Lecture 15 Flashcards
How many air breathing marine species of Amphibians are there?
None
How many air breathing marine species of reptiles are there? Name them (in Latin)
3
. Chelonia (turtles)
. Squamata (lizards and snakes)
. Crocodilia (crocodiles)
How many air breathing marine species of birds are there? Name in Latin
None completely aquatic but
Sphenisciformes (penguins)
How many air breathing marine mammals are there? Give names of order and sub-order that it is split into and give examples of species
. Pinnipeds
- Otariidae- furred seals
- Phocidae- ‘true’ seals
. Cetaceans- whales and dolphins
- Odontoceti- toothed whales e.g. orcas and the dolphins
- Mysticeti- baleen whales- e.g. the blue whales
What are the problems associated with returning to the sea?
. Think about how you are going to get O2)
. Issue with foraging in the sea floor (e.g. the grey whale)
What is the issue with foraging at the sea floor when you are air-breathing? Give an example
Wasting time going to the surface and down and staying at the surface to breath, which they could have been foraging
E.g. sperm whales prey is highly mobile squid, which may have gone while they were breathing (also grey whales forage this way)
What are the advantages of using air over water as a respiratory medium?
. Easy to move air compared to water
. 30 times more O2 in 1 litre of air compared to 1 litre of water- energy consuming (ok for some low metabolic rate ectotherms (e.g. sea snakes) but endotherms with high metabolic rate can’t extract enough to survive)
. Mass of medium
. Viscosity of medium
. O2 is relatively easy to access and is fairly constant in air. O2 is in high supply in the air whereas even in the most saturated of water it is much lower
. Air has a low heat conductivity and low heat capacity
Explain the mass of the medium air in relation to how much oxygen it contains in a litre and the amount of air animals have to move when breathing
. 1 litre of air contains 210ml O2
. 210ml of O2 weighs 280mg to access this an animals has to move 1190mg of air (790ml of N2 weighs 910mg)
Explain the mass of the medium water in relation to how much O2 it contains, how much water an animal needs to move to get oxygen
. 1 litre of water equilibrated with air contains 7ml of oxygen
. 7ml of air weighs 9mg to access this an animal has to move 1,000,000mg of water. So this takes a lot of energy type extract the O2 from the water
For an equivalent amount of O2 how much more water would an animal have to move?
25,000 times
What are global problems and benefits of air breathing marine species?
. Breathing air is a problem with which all marine reptile, birds and mammals have to contend
. Water is more viscous therefore more energy is needed to move through it. Increased energy due to increased drag which means that the body forms tend to be more compromised (most Cetacean have a very similar body form)
. Water is more supportive (so not contending with gravity) therefore less energy needed to support a body
. Buoyancy (pro and con)
How many species of Mysticetes (baleen whales) are there?
14
How many species of Odonotocetes (toothed whales) are there?
76
How many species of Otariidae (sea lions and fur seals) are there?
13
How many species of Odobenidae (walrus) are there?
1
How many species of Phocidae (true seals) are there?
18
How many species of Sirenia (dugongs and manatees) are there?
4
How many species of Ursidae/ Ursinae (polar bear) are there?
1
How many species of Mustelidae (sea otter) are there?
1