Partitioning of diet between species and life history stages of sympatric and cryptic snappers (Lutjanidae) based on DNA metabarcoding

Miwa Takahashi,Joseph D Dibattista,Michael Bunce,Simon Jarman,Corey B Wakefield,Euan S Harvey,Stephen J Newman

doi:10.1038/s41598-020-60779-9

Miwa Takahashi, Joseph D Dibattista + Show 5 more

Open Access

https://doi.org/10.1038/s41598-020-60779-9

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Abstract

Lutjanus erythropterus and L. malabaricus are sympatric, sister taxa that are important to fisheries throughout the Indo-Pacific. Their juveniles are morphologically indistinguishable (i.e. cryptic). A DNA metabarcoding dietary study was undertaken to assess the diet composition and partitioning between the juvenile and adult life history stages of these two lutjanids. Major prey taxa were comprised of teleosts and crustaceans for all groups except adult L. erythropterus, which instead consumed soft bodied invertebrates (e.g. tunicates, comb jellies and medusae) as well as teleosts, with crustaceans being notably absent. Diet composition was significantly different among life history stages and species, which may be associated with niche habitat partitioning or differences in mouth morphology within adult life stages. This study provides the first evidence of diet partitioning between cryptic juveniles of overlapping lutjanid species, thus providing new insights into the ecological interactions, habitat associations, and the specialised adaptations required for the coexistence of closely related species. This study has improved our understanding of the differential contributions of the juvenile and adult diets of these sympatric species within food webs. The diet partitioning reported in this study was only revealed by the taxonomic resolution provided by the DNA metabarcoding approach and highlights the potential utility of this method to refine the dietary components of reef fishes more generally.

Highlights

Reef fish communities are extraordinarily diverse[1], and there is often partitioning of resources, for food and habitat, between sympatric reef fishes[2,3,4]
A total of 7,166,024 reads remained after quality filtering. These reads were dereplicated to a total of 1244 amplicon sequence variants (ASVs); 863 ASVs were assigned to taxa, and 179 ASVs were considered as potential primary prey items, which consisted of 37 unique prey taxa
The mean number of reads obtained from each life history stage and species were significantly different (ANOVA: F3,41 = 11.6, p

Summary

Introduction

Reef fish communities are extraordinarily diverse[1], and there is often partitioning of resources, for food and habitat, between sympatric reef fishes[2,3,4]. Lutjanus erythropterus (Bloch, 1790) and L. malabaricus (Bloch & Scheneider, 1801) are sympatric snapper species that co-exist in the tropical and subtropical Indo-Pacific region[14] They are sister taxa[15], and the juveniles are phenotypically cryptic[8]. DNA metabarcoding simultaneously generates millions of copies of DNA sequences of digested prey from predators’ gut contents or faeces, and matches them against barcode sequences in databases to reveal the taxa of consumed species[6,29] This method lends itself to more comprehensive evaluation of dietary partitioning of sympatric, cryptic species at a much finer-scale[30,31]. Information on how diet varies between sister taxa and life history stages will improve our understanding of the ecological processes allowing them to coexist in marine ecosystems

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