A real‐time PCR assay to detect predation by spiny dogfish on Atlantic cod in the western North Atlantic Ocean
Abstract 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 overfis...
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ftdoajarticles:oai:doaj.org/article:74f91eff584844418ef6dc697fb66ecf 2023-05-15T15:27:23+02:00 A real‐time PCR assay to detect predation by spiny dogfish on Atlantic cod in the western North Atlantic Ocean Steven C. Pitchford Brian E. Smith Richard S. McBride 2020-10-01T00:00:00Z https://doi.org/10.1002/ece3.6694 https://doaj.org/article/74f91eff584844418ef6dc697fb66ecf EN eng Wiley https://doi.org/10.1002/ece3.6694 https://doaj.org/toc/2045-7758 2045-7758 doi:10.1002/ece3.6694 https://doaj.org/article/74f91eff584844418ef6dc697fb66ecf Ecology and Evolution, Vol 10, Iss 20, Pp 11022-11030 (2020) diet analysis fish Fisheries Management food webs predator prey interactions Ecology QH540-549.5 article 2020 ftdoajarticles https://doi.org/10.1002/ece3.6694 2022-12-30T20:27:46Z Abstract 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 1,600 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, partially digested fish that could be recognized in hindsight as cod. Cod DNA was observed in dogfish stomachs year round: in January (1 of 1 trip), February (1 of 1), May (1 of 3), June (0 of 1), July (3 of 4), August (1 of 2), and October (3 of 3). Although these data suggest higher interaction rates between dogfish and cod than previously observed, addressing the population consequences of this predator–prey relationship requires a robust sampling design, estimates of digestion rates by dogfish to account for complete degradation of DNA sequences, and consideration for dogfish scavenging during fishing operations. Article in Journal/Newspaper atlantic cod Gadus morhua North Atlantic spiny dogfish Directory of Open Access Journals: DOAJ Articles Ecology and Evolution 10 20 11022 11030 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
diet analysis fish Fisheries Management food webs predator prey interactions Ecology QH540-549.5 |
spellingShingle |
diet analysis fish Fisheries Management food webs predator prey interactions Ecology QH540-549.5 Steven C. Pitchford Brian E. Smith Richard S. McBride A real‐time PCR assay to detect predation by spiny dogfish on Atlantic cod in the western North Atlantic Ocean |
topic_facet |
diet analysis fish Fisheries Management food webs predator prey interactions Ecology QH540-549.5 |
description |
Abstract 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 1,600 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, partially digested fish that could be recognized in hindsight as cod. Cod DNA was observed in dogfish stomachs year round: in January (1 of 1 trip), February (1 of 1), May (1 of 3), June (0 of 1), July (3 of 4), August (1 of 2), and October (3 of 3). Although these data suggest higher interaction rates between dogfish and cod than previously observed, addressing the population consequences of this predator–prey relationship requires a robust sampling design, estimates of digestion rates by dogfish to account for complete degradation of DNA sequences, and consideration for dogfish scavenging during fishing operations. |
format |
Article in Journal/Newspaper |
author |
Steven C. Pitchford Brian E. Smith Richard S. McBride |
author_facet |
Steven C. Pitchford Brian E. Smith Richard S. McBride |
author_sort |
Steven C. Pitchford |
title |
A real‐time PCR assay to detect predation by spiny dogfish on Atlantic cod in the western North Atlantic Ocean |
title_short |
A real‐time PCR assay to detect predation by spiny dogfish on Atlantic cod in the western North Atlantic Ocean |
title_full |
A real‐time PCR assay to detect predation by spiny dogfish on Atlantic cod in the western North Atlantic Ocean |
title_fullStr |
A real‐time PCR assay to detect predation by spiny dogfish on Atlantic cod in the western North Atlantic Ocean |
title_full_unstemmed |
A real‐time PCR assay to detect predation by spiny dogfish on Atlantic cod in the western North Atlantic Ocean |
title_sort |
real‐time pcr assay to detect predation by spiny dogfish on atlantic cod in the western north atlantic ocean |
publisher |
Wiley |
publishDate |
2020 |
url |
https://doi.org/10.1002/ece3.6694 https://doaj.org/article/74f91eff584844418ef6dc697fb66ecf |
genre |
atlantic cod Gadus morhua North Atlantic spiny dogfish |
genre_facet |
atlantic cod Gadus morhua North Atlantic spiny dogfish |
op_source |
Ecology and Evolution, Vol 10, Iss 20, Pp 11022-11030 (2020) |
op_relation |
https://doi.org/10.1002/ece3.6694 https://doaj.org/toc/2045-7758 2045-7758 doi:10.1002/ece3.6694 https://doaj.org/article/74f91eff584844418ef6dc697fb66ecf |
op_doi |
https://doi.org/10.1002/ece3.6694 |
container_title |
Ecology and Evolution |
container_volume |
10 |
container_issue |
20 |
container_start_page |
11022 |
op_container_end_page |
11030 |
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1766357816934662144 |