Transcript SLEEPER SHARKS - Charles E. Schmidt College of Science

SLEEPER SHARKS
Family somniosidae
Classification
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Kingdom animalia
Phylum chordata
Class chondrichthyes
Order squaliformes
Family somniosidae
7 genera
18 species
Characteristics of the
family
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2 small dorsal fins, no spines
Small pectoral fins
Short, broad caudal fin
No anal fins
Small eyes
Small upper spike like teeth
Small lower teeth tightly overlapped
 Good for cutting
 Slate gray to brown and some with spots
Family name derivation
 Somniosidae = “sleep”
 Know to be sluggish but can have bursts
of speed to catch fast moving prey
Most familiar species
 From genus Somniosus
 Somniosus pacificus- pacific sleeper shark
 Somniosus microcephalus- greenland shark
 Others include little sleeper, and different
kinds of dogfish
Pacific
Sleeper
Pacific Sleeper Shark
Greenland Shark
Greenland shark
Greenland
Shark
Greenland teeth
Size of sleepers
 Small to over 7m
 Size variable at different depths for S.
pacificus
 larger at deeper depths for S.
microcephalus
 ~ 40cm at birth
Habitat of pacific sleeper
 Live in the Artic, and North Pacific
 Cold water -1-12C
 At lower latitudes = live deeper
 epibenthic
 High latitudes= live shallower; even
intertidal
 Can be found up to 2000m deep
Habitat of Greenland
shark
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Arctic
North Atlantic
Found up to 2200 m deep
epibenthic
Food habits of Pacific
sleeper
 Eat cephalopods, teleosts, crustaceans,
marine mammals (cetaceans)
 Thought responsible for decline of stellar sea
lion but found untrue
 Feed on bottom but are known to travel
vertically and feed on pelagic fast moving prey
 Known to be sluggish but with quick bursts of
energy
Food habits of Greenland
sharks
 Feed on gastropods, cephalopods,
echinoderms, elasmobranchs, teleosts,
marine mammals ( pinnipeds)
 Smaller (<200cm) mostly cephalopods
Reproduction of sleepers
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Ovoviviparous
2 equally developed ovaries with pleats
Males and females mature at ~400 cm
5-10 young at a time
40 cm at birth
Gestation ~ 2years
Special adaptations of
sleepers
 Live in cold deep water
 Liver oil contains no squalene
 Instead have “DAGE” and “TAG”
 Acts as “antifreeze”
 Besides urea also produce trimethylamine
oxide (TMAO)
 Stabilizes proteins against crushing pressure and
cold
 People eat rotten meat of Greenland sharks
said to taste like ammonia
Parasites of sleepers
 Both S. microcephalus and S. pacificus have
been found to contain copepod parasites,
Ommatokoita elongata,on their eyes
 Causes lesions and thickening of the cornea
 Thought to affect image formation
 Have ability to detect light
 Rely on other senses
Parasite copepod on eye
videos
 http://video.nationalgeographic.com/video/play
er/places/cultureplaces/food/iceland_rottensharkmeat.html
 http://www.youtube.com/watch?v=NPEi_L0hG
Zo
 http://www.youtube.com/watch?v=B-whabKr_r0
 http://www.youtube.com/watch?v=LJm7PwhrL
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Literature cited
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Benz, GW; Borucinska, JD; Lowry, LF; Whiteley, HE ( 2002). Ocular lesions associated
with attachment of the copepod Ommatokoita elongata (Lernaeopodidae : Siphonostomatoida) to
corneas of Pacific sleeper sharks Somniosus pacificus captured off Alaska in Prince William Sound
JOURNAL OF PARASITOLOGY. 88 (3), 474-481.
Benz, GW; Lucas, Z; Lowry, LF (1998). New host and ocean records for the copepod Ommatokoita elongata
(Siphonostomatoida : Lernaeopodidae), a parasite of the eyes of sleeper sharks. JOURNAL OF
PARASITOLOGY. 84 (6), 1271-1274 .
Frid, A; Baker, GG; Dill, LM. (2006) Do resource declines increase predation rates on North Pacific harbor
seals? A behavior-based plausibility model. MARINE ECOLOGY-PROGRESS SERIES. 312, 265275.
Hulbert, LB (Hulbert, L. B.); Sigler, MF (Sigler, M. F.); Lunsford, CR (Lunsford, C. R.). (2006). Depth and
movement behaviour of the Pacific sleeper shark in the north-east Pacific Ocean. JOURNAL OF FISH
BIOLOGY. 69 (2), 406-425.
Sigler, MF (Sigler, M. F.); Hulbert, LB (Hulbert, L. B.); Lunsford, CR (Lunsford, C. R.); Thompson, NH
(Thompson, N. H.); Burek, K (Burek, K.); O'Corry-Crowe, G (O'Corry-Crowe, G.); Hirons, AC (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.
Yano, K (Yano, K.); Stevens, JD (Stevens, J. D.); Compagno, LJV (Compagno, L. J. V.). (2007) Distribution,
reproduction and feeding of the Greenland shark Somniosus (Somniosus) microcephalus, with notes
on two other sleeper sharks, Somniosus (Somniosus) pacificus and Somniosus (Somniosus)
antarcticus. JOURNAL OF FISH BIOLOGY. 70 (2), 374-390.