Marine Mammals lectures 11-14

Question 1

We use the “Linnean System” to classify marine birds and mammals using Taxonomic Classification. In which each unit at any particular level is called a “Taxon”.

What are the taxon’s in the hierarchal classification of how we classify animals?

remember: Donkey Kong Put Cups Of Flour Getting Super Sweet

Answer 1

Domain
Kingdom
Phyla
Class
Order
Family
Genus
Species
Subspecies

Question 2

Before we began sorting species into a Linnean System, we sorted them based on morphological similarity. No we sort them by evolutionary history, requiring expansion into species and subspecies.

They are placed using ____ Classification. Using _____ tree’s to represent the hypothesis of how animals are related to each other

Answer 2

They are placed using phylogenetic classification. Using phylogenetic tree’s to represent how animals are related to each other.

Question 3

Phylogenetics

Answer 3

Study of evolutionary development and classification of species or groups of organisms.

Question 4

The marine mammals that RETURNED TO WATER are divided into three orders:

Call Susan Campbelle

Answer 4

Carnivora
Sirena
Cetacea

Question 5

Order Carnivora marine mammals include:

They all eat fish

Answer 5

Polar bears (ursidae)
Walruses
Fur Seals
Sea Lions
Otters

Question 6

Order Sirena marine mammals include:

look like mermaids

Answer 6

Manatee’s
Dugongs

They are distributed int he tropics and completely aquatic, eat mainly the plant life at the bottom in shallow water. They swim slow and have thick/heavy bones. Their closest living relative are elephants who they diverged from 60 mya.

Question 7

Order Cetacea marine mammals include:

Answer 7

Whales
Dolphins
Porpoises
-lots of variation in body size.
They have a fusiform body shape with no pelvic appendages, paddle like pectoral flippers and have their nostril on it’s dorsal (its a blow hole). Diverged 50-60 mya
Ambulocetus fossils found in ancient estuary sediments, we know from oxygen isotopes in bones it drank salt water. Whales after ambulocetus have higher levels of salt water oxygen isotopes.

Question 8

Order Carnivora

FAMILY: Ursidae

Answer 8

the family ursidae in carnivora are the polar bears. They diverged from regular bears 150 thousand years ago. We are able to tell this by studying fossilized jaw bones of bears.

They only live in the arctic, they are strong swimmers but spend most of their time on land. feed on mainly seals.

Question 9

Order Carnivora

FAMILY: Mustelidae

Answer 9

the family musteldae of the order carnivora include: Mink, Badgers, wolverines, river/sea otters, and weasels. Which diverged from each other 23 million years ago. They reside from Alaska to California coasts, dive deep for clams, urchins and crabs at the bottom. Have folded belly fat to use as pouch for food/tools.

Question 10

Carnivora are the ancestors of modern pinnipeds that evolved_____ years ago

Answer 10

21-24 million years ago.

Question 11

Pinnipedea is a SUB ORDER of Carnivora

it includes:

Answer 11

Include walruses and true seals

Pinnipedea means “feather footed” and they are all amphibious. They have pelvic and pectoral flippers for locomotion in water. They bring their flippers under them by rotating their pelvis and support themselves on their pectoral flippers on land. They also have delayed implantation of embryo for mating to coordinate breeding. Enhanced diving compared to other carnivores

Question 12

In the SUB ORDER PINNIPEDEA, there is the FAMILY ODOBENIDEA

Answer 12

The family Odobenidea includes WALRUSES. Sea Lions and Fur Seals.

They reside in the arctic only, females have larger tusks, forage for clams and other invertebrate on the bottom, adults also have very wrinkled and thick skin.

Sea Lions and Fur seals live in the tropics, are external pinna (eared seals) and diet mainly on fish, they engage in polygynous (man with many females) breeding system where males defend females to woo them. There IS sexual dimorphism

Question 13

In the SUB ORDER PINNIPEDEA, there is the FAMILY PHOCIDAE

Answer 13

Phocidae include true seals, they live in the tropics and poles. As they are TRUE SEALS they have NO EARS. They eat mainly fish, have superior diving ability and no dimorphism (except in elephant seals).

Question 14

Mysticeti is a SUB ORDER of Cetacea that encompasses:

Answer 14

Mysticeti includes Baleen whales. Which have plates of keratin hanging from the upper jaw, the jaw is asymetrical, eat fish or invertebrate such as krill. They have two blow holes, large organisms and have reverse sexual dimorphism with females larger than the males.

Question 15

Odontoceti is the SUB ORDER of Cetacea that encompases:

Answer 15

odontocenti is the sub order of cetacea that encompases toothed whales, dolphins and porpoises.

They have conical teeth and a diet of fish and other marine mammals. Sperm whales have a small lower jaw and a boxed shaped head, Narwhals have a long tooth sticking out of its head.

Question 16

Common selective pressures among marine mammals:
1)
2)
3)
4)

Answer 16

1) efficient locomotion in water
2) osmoregulation in a slat water environment
3) Thermoregulation as endotherms, homeostasis
4) Breathing air

Question 17

Convergent evolution

Answer 17

common selective pressures in distantly related taxa often result in similar adaptations. One example in marine mammals is a fusiform body shape. Penguins have two layers of feathers and blubber for insulation, like most marine mammals.

Question 18

Thermoregulation-keeping warm

Answer 18

• thermal conductivity of water-loss of heat is 25x more that in water than of air so must produce heat at same rate as lost.-metabolic rate may be higher than other mammals.
• They can adjust their surface area. Like land mammals.
• Fur provides insulation by trapping in air against the skin, this is best for amphibious marine mammals like polar bears, sea otters and fur seals-but a bad thermal conductor-primary insulator. Fur acts as a thermal blanket scattering infrared radiation but the sun doesn’t perpetrate it. Only thick dense fur can keep skin dry when wet, like of sea otters.
• Most marine mammals use blubber

Question 19

Thermoregulation-keeping cool

Answer 19

Hawaiian monk seals cool down by hauling onto the beach to escape warm waters.
Some bypass their insulation layer by blood vessels in flippers, fins, flukes as heat sinks. Flow can be constricted using sphincter around vessel. Otters use flippers, Cetaceans use dorsal fins, flukes or flippers.

Question 20

How do they move

Answer 20

On land pinnipeds like walruses and seals waddle on land-use pelvic flippers for propulsion and pectorals for steering.
Sea lions and fur seals use Pelvic flippers to stear and pelvic to thrust.
have fusiform body shape and thrust with propulsion in water to overcome drag.
Sirenians paddle with pectoral flippers or rounded tail fluke.
Polar bears dog paddle

Question 21

How do they keep water out of lungs?

Answer 21

Blow from whale spout or spray form pinnipeds upon surfacing.
Default position of nares (nostrils) is closed.
Elephant seals sleep with nostrils closed.
Some cetaceans have nasal plugs, blow hole closed.

Question 22

Eating underwater

Answer 22

Nares closed prevent water from entering lungs. Epiglottis folds over trachea to prevent water watering while swallowing.
Specialized larynx in odonocotes allows them to vocalize and swallow water.

Question 23

Diving

Answer 23

Most marine mammals go through extended periods of breath holding. Keep air in lungs, hemoglobin in RBC’s. Myoglobin in muscle cells.
Alveolar collapse-collapse lungs.
short dives.