Institute of Zoology, Regent's Park, London, NW1 4RY, UK
| | | | - Tobias Schaffeld
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, 25761, Büsum, Schleswig-Holstein, Germany
| | - Jean-Pierre Thomé
- Laboratory of Animal Ecology and Ecotoxicology (CART-LEAE) B6c, Liège University, Liège, Belgium
| | - Ralph Tiedemann
- Unit of Evolutionary Biology/Systematic Zoology, Institute for Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany
| | - Krishna Das
- Freshwater and Oceanic sciences Unit of reSearch - Oceanology, University of Liège, Allée du 6 Août, B6C, 4000, Liège, Belgium
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, 25761, Büsum, Schleswig-Holstein, Germany
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