Hybridization in bottlenose dolphins-A case study of Tursiops aduncus × T. truncatus hybrids and successful backcross hybridization events

T Gridley; S H Elwen; G Harris; D M Moore; A R Hoelzel; F Lampen

doi:10.1371/journal.pone.0201722

Hybridization in bottlenose dolphins-A case study of Tursiops aduncus × T. truncatus hybrids and successful backcross hybridization events

PLoS One. 2018 Sep 12;13(9):e0201722. doi: 10.1371/journal.pone.0201722. eCollection 2018.

Authors

T Gridley¹, S H Elwen², G Harris³, D M Moore⁴, A R Hoelzel⁴, F Lampen³

Affiliations

¹ Centre for Statistics in Ecology, Environment and Conservation, Department of Statistical Sciences, University of Cape Town, C/o Sea Search Research and Conservation NPC, Muizenberg Cape Town, South Africa.
² Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, C/o Sea Search Research and Conservation NPC, Muizenberg Cape Town, South Africa.
³ The South African Association for Marine Biological Research, uShaka Sea World, Point, Durban, South Africa.
⁴ Department of Biosciences, Durham University, Durham, United Kingdom.

Abstract

The bottlenose dolphin, genus Tursiops is one of the best studied of all the Cetacea with a minimum of two species widely recognised. Common bottlenose dolphins (T. truncatus), are the cetacean species most frequently held in captivity and are known to hybridize with species from at least 6 different genera. In this study, we document several intra-generic hybridization events between T. truncatus and T. aduncus held in captivity. We demonstrate that the F1 hybrids are fertile and can backcross producing apparently healthy offspring, thereby showing introgressive inter-specific hybridization within the genus. We document that female F1 hybrids can reach sexual maturity at 4 yr and 3 mo of age, and can become pregnant and give birth before being fully weaned. The information presented has implications for understanding hybrid reticulation among cetacean species and practical implications for captive facilities housing either Tursiops species or hybrids thereof.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Bottle-Nosed Dolphin / physiology*
Crosses, Genetic*
Female
Male
Reproduction / physiology*

Grants and funding

This research was supported in part by a Claude Leon Post Doctoral Fellowship to TG (www.leonfoundation.co.za) and National ResearchFoundation Fellowship to SE (www.nrf.ac.za/). Sea Search Africa Pty provided travel funding to TG (www.seasearch.co.za). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.The author(s) GH and FL received no specific funding for this work. The funder provided support in the form of salaries for authors as follows: Claude Leon Post Doctoral Fellowship to TG, National Research Foundation Fellowship to SE. Salaries from SAAMBR uShaka Sea World to GH and FL, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.