Naslov
MORPHOLOGICAL AND DNA METABARCODING ANALYSIS OF THE STOMACH CONTENTS OF ATLANTIC BLUEFIN TUNA (Thunnus thynnus Linnaeus, 1758) IN THE ADRIATIC SEA

Autori
Žuvić, Luka ; Bakarić, Klara ; Hrabar, Jerko ; Talijančić, Igor ; Žužul, Iva ; Grubišić, Leon ; Šegvić-Bubić, Tanja

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
7th FACULTY OF SCIENCE PhD STUDENT SYMPOSIUM, BOOK OF ABSTRACTS / Pavlek, Katarina - : Prirodoslovno-matematički fakultet Sveučilišta u Zagrebu, 2023, 41-41

Skup
7th FACULTY OF SCIENCE PhD STUDENT SYMPOSIUM

Mjesto i datum
Zagreb, Hrvatska, 21.04.2023. - 22.04.2023

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Domaća recenzija

Ključne riječi
Atlantic bluefin tuna, morphological analysis, DNA metabarcoding, COI, 18S

Sažetak
Atlantic bluefin tuna (BFT), Thunnus thynnus Linnaeus, 1758, is among the most important marine predators and is an important target species for commercial and recreational fisheries. BFT is also important for aquaculture in Croatia, where 85% of the commercial catch is destined for aquaculture. Here, we analysed the stomachs of 24 BFT (including juvenile and adult individuals of approximately 8 to 80 kg) collected in the eastern Adriatic Sea using morphological inventory and DNA metabarcoding. DNA metabarcoding was preliminary tested on five individuals. DNA was obtained with a commercially available kit by extracting DNA from a stomach swab and a homogenate of stomach contents. Universal primers for metazoans were applied for amplification of partial fragments from two gene regions (cytochrome c oxidase subunit I and the ribosomal 18S-V1V2 region) [1] and commercially sequenced using the Illumina Miseq platform. Prey identification using the molecular DNA metabarcoding approach yielded a greater diversity of prey than using the morphological approach. We also noted a large difference in sequencing reads between the two types of DNA samples, with most reads in the case of the stomach swab coming from tuna DNA, i.e. from the host. The most abundant prey species were sardine (Sardina pilchardus, ≈51%), anchovy (Engraulis encrasicolus, ≈20%), Mediterranean horse mackerel (Trachurus mediterraneus, ≈17%), mackerel (Scomber colias, ≈9%), and cephalopods (≈3%). It is noteworthy that some demersal and gelatinous species were detected as prey, such as Atlantic stargazer (Uranoscopus scaber), European hake (Merluccius merluccius), red mullet (Mullus barbatus), small-spotted catshark (Scyliorhinus canicula) and Salpa spp. These results suggest that ABT is an opportunistic forager and that DNA metabarcoding approach enables more accurate prey identification and provides greater prey diversity in comparison to the morphological approach. Therefore, DNA metabarcoding can be used as a powerful tool for analysing the stomach contents of important marine predators, but unlike the morphological approach, it is limited in quantifying prey species, so these two methods should be used side by side to complement each other.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

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