Original Research ARTICLE
New Determination of Prey and Parasite Species for Northern Indian Ocean Blue Whales
- 1The Sri Lankan Blue Whale Project and Oceanswell, Sri Lanka
- 2Australian Antarctic Division, Australia
- 3Menzies Institute for Medical Research, Australia
- 4CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Portugal
- 5Department of Environment and Agriculture, Curtin University, Australia
Blue whales are little studied, face significant anthropogenic threats and within the Northern Indian Ocean, have a restricted range, making them an archetype for conservation needs of megafauna around the world. We studied feeding behaviour of blue whales using dietary DNA metabarcoding of faecal samples. While globally blue whale populations feed predominantly on Euphausiidae, 87 % of prey DNA amplicons extracted from faecal samples from this population were sergestid shrimp, demonstrating that blue whales can locate and feed on dense swarms of other types of prey when they occur. Within the Indian Ocean sergestids are present within the top 300 m, which correlates with the deep scattering layer observed by hydroacoustics. Studies suggest that this requirement to dive deeper in search of prey likely explains the prevalence of fluke up diving within this population of blue whales relative to other parts of the globe. Furthermore, this study revealed the presence of acanthocephalan endoparasites within the stomach and intestines of the Northern Indian Ocean blue whales. This represents the first record of Acanthocephala in blue whales in the Northern Indian Ocean and highlights the need for further studies on both the ecto- and endoparasitic flora and monitoring of health of these cetaceans for their management and conservation.
Keywords: DNA metabarcoding, Sri Lanka, Blue whales, feeding, Northern Indian Ocean, faeces, Sergestid, Euphausiidae, Acanthocephala, shrimp, krill, behaviour
Received: 31 May 2017;
Accepted: 14 Mar 2018.
Edited by:Ellen Hines, San Francisco State University, United States
Reviewed by:Mark P. Simmonds, University of Bristol, United Kingdom
Brittany Hanser, NOAA/NMFS, United States
Frank Cipriano, Retired, United States
Copyright: © 2018 de Vos, Faux, Marthick, Dickinson and Jarman. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Asha de Vos, The Sri Lankan Blue Whale Project and Oceanswell, 131 W.A.D. Ramanayake Mawatha, Colombo 2, Sri Lanka, firstname.lastname@example.org