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SCIENTIFIC NAME: Balaenoptera musculus
COMMON NAME: Blue Whale; also known as sulphurbottom, for the yellow-brown appearance of diatoms flourishing on the skin after the whales have been in polar waters for long periods of time.
DISCOVERED: Linnaeus, 1758
GEOGRAPHICAL DISTRIBUTION:
 Widely distributed in every ocean of the world
Migrate long distances along well-known routes between rather restricted high-latitude summering grounds and low-latitude wintering grounds
EXTERNAL ANATOMY:
Largest living animals
Avg. adult length = 25m (males) 26.2 m (females)
Avg. adult body weight = 100-120 tons
Blue-gray body color
Mottled appearance
Broad, flattened, u-shaped head
Dorsal fin a small nubbin located in the last fourth of the back
Slender, pointed flipper are about 14% of body size in length
Large blowhole splash guard
Uniformly black baleen plates with coarse bristles
Color often masked by appearance of microscopic algae, called diatoms, which attach the whale¹s body and produced yellowish color-only in cold waters, polar
29 1\2 ft. (9 m) high blow
NATURAL HISTORY
HABITAT:
Pelagic
Occur primarily along the edge of the continental shelves
Also venture into deep oceanic zones and shallow inshore regions
FOOD & FEEDING:
Shallow feeders
Preferred food appears to be krill
Adult blue whale may up to 8 tons of krill in a day
Feeding takes place during the evening and early morning
LIFE CYCLE:
Calving occurs every 2-3 yrs.
Gestation lasts 12 months
Weaning period is 8 months
BEHAVIOR:
Usually found as a solitary animals or in pairs
In feeding grounds, there may be a greater concentration of whales
Do not dive deeply-maximum abound 200 m
Segregation in migration- pregnant females first to migrate
Vocalizations include low-frequency moans, pulses, buzzes, rasps, of ultrasonic clicks
When relaxed, blows every 10-20 seconds for up to 6 min. and dives for 5-20 mins.
When chased, can accelerate to over 19 mph (30 km\h)
Adults rarely breach
WORLD POPULATION:
Estimate 10,000 - 15,000 worldwide
HUMAN INFLUENCES:
Depleted by hunting
No real recent whaling
Approximately 10,000 whales worldwide
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