Jump to content

Pacific sleeper shark: Difference between revisions

From Wikipedia, the free encyclopedia
Browse history interactively
← Previous edit
Content deleted Content added
VisualWikitext
No edit summary
Cyanochic (talk | contribs)
90 edits
m added 2 citations
 
(31 intermediate revisions by 23 users not shown)
Line 1: Line 1:
{{Short description|Species of shark}}
{{speciesbox
{{Speciesbox
| name = Pacific sleeping shark
| image = Pacific sleeper shark.png
| name = Pacific sleeper shark
| image = Pacific sleeper shark (illustration).jpg
| status = DD
| status = NT
| status_system = IUCN3.1
| status_system = IUCN3.1
| status_ref = <ref name="IUCN">{{Cite iucn | author = Ebert, D.A. | author2 = Goldman, K.J. | author3 = Orlov, A.M. | last-author-amp = yes | title = ''Somniosus pacificus'' | volume = 2009 | page = e.T161403A5416294 | date = 2009 | doi = 10.2305/IUCN.UK.2009-2.RLTS.T161403A5416294.en }}</ref>
| status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author=Rigby, C.L. |author2=Derrick, D. |author3=Dyldin, Y.V. |author4=Ebert, D.A. |author5=Herman, K. |author6=Ho, H. |author7=Hsu, H. |author8=Ishihara, H. |author9=Jeong, C.-H. |author10=Pacoureau, N. |author11=Semba, Y. |author12=Tanaka, S. |author13=Volvenko, I.V. |author14=Walls, R.H.L. |author15=Yamaguchi, A. |date=2021 |title=''Somniosus pacificus'' |volume=2021 |page=e.T161403A887942 |doi=10.2305/IUCN.UK.2021-2.RLTS.T161403A887942.en |access-date=19 November 2021}}</ref>
| genus = Somniosus
| genus = Somniosus
| species = pacificus
| species = pacificus
Line 14: Line 15:
}}
}}
[[File:Somniosus pacificus noaa2.jpg|thumb|Pacific sleeper shark carcasses]]
[[File:Somniosus pacificus noaa2.jpg|thumb|Pacific sleeper shark carcasses]]
The '''Pacific sleeper shark''' (''Somniosus pacificus'') is a [[sleeper shark]] of the [[family (biology)|family]] [[Somniosidae]], found in the North Pacific on [[continental shelves]] and slopes in [[Arctic]] and [[temperate]] waters between [[latitude]]s [[70th parallel north|70°N]] and [[22nd parallel north|22°N]], from the surface to {{convert|2000|m|ft}} deep.<ref name="IUCN"/><ref name=fishbase>{{FishBase | genus = Somniosus | species = pacificus | month = March| year = 2016}}</ref> Records from southern oceans are likely misidentifications of [[Somniosus|relatives]].<ref name="IUCN"/> Its length is up to {{convert|4.4|m|ft|abbr=on}}, although it could possibly reach lengths in excess of {{convert|7|m|ft|abbr=on}}.<ref name=fishbase/>
The '''Pacific sleeper shark''' ('''''Somniosus pacificus''''') is a [[sleeper shark]] of the [[family (biology)|family]] [[Somniosidae]], found in the North Pacific on [[continental shelves]] and slopes in [[Arctic]] and [[temperate]] waters between [[latitude]]s [[70th parallel north|70°N]] and [[22nd parallel north|22°N]] and in at least two places in the western tropical Pacific near [[Palau]] and the [[Solomon Islands]], from the surface to {{convert|2000|m|ft}} deep.<ref name="iucn status 19 November 2021" /><ref name=fishbase>{{FishBase |genus=Somniosus |species=pacificus |month=March |year=2016}}</ref> The first evidence of the sharks in the western tropical Pacific emerged from a [[National Geographic]] video taken near the Solomon Islands in 2015.<ref>Claassens, L., Phillips, B., Ebert, D. A., Delaney, D., Henning, B., Nestor, V., Ililau, A., & Giddens, J. (2023). First records of the Pacific sleeper shark Somniosus cf. pacificus in the western tropical Pacific. Journal of fish biology, 10.1111/jfb.15487. Advance online publication. https://doi.org/10.1111/jfb.15487</ref> Its length is up to {{convert|4.4|m|ft|abbr=on}}, although it could possibly reach lengths in excess of {{convert|7|m|ft|abbr=on}}.<ref name=fishbase/>


==Feeding habits==
==Feeding habits==
{{Unreferenced section|date=November 2015}}
{{Unreferenced section|date=November 2015}}
Pacific sleeper sharks, which are thought to be both predators and scavengers, can glide through the water with little body movement and little hydrodynamic noise, making them successful stealth predators. They feed by means of suction and cutting of their prey. They have large mouths that can essentially inhale prey and their teeth cut up any pieces that are too large to swallow. They show a characteristic rolling motion of the head when feeding. Only in [[Alaska]] has the shark's diet been studied - most sharks' stomachs contain remains of [[giant Pacific octopus]]. They are also known to feed on bottom-dwelling [[teleost]] fishes, as well as [[Sole (fish)|soles]], [[flounder]]s, [[Alaska pollock]], [[Sebastes|rockfishes]], [[shrimp]]s, [[hermit crab]]s, and even marine [[snail]]s. Larger Pacific sleeper sharks are also found to feed on fast-swimming prey such as [[squid]]s, [[Pacific salmon]], and [[harbor porpoise]]s. The diet of the Pacific sleeper shark seems to broaden as they increase in size. For example, a 3.7-m female shark found off [[Trinidad, California]] was found to have fed mostly on [[giant squid]]. Sleeper sharks found in Alaskan waters from {{convert|2|to|3|m|ft|abbr=on}} seem to feed mostly on flounder, pollock, and [[cephalopoda|cephalopods]], while sleeper sharks {{convert|3.3|to|4.25|m|ft|abbr=on}} long seem to consume teleosts and cephalopods, as well as [[marine mammal]]s. A recent study in the Gulf of Alaska suggests that sleeper sharks may prey on juvenile Steller sea lions.<ref>{{cite journal|author=Markus Horning|author2=Jo-Ann Mellish|last-author-amp=yes|title=In cold blood: evidence of Pacific sleeper shark (''Somniosus pacificus'') predation on Steller sea lions (''Eumetopias jubatus'') in the Gulf of Alaska|doi=10.7755/FB.112.4.6|year=2014|journal=Fishery Bulletin|volume=112|issue=4|pages=297–310|url=http://ir.library.oregonstate.edu/xmlui/bitstream/1957/54605/1/HorningMarkusFisheriesWildlifeInColdBlood.pdf}}</ref>
Pacific sleeper sharks, which are thought to be both predators and scavengers, can glide through the water with little body movement and little hydrodynamic noise, making them successful stealth predators. They feed by means of suction and cutting of their prey. They have large mouths that can essentially inhale prey and their teeth cut up any pieces that are too large to swallow. They show a characteristic rolling motion of the head when feeding. Only in [[Alaska]] has the shark's diet been studied - most sharks' stomachs contain remains of [[giant Pacific octopus]]. They are also known to feed on bottom-dwelling [[teleost]] fishes, as well as [[Sole (fish)|soles]], [[flounder]]s, [[Alaska pollock]], [[Sebastes|rockfishes]], [[shrimp]]s, [[hermit crab]]s, and even marine [[snail]]s<ref>{{Cite journal |last=Yang |first=Mei-Sun |last2=Page |first2=Benjamin N. |date=1999 |title=Diet of Pacific sleeper shark, Somniosus pacificus, in the Gulf of Alaska |url=https://oceanrep.geomar.de/id/eprint/52941/1/3706.pdf |journal=Fishery Bulletin |publisher=NOAA |volume=97 |pages=406-409}}</ref>. Larger Pacific sleeper sharks are also found to feed on fast-swimming prey such as [[squid]]s, [[Pacific salmon]], and [[harbor porpoise]]s<ref>{{Cite journal |last=Sigler |first=M. F. |last2=Hulbert |first2=L. B. |last3=Lunsford |first3=C. R. |last4=Thompson |first4=N. H. |last5=Burek |first5=K. |last6=O’Corry‐Crowe |first6=G. |last7=Hirons |first7=A. C. |date=2006 |title=Diet of Pacific sleeper shark, a potential Steller sea lion predator, in the north‐east Pacific Ocean |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1095-8649.2006.01096.x |journal=Journal of Fish Biology |language=en |volume=69 |issue=2 |pages=392–405 |doi=10.1111/j.1095-8649.2006.01096.x |issn=0022-1112}}</ref>. The diet of the Pacific sleeper shark seems to broaden as they increase in size. For example, a 3.7-m female shark found off [[Trinidad, California]] was found to have fed mostly on [[giant squid]]. Sleeper sharks found in Alaskan waters from {{convert|2|to|3|m|ft|abbr=on}} seem to feed mostly on flounder, pollock, and [[cephalopoda|cephalopods]], while sleeper sharks {{convert|3.3|to|4.25|m|ft|abbr=on}} long seem to consume teleosts and cephalopods, as well as [[marine mammal]]s. A recent study in the Gulf of Alaska suggests that sleeper sharks may prey on juvenile [[Steller sea lion]]s.<ref>{{cite journal |author=Markus Horning |author2=Jo-Ann Mellish |name-list-style=amp |title=In cold blood: evidence of Pacific sleeper shark (''Somniosus pacificus'') predation on Steller sea lions (''Eumetopias jubatus'') in the Gulf of Alaska |doi=10.7755/FB.112.4.6 |year=2014 |journal=Fishery Bulletin |volume=112 |issue=4 |pages=297–310 |url=http://ir.library.oregonstate.edu/xmlui/bitstream/1957/54605/1/HorningMarkusFisheriesWildlifeInColdBlood.pdf |doi-access=free |access-date=2018-10-24 |archive-date=2020-05-29 |archive-url=https://web.archive.org/web/20200529032441/https://ir.library.oregonstate.edu/downloads/cc08hh483 |url-status=live }}</ref>


==Reproduction==
==Reproduction==
Line 24: Line 25:


==Size==
==Size==
The average mature size is {{convert|3.65|m|ft|abbr=on}} and {{convert|318|-|363|kg|lb|abbr=on}}. The largest Pacific sleeper shark verified in size measured {{convert|4.4|m|ft|abbr=on}} long and weighed {{convert|888|kg|lb|abbr=on}}, although it could possibly reach {{convert|7|m|ft|abbr=on}} or more.<ref name=fishbase/><ref name= Castro>Castro, José I., ''The Sharks of North America''. Oxford University Press (2011), {{ISBN|978-0-19-539294-4}}</ref> In 1989, an enormous Pacific sleeper shark was attracted to a bait in deep water outside [[Tokyo Bay]], [[Japan]], and filmed. The shark was estimated by [[Eugenie Clark]] to be about {{convert|7|m|ft|abbr=on}} long.<ref name="RQ">{{cite web|author=Martin, R. Aidan|title=Elasmo Research|publisher=ReefQuest|accessdate=6 May 2009|url=http://www.elasmo-research.org/education/ecology/deepsea-pacific_sleeper.htm}}</ref>
The average mature size is {{convert|3.65|m|ft|abbr=on}} and {{convert|318|-|363|kg|lb|abbr=on}}. The largest Pacific sleeper shark verified in size measured {{convert|4.4|m|ft|abbr=on}} long and weighed {{convert|888|kg|lb|abbr=on}}, although it could possibly reach {{convert|7|m|ft|abbr=on}} or more.<ref name=fishbase/><ref name= Castro>Castro, José I., ''The Sharks of North America''. Oxford University Press (2011), {{ISBN|978-0-19-539294-4}}</ref> In 1989, an enormous Pacific sleeper shark was attracted to a bait in deep water outside [[Tokyo Bay]], [[Japan]], and filmed. The shark was estimated by [[Eugenie Clark]] to be about {{convert|7|m|ft|abbr=on}} long.<ref name="RQ">{{cite web |author=Martin, R. Aidan |title=Elasmo Research |publisher=ReefQuest |access-date=6 May 2009 |url=http://www.elasmo-research.org/education/ecology/deepsea-pacific_sleeper.htm |archive-date=20 April 2013 |archive-url=https://web.archive.org/web/20130420170134/http://www.elasmo-research.org/education/ecology/deepsea-pacific_sleeper.htm |url-status=live }}</ref> A single unconfirmed account exists of an enormous Pacific sleeper shark that potentially measured more than {{convert|9.2|m|ft|abbr=on}} long.<ref name = "Behrman, Daniel, (1969)">The New World of the Oceans: Men and Oceanography</ref> If true, this would make the species the largest extant macro-predatory shark, and the third largest shark overall after the [[whale shark]] and the [[basking shark]].


==Adaptations==
==Adaptations==
Due to living in frigid depths, the sleeper shark's [[Shark liver oil|liver oil]] does not contain [[squalene]], which would solidify into a dense, nonbuoyant mass. Instead, the low-density compounds in the sharks' liver are diacylglyceryl ethers <!-- (DAGE) --> and [[Triglyceride|triacylglycerol]], which maintain their fluidity even at the lowest temperatures. Also, they store very little [[urea]] in their skin (like many deep sea sharks), but like other [[elasmobranch]]s, have high concentrations of urea and [[trimethylamine N-oxide|trimethylamine oxide]] (nitrogenous waste products) in their tissues as [[osmoprotectant]]s and to increase their [[buoyancy]].<ref name = "Withers1994">{{cite journal | last1 = Withers | first1 = P. C. | last2 = Morrison | first2 = G. | last3 = Guppy | first3 = M. | title = Buoyancy Role of Urea and TMAO in an Elasmobranch Fish, the Port Jackson Shark, ''Heterodontus portusjacksoni'' | journal = Physiological Zoology | volume = 67 | issue = 3 | pages = 693–705 | date = May 1994 | jstor = 30163765 | doi=10.1086/physzool.67.3.30163765}}</ref> Trimethylamine oxide also serves to counteract the [[protein]]-[[protein folding#Disruption of the native state|destabilizing]] tendencies of [[urea#Laboratory uses|urea]]<ref name = Bennion2004>{{cite journal|last1=Bennion|first1=B. J.|last2= Daggett|first2= V.|title= Counteraction of urea-induced protein denaturation by trimethylamine N-oxide: a chemical chaperone at atomic resolution|journal=Proceedings of the National Academy of Sciences|volume= 101|issue= 17|date= 27 April 2004|pages= 6433–6438|doi= 10.1073/pnas.0308633101|pmid=15096583|pmc=404062}}</ref> and pressure.<ref name="Yancey2014">{{cite journal|last1= Yancey|first1=P. H.|last2= Gerringer|first2=M. E.|last3= Drazen|first3=J. C.|last4= Rowden|first4=A. A.|last5= Jamieson|first5= A.|title= Marine fish may be biochemically constrained from inhabiting the deepest ocean depths|journal=Proceedings of the National Academy of Sciences|volume= 111|issue= 12|date= 2014-03-03|pages= 4461–4465|doi= 10.1073/pnas.1322003111|pmid=24591588|pmc=3970477}}</ref> Its presence in the tissues of both elasmobranch and [[teleost]] fish has been found to increase with depth.<ref name="Yancey2014" /><ref name="Treberg2002">{{cite journal|last1= Treberg|first1=J. R.|last2= Driedzic|first2=W. R.|title=Elevated levels of trimethylamine oxide in deep-sea fish: evidence for synthesis and intertissue physiological importance|journal= Journal of Experimental Zoology|volume= 293|issue= 1|date= 2002-05-30 |pages =39–45|doi= 10.1002/jez.10109|pmid=12115917}}</ref>
Due to living in frigid depths, the sleeper shark's [[Shark liver oil|liver oil]] does not contain [[squalene]], which would solidify into a dense, nonbuoyant mass. Instead, the low-density compounds in the sharks' liver are diacylglyceryl ethers <!-- (DAGE) --> and [[Triglyceride|triacylglycerol]], which maintain their fluidity even at the lowest temperatures. Also, they store very little [[urea]] in their skin (like many deep sea sharks), but like other [[elasmobranch]]s, have high concentrations of urea and [[trimethylamine N-oxide|trimethylamine oxide]] (nitrogenous waste products) in their tissues as [[osmoprotectant]]s and to increase their [[buoyancy]].<ref name = "Withers1994">{{cite journal |last1=Withers |first1=P. C. |last2=Morrison |first2=G. |last3=Guppy |first3=M. |title=Buoyancy Role of Urea and TMAO in an Elasmobranch Fish, the Port Jackson Shark, ''Heterodontus portusjacksoni'' |journal=Physiological Zoology |volume=67 |issue=3 |pages=693–705 |date=May 1994 |jstor=30163765 |doi=10.1086/physzool.67.3.30163765 |s2cid=100989392}}</ref> Trimethylamine oxide also serves to counteract the [[protein]]-[[protein folding#Disruption of the native state|destabilizing]] tendencies of [[urea#Laboratory uses|urea]]<ref name = Bennion2004>{{cite journal |last1=Bennion |first1=B. J. |last2=Daggett |first2=V. |title=Counteraction of urea-induced protein denaturation by trimethylamine N-oxide: a chemical chaperone at atomic resolution |journal=Proceedings of the National Academy of Sciences |volume=101 |issue=17 |date=27 April 2004 |pages=6433–6438 |doi=10.1073/pnas.0308633101 |pmid=15096583 |pmc=404062 |bibcode=2004PNAS..101.6433B |doi-access=free}}</ref> and pressure.<ref name="Yancey2014">{{cite journal |last1=Yancey |first1=P. H. |last2=Gerringer |first2=M. E. |last3=Drazen |first3=J. C. |last4=Rowden |first4=A. A. |last5=Jamieson |first5=A. |title=Marine fish may be biochemically constrained from inhabiting the deepest ocean depths |journal=Proceedings of the National Academy of Sciences |volume=111 |issue=12 |date=2014-03-03 |pages=4461–4465 |doi=10.1073/pnas.1322003111 |pmid=24591588 |pmc=3970477 |bibcode=2014PNAS..111.4461Y |doi-access=free}}</ref> Its presence in the tissues of both elasmobranch and [[teleost]] fish has been found to increase with depth.<ref name="Yancey2014" /><ref name="Treberg2002">{{cite journal |last1=Treberg |first1=J. R. |last2=Driedzic |first2=W. R. |title=Elevated levels of trimethylamine oxide in deep-sea fish: evidence for synthesis and intertissue physiological importance |journal=Journal of Experimental Zoology |volume=293 |issue=1 |date=2002-05-30 |pages=39–45 |doi=10.1002/jez.10109 |pmid=12115917|bibcode=2002JEZ...293...39T }}</ref>


Because food is relatively scarce on the deep sea floor, the sleeper shark is able to store food in its capacious stomach. The sleeper shark's jaws are able to produce a powerful bite due to their short and transverse shape. The upper jaw teeth of the sleeper shark are spike-like, while the lower jaw teeth are oblique cusps and overlapping bases. This arrangement allows grasping and sawing of food too large to swallow. Pacific sleeper sharks have a short [[caudal fin]], which allows them to store energy for fast and violent bursts of energy to catch prey.<ref name="RQ"/>
Because food is relatively scarce on the deep sea floor, the sleeper shark is able to store food in its capacious stomach. The sleeper shark's jaws are able to produce a powerful bite due to their short and transverse shape. The upper jaw teeth of the sleeper shark are spike-like, while the lower jaw teeth are oblique cusps and overlapping bases. This arrangement allows grasping and sawing of food too large to swallow. Pacific sleeper sharks have a short [[caudal fin]], which allows them to store energy for fast and violent bursts of energy to catch prey.<ref name="RQ"/>


In 2015 a pacific sleeper shark was filmed near the Solomon Islands underneath an active volcano. The shark is able to survive in water with a high temperature and acidity.<ref>{{cite web|url=https://www.express.co.uk/news/world/794361/robots-investigate-sharks-living-underwater-volcano-solomon-islands|title=Mysterious sharks living INSIDE active underwater VOLCANO investigated by robots|first=Katie|last=Mansfield|date=20 April 2017|website=express.co.uk}}</ref><ref>{{cite web|url=https://www.youtube.com/watch?time_continue=17&v=d79LoSLD8HU|title=Rarely Seen Shark Filmed Near Underwater Volcano - National Geographic|first=|last=National Geographic|date=8 July 2015|publisher=|via=YouTube}}</ref>
In 2015 a pacific sleeper shark was filmed near the Solomon Islands underneath an active volcano. <ref>{{cite web |url=https://www.express.co.uk/news/world/794361/robots-investigate-sharks-living-underwater-volcano-solomon-islands |title=Mysterious sharks living INSIDE active underwater VOLCANO investigated by robots |first=Katie |last=Mansfield |date=20 April 2017 |website=express.co.uk |access-date=21 March 2018 |archive-date=22 March 2018 |archive-url=https://web.archive.org/web/20180322015222/https://www.express.co.uk/news/world/794361/robots-investigate-sharks-living-underwater-volcano-solomon-islands |url-status=live }}</ref><ref>{{cite web |url=https://www.youtube.com/watch?time_continue=17&v=d79LoSLD8HU |title=Rarely Seen Shark Filmed Near Underwater Volcano - National Geographic |last=National Geographic |date=8 July 2015 |via=YouTube |access-date=21 March 2018 |archive-date=14 April 2019 |archive-url=https://web.archive.org/web/20190414144206/https://www.youtube.com/watch?time_continue=17&v=d79LoSLD8HU |url-status=live }}</ref>


== Known predators ==
== Known predators ==
Sleeper sharks are preyed on by the offshore ecotype of [[killer whale]]s off British Columbia.<ref name="The Canadian Press">{{cite web|author=Keven Drews|author2=The Canadian Press|title=Killer whales feast on sharks off B.C. coast|publisher=The Canadian Press|accessdate=5 Sep 2011|url=http://www.ctvbc.ctv.ca/servlet/an/local/CTVNews/20110905/bc_killer_whales_eat_sharks_110905/20110905?hub=BritishColumbiaHome}}</ref> In addition, like the [[Greenland shark]], the parasitic [[copepod]] ''[[Ommatokoita elongata]]'' can often be observed consuming the shark's corneal tissue.
Sleeper sharks are preyed on by the [[orca types and populations#North Pacific Offshore|offshore ecotype]] of [[killer whale]] off British Columbia.<ref name="The Canadian Press">{{cite web |author=Keven Drews |author2=The Canadian Press |title=Killer whales feast on sharks off B.C. coast |date=5 September 2011 |publisher=The Canadian Press |access-date=5 Sep 2011 |url=https://bc.ctvnews.ca/killer-whales-feast-on-sharks-off-b-c-coast-1.692711 |archive-date=13 August 2013 |archive-url=https://web.archive.org/web/20130813202435/http://bc.ctvnews.ca/killer-whales-feast-on-sharks-off-b-c-coast-1.692711 |url-status=live }}</ref> In addition, like the [[Greenland shark]], the parasitic [[copepod]] ''[[Ommatokoita elongata]]'' can often be observed consuming the shark's corneal tissue.


==See also==
==See also==
Line 45: Line 46:


;General references
;General references
* {{ITIS |id=160610 |taxon=Somniosus pacificus |accessdate=23 January 2006}}
* {{ITIS |id=160610 |taxon=Somniosus pacificus |access-date=23 January 2006}}
* {{cite web | title=New giant squid predator found | url=http://news.bbc.co.uk/2/hi/science/nature/3370019.stm | accessdate=February 14, 2007 | work=BBC News | date=2004-01-08}}
* {{cite web | title=New giant squid predator found | url=http://news.bbc.co.uk/2/hi/science/nature/3370019.stm | access-date=February 14, 2007 | work=BBC News | date=2004-01-08}}
* Castro, Jose. "Pacific Sleeper Sharks (Somniosus pacificus)." Conservation Science Institute. 1983. [https://web.archive.org/web/20090513051928/http://conservationinstitute.org/ocean_change/predation/sleepershark.htm].
* Castro, Jose. "Pacific Sleeper Sharks (Somniosus pacificus)." Conservation Science Institute. 1983. [https://web.archive.org/web/20090513051928/http://conservationinstitute.org/ocean_change/predation/sleepershark.htm].
* Martin, R. A. "Pacific Sleeper Shark Bibliography." Biology of Sharks and Reys. ReefQuest Centre for Shark Research.[http://elasmo-research.org/education/ecology/biblio-pacific_sleeper.htm].
* Martin, R. A. "Pacific Sleeper Shark Bibliography." Biology of Sharks and Reys. ReefQuest Centre for Shark Research.[http://elasmo-research.org/education/ecology/biblio-pacific_sleeper.htm].
* "Megalodon caught on tape." My Paranormal Life. Google. [http://myparanormallife.blogspot.com/2006/11/megalodon-caught-on-tape.html]. (Erroneously-labelled footage of a sleeper shark)
* "Megalodon caught on tape." My Paranormal Life. Google. [http://myparanormallife.blogspot.com/2006/11/megalodon-caught-on-tape.html]. (Erroneously labelled footage of a sleeper shark)
* Carroll, Amy. "Sleeper Sharks: Awake and Hungry Sleeper sharks Not Culprits in Sea Lion Declines." Alaska Fish and Wildlife News. 1999. Alaska Department of Fish and Game.[http://www.wc.adfg.state.ak.us/index.cfm?adfg=wildlife_news.view_article&issue_id=26&articles_id=146].
* Carroll, Amy. "Sleeper Sharks: Awake and Hungry Sleeper sharks Not Culprits in Sea Lion Declines." Alaska Fish and Wildlife News. 1999. Alaska Department of Fish and Game.[http://www.wc.adfg.state.ak.us/index.cfm?adfg=wildlife_news.view_article&issue_id=26&articles_id=146].


Line 58: Line 59:
{{Selachimorpha|D.}}
{{Selachimorpha|D.}}
{{Taxonbar|from=Q533894}}
{{Taxonbar|from=Q533894}}
{{Authority control}}


{{DEFAULTSORT:Pacific sleeper shark}}
{{DEFAULTSORT:Pacific sleeper shark}}

Latest revision as of 17:57, 16 September 2024

Pacific sleeper shark
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Subdivision: Selachimorpha
Order: Squaliformes
Family: Somniosidae
Genus: Somniosus
Species:
S. pacificus
Binomial name
Somniosus pacificus
Range of the Pacific sleeper shark
Pacific sleeper shark carcasses

The Pacific sleeper shark (Somniosus pacificus) is a sleeper shark of the family Somniosidae, found in the North Pacific on continental shelves and slopes in Arctic and temperate waters between latitudes 70°N and 22°N and in at least two places in the western tropical Pacific near Palau and the Solomon Islands, from the surface to 2,000 metres (6,600 ft) deep.[1][2] The first evidence of the sharks in the western tropical Pacific emerged from a National Geographic video taken near the Solomon Islands in 2015.[3] Its length is up to 4.4 m (14 ft), although it could possibly reach lengths in excess of 7 m (23 ft).[2]

Feeding habits

[edit]

Pacific sleeper sharks, which are thought to be both predators and scavengers, can glide through the water with little body movement and little hydrodynamic noise, making them successful stealth predators. They feed by means of suction and cutting of their prey. They have large mouths that can essentially inhale prey and their teeth cut up any pieces that are too large to swallow. They show a characteristic rolling motion of the head when feeding. Only in Alaska has the shark's diet been studied - most sharks' stomachs contain remains of giant Pacific octopus. They are also known to feed on bottom-dwelling teleost fishes, as well as soles, flounders, Alaska pollock, rockfishes, shrimps, hermit crabs, and even marine snails[4]. Larger Pacific sleeper sharks are also found to feed on fast-swimming prey such as squids, Pacific salmon, and harbor porpoises[5]. The diet of the Pacific sleeper shark seems to broaden as they increase in size. For example, a 3.7-m female shark found off Trinidad, California was found to have fed mostly on giant squid. Sleeper sharks found in Alaskan waters from 2 to 3 m (6.6 to 9.8 ft) seem to feed mostly on flounder, pollock, and cephalopods, while sleeper sharks 3.3 to 4.25 m (10.8 to 13.9 ft) long seem to consume teleosts and cephalopods, as well as marine mammals. A recent study in the Gulf of Alaska suggests that sleeper sharks may prey on juvenile Steller sea lions.[6]

Reproduction

[edit]

Very little is known about the early life of Pacific sleeper sharks. They are believed to produce eggs that hatch inside the female's body (reproduction is ovoviviparous), but gestation time is unknown and litter sizes are thought to be about 10 pups. Its length at birth is about 42 cm (1.38 ft) or less.[7]

Size

[edit]

The average mature size is 3.65 m (12.0 ft) and 318–363 kg (701–800 lb). The largest Pacific sleeper shark verified in size measured 4.4 m (14 ft) long and weighed 888 kg (1,958 lb), although it could possibly reach 7 m (23 ft) or more.[2][8] In 1989, an enormous Pacific sleeper shark was attracted to a bait in deep water outside Tokyo Bay, Japan, and filmed. The shark was estimated by Eugenie Clark to be about 7 m (23 ft) long.[7] A single unconfirmed account exists of an enormous Pacific sleeper shark that potentially measured more than 9.2 m (30 ft) long.[9] If true, this would make the species the largest extant macro-predatory shark, and the third largest shark overall after the whale shark and the basking shark.

Adaptations

[edit]

Due to living in frigid depths, the sleeper shark's liver oil does not contain squalene, which would solidify into a dense, nonbuoyant mass. Instead, the low-density compounds in the sharks' liver are diacylglyceryl ethers and triacylglycerol, which maintain their fluidity even at the lowest temperatures. Also, they store very little urea in their skin (like many deep sea sharks), but like other elasmobranchs, have high concentrations of urea and trimethylamine oxide (nitrogenous waste products) in their tissues as osmoprotectants and to increase their buoyancy.[10] Trimethylamine oxide also serves to counteract the protein-destabilizing tendencies of urea[11] and pressure.[12] Its presence in the tissues of both elasmobranch and teleost fish has been found to increase with depth.[12][13]

Because food is relatively scarce on the deep sea floor, the sleeper shark is able to store food in its capacious stomach. The sleeper shark's jaws are able to produce a powerful bite due to their short and transverse shape. The upper jaw teeth of the sleeper shark are spike-like, while the lower jaw teeth are oblique cusps and overlapping bases. This arrangement allows grasping and sawing of food too large to swallow. Pacific sleeper sharks have a short caudal fin, which allows them to store energy for fast and violent bursts of energy to catch prey.[7]

In 2015 a pacific sleeper shark was filmed near the Solomon Islands underneath an active volcano. [14][15]

Known predators

[edit]

Sleeper sharks are preyed on by the offshore ecotype of killer whale off British Columbia.[16] In addition, like the Greenland shark, the parasitic copepod Ommatokoita elongata can often be observed consuming the shark's corneal tissue.

See also

[edit]

References

[edit]
  1. ^ a b Rigby, C.L.; Derrick, D.; Dyldin, Y.V.; Ebert, D.A.; Herman, K.; Ho, H.; Hsu, H.; Ishihara, H.; Jeong, C.-H.; Pacoureau, N.; Semba, Y.; Tanaka, S.; Volvenko, I.V.; Walls, R.H.L.; Yamaguchi, A. (2021). "Somniosus pacificus". IUCN Red List of Threatened Species. 2021: e.T161403A887942. doi:10.2305/IUCN.UK.2021-2.RLTS.T161403A887942.en. Retrieved 19 November 2021.
  2. ^ a b c Froese, Rainer; Pauly, Daniel (eds.). "Somniosus pacificus". FishBase. March 2016 version.
  3. ^ Claassens, L., Phillips, B., Ebert, D. A., Delaney, D., Henning, B., Nestor, V., Ililau, A., & Giddens, J. (2023). First records of the Pacific sleeper shark Somniosus cf. pacificus in the western tropical Pacific. Journal of fish biology, 10.1111/jfb.15487. Advance online publication. https://doi.org/10.1111/jfb.15487
  4. ^ Yang, Mei-Sun; Page, Benjamin N. (1999). "Diet of Pacific sleeper shark, Somniosus pacificus, in the Gulf of Alaska" (PDF). Fishery Bulletin. 97. NOAA: 406–409.
  5. ^ Sigler, M. F.; Hulbert, L. B.; Lunsford, C. R.; Thompson, N. H.; Burek, K.; O’Corry‐Crowe, G.; Hirons, A. C. (2006). "Diet of Pacific sleeper shark, a potential Steller sea lion predator, in the north‐east Pacific Ocean". Journal of Fish Biology. 69 (2): 392–405. doi:10.1111/j.1095-8649.2006.01096.x. ISSN 0022-1112.
  6. ^ Markus Horning & Jo-Ann Mellish (2014). "In cold blood: evidence of Pacific sleeper shark (Somniosus pacificus) predation on Steller sea lions (Eumetopias jubatus) in the Gulf of Alaska" (PDF). Fishery Bulletin. 112 (4): 297–310. doi:10.7755/FB.112.4.6. Archived from the original on 2020-05-29. Retrieved 2018-10-24.
  7. ^ a b c Martin, R. Aidan. "Elasmo Research". ReefQuest. Archived from the original on 20 April 2013. Retrieved 6 May 2009.
  8. ^ Castro, José I., The Sharks of North America. Oxford University Press (2011), ISBN 978-0-19-539294-4
  9. ^ The New World of the Oceans: Men and Oceanography
  10. ^ Withers, P. C.; Morrison, G.; Guppy, M. (May 1994). "Buoyancy Role of Urea and TMAO in an Elasmobranch Fish, the Port Jackson Shark, Heterodontus portusjacksoni". Physiological Zoology. 67 (3): 693–705. doi:10.1086/physzool.67.3.30163765. JSTOR 30163765. S2CID 100989392.
  11. ^ Bennion, B. J.; Daggett, V. (27 April 2004). "Counteraction of urea-induced protein denaturation by trimethylamine N-oxide: a chemical chaperone at atomic resolution". Proceedings of the National Academy of Sciences. 101 (17): 6433–6438. Bibcode:2004PNAS..101.6433B. doi:10.1073/pnas.0308633101. PMC 404062. PMID 15096583.
  12. ^ a b Yancey, P. H.; Gerringer, M. E.; Drazen, J. C.; Rowden, A. A.; Jamieson, A. (2014-03-03). "Marine fish may be biochemically constrained from inhabiting the deepest ocean depths". Proceedings of the National Academy of Sciences. 111 (12): 4461–4465. Bibcode:2014PNAS..111.4461Y. doi:10.1073/pnas.1322003111. PMC 3970477. PMID 24591588.
  13. ^ Treberg, J. R.; Driedzic, W. R. (2002-05-30). "Elevated levels of trimethylamine oxide in deep-sea fish: evidence for synthesis and intertissue physiological importance". Journal of Experimental Zoology. 293 (1): 39–45. Bibcode:2002JEZ...293...39T. doi:10.1002/jez.10109. PMID 12115917.
  14. ^ Mansfield, Katie (20 April 2017). "Mysterious sharks living INSIDE active underwater VOLCANO investigated by robots". express.co.uk. Archived from the original on 22 March 2018. Retrieved 21 March 2018.
  15. ^ National Geographic (8 July 2015). "Rarely Seen Shark Filmed Near Underwater Volcano - National Geographic". Archived from the original on 14 April 2019. Retrieved 21 March 2018 – via YouTube.
  16. ^ Keven Drews; The Canadian Press (5 September 2011). "Killer whales feast on sharks off B.C. coast". The Canadian Press. Archived from the original on 13 August 2013. Retrieved 5 Sep 2011.
General references
  • "Somniosus pacificus". Integrated Taxonomic Information System. Retrieved 23 January 2006.
  • "New giant squid predator found". BBC News. 2004-01-08. Retrieved February 14, 2007.
  • Castro, Jose. "Pacific Sleeper Sharks (Somniosus pacificus)." Conservation Science Institute. 1983. [1].
  • Martin, R. A. "Pacific Sleeper Shark Bibliography." Biology of Sharks and Reys. ReefQuest Centre for Shark Research.[2].
  • "Megalodon caught on tape." My Paranormal Life. Google. [3]. (Erroneously labelled footage of a sleeper shark)
  • Carroll, Amy. "Sleeper Sharks: Awake and Hungry Sleeper sharks Not Culprits in Sea Lion Declines." Alaska Fish and Wildlife News. 1999. Alaska Department of Fish and Game.[4].
[edit]
Retrieved from "https://en.wikipedia.org/w/index.php?title=Pacific_sleeper_shark&oldid=1246066119"