(DRAFT) - Taxonomy
Species shark, basking
Species Id M010715
Date 26 AUG 96
TAXONOMY
NAME - shark, basking
OTHER COMMON NAMES - bone shark and nurse shark
ELEMENT CODE -
CATEGORY - Fish
PHYLUM AND SUBPHYLUM - Chordata, Vertebrata
CLASS AND SUBCLASS - Chondrichthyes, Elasmobranchii
ORDER AND SUBORDER - Squaliformes,
FAMILY AND SUBFAMILY - Lamnidae,
GENUS AND SUBGENUS - Cetorhinus,
SPECIES AND SSP - maximus,
SCIENTIFIC NAME - Cetorhinus maximus
AUTHORITY - Gunnerus
TAXONOMY REFERENCES - 258
COMMENTS ON TAXONOMY -
(Gunnerus, 1765)*258*
Taxonomy - 1 (DRAFT) - Status
Species shark, basking
Species Id M010715
Date 26 AUG 96
STATUS
Coded Status
Sport Fish
Commercial
Migrant
REFERENCES FOR STATUS - 258
COMMENTS ON STATUS -
Only a few species, mostly deep-dwelling forms, occur in Canadian Atlantic
waters year-round. In summer and fall, when waters warm up, sharks from
southern regions move into Canadian waters, presumably attracted by the
abundance of prey species, while during winter northern coldwater species
may move southward in the Canadian area.*258*
Fished commercially, on occasion, in many parts of the world including
Norway, Ireland, Scotland, Iceland, Newfoundland, Peru, China, and
Japan.*258*
Status - 1 (DRAFT) - Distribution
Species shark, basking
Species Id M010715
Date 26 AUG 96
DISTRIBUTION
Distribution - 1 HABITAT ASSOCIATIONS
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Marine OW0
REFERENCES FOR NWI - 258
Habitat Associations - 1 (DRAFT) - Food Habits
Species shark, basking
Species Id M010715
Date 26 AUG 96
FOOD HABITS
TROPHIC LEVEL -
CARNIVORE
FILTERER
REFERENCES FOR TROPHIC LEVEL - 258
LIFESTAGE FOOD FOOD PART
General Plankton Not Specified
General Crustaceans Not Specified
General Copepods Not Specified
General Fish Egg/Fetus stage
General Fish Larva stage
REFERENCES FOR GENERAL FOOD - 258
COMMENTS ON FOOD -
Basking sharks feed by swimming with their mouths open, engulfing minute
planktonic organisms and filtering them from the water with their long,
close-set gill rakers. All available plankters are consumed, especially
copepods and other crustaceans, fish eggs, and larvae. The gill rakers are
said to be shed in winter.*258*
Food Habits - 1 (DRAFT) - Environment Associations
Species shark, basking
Species Id M010715
Date 26 AUG 96
ENVIRONMENTAL ASSOCIATIONS
Environment Associations - 1 (DRAFT) - Life History
Species shark, basking
Species Id M010715
Date 26 AUG 96
LIFE HISTORY
PHYSICAL DESCRIPTION:
Body elongate, stout, cylindrical in cross section, caudal peduncle with
strong lateral keels. Head large; snout pointed; mouth very large,
subterminal, overhung by snout; teeth minute, tuberculate, numerous; eye
small; pectoral origin behind lat gill slit; gill slits enormous, seeming to
sever the head from the body. Fins: dorsals, 2, first large, triangular,
second much smaller; caudal somewhat asymmetrical but lower lobe well
developed, upper lobe with subterminal notch; anal small, about same size as
second dorsal and below and slightly behind second dorsal; pelvics slightly
larger than anal; pectorals rather broad and short. Size commonly to
6.1-7.6 m long, sometimes larger. Color: upper surface grayish brown to
slate gray, to nearly black; undersurface lighter, sometimes with light
patches.*258*
REPRODUCTION:
Considered to be ovoviviparous, the embryos developing within the female,
and the young probably feeding on eggs and siblings (cannibalizing) within
the oviduct or brood chamber. The young are thought to be about 1.5-1.7 m
long at birth, but reproductive biology is not well known.*258*
LIMITING FACTORS:
Predation and competition. Little is known, but basking sharks probably
have few enemies other than man.*258*
POPULATION ATTRIBUTES:
Growth. Ages have been estimated using growth rings on the faces of
vertebral centra but doubt exists concerning the validity of the method.
Males mature at a length of 4-5 m, females at 8.1-9.8 m. The basking shark
is exceeded in size only by the whale shark, so it is the second largest
fish in the world. It attains lengths of over 10 m and a weight of 3 t, but
the average size in the Canadian region is about 5-7 m long.*258*
Life History - 1 (DRAFT) - Management Practices
Species shark, basking
Species Id M010715
Date 26 AUG 96
MANAGEMENT PRACTICES
Management Practices - 1 (DRAFT) - References
Species shark, basking
Species Id M010715
Date 26 AUG 96
References
258 * Scott, W.B., M.G. Scott. 1988. Atlantic Fishes of Canada.
Canadian Bulletin of Fisheries and Aquatic Sciences (219) (ed.).
University of Toronto Press Toronto, Canada:731.
References - 1