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Molecular analysis of predator scats reveals role of salps in temperate inshore food webs


Cavallo, C and Chiaradia, A and Deagle, BE and McInnes, JC and Sanchez, S and Hays, GC and Reina, RD, Molecular analysis of predator scats reveals role of salps in temperate inshore food webs, Frontiers in Marine Science, 5, (OCT) Article 381. ISSN 2296-7745 (2018) [Refereed Article]


Copyright Statement

Copyright 2018 The Author(s) Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0)

DOI: doi:10.3389/fmars.2018.00381


High precision, high coverage DNA-based diet analysis tools allow great insight into the food web interactions of cryptic taxa. We used DNA fecal-metabarcoding to look for unrecorded taxa within the diet of a generalist central-placed predator, the little penguin Eudyptula minor. We examined 208 scats from 106 breeding pairs throughout August–February in a large colony at Phillip Island, Australia. While we confirmed a largely piscivorous diet, we also recovered DNA sequences from gelatinous and crustaceous plankton groups that have not previously been detected in the little penguin diet using other diet analysis methods. Gelatinous plankton, including salps, appendicularians, scyphozoans, and hydrozoans were present in 76% of samples and represented 25% of all sequences. DNA recovered from minute copepods and appendicularians may indicate links between trophic levels through secondary predation. Percentage frequency of occurrence (%FOO) demonstrated that little penguin diet composition changed over months and stages (incubation, guard, and post-guard) of the breeding season (month: χ2 = 201.91, df = NA, p < 0.01; stage: χ2 = 33.221, df = NA, p = 0.015). Relative read abundance (RRA) uncovered variations in the relative abundance of taxa in the diet over months and stages (month: F = 53.18, df = 59, p < 0.001; stage: F = 66.56, df = 29, p < 0.001). The diet became progressively fish-focused over months of the season and stages, while salps were only present in 4 out of 6 months, with a peak in September. Based on their prevalence in this dataset, in this year of very high breeding success (2.15 chicks per pair), salps may constitute a food source for this largely piscivorous generalist. Our work highlights how DNA metabarcoding can improve our understanding of the trophic role of gelatinous plankton and other cryptic taxa.

Item Details

Item Type:Refereed Article
Keywords:next-generation sequencing, foraging ecology, DNA barcoding, eDNA, jellyfish
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Marine and estuarine ecology (incl. marine ichthyology)
Objective Division:Environmental Management
Objective Group:Marine systems and management
Objective Field:Marine biodiversity
UTAS Author:McInnes, JC (Dr Julie McInnes)
ID Code:131770
Year Published:2018
Web of Science® Times Cited:16
Deposited By:Ecology and Biodiversity
Deposited On:2019-04-04
Last Modified:2019-05-01
Downloads:27 View Download Statistics

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