A real-time PCR assay to detect predation by spiny dogfish on Atlantic cod in the western North Atlantic Ocean. ...

• Main Authors: Pitchford, Steven, Smith, Brian E., McBride, Richard
• Format: Dataset
• Language: English
• Published: Dryad 2020
• Subjects: atlantic cod; Gadus morhua; North Atlantic; spiny dogfish
• Online Access: https://dx.doi.org/10.5061/dryad.8w9ghx3jv; https://datadryad.org/stash/dataset/doi:10.5061/dryad.8w9ghx3jv

Conventional observations show spiny dogfish (Squalus acanthius Linnaeus) rarely eat Atlantic cod (Gadus morhua Linnaeus; 0.02% of stomachs) in the northwestern Atlantic Ocean. Critics express concern that digestion may limit species-level prey identification, and with recovery from overfishing, dogfish populations may be suppressing cod by competition or predation. This study applied a real-time PCR TaqMan assay to identify cod in dogfish stomachs collected by cooperating fishing boats during normal trawling operations (May 2014 – May 2015; Gulf of Maine, Georges Bank). Conventional methods observed 51 different prey taxa and nearly 1600 individual prey items, but no cod were observed. Cod DNA was detected in 31 (10.5%) of the dogfish stomachs, with a higher percentage of these from the homogenate of amorphous, well-digested prey and stomach fluids (20 stomachs or 65%) than from discrete animal tissues (11 stomachs or 35%). Re-examination of photographs of these 11 tissue samples revealed one whole, ... : Please see Materials and Methods within the article for a description of how these data were collected and processed. ...