Skip to main content

Advertisement

Log in

Tursiops truncatus nuuanu, a new subspecies of the common bottlenose dolphin from the eastern tropical Pacific

  • Original Paper
  • Published:
Journal of Mammalian Evolution Aims and scope Submit manuscript

Abstract

In the eastern Pacific Ocean, three distinct forms of common bottlenose dolphin (Tursiops truncatus) have been identified, with suggestions they may be different species: a southern California/Mexico coastal, a northern temperate offshore, and an eastern tropical Pacific (ETP) offshore form. Currently, only one species (T. truncatus) is recognized in the region, with the first two forms described as distinct ecotypes. The goal of this study was to improve our understanding of the taxonomic status of these previously described forms through a re-examination of their morphological differentiation. We analyzed 135 skulls from the eastern and western Pacific, including the two nominal species, T. gillii and T. nuuanu, previously described for the eastern North Pacific and ETP, respectively. Additionally, we examined the holotypes of two currently recognized species in the genus, T. truncatus and T. aduncus. Our results showed significant morphological differentiation among bottlenose dolphins in the Pacific Ocean. The ETP offshore bottlenose dolphins were smaller in skull and body size and diagnostically distinct from dolphins in the western North Pacific and other regions in the eastern Pacific. Our results also indicated that, while other bottlenose dolphins in the Pacific were more similar to the globally distributed T. truncatus, the ETP offshore dolphins shared similarities with a previously described species in that region. The distinct environmental conditions in the ETP may be driving the evolutionary differentiation of these bottlenose dolphins. Given these results, we here recommend the recognition of ETP offshore bottlenose dolphins as a distinct subspecies, Tursiops truncatus nuuanu.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6

Similar content being viewed by others

Data Availability

The dataset generated and analyzed during the current study is available in the Figshare repository, https://doi.org/10.6084/m9.figshare.20769460.

Notes

  1. A majority of the CA samples (n = 61) were strandings, 11 were captured in offshore waters (around Santa Catalina and St. Miguel Islands) and three captured in coastal waters (around San Diego).

References

  • Ackermann M, Doebeli M (2004) Evolution of niche width and adaptive diversification. Evolution 58:2599–2612. https://doi.org/10.1111/j.0014-3820.2004.tb01614.x

    Article  PubMed  Google Scholar 

  • Andrews RC (1911) Description of an apparently new porpoise of the genus Tursiops, with remarks upon a skull of Tursiops gillii Dall. Bull. Am. Mus. Nat. Hist. 30:233–237.

    Google Scholar 

  • Anthony HE (1928) Field Book of North American Mammals. G. P. Putnum’s Sons, New York.

    Google Scholar 

  • Archer FI (2020) rfPermute: estimate permutation p-values for Random Forest importance metrics. R package version 2.1.81. https://CRAN.R-project.org/package=rfPermute

  • Archer FI, Martien KK, Taylor BL (2017) Diagnosability of mtDNA with Random Forests: using sequence data to delimit subspecies. Mar. Mamm. Sci. 33:101–131. https://doi.org/10.1111/mms.12414

    Article  CAS  Google Scholar 

  • Au DW, Perryman WL (1985) Dolphin habitats in the eastern Tropical Pacific. Fish. Bull. 83:623–644.

    Google Scholar 

  • Barlow J (2003) Preliminary estimates of the abundance of cetaceans along the U.S. west coast: 1991–2001. NOAA, NMFS, SWFSC Admin. Report LJ-03-03:1–33.

  • Carretta JV, Oleson EM, Forney K, Muto MM, Weller DW, Lang AR, Baker J, Hanson B, Orr AJ, Barlow J, Moore JE (2021) US Pacific marine mammal stock assessments 2020. NOAA Tech Memo NMFS-SWFSC-646:1–394.

    Google Scholar 

  • Committee on Taxonomy (2022) List of marine mammal species and subspecies. Society for Marine Mammalogy. www.marinemammalscience.org.

  • Costa APB, Fruet PF, Secchi ER, Daura-Jorge FG, Di Tullio JC, Rosel PE (2021) Ecological divergence and speciation in the common bottlenose dolphin of the western South Atlantic. J. Evol. Biol. 34:16–32. https://doi.org/10.1111/jeb.13575

    Article  PubMed  Google Scholar 

  • Costa APB, McFee W, Wilcox LA, Archer FI, Rosel PE (2022) The common bottlenose dolphin (Tursiops truncatus) ecotypes of the western North Atlantic revisited: An integrative taxonomic investigation supports the presence of distinct species. Zool. J. Linn. Soc. https://doi.org/10.1093/zoolinnean/zlac025

    Article  Google Scholar 

  • Costa APB, Rosel PE, Daura-Jorge FG, Simões-Lopes PC (2016) Offshore and coastal common bottlenose dolphins of the western South Atlantic face-to-face: what the skull and the spine can tell us. Mar. Mamm. Sci. 32:1433–1457. https://doi.org/10.1111/mms.12342

    Article  Google Scholar 

  • Defran RH, Caldwell M, Morteo E, Lang AR, Rice MG, Weller DW (2015) Possible stock structure of coastal bottlenose dolphins off Baja California and California revealed by photo-identification research. Bull. S. Calif. Acad. Sci. 114:1–11. https://doi.org/10.3160/0038-3872-114.1.1

    Article  Google Scholar 

  • Dizon AE, Perrin WF, Akin PA (1994) Stocks of dolphins (Stenella spp. and Delphinus delphis) in the eastern Tropical Pacific: a phylogeographic classification. NOAA Tech Memo NMFS-119:1–20.

    Google Scholar 

  • Esteves-Ponte MA, Aurioles-Gamboa D, García-Rodríguez FJ (2022) Skull morphometric variability related to offshore and inshore ecotypes of the common bottlenose dolphin (Tursiops truncatus) from northwestern Mexico. Mar. Mamm. Sci. 38:1088–1103. https://doi.org/10.1111/mms.12914

    Article  Google Scholar 

  • Fiedler PC, Redfern JV, Ballance LT (2017) Oceanography and cetaceans of the Costa Rica Dome region. NOAA Tech Memo NMFS-SWFSC-590:1–37.

    Google Scholar 

  • Ford JKB, Ellis GM, Barrett-Lennard LG, Morton AB, Palm RS, Balcomb III KC (1998) Dietary specialization in two sympatric populations of killer whales (Orcinus orca) in coastal British Columbia and adjacent waters. Can. J. Zool. 76:1456–1471. https://doi.org/10.1139/z98-089

    Article  Google Scholar 

  • Guevara-Aguirre D, Gallo-Reynoso JP (2016) Habitat use of two ecotypes of bottlenose dolphins (Tursiops truncatus) in the Gulf of California, Mexico. Rev. Mex. Biodivers. 87:1045–1054. https://doi.org/10.1016/j.rmb.2016.07.015

    Article  Google Scholar 

  • Halpin LR, Towers JR, Ford JKB (2018) First record of common bottlenose dolphin (Tursiops truncatus) in Canadian Pacific waters. Mar. Biodivers. Rec. 11:3. https://doi.org/10.1186/s41200-018-0138-1

    Article  Google Scholar 

  • Hamilton TA, Redfern JV, Barlow J, Ballance LT, Gerrodette T, Holt RS, Forney KA, Taylor BL (2009) Atlas of cetacean sightings for Southwest Fisheries Science Center cetacean and ecosystem surveys, 1986-2005. NOAA Tech. Memo. NMFS-SWFSC 440:1–77.

    Google Scholar 

  • Hanson MT, Defran RH (1993) The behavior and feeding ecology of the Pacific coast bottlenose dolphin, Tursiops truncatus. Aquat. Mamm. 19:127–142.

    Google Scholar 

  • Hershkovitz P (1963) Notes on South American dolphins of the genera Inia, Sotalia and Tursiops. J Mammal 44:98–103.

  • Hershkovitz P (1966) Catalogue of living whales. Bull US Natl Mus 246:1–259.

  • Heyning E, Perrin WF (1994) Evidence for two species of common dolphins (genus Delphinus) from the eastern North Pacific. Contr Sci (Los Angel Calif) 442:1–35.

    Google Scholar 

  • Huey LM (1964) The mammals of Baja California, Mexico. Trans S Diego Soc Nat Hist 13:85–168.

    Google Scholar 

  • Hwang A, Defran RH, Bearzi M, Maldini D, Saylan CA, Lang AR, Dudzik KJ, Guzon-Zatarain OR, Kelly DL, Weller DW (2014) Coastal range and movements of common bottlenose dolphins off California and Baja California, Mexico. Bull. S. Calif. Acad. Sci. 113:1–13. https://doi.org/10.3160/0038-3872-113.1.1

    Article  Google Scholar 

  • Jedensjö M, Kemper CM, Milella M, Willems EP, Krützen M (2020) Taxonomy and distribution of bottlenose dolphins (genus Tursiops) in Australian waters: an osteological clarification. Can. J. Zool. 98:461–479. https://doi.org/10.1139/cjz-2018-0270

    Article  Google Scholar 

  • Keller I, Seehauser O (2012) Thermal adaptation and ecological speciation. Mol. Ecol. 21:782–799. https://doi.org/10.1111/j.1365-294X.2011.05397.x

    Article  CAS  PubMed  Google Scholar 

  • Liaw A, Wiener M (2002) Classification and regression by randomForest. R News 2:18–22.

    Google Scholar 

  • Lowther-Thieleking JL, Archer FI, Lang AR, Weller DW (2015) Genetic differentiation among coastal and offshore common bottlenose dolphins, Tursiops truncatus, in the eastern North Pacific Ocean. Mar. Mamm. Sci. 31:1–20. https://doi.org/10.1111/mms.12135

    Article  Google Scholar 

  • May-Collado L, Gerrodette T, Calambokidis J, Rasmussen K, Sereg I (2005) Patterns of cetacean sighting distribution in the Pacific Exclusive Economic Zone of Costa Rica based on data collected from 1979-2001. Rev. Biol. Trop. 53:249–263.

    PubMed  Google Scholar 

  • Mayer WV (1950) Tursiops gillii, the bottlenosed dolphin, a new record from the Gulf of California, with remarks on Tursiops nuuanu. Am. Midl. Nat. 43:183–185.

    Article  Google Scholar 

  • Meiri S, Dayan T (2003) On the validity of Bergmann’s rule. J. Biogeogr. 30:331–351. https://doi.org/10.1046/j.1365-2699.2003.00837.x

    Article  Google Scholar 

  • Nichols JT (1908) Notes on two porpoises captured on a voyage into the Paciflc Ocean. Bull. Am. Mus. Nat. Hist. 24:217–219.

    Google Scholar 

  • Palacios DM, Herrera JC, Gerrodette T, Garcia CA, Soler GA, Avila IC, Bessudo SA, Hernandez EL, Trujillo FE, Flórez-González LI, Kerr I (2012) Cetacean distribution and relative abundance in Colombia’s Pacific EEZ from survey cruises and platforms of opportunity. J. Cetacean Res. Manag. 12:45–60.

    Article  Google Scholar 

  • Pedersen TL, Hughes S, Qiu X (2017) densityClust: clustering by fast search and find of density peaks. R package version 0.3. https://CRAN.R-project.org/package=densityClust

  • Perrin WF (1972a) Color patterns of spinner porpoises (Stenella cf. S. longirostris) of the eastern Pacific. Fish Bull 70:983.

  • Perrin WF (1972b) Variation and taxonomy of spotted and spinner porpoises (genus Stenella) of the eastern tropical Pacific and Hawaii. Dissertation, University of California.

  • Perrin WF (1975a) Variation of spotted and spinner porpoise (genus Stenella) in the eastern Tropical Pacific and Hawaii. Bull. Scripps Inst. Oceanogr. 21:1–206.

    Google Scholar 

  • Perrin WF (1975b) Distribution and differentiation of populations of dolphins of the genus Stenella in the eastern tropical Pacific. J. Fish. Res. Board Can. 32:1059–1067.

    Article  Google Scholar 

  • Perrin WF (1990) Subspecies of Stenella longirostris (Mammalia: Cetacea: Delphinidae). Proc. Biol. Soc. Wash. 103:453–463.

    Google Scholar 

  • Perrin WF, Coe JM, Zweifel JR (1976) Growth and reproduction of the spotted porpoise, Stenella attenuata, in the offshore eastern Tropical Pacific. Fish. Bull. 74:229–269.

    Google Scholar 

  • Perrin WF, Heyning JE (1993) Rostral fusion as a criterion of cranial maturity in the common dolphin, Delphinus delphis. Mar. Mamm. Sci. 9:195–197.

    Article  Google Scholar 

  • Perrin WF, Robertson KM, van Bree PJH, Mead JG (2007) Cranial description and genetic identity of the holotype specimen of Tursiops aduncus (Ehrenberg, 1832). Mar. Mamm. Sci. 23:343–357. https://doi.org/10.1111/j.1748-7692.2007.00119.x

    Article  CAS  Google Scholar 

  • Perrin WF, Smith TD, Sakagawa GT (1982) Status of populations of spotted dolphin, Stenella attenuata, and spinner dolphin, Stenella longirostris, in the eastern Tropical Pacific. Mammals in the Seas, FAO Fisheries Series 5:67–83.

    Google Scholar 

  • Perrin WF, Thieleking JL, Walker WA, Archer FI, Robertson KM (2011) Common bottlenose dolphins (Tursiops truncatus) in California waters: cranial differentiation of coastal and offshore ecotypes. Mar. Mamm. Sci. 27:769–792. https://doi.org/10.1111/j.1748-7692.2010.00442.x

    Article  Google Scholar 

  • Pilot M, Jedrzejewski W, Sidorovich VE, Meier-Augenstein W, Hoelzel AR (2012) Dietary differentiation and the evolution of population genetic structure in a highly mobile carnivore. PLOS One 7:e39341. https://doi.org/10.1371/journal.pone.0039341

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  • R Core Team (2021) R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna.

    Google Scholar 

  • Reilly SB (1990) Seasonal changes in distribution and habitat differences among dolphins in the eastern Tropical Pacific. Mar. Ecol. Prog. Ser. 66:1–11.

    Article  Google Scholar 

  • Rodrigues A, Laio A (2014) Clustering by fast search and find of density peaks. Science 344:1492. https://doi.org/10.1126/science.124207

    Article  Google Scholar 

  • Ruffler C, Van Dooren TJM, Metz JAJ (2007) The interplay between behavior and morphology in the evolutionary dynamics of resource specialization. Am. Nat. 169:E34–E52. https://doi.org/10.1086/510635

    Article  Google Scholar 

  • Scammon CM (1874) The Marine Mammals of the North-Western Coast of the North America. G. P. Putnam’s Sons, New York.

    Google Scholar 

  • Schluter D (2001) Ecology and the origin of species. Trends Ecol. Evol. 16:372–380. https://doi.org/10.1016/S0169-5347(01)02198-X

    Article  CAS  PubMed  Google Scholar 

  • Segura I, Rocha-Olivares A, Flores-Ramírez S, Rojas-Bracho L (2006) Conservation implications of the genetic and ecological distinction of Tursiops truncatus ecotypes in the Gulf of California. Biol. Conserv. 133:336–346. https://doi.org/10.1016/j.biocon.2006.06.017

    Article  Google Scholar 

  • Segura-García I, Rojo-Arreola L, Rocha-Olivares A, Heckel G, Gallo-Reynoso JP, Hoelzel R (2018) Eco-evolutionary processes generating diversity among bottlenose dolphin, Tursiops truncatus, populations off Baja California, Mexico. Evol. Biol. 45:223–236. https://doi.org/10.1007/s11692-018-9445-z

    Article  PubMed  PubMed Central  Google Scholar 

  • Smith TB, Skúlason S (1996) Evolutionary significance of resource polymorphisms in fishes, amphibians, and birds. Annu. Rev. Ecol. Evol. Syst. 27:111–133.

    Article  Google Scholar 

  • South A (2017) rnaturalearth: world map data from natural earth. R package version 0.1.0. https://CRAN.R-project.org/package=rnaturalearth

  • Taylor BL, Archer FI, Martien KK, Rosel PE, Hancock-Hanser BL, Lang AR, Leslie MS, Mesnick SL, Morin PA, Pease VL, Perrin WF (2017) Guidelines and quantitative standards to improve consistency in cetacean subspecies and species delimitation relying on molecular genetic data. Mar. Mamm. Sci. 33:132–155. https://doi.org/10.1111/mms.12411

    Article  Google Scholar 

  • Teske PR, Sandoval-Castillo J, Golla TR, Emami-Khoyi A, Tine M, von der Heyden S, Beheregaray LB (2019) Thermal selection as a driver of marine ecological speciation. Proc. Royal Soc. B: Biol. Sci. 286:20182023. https://doi.org/10.1098/rspb.2018.2023

    Article  CAS  Google Scholar 

  • Townsend CH (1916) Voyage of the 'Albatross' to the Gulf of California in 1911. Bull. Am. Mus. Nat. Hist. 35:399–476.

    Google Scholar 

  • True FW (1889) Contributions to the natural history of the cetaceans, a review of the family Delphinidae. Bull. U.S. Natl. Mus. 36:1–191.

    Google Scholar 

  • Van Gelder RG (1960) Results of the Puritan-American Museum of Natural History expedition to western Mexico. Marine mammals from the coasts of Baja California and the Tres Marías Islands, Mexico. Am. Mus. Novit. 1992:1–27.

    Google Scholar 

  • Van Waerebeek K, Reyes JC, Read AJ, McKinnon JS (1990) Preliminary observations of bottlenose dolphins from the Pacific coast of South America. In: Leatherwood S, Reeves RR (eds). The Bottlenose Dolphin. Academic Press, San Diego, United States, pp 143–154.

    Chapter  Google Scholar 

  • Van Waerebeek K, Reyes JC, Sanino GP, Felix F, Van Bressem M-F, Avila IC, Santillan L, Montes D, Garcia-Godos I, Echegaray M, Abad AV (2017) Common bottlenose dolphins Tursiops truncatus of Pacific South America, a synoptic review of population identification data. Bled, May 2017, Report of IWC Scientific Committee Meeting SC/67A/SM/10.

  • Vu VQ (2011) ggbiplot: a ggplot2 based biplot. R package version 0.55. http://github.com/vqv/ggbiplot

  • Wang JY, Chou L-S, White BN (2000) Osteological differences between two sympatric forms of bottlenose dolphins (genus Tursiops) in Chinese waters. J. Zool. 252:147–162. https://doi.org/10.1111/j.1469-7998.2000.tb00611.x

    Article  Google Scholar 

  • Walker WA (1981) Geographical variation in morphology and biology of bottlenose dolphins (Tursiops) in the eastern North Pacific. NOAA, NMFS, SWFSC Admin. Report LJ-81-03C:1–54.

  • Wickham H (2016) ggplot2: Elegant Graphics for Data Analysis. Springer-Verlag, New York.

    Book  Google Scholar 

  • Winker K (2010) Subspecies represent geographically partitioned variation, a gold mine of evolutionary biology, and a challenge for conservation. Ornithol. Monogr. 67:6–23. https://doi.org/10.1525/om.2010.67.1.6

    Article  Google Scholar 

  • Wolf JBW, Harrod C, Brunner S, Salazar S, Trillmich F, Tautz D (2008) Tracing early stages of species differentiation: ecological, morphological and genetic divergence of Galapagos sea lion populations. BMC Evol. Biol. 8:150. https://doi.org/10.1186/1471-2148-8-150

    Article  CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

We dedicate this work to Dr. William F. Perrin, who passed on July 11, 2022. Starting in the late 1960s, his research in the eastern tropical Pacific was instrumental in highlighting the killing of dolphins in the tuna purse-seine fishery and played a crucial role in creation of the Marine Mammal Protection Act of 1972. Additionally, he is considered the father of modern marine mammal taxonomy due to his pioneering work on both small cetaceans and large whales. Dr. Perrin approved the submission of this manuscript prior to his passing, but sadly passed before its acceptance and publication. We thank James Mead, John Ososky, and Michael McGowen (Smithsonian National Museum of Natural History) for the sample access provided to APBC and FIA. Our acknowledgements are also extended to Neil Duncan and Eleanor Hoeger (American Museum of Natural History, New York) for access to specimens, including the holotype of T. nuuanu (AMNH 35045), and to Richard Sabin (Natural History Museum, London) for his help with access to the holotype of T. truncatus (NHMUK 353a). We are grateful to Anke Klüter, who assisted FIA during the collection of measurements of some of the specimens used. We also thank all curators and collection managers that provided access to specimens to WFP in previous years (California Academy of Sciences, Los Angeles County Museum, Santa Barbara Museum of Natural History, San Diego Natural History Museum, Museum of Comparative Anatomy, American Museum of Natural History, and Smithsonian National Museum of Natural History), and to Toshio Kasuya, who collected the 19 Taiji skulls (offshore Japan – WNP) used in this study and deposited in the Smithsonian National Museum of Natural History. Special acknowledgments to Robert Brownell Jr., Thomas Jefferson, and Phillip Morin for insightful comments and suggestions on the first versions of this manuscript, and to two anonymous reviewers for their comments on the final version. The scientific results and conclusions, in addition to any views or opinions expressed herein, are those of the authors and do not necessarily reflect those of NOAA or the Department of Commerce.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to A. P. B. Costa.

Additional information

Deceased July 11, 2022. This work is dedicated to William F. Perrin.

A. P. B. Costa and F. I. Archer shared co-first authorship.

Supplementary Information

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Costa, A.P.B., Archer, F.I., Rosel, P.E. et al. Tursiops truncatus nuuanu, a new subspecies of the common bottlenose dolphin from the eastern tropical Pacific. J Mammal Evol 30, 213–229 (2023). https://doi.org/10.1007/s10914-022-09641-5

Download citation

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10914-022-09641-5

Keywords

Navigation