Lecture 2 Flashcards
Over the past 60 million years, marine mammals have evolved and adapted physiologically and anatomically to do what?
Allowed them to spend all or some part of their lives in water
List and give examples(if any) for special adaptions
6
- locomotion (swimming, buoyancy)
- Skin (type and colour) ie: polar bears
- Sensory (smell/hearing)
- Respiration (dives)
- Cardiovascular (dives)
- Movement (propulsion; flippers, tail, webbed feet)
Describe how body planes are located?
Body is divided into planes with the body of ht e animal/human on feet/hands facing away
Identify the 4 planes
Anterior (front part = head)
Dorsal (back part)
Posterior (back end = butt)
Ventral (abdomens = stomach)
In cetaceans, how are appendages named and what are they?
Fins are forearms (b.c they no longer have hind limbs)
They can either be pectoral finds (equivalent to arms located on the side of the chest) or dorsal fins (presented on the dorsal plane (back) and roughly in the middle) OR caudal fins (located n the posterior plane or area)
What are flippers?
Flippers are appendages or limbs of Pinnipedia; again similar to cetaceans they are named according to where they are situated in the body.
Ie: pectoral flippers = fore limbs; pelvic flippers = hind limbs
List the characteristics of Cetaceans (8)
1) have nostrils (blow holes) on dorsal side of the head
2) large breathing capacity
3) have blubber for thermoregulation and food
4) cardiovascular adapted (thermoregulation and divine)
5) body size is proportional to buoyancy
6) propulsion
7) stability (dorsal fin)
8) echolocation (hunting)
List the characteristics of Pinnipeds (7)
1) more amphibious (less extreme aquatic adaptions than cetaceans)
2) propulsion (hind legs/flippers)
3) dense fur
4) Nostrils
5) Dentition (carnivorous)
6) sensory (vision, touch)
7) more varied diving capabilities
List characteristics for Sirenians (5)
1) share similar body shape with cetaceans
2) paired nostrils (reduces gas exchange)
3) dense bones (buoyancy)
4) flexible lip with bristles
5) dentition (plants)
List characteristics of Polar bears (5)
1) covered in fur (reduce heat loss)
2) skin coloration is black (absorbs heat)
3) Thick layer of FAT (fasting and buoyancy)
4) streamlined head and body (swimming)
5) forepaws (swimming)
List characteristics of sea/marine otters (5)
- Flexible bodies and long tails (allows for both movement on land and water)
- Has higher metabolic rate (eats large amounts of food compared to body weight)
- Densest fur: 164, 662 hairs/cm2 (thermoregulation)
- Has FAT
- Vision (hitting, sighting enemies above and below water)
List characteristics of Humpback whale and what suborder are they in?
suborder: Mysteceti
- found in all oceans
- extremely long pectoral fins (1/3rd of body length); small dorsal fin
- caudal fin with flukes (serrated or jagged) with distinctive underside patterns (birthmark)
- Colour: black on dorsal surface; white/black/mottled on ventral surface)
- Ventral pleats (folds) –> for baleen expansions
- bubble netting
- blow hole: 2 centre; not separate (parallel system)
List characteristics of Killer whales and which suborder do they belong to?
Suborder: Odontoceti
- blow hole: single centre
- 2nd most widely distributed mammal around the world
- Found in all oceans and seas
- max body length: 9 m
- weight: 5600 kg
- pectoral fins: M»F
- caudal fins with flukes (males are usually curled)
- dorsal fins erect (males = 1.8 m)
- colouration: back on dorsal, white on ventral, white patch above and behind eye, saddle patch (grey area on base of dorsal fin)
- only cetacean that routinely feeds n other marine mammals and also feeds on fish, sea turtles, etc)
- 2 distinct populations along eastern pacific coast: resident group (eats salmon) and transient group (eats marine mammals)
- in Argentina they eat seals; they would strand themselves on the beaches to grasp the seal and slide back to the ocean
List characteristics of Sperm whale and what suborder do they belong to?
Suborder: Odontoceti
- blow hole: off centre single; S-shaped
- largest existing species of toothed whales (19m; 57,000kg)
- found in all oceans
- longest diving. (138 mins) and deepest diver (3000m)
- the head is 1/3 or 1/4th of the length
- spermaceti organ: creates and focuses sounds (clicks)
- largest brain of any animal (7.8 kg)
- jaw: 20-26 comically shaped teeth on each side of its LOWER jaw only! But not used for feeding. Upper jay = vestigial and rarely erupted teeth
- colour: dark grey with white area on ventral surface or lining of the mouth may be white
- pectoral fins: paddle shaped and small
- flukes: flat and triangular
- dorsal fin: thick, low and often rounded
- spermaceti oil is in the head which is different than oils of other melon of the Odontocetis
List characteristics of Beluga/Narwhal and which suborder do they belong to?
Suborder: Odontoceti –> technically monodontae (one toothed whales)
- 2 living species of ht is family
- live primarily in the arctic regions of ht e northern hemi
- med. sized whales (5m; 1600 kg)
- Pectoral fins: broad
- Caudal fin: ornately shaped fluke
- lack dorsal fin but they have a ridge used to break ice
- young are black/grey –> adults: white
- very flexible necks (Cervical vertebrae are NOT fused)
- melon heads (trill, squeak and make noises) -_> “Canaanites of the seas”
- Blow hole: single and centre