Naslov
Feeding habits of the invasive Magallana gigas and native Ostrea edulis oysters in the Adriatic Sea – are they in competition?

Autori
Ezgeta-Balić, Daria ; Šegvić Bubić, Tanja ; Žužul, Iva ; Bojanić Varezić, Dubravka ; Stagličić, Nika ; Peharda, Melita ; Mandić, Ivana

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

Izvornik
MARINE INVADERS - assessment and impact on aquatic ecosystems / Neto, JoãoM. ; Lemos, Marco F.L. ; Novais Sara C. - Peniche : Escola Superior de Turismo e Tecnologia do Mar, 2018, 14-14

Skup
International Meeting on Marine Research (IMMR 2018)

Mjesto i datum
Peniche, Portugal, 05.07.2018. - 06.07.2018

Vrsta sudjelovanja
Poster

Vrsta recenzije
Podatak o recenziji nije dostupan

Ključne riječi
Crassostrea gigas, Ostrea edulis, Adriatic Sea, feeding, oyster larvae

Sažetak
In the eastern Adriatic Sea non-native invasive oyster Magallana gigas (Thunberg, 1793) started to spread and could present a threat to the native European flat oyster Ostrea edulis Linnaeus, 1758, especially in the aquaculture areas. Although, M. gigas is cultured in the Italian part of Adriatic, in the Croatian part it is not the case, and it is considered an invasive species. Magallana gigas is detected in the eastern Adriatic, but there is no information about its effect on the native oyster populations. The main objective of this study was to explore food competition between the invasive and native oysters applying three different approaches: microscopically and molecular analysis of stomach content and analysis of stable isotopes. The study was conducted at the Lim Bay, bivalve aquaculture area where all production relies entirely on seed collected from nature. Magallana gigas individuals were put in the experimental aquaculture in the same area with O. edulis. Each month, 15 specimens of both species were collected, fixed with 70% ethanol and stomach content was isolated and examined under the microscope. Results confirmed that both species consume phytoplankton, zooplankton, and also considerable quantities of undetermined detritus. Ingested zooplankton taxa were mostly bivalve larvae, copepods, unidentified eggs and gastropod larvae. Stable isotope analysis will reveal detailed diet overlapping of native and invasive oysters. As bivalve larvae were present in the M. gigas stomach, further analysis was performed to determinate if those are of O. edulis. Bivalve larvae were isolated from the water column and from the stomach of M. gigas, fixed in 96% ethanol and used for genetic analyses. Species-specific primers designed for O. edulis were used for cytochrome oxidase I (COI) partial region amplification. The obtained results genetically confirmed that adult M. gigas consumed larval stages of O. edulis. In order to analyse the effect of time after prey ingestion on species identification, M. gigas individuals were fed by O. edulis larva under controlled conditions. M. gigas stomach analysis was conducted at specified time- intervals (15, 30, 60 min, 1, 2, 6, 12, 48, 72 hours) after prey ingestion. Results showed that molecular signal of O. edulis larva was present in the stomach of M. gigas even after 72 h. Findings are discussed in the context of the possible effects that M. gigas introduction in the aquaculture could have on the O. edulis in this region.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA