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New England Seabirds

 Wilson's Storm-petrel  Dave Jones

Other Sea Life

Cetaceans Index

Page 1
Taxonomy of whales and dolphins

Page 2
Behaviors of whales and dolphins

Comments to webmaster

Cetaceans Index

Baleen Whales
Humpback Whale
Minke Whale
Fin Whale
Sei Whale
Blue Whale
Right Whale

Toothed Whales
Sperm Whale
Pilot Whale
Beaked Whales

Dolphins & Porpoises
White-sided Dolphin
Common Dolphin
Common Bottlenose Dolphin
Risso's Dolphin
Spotted Dolphin
Striped Dolphin
Harbor Porpoise

Humpback Whale head Leonard Medlock

You may get very close to a whale as in this photograph by Leonard Medlock of the head and jaw of a Humpback Whale.  Sometimes too close for a long lens.

Taxonomy of Whales and Dolphins Page 1

Order Cetacean
Whales, dolphins, and porpoises belong to the mammalian order Cetacean. Cetaceans are mammals that spend their entire lives in water. They do not come onto land to breed or mate. A few have adapted to fresh water, but most live in the marine environment. Cetaceans are carnivores. They may eat fish or crustaceans or even larger animals.

Cetaceans evolved from land animals that returned permanently to living in water. The limbs of Cetaceans have become flippers totally unsuited to walking on land. The nose has migrated from the face to the top of the head so that they can breath in and out without lifting their mouth from the water, an adaptation that any serious swimmer can tell you is valuable. The mouth and digestive track are not connected with the lungs and the air passages unlike our system which allows us to choke on a piece of food.

The Cetaceans can be divided into two suborders: the Baleen Whales, and the Toothed Whales (includes dolphins and porpoise).

Baleen Whales Suborder Mysticeti

Filter Feeders

The Baleen Whales lack teeth and instead have baleen plates which are fingernail like horny plates which hang from the upper jaw. Baleen Whales feed by swimming through the water with their mouths open capturing fish and water. Then they close their mouth and push the water thru the baleen plates which filters the food particle out of the water. Thus they are filter feeders. 

Humpback Whale mouth closing to filter food.  Peter Trull

This photograph by Peter Trull of the open mouth of a Humpback Whale shows the baleen plates that hang from the upper jaw and the expanded throat groves which shows the whale has been swimming through the water with its mouth open capturing both food prey and water.

It is now closing its mouth pressing the water out through the baleen plates and capturing the prey items in the mouth. The birds know that some prey will escape and are there to grab their share.

It is so interesting that some of the largest animals on earth feed on small prey like plankton and small fish.  In order to survive the large filter feeding whales need schools of prey.  They certainly cannot catch sand eels one fish at a time.  Fishing using large drag nets scatters the schools of fish and deprives whales of their livelihood forcing them to move on.

Humpback Whale mouth closed Lauren Kraus

Left: Lauren Kraus photo of Humpback Whale with mouth almost fully closed and throat pleats expanded. Whale is now squeezing the water through the baleen plates catching the food and expelling the water.

Right: Humpback Whale breech showing the throat pleats that expand when filled with water and food. Photo by Emmalee Tarry



Humpback Whale breech EBTarry

Two Blow Holes on top of head
The Baleen Whales have double nostrils or blow holes on top of their heads. Toothed Whales and dolphins have only one.

The blow hole of a whale corresponds to the nose of land mammals.
Whales and dolphins have the blow hole on top of the head, the most convenient place for an animal that lives in the water. This is not true of seals, or sea lions who must lift their entire head to breath.

This excellent photo by Jim Besada shows the two blow holes of a Humpback Whale.  Notice also the long white flipper which you can see under the water on the whaleès left side.  The  Humpback Whale is the only  whale with long flippers.

Humpback Whale 2 blow holes  JBeseda

Four Families of Mysticeti or Baleen Whales
There are four families of Mysticeti, two of which have species that can be seen in the  North Atlantic. Species usually or rarely seen in New England are bold.


Species and  Description


Right Whale , Bowhead Whale (far north only)
Balaenidae have no dorsal fin,  no throat groves, the blow is  "V" shaped.

Balenopteridae or Roquals

Humpback, Fin, Minke, Blue, Bryde's ( Buda's). Sei (Sigh) - All have a dorsal fin and throat grooves. Blow tall and columnar or bushy, but usually appears undivided.


Gray Whales now extirpated in the North  Atlantic,  Common off the coast of California.


Pygmy Right Whales are found only in the southern hemisphere.

Toothed Whales Suborder  Odontoceti

The Suborder Odontoceti includes:   Toothed whales, dolphins, and porpoises.   All have teeth of some variety although not necessarily used for chewing and not visible in the water. One blow hole rather than two. Kinze (1994)

Baby Atlantic White-sided Dolphin photographed by Leonard Medlock and showing that dolphins have a single blow hole on top of their heads.

Sperm Whale single blow hole Dave Jones

 Dave Jones photograph of the single blow hole of a Sperm Whale located on the left side of the front of the whale. Really nice photo Dave.

      Eight families of Toothed Whales,  five of which occur in the North Atlantic.
                   Family                      Species                                                                           
There are at least 33 species world wide. In the North Atlantic
look for:  White-sided Dolphin, Common Dolphin, Bottlenose Dolphin,

Subfamily Orcinae  Blackfish and Killer Whales Small to medium sized
species having a rounded head without a well defined beak.
Pilot WhalesRisso's Dolphin (true dolphin??) , Orca Whale
Harbor Porpoise
Belunga Whale (Occasionally seen primarily further north), Narwal (further north)
Beaked Whales
Well defined beak, dorsal fin behind small fins.  Cuvier's Beaked Whale (seen on offshore trips only),
Look for Sowerby's Beaked Whale, Blainville's Bealed Whale, True's Beaked Whale, and Northern Bottlenose Whale
Sperm Whale
Seen on offshore trips. Once on the Nantucket Shoals and recently a few in the Gulf of Maine.

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Folkens, Peter (2002) Guide to Marine Mammals of the World Alfred A. Knopf New York

Kinze, Carl Charistian (2001) Marine Mammals of the North Atlantic Princeton University Press Princeton NJ