Evidence map›Paper›PMID 41688506›Full record

ArticleScientific reports2026

Biogeographic variation in the diet of juvenile blacktip sharks across the Galapagos Archipelago.

Savannah J Ryburn, Eldridge Wisely, Eduardo Espinoza, Daniel Armijos, Haley E Capone, Diana A Pazmiño, Alex Hearn, John F Bruno

Abstract read
In one paragraph

Article in Scientific reports, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

8 authors.

Savannah J RyburnEnvironment, Ecology, and Energy Program, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599 - 3275, USA. savannahjryburn@gmail.com.ORCID https://orcid.org/0000-0002-6157-9111
Eldridge WiselyScripps Institution of Oceanography, University of California San Diego, San Diego, CA, 92121, USA.
Eduardo EspinozaGalapagos National Park Directorate, Puerto Ayora, Galapagos Islands, Ecuador.
Daniel ArmijosGalapagos Science Center GSC, Universidad San Francisco de Quito and University of North Carolina at Chapel Hill, Av. Alsacio Northia, Isla San Cristóbal, Galápagos, Ecuador.
Haley E CaponeRestoration Center, Office of Habitat Conservation, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Silver Spring, MD, 20910, USA.
Diana A PazmiñoGalapagos Science Center GSC, Universidad San Francisco de Quito and University of North Carolina at Chapel Hill, Av. Alsacio Northia, Isla San Cristóbal, Galápagos, Ecuador.
Alex HearnMigraMar, Olema, CA, 94950, USA.
John F BrunoThe Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599 - 3280, USA.

Funding

National Science Foundation OCE #2128592
6 · The paper itself

Abstract

Juvenile blacktip sharks (Carcharhinus limbatus) are highly abundant in the mangrove-fringed bays throughout the Galapagos Archipelago, utilizing these habitats as nursery grounds. Due to spatial variation in factors including temperature and larval connectivity, fish species richness is higher in the eastern portion of the archipelago. Predator diets often reflect regional prey availability, leading us to hypothesize that juvenile blacktip sharks in the eastern Galapagos would have greater prey taxa richness than those in the west. Here, we used DNA metabarcoding of fecal matter collected via non-lethal cloacal swabs to describe and quantify juvenile blacktip shark diets. We collected samples from 107 sharks across 240 km, spanning 14 bays on four islands, and released all sharks alive. The most common prey taxa identified were Thoburn's mullet (Mugil thoburni; 20.0%, based on percent of occurrence), followed by fishes in the genus Abudefduf (sergeant-majors; 13.4%), Galapagos ringtail damselfish (Stegastes beebei; 12.7%), scalloped hammerhead shark (Sphyrna lewini; 11.7%), and yellowtail damselfish (Stegastes arcifrons; 10.7%). Prey taxa richness was highest among sharks sampled in the bays of San Cristobal, possibly due to geographic variation in prey availability. Additionally, sharks sampled during a La Niña event in 2021 had higher prey taxa richness than those sampled during an El Niño event in 2023, which could be due to El Niño-induced declines in species richness and abundance resulting from shifts in primary productivity and upwelling. A deeper understanding of shark diets can improve our ability to predict how changes in food web dynamics and prey availability affect shark populations. This knowledge is especially vital in the face of overfishing and climate change, helping to inform more effective conservation strategies and support shark survival.

Indexed as

DietSharksAnimalsDNA Barcoding, TaxonomicEcosystemEcuadorPredatory BehaviorCarcharhinus limbatusCloacal swabDiet reconstructionENSOfDNAMetabarcoding

Identifiers

PMID41688506
PMCPMC12996282

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.