Atlantic white sided dolphin (Lagenorhynchus acutus) is found in the northern Atlantic Ocean from New England east to Greenland, and further east to Norway and the British Isles. This has been recorded as far south as Spain, and in North America along the east coast. This dolphin can reach about 10 feet in length. It is generally dark colored. The dorsal fin is large, elongated, and falcate, and the flippers are rear swept and pointed. There is a pale area just above the base of the flipper.

The dolphin genus Lagenorhynchus can reach about 10 feet in length. The dusky dolphin is much smaller. The color patterns are usually sharply defined, and the dorsal fin and flippers are large. The beak is formed by an extension of the head and lower jaw, and is not clearly discernable. These dolphins are usually found in the Atlantic and Pacific Oceans, but are also known in the southern Indian Ocean.

Dolphin family (Delphinapteridae equal Delphinidae) contains mostly smaller animals that are usually less than fifteen feet in length. The tail is notched, and the dorsal fin is usually quite large. The members of this family have pegged teeth.

This mega family can be divided a number of ways. The three main groups are: river dolphins (including perhaps four families); porpoises (Phocoenidae); and marine dolphins (Delphinidae). There are about forty-five species of which several of the better known are listed below.

River Dolphins (Iniidae, Lipotidae, Platanistidae, and Pontoporiidae) contains five species:

SPECIES - - - - - COMMON NAME - - - - - - LOCATION
Inia geoffrensis - Amazon Dolphin - Amazon River
Lipotes vexillifer - China River - Tung Ting Lake
Platanista gangetica - Gangetic Dolphin - India
Platanista minor - Indus - Pakistan
Stenodelphis blainvillei - La Plata - Uruguay, Brazil

Porpoises (Phocaenidae) contains six (perhaps seven) species:

SPECIES - - - - - - COMMON NAME - - - - - LOCATION
Neomeris phoceanoides - India Porpoise - India to Japan
Phocaena dioptrica - Spectacled - S. America to Georgia
Phocaena phoecana - Harbor Porpoise - Atlantic Ocean
Phocaena spinipinnis - Burmeister - South America
Phocaena vomerina - Harbor Porpoise - Pacific

Phocaenoides truei - - - - - North Pacific
Phoceanoides dalli - Dalls Porpoise - North Pacific

True Long Snouted Dolphins (Stenidae)
SPECIES - - - - - COMMON NAME - - - LOCATION
Stenella atttenuata - Bridled - Southern Waters
Stenella frontalis* - Cuvier - S. Carolina and south
Stenella plagiodon - Spotted - N. Carolina, Texas, & S
Stenella styx - Longsnout - N. Atlan. and N. Pac.
Stenella coreuleoalba - Striped - Widespread
Stenella longirostris - Spinner - Tropical Oceans

Steno bredanensis - Longbeak - Atlantic and Pacific
Sousa teuszii - Humpbacked - Atlantic
Sousa chinensis - Ind-Pac Humback - Indian Ocean
Sotalia fluviatillis - Tucuxi - Amazon River
Sotalia guianensis - Guiana Dolphin - South America

*Stenella frontalis might be a subspecies of S. attenuata.

Dolphins (Delphinidae) contains thirty-four species of marine dolphins and long snouted dolphins combined:

Cephalorhynchus albiventris - - - - - - South Oceans
Cephalorhynchus commersoni - Piebald - South Oceans
Cephalorhynchus heavisidei - - - - - - - South Oceans
Cephalorhynchus hectori - - - - - - - South Oceans

Delphinus delphis - Common - Atlantic Ocean
Delphinus bairdi? - Common - Pacific Ocean

Feresa attenuata - Pygmy Killer - Japan

Globicephala edwardii(?) - Pilot Whale - South Oceans
Globicephala macrorhyncha - Short Fin - Atlantic and Indian
Globicephala melaena - Pilot Whale - North Atlantic
Globicephala scammoni? - Pilot Whale - Pacific

Orcaella brevirostris - Irawadi - India to Borneo
Orcinus orca - Killer Whale - North Atlantic
Orcinus rectipinna? - Killer Whale - Pacific

Grampus griseus - Risso - Europe and World

Lagenodelphis hosei - - - - - - - - - Borneo
Lagenorhynchus acutus - Atl. White Side - North Atlantic

Lagenorhynchus albirostris - Whitebeak - North Atlantic
Lagenorhynchus australis - - - - - - - - South oceans
Lagenorhynchus cruciger - - - - - - - - South Pacific
Lagenorhynchus electra - - - - - - - - Worldwide
Lagenorhynchus obliquidens - P. White Side - Pacific
Lagenorhynchus obscurus - Dusky - South oceans

Lissodelphis peroni - S. Right - Southern Seas
Lissodelphis borealis - N. Right - N. Pacific Bering S
Pseudorca crassidens False Killer Pacific & Atlantic

Tursipos truncata - A. Bottlenose - Atlantic Ocean
Tursipos gilli? - P. Bottlenose - North Pacific
Tursiops aduncus? - - - - - - - - - Indian Ocean

Note:
Delphinus bairdi might be a subspecies of D. delphis.
Glob. scammoni might be a subspecies of G. melaena.
Orcinus rectippinna might be a subspecies of O. orca.
Tursipus gilli and aduncus might be subspecies of T. truncata.
Feresa attenuata was once thought extinct as it had been found only off Japan.
Lagenodelphis hosei was originally found in Borneo and was also thought to be extinct.


Whales and Dolphins (Order Cetacea) are a group of mammals that are especially modified for swimming. Their rear legs are undeveloped. Their modified front legs and a streamlined body which tapers into a tail facilitate swimming.

There are two main groups in this order. The fish-eating and the plankton-eating groups. The total number of these marine mammals is about eight-two species. The fish-eating groups contain such animals as the Dolphins and Killer Whales. The plankton-eating groups contain the giant whales that filter the plankton from the sea. All members of this order have horizontal tails. (One scientist notes relationships with the hippopotamus.)

Many authors now separate the two groups of whales and dolphins in order to place the meat-eating dolphins nearer the carnivores. However, others argue that both groups share a common land ancestor in the suborder Archaeoceti.

Some representative whale sizes:
Blue Whale (Baleen)- 100 feet
Finback Whale (Baleen)- 80 feet
Bowhead Whale(Baleen)- 60 feet
Sperm Whale (Sperm)- 60 feet
North Atlantic Right Whale(Baleen)- 60 feet
Rorqual (Baleen)- 60 feet
Humback (Baleen)- 50 feet
Pacific Gray Whale (Baleen)- 45 feet
Bairds Whale (Beaked)- 40 feet
Piked Whale (Baleen)- 33 feet
Bottle-nosed Whale (Beaked)- 30 feet
Killer Whale (Dolphin)- 30 feet
Pigmy Right Whale(Baleen)- 20 feet

Mammals (Class Mammalia), together with the birds, are among the youngest of the classes of animals. In species count, mammals number about fifty-one hundred, trailing reptiles (approximately fifty-five hundred), fish (approximately eighteen thousand), and birds (approximately eighty-six hundred).

There are three sub-types of mammals:

monotremes, the most primitive:
Develop in reptilian-like eggs and suckle milk emerging (i.e., spiny anteater, duckbilled platypus)
marsupials
Newborn emerges very underdeveloped and continue to mature in a pouch on its mother's abdomen (i.e., opossums, koala, kangaroo)
placental
Embryo develops within the uterus of the female and is dependent on a placenta for nutrition and waste removal (i.e., humans, lions, monkeys)

About sixty-five million years ago, the Tertiary era produced thirty-five orders of mammals. Of this number, eighteen have survived to represent Earth's most diversified as well as its most highly developed classification of animals.

Extinction of mammals is fast becoming a serious issue. Duff and Lawson present a list of forty-one extinct species that reached extinction prior to 1800. These forty-one species are not acknowledged in the counts of the various families. Duff and Lawson also present a list of forty-six species including three gazelles, one zebra, one seal, one deer, and one wolf that have probably gone extinct since 1800. These forty-six species are included in the family counts. Science is adding about forty to fifty new species a year to the list. Many of these are the result of divisions of prior species; some are recent discoveries.

Mammals owe their survival to adaptive capabilities that include the ability to exploit whatever sources of food are available to them, as well as their ability to adjust to various climes. Food specialization influenced evolution to such a great extent that the teeth structure can and has been used to provide extensive information on the food needs and various lifestyles of extinct species.

Despite the vast diversity among mammals in terms of size, habitats and adaptations, they share without exception many characteristics such as:

a. body hair
b. mammary glands
c. certain skull characteristics
d. four limbs that permit speed
e. parallel not perpendicular limbs
f. compartmentalized internal organs
g. a four-chambered heart and pulmonary circulation

Backboned Animals (Phylum Chordata) are the most advanced group of animals on earth. These animals are characterized by having a spinal cord or backbone. Most members have a clearly defined brain that controls the organism through a spinal cord. Fish, amphibians, reptiles, birds, and mammals are in this phylum.

Currently, some taxonomists believe that the fish should be divided into two groups (sharks and regular fishes) and that there are some other primitive groups in the phylum such as hagfish or lampreys.

Animal Kingdom contains numerous organisms that feed on other animals or plants. Included in the animal kingdom are the lower marine invertebrates such as sponges and corals, the jointed legged animals such as insects and spiders, and the backboned animals such as fish, amphibians, reptiles, birds, and mammals.

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