BIOL 3626: Class 1

Mammalian Characteristics

• nurse young

• born alive

• bodies covered with hair

• seven cervical vertebrae and two occipital condyles

• breathe air (lungs)

• warm blooded (homeotherms)

• unique jaw articulation

• four chambered heart

• diverse dentiton

Marine Mammal

• catch all category for all mammals that spend a significant portion of their lives by or in the sea

• must get most of their food from the aquatic environment

• no hard or fast rule about which species belong in this group

Cetaceans Taxonomy/Division

• order Artiodactyla

• class Cetacea

  • Mysticeti

  • Odontoceti

Mysticeti vs. Odontoceti

• Mysticeti (baleen whales)

  • 2 blow holes

  • 16 species

• Odontoceti (toothed whales)

  • 1 blow hole

  • 73 species

Balaenidae

• right whale family

  • Mysticeti

• no dorsal fin

• bowed mouths

• portly

• broad pectoral fins and tails

• all cervical vertebrae fused

• baleen up to 9ft long

• the “whaling” whales

Balaenopteridae

• the great whale family

  • Mysticete

• ventral grooves/pleats as a method of eating

  • lack the large baleen of Balaenidae

• includes:

  • humpback

  • fin whales

  • blue whales

  • minke whale

  • sei whale

Delphinidae

• oceanic dolphins

  • odontoceti

• distinct beaks

• several fused vertebrae

• 20+ pairs of teeth

• includes:

  • atlantic white sided dolphins

  • white beaked dolphins

  • common dolphin

  • common bottlenose dolphin

  • long finned pilot whale

Phocoenidae

• Poirposes

  • Odontocetes

• includes

  • harbour porpoise

Physeteridae

• sperm whale family

  • Odontocete

• teeth only in lower jaw

• proportional body

• includes:

  • sperm whale

Kogiidae

• dwarf and pygmy sperm whale family

  • Odontocete

• blowhole also on left side of teh head

• false gill

• includes:

  • dwarf sperm whale

  • pygmy sperm whale

Ziphiidae

• beaked sperm whale family

  • Odontocetes

• includes:

  • northern bottlenose whale

  • beaked whales

Monodontidae

• narwhal and beluga family

  • Odontocetes

• includes:

  • narwhal

  • beluga

Non-local Cetaceans

• family Iniidae

  • river dolphin

• family Lipotidae

  • Baiji

• family Platanistidae

  • south asian river dolphin

• family Pontoporiidae

  • la plata river dolphin

Dolphin vs. Porpoise

• dolphin

  • conical teeth

  • pronounced snout

  • asymmetrical skull

  • prominent dorsal fin

  • larger (most)

  • leaner

  • 36 species

• porpoise

  • spade shaped teeth

  • symmetrical skull

  • triangular dorsal fin

  • smaller (most)

  • portly

  • 6 species

Pinniped Families

• includes families:

  • Otariidae (eared seals)

  • Odobenidae (walrus)

  • Phocidae (true seals)

Phocids

• 18 species

• ice breeding

  • largely polar

• poor locomotion on land

• larger than Otariids

  • more blubber

• includes:

  • harbour seal

  • grey seal

  • harp seal

  • hooded seal

Otariids

• 15 species

• land breeding

  • good locomotion on land

• more temperate waters

• smaller than phocids

  • less blubber

• includesL

  • sea lions

  • fur seals

Odobenidae

• the walrus family

  • Pinnipeds

Mustelidae

• river otter

• common around river mouths and harbours

  • also found many places along the coastline

Ursidae

• polar bear

  • close relative of the grizzly

• depends on sea ice to hunt for seals and belugas/narwhals

• scavenges whales

• delayed implantation

Sea Otters

• keystone species

• historical range varies greatly from the current range

Sirenians

• includes families:

  • Dugongidae

  • Trichechidae

Dugongidae

• Dugong family

  • Sirenia

Trichechidae

• Manatee family

  • Sirenian

Grey Seal

• Halichoerus grypus

  • “hooked-nose sea pig”

  • Phocids

• sexually dimorphic

  • males much larger than females

• long lived

  • 25-40 years

GREY SEAL GUEST LECTURE

PILOT WHALE LECTURE