Marine Mammals Flashcards
Give the ecological definition of marine mammals.
Mammals of several lineages which have returned to the sea of a full or part time basis.
What are the 3 orders of marine mammals?
Cetariodactyla, sirenia and carnivora.
Describe uni-hemispheric sleep.
An organism’s contra-lateral eye remains open during sleep, allowing greater activity levels, vigilance and maintenance of social contact during sleep.
Which families are known to carry out uni-hemispheric sleep?
Odontecetes, otariids and obodenidae.
Describe the 2 ways sperm whales drift while resting.
Head facing up, and head facing down to drift up.
Which orders live in the sea full time?
Cetacea and sirenia.
What does a Dtag record?
Movements in 1D, body posture and sound (flow sound reflects speed).
What type of thermoregulators are marine mammals?
Homeothermic endotherms.
Give 3 ways marine mammals could reduce heat loss.
Reduction of body temperature, surface area : volume ratio and thermal conductance.
How does fur work as insulation?
A layer of air is trapped in the under-fur and the long guard hairs provide protection.
Blubber is adipose tissue thickened by _____ and _____ fibres.
Collagen and elastic
Give some other functions of blubber.
Improving hydro-dynamic shape, storing elastic entertainment, acting as an energy reservoir and buoyancy.
Explain venous return systems in cetaceans.
They have veins close to the skin to lose hear and veins close the arteries to conserve heat, allowing a countercurrent heat exchange system.
Give 3 ways to increase oxygen stores.
Increase lung volume and blood (higher red cell concentration) and muscle (higher myoglobin concentration) volume and storage capacity.
Which sense do they have the strongest adaptations for?
Sound
