European hake (Merluccius merluccius), is a demersal fish distributed from the North Sea and Atlantic to the Levantine Sea in the Mediterranean. It is an important predator of deep Mediterranean upper shelf slope communities currently characterised by growth overexploitation. M. merluccius adults feed mainly on fish and squids whereas the juveniles (<16 cm) feed on crustaceans. All current European hake diet studies relied on the morphological identification of prey remains in stomach content, however this method is labour intensive and it precludes the identification of strongly digested food. In this study we applied High-Throughput Sequencing (HTS) approaches that allow the simultaneous detection of many consumed species (DNA metabarcoding). Our approach is based on COI (cytochrome oxydase I) PCR amplification of stomach content remains and sequencing by using the Miseq Illumina paired-end technology. We sequenced 95 stomach remains of M. merluccius (representing all the size classes) and one pooled DNA sample of European hake preys used to assess the efficiency of the technique. Classic microscopic morphological analyses on stomach content remains have been carried out contextually to compare the results of the two methods. The molecular approach clearly outperformed the morphological prey analysis both in sensitivity and specificity. Statistical analysis of diet composition revealed a lack of differentiation among the size classes, suggesting an opportunistic feeding behaviour also supported by the homogenous bathymetry and, therefore, relatively homogeneous biocenosis of the sampling sites. Moreover the results of the artificially pooled sample allowed to confirm the semi-quantitative nature of this analysis.

EUROPEAN HAKE DIET IN THE ADRIATIC SEA: A METABARCODING APPROACH

RICCIONI, GIULIA;STAGIONI, MARCO;TINTI, FAUSTO;PICCINETTI, CORRADO;
2016

Abstract

European hake (Merluccius merluccius), is a demersal fish distributed from the North Sea and Atlantic to the Levantine Sea in the Mediterranean. It is an important predator of deep Mediterranean upper shelf slope communities currently characterised by growth overexploitation. M. merluccius adults feed mainly on fish and squids whereas the juveniles (<16 cm) feed on crustaceans. All current European hake diet studies relied on the morphological identification of prey remains in stomach content, however this method is labour intensive and it precludes the identification of strongly digested food. In this study we applied High-Throughput Sequencing (HTS) approaches that allow the simultaneous detection of many consumed species (DNA metabarcoding). Our approach is based on COI (cytochrome oxydase I) PCR amplification of stomach content remains and sequencing by using the Miseq Illumina paired-end technology. We sequenced 95 stomach remains of M. merluccius (representing all the size classes) and one pooled DNA sample of European hake preys used to assess the efficiency of the technique. Classic microscopic morphological analyses on stomach content remains have been carried out contextually to compare the results of the two methods. The molecular approach clearly outperformed the morphological prey analysis both in sensitivity and specificity. Statistical analysis of diet composition revealed a lack of differentiation among the size classes, suggesting an opportunistic feeding behaviour also supported by the homogenous bathymetry and, therefore, relatively homogeneous biocenosis of the sampling sites. Moreover the results of the artificially pooled sample allowed to confirm the semi-quantitative nature of this analysis.
2016
abstractbookSite2016
187
187
Riccioni, G.; Stagioni, M.; Tinti, F.; Piccinetti, C.; Libralato, S.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/583004
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