Minke Whale

Common Name: Minke Whale

Class: Mammalia

Order: Cetacea

Suborder: Mysticeti

Family: Balaenopteridae

Genus: Balaenoptera

Species: Balaenoptera acutorostrata

 

Taxonomy/Description

Minke whales belong to the Mammalian Order Cetacea, in the suborder Mysticeti.  All baleen whales belong to the suborder Mysticeti, which is Latin for "mustached whales".  The minke whale belongs to the rorqual family, Balaenopteridae.  The word "rorqual" means "tube whale or furrowed whale", referring to the pleats on the lower jaws of rorquals.  All rorquals have baleen, a dorsal fin and throat grooves.  Other members of this family include the humpback whale, fin whale, and blue whale.  The blue whale's scientific name is Balaenoptera acutorostrata.  Its generic name, Balaenoptera, means "winged whale", which refers to the minke whale's dorsal fin.  The minke whale's specific name, acutorostrata, means "pointed nose".  The minke whale is the smallest rorqual species.  Minke whales may are about ft in length and tons in weight.  Female minke whales are usually larger than males of the same age.  Some researchers recognize two species of minke whale, a northern minke whale or Balaenoptera acutorostrata, and an Antarctic minke whale or Balaenoptera bonarensis. A population of minkes inhabiting the Great Barrier Reef, off the coast of Northern Australia, have been recognized as dwarf minke whales.  Their status as a separate species is debatable, but such a distinct population is certainly worthy of notation.

The dorsal fin of the minke whale is very similar to that of the pygmy right whale's fin.  This has resulted in the misidentification of pygmy right whales as minke whales.   The identifying characteristic of the mink whale are the thick white bands on each of the whales pectoral fins.  Minke whales grow to about 20ft in length and five tons in weight.  Female minke right whales are slightly larger than males of the same age.

Habitat/Diet

Minke whales are found in coastal waters of all oceans. Whales of the Northern Hemisphere feed on a variety of food sources, including plankton, squid, cod, sardines, herring, and other small fish.  The minkes of the Southern Hemisphere feed only on plankton.  As the whale opens its large mouth to gulp up the prey, the pleats of its lower jaw expand to contain the large volume of water.  The whale then presses its tongue up against the roof of its mouth, straining the water through its 300 baleen plates.  These 11 inch plates are composed of keratin, the same substance of fingernails and hair.  The ends of baleen are brush-like, preventing the prey from escaping.  The copepods remain inside, and are consequently swallowed.

Behavior/Reproduction

 Minke whales are fast swimmers, attaining speeds of 15-21 miles per hour.  Whales of the Northern Hemisphere migrate from cooler northern waters to warmer equatorial waters in the autumn, returning to the cool northern waters in the spring.  The whales of the Southern Hemisphere migrate from cooler southern waters to warmer equatorial waters in the spring, returning to the cool southern waters in the autumn.  Groups of 6-7 are not uncommon.  Mating and birthing occurs while the whales are in warm waters.  The whales do not feed during the breeding season.  Gestation lasts ten months.  Newborn calves are 8 feet in length.  Calves nurse for 6 months and reach sexual maturity as early as five years for males and six years for females.  Minke whales are estimated to live about 40 years.

Conservation

As larger rorqual populations decreased from the whaling industry, minke whale populations increased.  Minke whales of the Southern Hemisphere number about 700,000, those of the western North Pacific about 25,000, and those of the North Atlantic about 100,000.  The human fishing industry also competes with minkes for fish species and krill.

 

Content provided by Canisius College students under the direction of Michael Noonan, PhD.