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Spatio-temporal distribution and trophic ecology of Australian cownose rays (Rhinoptera neglecta)

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posted on 2022-08-05, 03:30 authored by Alysha J. Chan

Australian cownose rays (Rhinoptera neglecta) are an understudied species of epipelagic schooling ray that occur along Australia’s north and east coasts. The species is considered Data Deficient on the IUCN Red List of Threatened Species, with extensive knowledge gaps surrounding their biology and ecology. This project provides the first detailed examination of the species’ spatio-temporal distribution and trophic ecology along the temperate coast of New South Wales, Australia. A multi-year dataset of R. neglecta coastal sightings, collected during aerial surveys conducted by the New South Wales government fisheries department, was analysed using generalised additive models to identify biotic and abiotic drivers of R. neglecta occurrence and group size in the region. Opportunistic access to specimens enabled the examination of the species’ trophic niche through stable isotope (δ13C, δ15N and δ34S) analysis. The trophic ecology of R. neglecta was compared to that of Aetobatus ocellatus (whitespotted eagle ray) as the two species are thought to share a similar distribution and ecology in the region. This study provides the first insight into R. neglecta occurrence and relative abundance along the full extent of the New South Wales coastline whilst reporting the species’ isotopic niche and resource use.


Table of Contents

Chapter 1: General Introduction -- Chapter 2: Variation and drivers of cownose ray (Rhinoptera neglecta) occurrence and group size along the temperate coast of New South Wales, Australia -- Chapter 3: Examining the trophic niche and resource use of two co-occurring batoid species along the coast of temperate New South Wales, Australia -- Chapter 4: General Discussion -- Reference List -- Supplementary material


Submitted: January 8, 2021 as part of the requirements for completion of the degree of Master of Research

Awarding Institution

Macquarie University

Degree Type

Thesis MRes


Thesis (MRes), Macquarie University, Faculty of Science and Engineering, 2021

Department, Centre or School

Department of Biological Sciences

Year of Award


Principal Supervisor

Fabrice Jaine

Additional Supervisor 1

Jane Williamson


Copyright disclaimer: Copyright Alysha J. Chan 2021.




vi, 71 pages

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