Taxonomy
What two families are Sirenia?
• Family Trichechidae - manatees
• Family Dugongidae - dugongs
4 types of drag
1. Frictional/viscous drag
2. Pressure drag
3. Induced drag
4. Wave drag
Pinniped fur is not for thermoregulation, it is for protection
against fights, substrate, and UV radiation
Why do sirenians have long intestines?
• Nutrient AND water reabsorption
• Hindgut fermenters
Respiratory pathway
Nostrils/Mouth
Pharynx
Larynx
Trachea
Bronchi
Lobes of Lungs
Alveoli
Blood
Two physical biogeography drivers
Temperature and coastal shelves
In dolphins, the propulsive musculature is
composed of muscles associated with the
vertebral column:
• Hypaxial (ventral)
• Epaxial (dorsal)
What two pinniped species molt their skin
Hawaiian monk seals and elephant seals
Pyloric sphincter tightly controls flow of digested food
into the
duodenal ampulla
Blood flow maintained to the brain, thorax, and heart to help prevent
prevent rib cage collapse
What gave rise to modern cetaceans?
Archaeoceti
Sea Otter Swim style
pelvic paddling when at the surface and pelvic undulation when submerged
Fick Equation is
Rate of Heat Transferred is
• Directly proportional to thermal conductivity of material (k)
• Directly proportional to area of contact (A)
• Directly proportional the temperature difference between the two bodies (T)
• Inversely proportional to thickness of the material
Peristalsis:
undulating waves of concentric muscular contraction
pushes the food in one direction toward the stomach
Lungs and trachea collapse at depth due to
Hydrostatic pressure
Which cetacean family has no throat grooves (true filter feeders)?
Family Balaenidae
Cetaceans flukes attached to caudal vertebrae and intervertebral discs by
a thick mass of collagen fibers
Purposes of blubber
thermal insulation, primary source for metabolic energy storage, hydrodynamics, and contributes to positive buoyancy
Omentum is a
thin, 2-layered, fatty tissue that helps support the intestines and control infection within the abdomen.
Side-effect of moving blood away fromlocomotor muscles
build up of lactate (post-
dive recovery period) or hemoglobin/myoglobin
stores are sufficient (ADL)
Freshwater tolerant delphinidae (2)
Guiana, Tucuxi
The cetacean spine lacks _______ and has more space
Lack zygopophyses
benefit of CCHE in nasal passages and a species that uses this
to reduce respiratory water loss.
Moisture in the air is cooled by nasal passage and air condenses and is breathed back in.
(Elephant seals, hooded seals, and other phocids)
What two things activates aquaporins to help transport water from urine to plasma (concentrating urine) and involved in hormone regulation
arginine vasopressin(AVP)
antidiuretic hormone (ADH)
during a dive the large
spleen of this animal contracts and injects RBCs into
circulation and increases 60% in first 10
mins of a dive
Weddell seal