scholarly journals Genetic divergence and fine scale population structure of the common bottlenose dolphin (Tursiops truncatus, Montagu) found in the Gulf of Guayaquil, Ecuador

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4589 ◽  
Author(s):  
Rosa de los Ángeles Bayas-Rea ◽  
Fernando Félix ◽  
Rommel Montufar

The common bottlenose dolphin, Tursiops truncatus, is widely distributed along the western coast of South America. In Ecuador, a resident population of bottlenose dolphins inhabits the inner estuarine area of the Gulf of Guayaquil located in the southwestern part of the country and is under threat from different human activities in the area. Only one genetic study on South American common bottlenose dolphins has been carried out to date, and understanding genetic variation of wildlife populations, especially species that are identified as threatened, is crucial for defining conservation units and developing appropriate conservation strategies. In order to evaluate the evolutionary link of this population, we assessed the phylogenetic relationships, phylogeographic patterns, and population structure using mitochondrial DNA (mtDNA). The sampling comprised: (i) 31 skin samples collected from free-ranging dolphins at three locations in the Gulf of Guayaquil inner estuary, (ii) 38 samples from stranded dolphins available at the collection of the “Museo de Ballenas de Salinas,” (iii) 549 mtDNA control region (mtDNA CR) sequences from GenBank, and (iv) 66 concatenated sequences from 7-mtDNA regions (12S rRNA, 16S rRNA, NADH dehydrogenase subunit I–II, cytochrome oxidase I and II, cytochrome b, and CR) obtained from mitogenomes available in GenBank. Our analyses indicated population structure between both inner and outer estuary dolphin populations as well as with distinct populations of T. truncatus using mtDNA CR. Moreover, the inner estuary bottlenose dolphin (estuarine bottlenose dolphin) population exhibited lower levels of genetic diversity than the outer estuary dolphin population according to the mtDNA CR. Finally, the estuarine bottlenose dolphin population was genetically distinct from other T. truncatus populations based on mtDNA CR and 7-mtDNA regions. From these results, we suggest that the estuarine bottlenose dolphin population should be considered a distinct lineage. This dolphin population faces a variety of anthropogenic threats in this area; thus, we highlight its fragility and urge authorities to issue prompt management and conservation measures.


2007 ◽  
Vol 19 (5) ◽  
pp. 465-470 ◽  
Author(s):  
Hendrik H. Nollens ◽  
Linda G. Green ◽  
Diane Duke ◽  
Michael T. Walsh ◽  
Beth Chittick ◽  
...  

Antibodies directed against species-specific immunoglobulin G (IgG) have a broad range of applications in serologic and immunologic research and in the development of clinical assays. Validated anti-IgG antibodies for marine mammal species are in short supply. The objective of this study was to produce and validate antibodies with specificity for IgG of the common bottlenose dolphin ( Tursiops truncatus). Bottlenose dolphin IgG was purified using protein G. Two mouse monoclonal antibodies and a rabbit polyclonal antibody were developed from mice and rabbits immunized with bottlenose dolphin IgG. The specificity of the monoclonal antibodies and the polyclonal antibody for bottlenose dolphin IgG was first verified by Western blot analysis and enzyme-linked immunosorbent assay (ELISA). For further validation, both monoclonal antibodies and the polyclonal antibody were incorporated in an indirect ELISA for the detection of the immune response of bottlenose dolphins to a vaccine antigen. Three bottlenose dolphins were immunized with a commercial Erysipelothrix rhusiopathiae vaccine, and serial blood samples were collected from all dolphins for measurement of levels of circulating antibodies. Seroconversion was observed in all 3 dolphins by use of both monoclonal antibodies and the polyclonal antibody. Circulating antibodies were detectable as early as 6 days after immunization in 1 dolphin. Peak antibody levels were detected 14 days after the immunization. The ability to detect seroconversion in all 3 immunized bottlenose dolphins firmly establishes the specificity of the monoclonal antibodies and the polyclonal antibody for IgG of the common bottlenose dolphin.



2020 ◽  
Vol 98 (7) ◽  
pp. 461-479 ◽  
Author(s):  
M. Jedensjö ◽  
C.M. Kemper ◽  
M. Milella ◽  
E.P. Willems ◽  
M. Krützen

Species relationships in the bottlenose dolphin (genus Tursiops Gervais, 1855) are controversial. We carried out a comprehensive osteological study of 264 skulls, including type specimens, and 90 postcranial skeletons of Tursiops spp. to address taxonomic uncertainties in Australia using two-dimensional (2D) measurements, and three-dimensional geometric morphometrics (3DGM), tooth and vertebral counts, and categorical data. Analyses provided support for the presence of two forms, aligned to the Indo-Pacific bottlenose dolphin (Tursiops aduncus (Ehrenberg, 1832)) and the common bottlenose dolphin (Tursiops truncatus (Montagu, 1821)), including type specimens. The Burrunan dolphin (Tursiops australis Charlton-Robb, Gershwin, Thompson, Austin, Owen and McKechnie, 2011) fell well within T. truncatus for both 2D and 3DGM methods. Thirteen Tursiops spp. specimens, no T. australis specimens, were of intermediate size (2D) and could not be assigned to either species. For 3DGM data, there was a strong allometric influence and few non-allometric differences between species. Length and width of the cranium and rostrum were important discriminating variables. Tursiops aduncus was smaller, had more teeth, fewer vertebrae, and more erosion on the pterygoids and frontals than T. truncatus. Overall cranium shape was round in T. aduncus and angular in T. truncatus. Skull length of T. aduncus was smaller in low than in high latitudes. This study highlights the importance of large sample size, multiple analytical methods, and extensive geographical coverage when undertaking taxonomic studies.



PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10960
Author(s):  
Serena Frau ◽  
Fabio Ronchetti ◽  
Francesco Perretti ◽  
Alberto Addis ◽  
Giulia Ceccherelli ◽  
...  

In a wide variety of habitats, including some heavily urbanised areas, the adaptability of populations of common bottlenose dolphin (Tursiops truncatus) may depend on the social structure dynamics. Nonetheless, the way in which these adaptations take place is still poorly understood. In the present study we applied photo-identification techniques to investigate the social structure of the common bottlenose dolphin population inhabiting the Gulf of Alghero (Sardinia, Italy), analysing data recorded from 2008 to 2019. The social structure analysis showed a division of the entire population into five different communities and the presence of non-random associations, while there was no evidence of segregation between sexes. Furthermore, results highlighted an important change in social structure through time, likely due to a reduction in fish farm activity since 2015. The division of the population into different communities, the presence of segregation based on the foraging strategy (inside or outside the fish farm area) and the social network measures were evaluated by analysing independently the two datasets: the intense and low farm activity periods: 2008–2014 and 2015–2020, respectively. Segregation among individuals belonging to the same foraging strategy class was found only in the earlier period, and the composition of the four communities was consistent with this result. Our study improves the knowledge about bottlenose dolphin adaptation, as a lower complexity in social structure was linked to a reduction in anthropogenic food availability.



2013 ◽  
Vol 18 (3) ◽  
pp. 107-114
Author(s):  
Asami TAKENAKA ◽  
Nobuyuki KASHIWAGI ◽  
Yuko MAEZONO ◽  
Tatsuko NAKAO ◽  
Yuka WANO ◽  
...  


2016 ◽  
Vol 4 (4) ◽  
pp. 242-271 ◽  
Author(s):  
Grisel Rodríguez-Ferrer ◽  
◽  
Richard S. Appeldoorn ◽  
Nikolaos V. Schizas ◽  
◽  
...  




2020 ◽  
Vol 36 (3) ◽  
pp. 802-812
Author(s):  
Madelyn G. Strahan ◽  
Dorian S. Houser ◽  
James J. Finneran ◽  
Jason Mulsow ◽  
Daniel E. Crocker


2019 ◽  
Vol 232 ◽  
pp. 42-49
Author(s):  
Guillaume Desoubeaux ◽  
Maria del Carmen Piqueras ◽  
Carolina Le-Bert ◽  
Vanessa Fravel ◽  
Tonya Clauss ◽  
...  


2003 ◽  
Vol 81 (8) ◽  
pp. 1421-1427 ◽  
Author(s):  
Kate Grellier ◽  
Philip S Hammond ◽  
Ben Wilson ◽  
Carol A Sanders-Reed ◽  
Paul M Thompson

For social mammals living in fission–fusion societies, the mother–infant bond is long and extends beyond the nursing period. We successfully developed a technique, using photo-identification data, to quantify mother–calf association patterns in a small population of bottlenose dolphins, Tursiops truncatus, off eastern Scotland. By statistically comparing association indices between young calves and their associates we assigned 17 individual adults as mothers to 20 young calves with a 5% level of probability. The mean index of association between calves and mothers remained high until at least year 8 of life. While calves were still found in the same schools as their mother, they surfaced beside her less often as their age increased. This is the first time that the mother–calf bond has been quantitatively assessed for any bottlenose dolphin population inhabiting temperate waters. Results are compared with those from subtropical populations and are discussed with respect to the viability of this population.



2013 ◽  
Vol 13 ◽  
Author(s):  
Liliane Lodi ◽  
Camilah Antunes Zappes ◽  
Álvaro Samuel Guimarães dos Santos

The objectives of this study were to understand the ecological aspects of the common bottlenose dolphin (Tursiops truncatus) in the Cagarras Archipelago, Rio de Janeiro, Brazil, and possible anthropogenic impacts by comparing the knowledge of local small-scale fishermen (GA) and the regulars in the archipelago (GB). The data obtained were compared with those available in the literature to propose strategies for monitoring and preservation. Between August and December 2010, we applied the methods of participant observation, interviews-questionnaires and use of illustrative posters. Sixty-one interviews were conducted, from which 83.6% were selected by considering correct answers about the identification of the species on posters (morphological characteristics) and description of time of occurrence in the archipelago (July to December) as reported for the species in the literature. Regarding the seven questions analyzed statistically, a significant difference was found between the accounts of the two groups with respect to anthropic threats to T. truncatus. Gill-nets and the decrease of fishing resources were the main causes identified by the GA group whereas the GB group pointed to the disorganized use of space, pollution and predatory fishing as the factors that have threatened the common bottlenose dolphins. The use of ethnobiological data in conservation programs brings opportunities for the collaboration and participation of the community that is directly inserted into the ecosystem as well as a chance for locals to get involved in issues concerning the sustainability of the archipelago.



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