Species of shark
Not to be confused with Bluntnose sixgill shark .
Sixgill sawsharkTemporal range:
23–0 Ma
PreꞒ
Ꞓ
O
S
D
C
P
T
J
K
Pg
N
Miocene to Present
[1]
Conservation status
Least Concern (IUCN 3.1 )[2]
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Chondrichthyes
Superorder:
Selachimorpha
Order:
Pristiophoriformes
Family:
Pristiophoridae
Genus:
Pliotrema Regan , 1906
Species:
P. warreni
Binomial name
Pliotrema warreni Regan , 1906
Range of sixgill sawshark shark (in blue)
The sixgill sawshark , Pliotrema warreni is a sawshark of the family Pristiophoridae . Presence of 6 pairs of gill slits highlights this genus among sharks; outside Hexanchiformes order, Pliotrema is the only shark with more than 5 gill slits. Unlike other sawsharks, the barbs on this shark's rostrum continue onto the sides of the head. Its barbels are also closer to its mouth than in other species. At maximum, females can reach over 136 cm long, and males can reach over 112 cm long.
Range and habitat [ ]
The sixgill sawshark is found in the temperate and subtropical waters of the western Indian Ocean between latitudes 23° S and 37° S , at depths of between 37 and 500 m. This shark lives in the benthic and benthopelagic zones of the continental shelf. Adults are partially segregated from juveniles, as they naturally tend to aggregate at lower depths.[3]
Behavior [ ]
Using their sensitive barbels and electric sense , sixgill sawsharks are able to find their prey and then incapacitate them with their rostrum. Their known diet includes small fish, crustaceans, and squids. The only observed predator of the sixgill sawshark is the tiger shark , though it is likely other large sharks predate this species. These sharks, like other sawsharks, are ovoviviparous . They are thought to breed annually, giving birth to around five to seven pups per litter. It is possible that they come to inshore pupping grounds to give birth. The pups are around 35 cm at birth, and they later mature at around 83 cm if they are male, and around 110 cm if they are female.[4]
Conservation [ ]
The sixgill sawshark is listed as Least Concern by the IUCN Red List . Though they are not sought after in any market, they are frequently caught as by-catch and disposed. Because of their deep habitat, sixgill sawsharks are not considered a threat to people.[2]
See also [ ]
Sharks portal
List of prehistoric cartilaginous fish
References [ ]
^ Sepkoski, Jack (2002). "A compendium of fossil marine animal genera (Chondrichthyes entry)" . Bulletins of American Paleontology . 364 : 560. Archived from the original on 2011-09-30. Retrieved 2008-01-09 .
^ a b Pollom, R.; Rigby, C.L.; Bennett, R.; Fennessy, S.; Gledhill, K.; Leslie, R.; Sink, K.; Winker, H.; Pacoureau, N.; Herman, K.; Cheok, J. (2020). "Pliotrema warreni " . IUCN Red List of Threatened Species . 2020 : e.T171728748A124432293. doi :10.2305/IUCN.UK.2020-3.RLTS.T171728748A124432293.en . Retrieved 18 November 2021 .
^ "Marine Species Identification Portal : Sixgill sawshark - Pliotrema warreni" .
^ Compagno, Leonardo, Dando, Marc and Fowler, Sarah. Sharks of the World. Princeton University Press. 2005. pg 131-132.
Froese, Rainer; Pauly, Daniel (eds.) (2006). "Pliotrema warreni " in FishBase . May 2006 version.
Extant shark species
Kingdom Animalia
Phylum Chordata
Subphylum Vertebrata
Class Chondrichthyes
Subclass Elasmobranchii
Subdivision Selachii
Order Carcharhiniformes (Ground sharks)
Hemigaleidae (Weasel sharks)
Leptochariidae
Leptocharias
Barbeled houndshark (L. smithii )
Proscylliidae (Finback sharks)
Pseudotriakidae
Gollum
Slender smooth-hound (G. attenuatus )
Pseudotriakis
False catshark (P. microdon )
Sphyrnidae (Hammerhead sharks)
Eusphyra
Winghead shark (E. blochii )
Sphyrna
Scalloped bonnethead (S. corona )
Whitefin hammerhead (S. couardi )
Scalloped hammerhead (S. lewini )
Scoophead (S. media )
Great hammerhead (S. mokarran )
Bonnethead (S. tiburo )
Smalleye hammerhead (S. tudes )
Smooth hammerhead (S. zygaena )
Triakidae (Houndsharks)
Carcharhinidae
Large family listed below
Scyliorhinidae
Large family listed below
Family Carcharhinidae (Requiem sharks)
Carcharhinus
Blacknose shark (C. acronotus )
Silvertip shark (C. albimarginatus )
Bignose shark (C. altimus )
Graceful shark (C. amblyrhynchoides )
Grey reef shark (C. amblyrhynchos )
Pigeye shark (C. amboinensis )
Borneo shark (C. borneensis )
Copper shark (C. brachyurus )
Spinner shark (C. brevipinna )
Nervous shark (C. cautus )
Whitecheek shark (C. dussumieri )
Silky shark (C. falciformis )
Creek whaler (C. fitzroyensis )
Galapagos shark (C. galapagenisis )
Pondicherry shark (C. hemiodon )
Finetooth shark (C. isodon )
Smoothtooth blacktip shark (C. leiodon )
Bull shark (C. leucas )
Blacktip shark (C. limbatus )
Oceanic whitetip shark (C. longimanus )
Hardnose shark (C. macloti )
Blacktip reef shark (C. melanopterus )
Dusky shark (C. obscurus )
Caribbean reef shark (C. perezii )
Sandbar shark (C. plumbeus )
Smalltail shark (C. porosus )
Blackspot shark (C. sealei )
Night shark (C. signatus )
Spottail shark (C. sorrah )
Australian blacktip shark (C. tilstoni )
Galeocerdo Glyphis (River sharks)
Ganges shark (G. gangeticus )
Northern river shark (G. garricki )
Speartooth shark (G. glyphis )
Irrawaddy river shark (G. siamensis )
Borneo river shark (Glyphis sp. B )
Isogomphodon
Daggernose shark (I. oxyrhynchus )
Lamiopsis Loxodon Nasolamia Negaprion
Sicklefin lemon shark (N. acutidens )
Lemon shark (N. brevirostris )
Prionace Rhizoprionodon Scoliodon
Spadenose shark (S. laticaudus )
Triaenodon
Whitetip reef shark (T. obesus )
Family Scyliorhinidae (Catsharks)
Order Heterodontiformes (Bullhead sharks)
Chlamydoselachidae
Chlamydoselachus
Frilled shark (C. anguineus )
Southern African frilled shark (C. africana )
Hexanchidae (Cow sharks)
Heptranchias Hexanchus
Bluntnose sixgill shark (H. griseus )
Bigeyed sixgill shark (H. nakamurai )
Notorynchus
Broadnose sevengill shark (N. cepedianus )
Order Lamniformes (Mackerel sharks)
Alopiidae
Alopias (Thresher sharks)
Pelagic thresher (A. pelagicus )
Bigeye thresher (A. superciliosus )
Common thresher (A. vulpinus )
Alopias sp. (A. sp. )
Cetorhinidae
Cetorhinus
Basking shark (C. maximus )
Lamnidae
Carcharodon
Great white shark (C. carcharias )
Isurus
Shortfin mako shark (I. oxyrinchus )
Longfin mako shark (I. paucus )
Lamna
Salmon shark (L. ditropis )
Porbeagle (L. nasus )
Megachasmidae
Megachasma
Megamouth shark (M. pelagios )
Mitsukurinidae
Mitsukurina
Goblin shark (M. owstoni )
Odontaspididae
Carcharias
Grey nurse shark (C. taurus )
Indian sand tiger (C. tricuspidatus )
Odontaspis
Smalltooth sand tiger (O. ferox )
Bigeye sand tiger (O. noronhai )
Pseudocarchariidae
Pseudocarcharias
Crocodile shark (P. kamoharai )
Order Orectolobiformes (Carpet sharks)
Brachaeluridae
Brachaelurus Heteroscyllium
Bluegrey carpetshark (H. colcloughi )
Ginglymostomatidae (Nurse sharks)
Ginglymostoma
Nurse shark (G. cirratum )
Nebrius
Tawny nurse shark (N. ferrugineus )
Pseudoginglymostoma
Short-tail nurse shark (P. brevicaudatum )
Hemiscylliidae (Bamboo sharks)
Chiloscyllium
Arabian carpetshark (C. arabicum )
Burmese bamboo shark (C. burmensis )
Bluespotted bamboo shark (C. caerulopunctatum )
Grey bamboo shark (C. griseum )
Hasselt's bamboo shark (C. hasseltii )
Slender bamboo shark (C. indicum )
Whitespotted bamboo shark (C. plagiosum )
Brownbanded bamboo shark (C. punctatum )
Hemiscyllium
Indonesian speckled carpetshark (H. freycineti )
H. galei
Papuan epaulette shark (H. hallstromi )
H. henryi
Epaulette shark (H. ocellatum )
Hooded carpetshark (H. strahani )
Speckled carpetshark (H. trispeculare )
Orectolobidae (Wobbegongs)
Parascylliidae (Collared carpet sharks)
Rhincodontidae
Stegostomatidae
Stegostoma
Zebra shark (S. fasciatum )
Order Pristiophoriformes (Sawsharks)
Order Squaliformes
Centrophoridae (Gulper sharks)
Centrophorus
Needle dogfish (C. acus )
Dwarf gulper shark (C. atromarginatus )
Gulper shark (C. granulosus )
Dumb gulper shark (C. harrissoni )
Blackfin gulper shark (C. isodon )
Lowfin gulper shark (C. lusitanicus )
Smallfin gulper shark (C. moluccensis )
Taiwan gulper shark (C. niaukang )
Leafscale gulper shark (C. squamosus )
Mosaic gulper shark (C. tessellatus )
Little gulper shark (C. uyato )
Deania
Dalatiidae
Euprotomicroides
Taillight shark (E. zantedeschia )
Heteroscymnoides
Longnose pygmy shark (H. marleyi )
Mollisquama Dalatias Isistius
Cookiecutter shark (I. brasiliensis )
South China cookiecutter shark (I. labialis )
Largetooth cookiecutter shark (I. plutodus )
Euprotomicrus Squaliolus
Smalleye pygmy shark (S. aliae )
Spined pygmy shark (S. laticaudus )
Etmopteridae
Aculeola
Hooktooth dogfish (A. nigra )
Centroscyllium Etmopterus (Lantern sharks) Miroscyllium
Rasptooth dogfish (M. sheikoi )
Trigonognathus
Viper dogfish (T. kabeyai )
Oxynotidae (Rough sharks)
Somniosidae (Sleeper sharks)
Squalidae (Dogfish sharks)
Order Squatiniformes (Angel sharks)