Coryphaenoides yaquinae
{{Short description|Species of fish}}
{{Speciesbox
| image = Gadiformes025.jpg
| image_caption = Front half specimen collected during a dive from the Okeanos Explorer in 2015
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| taxon = Coryphaenoides yaquinae
| authority = (Iwamoto & Stein, 1974)
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The rough abyssal grenadier (Coryphaenoides yaquinae) is a species of deep-sea grenadier fish in the family Macrouridae. First described as a separate species in 1974, the rough abyssal grenadier was historically confused with its congener, Coryphaenoides armatus. Unlike C. armatus, which has been recorded in the waters of the Atlantic, Pacific, Indian, and Southern oceans, observations of C. yaquinae have been confined exclusively to the Pacific ocean.{{Cite journal|last1=Jamieson |first1=A.J. |last2=Priede |first2=I.G. |last3=Craig |first3=J. |date=June 2012 |title=Distinguishing between the abyssal macrourids Coryphaenoides yaquinae and C. armatus from in situ photography |journal=Deep Sea Research Part I: Oceanographic Research Papers |volume=64 |pages=78–85 |doi=10.1016/j.dsr.2012.02.001|bibcode=2012DSRI...64...78J |doi-access=free|hdl=2164/5502 |hdl-access=free }} C. yaquinae tends to inhabit abyssopelagic depths between {{convert|3,400|and|5,800|m|spell=us}}.{{Cite journal|title=New records of the abyssal grenadiers Coryphaenoides armatus and C. yaquinae from the western North Pacific |url=https://www.researchgate.net/publication/225135439 |journal=ResearchGate |year=1992 |doi=10.1007/BF02905607|last1=Endo |first1=Hiromitsu |last2=Okamura |first2=Osamu |volume=38 |issue=4 |pages=433–437 |s2cid=82567179}} However, observations of C. yaquinae have been made as deep as {{convert|6,945|m|spell=us}} in the Japan Trench and {{convert|7,012|m|spell=us}} in the Mariana Trench.{{cite journal |last1=Jamieson |first1=Alan J. |last2=Linley |first2=Thomas D. |last3=Eigler |first3=Shane |last4=Macdonald |first4=Tim |title=A global assessment of fishes at lower abyssal and upper hadal depths (5000 to 8000 m) |journal=Deep Sea Research Part I: Oceanographic Research Papers |date=December 2021 |volume=178 |pages=103642 |doi=10.1016/j.dsr.2021.103642}} C. yaquinae is the only known macrourid from the hadal zone.
Diet and ecology
The rough abyssal grenadier is an active benthic forager, with a diet that features a variety of seafloor fauna.{{Cite journal |last1=Priede |first1=I. G. |last2=Bagley |first2=P. M. |last3=Armstrong |first3=J. D. |last4=Smith |first4=K. L. |last5=Merrett |first5=N. R. |date=June 1991 |title=Direct measurement of active dispersal of food-falls by deep-sea demersal fishes |url=https://www.nature.com/articles/351647a0 |journal=Nature |volume=351 |issue=6328 |pages=647–649 |doi=10.1038/351647a0 |bibcode=1991Natur.351..647P |s2cid=4363287 |issn=1476-4687|url-access=subscription }}{{Cite journal |last1=Drazen |first1=Jeffrey C. |last2=Popp |first2=Brian N. |last3=Choy |first3=C. Anela |last4=Clemente |first4=Tara |last5=Forest |first5=Lisa De |last6=Smith |first6=Kenneth L. |date=November 2008 |title=Bypassing the abyssal benthic food web: Macrourid diet in the eastern North Pacific inferred from stomach content and stable isotopes analyses |url=https://aslopubs.onlinelibrary.wiley.com/doi/epdf/10.4319/lo.2008.53.6.2644 |journal=Limnology and Oceanography |volume=53 |issue=6 |pages=2644–2654 |doi=10.4319/lo.2008.53.6.2644 |bibcode=2008LimOc..53.2644D |s2cid=15800062 |issn=0024-3590|url-access=subscription }} Squids, crustaceans, and polychaetes comprise the most consistent sources of prey for C. yaquinae, though stomach content analyses have revealed echinoderms, fish, and food scavenged from carrion. The availability of these food sources varies, however, as seasonal migrations of pelagic teleosts and changes in the rate of phytodetritus affect the amount of organic matter that reaches the ocean floor.{{Cite journal |last=Armstrong |first=John D. |last2=Priede |first2=Imants George |last3=Smith |first3=Kenneth L. |date=September 1991 |title=Temporal Change in Foraging Behavior of the Fish Coryphaenoides-(Nematonurus)-Yaquinae in the Central North Pacific |url=https://abdn.elsevierpure.com/en/publications/temporal-change-in-foraging-behavior-of-the-fish-coryphaenoides-n |journal=Marine Ecology Progress Series |language=en |volume=76 |issue=2 |pages=195–199 |issn=0171-8630}}