Order - Perciformes
Family - Scombridae
Genus - Thunnus
Species - atlanticus
Lesson first described the blackfin tuna as Thunnus atlanticus in 1831. The genus name Thunnus is derived
from the Greek "thynnos" meaning tunna. Synonyms referring to this fish include Thynnus balteatus Cuvier 1832,
Thunnus balteatus South 1845, Thunnus coretta South 1845, Orcynus balteatus Cuvier 1832, Parathunnus
rosengarteni Fowler 1934, Parathunnus ambiguus Mowbray 1935, and Parathunnus atlanticus Beebe and Hollister
The family Scombridae are primarily swift predators of the open seas and are among the most important of commercial and
Blackfin tuna (English), albacore (English), deep-bodied tunny (English), albacora (Portuguese), albacorinha
(Portuguese), atlanticheskyj tunets (Russian), atum-barbatana-negra (Portuguese), atum-preto (Portuguese), atun
(Spanish), atun aleta negra (Spanish), atun Atlantico (Spanish), atun des aleta negras (Spanish), bonite (French),
bonite noire (French), chernij tunets Russian), falsa albacora (Spanish), giromon (French), mini maguro (Japanese),
monte maguro (Japanese), petit thon (French), taiseiyomaguro (Japanese), thon noir (French), thon nuit (French), and
ton noir (Creole).
The blackfin tuna is one of the few tuna with a limited range. It occurs only in the western Atlantic Ocean from
Massachusetts (US) south to Rio de Janeiro (Brazil), including the Gulf of Mexico and Caribbean Sea. It is abundant in
tropical regions, however in the northern Gulf of Mexico the yellowfin tuna (Thunnus albacares) is more common
than the blackfin tuna. The blackfin tuna is a highly migratory species, moving into more temperate waters during the
World distribution map for the blackfin tuna
Blackfin tuna sometimes form large schools with the skipjack tuna pictured above
Occurring in oceanic waters in close proximity to the coastline, the blackfin tuna prefers clean water and warm
temperatures, usually seaward from the continental shelf. It is a strongly schooling, migratory fish, often forming
large mixed schools with skipjack tuna (Katsuwonus pelamis). During the summer months, the blackfin tuna
migrates to temperate waters remaining above 70°F (21°C). It is most abundant off the Florida coast during autumn,
winter, and spring.
Importance to Humans
Illustration of the blackfin tuna
(FAO Species Catalogue: Vol. 2 Scombrids of the World)
- · Distinctive Features
As one of the smaller tuna species, the blackfin tuna has a robust, fusiform body, with small, compact scales completely
covering the body. The mouth is oblique and the maxillary jaw terminates prior to the vertical from the center of the large
eye. The corselet, a band of larger scales forming a circle around the body behind the head, is small and inconspicuous.
Pectoral fins are moderately long, reaching below the origin of the second dorsal fin. There are separate finlets located
behind the anal and dorsal fins. The lunate caudal fin has short keels at its base. Blackfin tuna swim primarily through
movements of the caudal fin and body. The second spine on the dorsal fin is the highest with the first spine almost as
high. The anal fin is similar in appearance to the soft, low dorsal fin. Anteriorly, the lateral line has a distinctive
dip, descending posteriorly to the pectoral fin origin, then ascending to a point below the 3rd or 4th dorsal spine,
then continuing straight to the caudal keel.
The number of gill rakers, small, flesh-colored knobby structures located on the inside of each gill, can be used
to distinguish young blackfin tuna from other tuna species. The blackfin tuna has only about 20-23 on the first
arch, fewest of all the Atlantic tuna species. Most other species have approximately 30 or more gill rakers. The
ventral surface of the liver, visible as a pink-red organ in the chest region when opening the body cavity,
can also be used to positively identify the blackfin tuna. Other tuna species have striations on the ventral
surface of the liver while on the blackfin tuna, this surface is smooth. A small swim bladder is present.
Distinguishing characteristics of blackfin tuna and
(NMFS ABT Tech Sheet No. 4)
- · Coloration
The blackfin tuna has a bluish-black back with gray to silver sides and a white belly. A broad, brown stripe
is located along the upper portion of the eye. There is a prominent yellow to golden-colored lateral band present
on the sides, usually fading upon death. Small iridescent areas located on the sides of the abdomen are silvery.
This area is sometimes marked with vertical rows of pale dots along with slightly elongate spots between these rows.
The dorsal finlets are dusky with bronzy reflections and white edges while the ventral finlets are usually gray. The
absense of yellow on these finlets distiguishes the blackfin tuna from all other tunas. However, the dorsal finlets
sometimes fade to yellow upon death.
- ·Size, Age, and Growth
Blackfin tuna reach a maximum size of 39 inches (100 cm) in length and 46 pounds (21 kg) in weight.
They are most frequently taken at an average size of approximately 19.75 inches (50 cm), corresponding to a
weight of about 7 pounds (3.2 kg). Maturity is reached at lengths of 16-20 inches (40-50 cm). The blackfin
tuna may live past 5 years of age. Growth rates have been reported at .4-.6 inches (1-1.5 cm) per month. The
all-tackle world record for the blackfin tuna is 45 pounds 8 ounces (20.6 kg) caught off the coast of Florida.
Blackfin tuna feed on a variety of prey including
squid as shown here
- · Food Habits
Various fish, squid, amphipods, shrimp, crabs, and stomatopods constitute the diet of the blackfin tuna. It often
feeds in surface waters where they form large mixed schools with skipjack tuna (Euthynnus pelamis). It
directly competes with the skipjack tuna for prey, and is occasionally even preyed upon by it. Blackfin tuna feed
by straining prey from the water as well as chasing and capturing prey which is then engulfed.
- · Reproduction
Spawning occurs in April through November off the Florida coast, and June to September in the Gulf of Mexico,
well offshore in the blue oceanic waters of the Florida current as well as in the coastal waters of northern Brazil.
The fish release sperm and eggs into the water column where fertizilation occurs. The buoyant eggs produce pelagic
larvae, little else is known about the eggs. These larvae are found in the open ocean at depths ranging from the surface
down to 164 feet (50m). The vertebral column is developed by a length of 11.0 mm, while all fin rays develop by lengths
of approximately 20mm.
Larval blackfin tuna: A.5.1 mm NL, B. 6.0 SL, C. 8.5mm SL
(NOAA Technical Memorandum NMFS-SEFC-240))
Juvenile blackfin tuna
© George Burgess
At a length of 28mm, the young blackfin tuna has some pigmentation. The first dorsal fin is pigmented, but not entirely
black. Dark pigmentation also exists from the top of the head through to the brain region. The body is heavily
pigmented dorsally, with a concentration of pigment concentrated along the lateral line as well as areas along
the dorsal and lateral areas, resulting in a faint pattern of six vertical bars.
Blue marlin often feed on blackfin tuna
- · Predators
Dolphinfish (Coryphaena hippurus), blue marlin (Makaira nigricans), skipjack tuna (Euthynnus pelamis) and
various sea birds all prey on the blackfin tuna during its life cycle. In fact, it is one of the most common items in the
diet of the blue marlin. Cannibalism also occurs in this tuna.
- · Parasites
The blackfin tuna is a host to at least 9 species of parasites, with none being host-specific. Parasites include
digenea (flukes), monogenea (gillworms), cestoda (tapeworms), nematoda (roundworms), copepods, and the cookiecutter
shark (Isistius brasiliensis). Parasitic copepods associated with this tuna include Caligus coryphaena,
C. productus, Euryphorus brachypterus, and Pseudocycnus appendiculatus.
This tuna is important to the commerical and recreational fishing industry. There is a major fishery off the coast of
Cuba and throughout the Caribbean where it is common. Around south Florida and the Bahamas, the sport fishery is
also important due to the proximity to deep water. This tuna is highly regarded for its fighting ability. The flesh
is of excellent food quality and is marketed fresh, dried and salted, canned, and frozen. Off Cuba it is caught with
poles and live bait, while elsewhere it is caught by trolling and drift fishing.
This species of tuna is currently not listed with the World Conservation Union (IUCN) Redlist and is considered to be in no immediate threat. The IUCN is a global union of states, governmental agencies, and non-governmental
organizations in a partnership that assesses the conservation status of species.