- Title
- Short- and long-term diets of the threatened longhorned pygmy devil ray, Mobula eregoodoo determined using stable isotopes
- Creator
- Burgess, Katherine B.; Broadhurst, Matt K.; Raoult, Vincent; Laglbauer, Betty J. L.; Coleman, Melinda A.; Bennett, Michael B.
- Relation
- Journal of Fish Biology Vol. 97, Issue 2, p. 424-434
- Publisher Link
- http://dx.doi.org/10.1111/jfb.14381
- Publisher
- Wiley-Blackwell
- Resource Type
- journal article
- Date
- 2020
- Description
- Most mobulids are listed as near threatened to endangered. Nonetheless, effective conservation measures are hindered by knowledge gaps in their ecology and behaviour. In particular, few studies have assessed diets and trophic ecologies that could inform methods to avoid fishing mortality. Here, a shortfall in data for the longhorned pygmy devil ray, Mobula eregoodoo was addressed by describing temporal variability in dietary preferences using stable isotope analysis. During summer and autumn in 2017, five bather-protection gillnets were deployed off eastern Australia (29ᵒ S, 153.5ᵒ E). From the catches of these gillnets, 35 adult M. eregoodoo had liver, muscle and stomach contents sampled to determine δ¹³C and δ¹⁵N profiles. Analyses revealed that surface zooplankton and zooplanktivorous teleosts were important dietary components across short- and long-term temporal scales. Large quantities of undigested sandy sprat, Hyperlophus vittatus, in the stomachs of some specimens unequivocally confirm feeding on teleosts. A narrow isotopic niche and minimal isotopic overlap with reef manta rays, Mobula alfredi from the same geographic region in eastern Australia implies M. eregoodoo has unique and highly specialised resource use relative to other mobulids in the area. The species is clearly vulnerable to capture during inshore migrations, presumably where they feed on shallow-water shoaling teleosts. Female M. eregoodoo likely have a low annual reproductive output, so population recoveries from fishing-induced declines are likely to be slow. Measures to reduce the by catch of M. eregoodoo in local bather-protection gillnets, and artisanal fisheries more broadly, should be given priority.
- Subject
- diet; eastern Australia; Mobula; stable isotope analysis; trophic ecologies; SDG 14; Sustainable Development Goals
- Identifier
- http://hdl.handle.net/1959.13/1438343
- Identifier
- uon:40580
- Identifier
- ISSN:0022-1112
- Rights
- This is the peer reviewed version of the following article: Burgess, Katherine B.; Broadhurst, Matt K.; Raoult, Vincent; Laglbauer, Betty J. L.; Coleman, Melinda A.; Bennett, Michael B. “Short- and long-term diets of the threatened longhorned pygmy devil ray, Mobula eregoodoo determined using stable isotopes”. Journal of Fish Biology Vol. 97, Issue 2, p. 424-434 (2020), which has been published in final form at http://dx.doi.org/10.1111/jfb.14381. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.
- Language
- eng
- Full Text
- Reviewed
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