| BLUEFIN
TUNA
THUNNUS THYNNUS
Distinctive Characteristics Bluefin have a fusiform
body, compressed and stocky in front. The pectoral fin does not reach the origin of the
2nd dorsal fin. The height of the 2nd dorsal fin is greater than that of the 1st dorsal
fin.
The liver is striated on the ventral surface, and a
swimbladder is present. There are 34-43 gill rakers on the first gill arch. The back and
upper sides are dark blue to black with gray or green iridesence. The lower sides are
silvery, marked with gray spots and bands. The 2nd dorsal fin is reddish-brown, and the
anal fin is dusky with some yellow. The finlets are yellow, edged with black. The caudal
keel is black at the adult stage, but is semitransparent when immature.
Size
Maximum: over 118 inches
Common: 16 to 79 inches
Current IGFA all tackle record 1,496 pounds.
Distribution and Behavior
Bluefin are widely distributed throughout the
Atlantic. They are found in the western Atlantic along Labrador and Newfoundland,
southward to Tobago, Trinidad, Venezuela, and the Brazilian coast. Distribution in east
Atlantic extends as far north as Norway and Iceland, and as far south as northern West
Africa. Also exists in the Mediterranean Sea.
Western Atlantic bluefin tuna are sexually mature at
approximately age 8 (80 inches Curved Fork Length). Eastern Atlantic bluefin tuna spawn in
the Gulf of Mexico (April-June) and in the Mediterranean Sea (June-July).
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YELLOWFIN TUNA
Thunnus albacares
Distinctive Characteristics Fusiform body, more
slender than that of a bluefin or a bigeye. Small eyes and head, longer 2nd dorsal and
anal fins than any other tuna (which get longer with age). The liver is without striations
on the ventral surface, and a swimbladder is present. There are 26-35 gill rakers on the
first gill arch. The pectoral fins usually reach beyond the origin of the 2nd dorsal fin
but not beyond the end of its base.
Yellowfin have a dark blue back with a yellow
lateral band on the upper sides. The lower sides and belly are silvery-gray, often with
chains of white vertical lines and spots. The 2nd dorsal and anal fins are yellow, and the
finlets are yellow with a narrow black margin.
Size
Maximum: 75 inches
Common: 16 to 67 inches
Current IGFA all tackle record 388 pounds 12 ounces.
Distribution and Behavior
A warm-water species, yellowfin is the most tropical
species of tuna, and is abundant in tropical waters throughout the Atlantic. Young are
known to form large schools near surface. Adults inhabit fairly deep water but also live
near the surface.
Yellowfin are often found mixed with other species,
especially skipjack and bigeye. Yellowfin are sexually mature when they reach a length of
approximately 40 inches, and spawning occurs throughout the year in the core areas of
distribution (between 15 N and 15 S latitude), including the Gulf of Mexico, with peaks
occurring in summer months.
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ALBACORE
Thunnus alalunga
Distinctive Characteristics Albacore can be
distinguished from other tunas by a long pectoral fin that may reach to a point beyond the
anal fin. The pectoral fin in juvenile albacore may be similar to that of yellowfin or
bigeye. A swimbladder is present, but is poorly developed and not evident in individuals
smaller than about 25-32 gill rakers on the first gill arch.
Albacore lack any stripes or spots on the lower
flanks and belly. The tail fin has a thin white trailing edge. There is no yellow on the
main fins, but the dorsal finlets are yellowish. The anal finlets are silvery or dusky.
Size
Maximum: 50 inches
Common: 16-43 inches
Current IGFA all tackle record 88 pounds 2 ounces
Distribution and Behavior
A temperate species, found worldwide in tropical and
warm temperate seas. While albacore usually remain in tropical or warm waters, they do
make migrations into colder waters as far north as New England. In the Atlantic, larger
size classes (31-50 inches are associated with cooler water bodies, while smaller
individuals tend to occur in warmer waters.
Albacore reach sexual maturity at about 37 inches in
length, and spawn during June-July in the sub-tropical western areas of both hemispheres
and throughout the Mediterranean Sea.
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BONITO
Sarda sarda
Distinctive Characteristics Bonito can be
distinguished from other tunas by the presence of seven or more (often 9-12) oblique dark
stripes on the dorsal side of the fish. The back of the fish is steel-blue or blue-green
and the flanks and belly are silvery to whitish. The body is entirely covered with scales,
which are very small except in the pectoral region.
Bonito have large conical teeth on both the upper
and lower jaw. No swimbladder is present, and there are 16-24 gill rakers on the first
gill arch. The pectoral fins are very short, and there are 20-23 fin rays on the 1st
dorsal fin. The right and left lobes of the liver are elongate, while the center lobe is
short.
Size
Maximum; 36 inches
Common: 25 inches
Current IGFA all tackle record 18 pounds 4 ounces
Distribution and Behavior
Bonito are common in tropical and temperate waters
of the Atlantic from Argentina to Nova Scotia, and from South Africa to Norway, but they
are rare in the Caribbean and Gulf of Mexico. Known to skip or leap over the surface of
the water when in pursuit of prey. Found in schools 15-20 miles offshore, but are also
found close to shore.
Bonito reach sexual maturity at about 16 inches in
length and spawn in the western Atlantic in June and July. Spawning usually takes place
close to shore, in warm coastal waters.
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SKIPJACK
Katsuwonus pelamis
Distinctive Characteristics Skipjack can be
distinguished from other tunas by the presence of stripes on the belly. Usually 4-6
prominent, dark longitudinal stripes from the lower belly and sides toward the tail. The
top of the fish is a dark purplish-blue, and the lower flanks and belly are silvery.
The pectoral and ventral fins are short, and the two
dorsal fins are separated at the base by a small interspace. The teeth are small and
conical. No swimbladder is present. There are 53-63 gill rakers on the first fill arch,
more than any other tuna.
Size
Maximum: 40 inches
Common: 16 to 28 inches
Current IGFA all tackle record 41 pounds 14 ounces
Distribution and Behavior
An oceanic species, found worldwide in tropical and
subtropical waters. Skipjack are common throughout the tropical Atlantic, and can be found
as far north as Massachusetts in summer, and as far south as Brazil. Often schools with
blackfin in the western Atlantic, with school size reaching 50,000 individuals.
Skipjack tuna reach sexual maturity at about 18 to
20 inches in length. Spawning occurs in spurts throughout the year in tropical waters, and
from spring to early fall in subtropical waters with the spawning season becoming shorter
with increased distance from the equator.
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BLACKFIN TUNA
Thunnus alanticus
Distinctive Characteristics Finlets are uniformly
dusky with only a trace of yellow, not bright lemon yellow like other tunas, and may have
white edges. The 1st dorsal fin is dusky; 2nd dorsal and anal fins also dusky with a
silvery luster. The back of the fish is bluish-black, with the sides silvery-grey, and the
belly milky white. Some have light vertical stripes on sides which alternate with light
spots on lower flanks.
Gill rakers are fewer in number than in other
species of Thunnus, with 19-25 on the first gill arch. A smzll swimbladder is present. The
ventral surface of the liver is without striations, and the right lobe is longer than the
left and center lobes.
Size
Maximum: 40 inches
Common: 28 inches
Current IGFA all tackle record 42 pounds 8 ounces
Distribution and Behavior
Blackfin are found in the tropical and warm
temperate waters of the western Atlantic. The range of this species extends from Brazil to
Cape Cod, including the Caribbean and the Gulf of Mexico. Blackfin often feed near the
surface, and they frequently form large mixed schools with skipjack.
The blackfin's spawning grounds are believed to be
well offshore. Off Florida the spawning season extends from April to November with a peak
in May, while in the Gulf of Mexico it lasts from June to September.
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LITTLE TUNNY
(False Albacore)
Euthynnus alletteratus
Distinctive Characteristics The little tunny is
distinguished by a scattering of dark spots, usually 4-5 resembling fingerprints between
the pectoral and ventral fins. This species also has wavy markings found on the back above
the lateral line, located within a well marked border that never extends further forward
than the middle of the first dorsal fin.
The pectoral and ventral fins are short and broad,
and the two dorsal fins are separated at the base by a small interspace. The teeth are
small and conical. No swimbladder is present. There are 37-43 gill rakers on the first
gill arch.
Size
Maximum: 40 inches
Common: 25 inches
Current IGFA all tackle record 35 pounds 2 ounces
Distribution and Behavior
Little tunny are common in the tropical and warm
temperate waters of the Atlantic from New England to Brazil in the west, and from Great
Britain to South Africa in the east. They are not as migratory as other tuna species, and
can be found regularly in inshore waters, as well as offshore. Usually found in large
schools.
Little tunny reach sexual maturity at approximately
15 inches in length. Spawning occurs from about April to November in both the western and
eastern Atlantic.
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INFORMATION AND CONTACTS
The information in this guide was compiled by the
Highly Migratory Species Management Division (HMS) of the National Marine Fisheries
Service. Fishers are responsible for complying with current official regulations and since
fishery rules are subject to change, fishers must familiarize themselves with the latest
regulations. In order to help keep the public informed, HMS maintains an information line
for news and catch reports concerning Atlantic tunas. The HMS information line, which is
updated daily, announces closure notices, scooping and public hearing locations and times,
inseason quota adjustments, and updatres of landings of Atlantic Bluefin tuna. Callers may
reach the 24 hour information line by dialing (508)
281-9305, (301) 713-1279, or toll free at (888)
USA-TUNA.
For further information concerning the Atlantic
tuna fisheries or the Cooperative Gamefish Tagging Program, or for complete copies of
current regulations, contact:
Rebecca Lent, Division Chief
Chris Rogers, Fisheries Management Specialist
Highly Migratory Species Management Division Office of Sustainable Fisheries
Silver Springs, MD 20910 Mark Murray-Brown,
Fisheries Mgmt. Specialist
(301)
713-2347
Highly Migratory Species Management Division Office
of Sustainable Fisheries
Gloucester,MA 01930
(508)
281-9208
Cooperative Gamefish Tagging Program
(800) 437-3936
24 Hour HMS Information Line:
(508) 281-9305
(301) 713-1279
(888) USA-TUNA
REFERENCES
Collette,B.B and C.E. Nauen, 1983. Scombrids of the
World. Food and Agriculture Organization of the United Nations, Rome, Italy.
Gibbs, R.H. and B.B. Collette, 1996. Comparative
Anatomy and Systematics of the Tunas, Genus Thunnus. Fishery Bulletin 66(1)
International Game Fish Association, 1995. 1995
World Record Game fihes. International Game Fish Association, Pompano Beach, Florida
Smith, C.F. and E. Hasbrouck, 1998. a guide to
Identifying Tuna in New York Area Waters. Cornell Cooperative Extension of Suffolk County,
Marine Program, Riverhead, New York |
