Return to the Ocean I Flashcards
What are amphibians?
Tetrapods with aquatic legs
What is true of the amphibian respiratory system?
– Permeable skin and gills
– Lungs (?) (simple sacs divided by ridges, may simply supplement cutaneous respiration)
– positive pressure breathing: buccal pump + elastic recoil
When were marine reptiles succcessful?
In the mesozoic (75-250 mya)
What are examples of marine reptiles?
– Sauropterygians (plesiosaur)
– Ichthyopterygians
– Mosasaurs
– Sea turtles
How many species of marine reptile are there?
<70 extant spp.
– tropical/subtropical
– from 3 orders
What are 2 families in the order Squamata?
– Snakes
– Iguana – 1 sp. (Galapagos)
What is true of snakes of Squamata?
– true sea snakes (~50 spp. – fully marine – ovoviviparity
– sea kraits (~5 spp.) – some terrestrial needs - digestion on land - oviparity
– Highly venomous
– Coastal tropical, Indian & pacific oceans
– Excellent swimmers & divers
How many species are in the order Testudines and what are they?
8
Green, Black, Flatback, Loggerhead, Hawksbill, Olive Ridley, Kemp’s Ridley, Leatherback
What is true of testudines?
– Circumglobal, tropical
– Mainly coastal (except leatherback)
– Good swimmers: foreleg paddles
– Come ashore to lay eggs
– Distinguish spp. by head & shell
What are the 2 species in the Order Crocodylia?
– Crocodylus acutus (American Crocodile)
– Crocodylus porosus (Saltwater Crocodile)
What is true of the Reptilian respiratory system?
– Skin nearly impermeable to O2 (exc. cutaneous respiration in sea snakes)
– Increased reliance on lung as respiratory surface
– Lung volume constant
– Subdivision increases
– Negative pressure breathing (aspiration pump)
What is true of negative pressure breathing (aspiration pump)?
– Uncouples feeding and breathing
– Requires thoracic cavity
What are some marine reptile adaptations?
– usually very good swimmers
– Good divers (esp. turtles)
– Cutaneous respiration (seasnakes)
What is true of cutaneous respiration in seansakes?
– Do not become anaerobic despite up to 2h long dives
– Lung extends full length of body
– Posterior portion oxygen store
– Small, thin scales and flattened body
What is true of salt glands in marine lizards?
– On head
– Empties into nasal cavity
– Ridge prevents re-swallowing
– Sudden exhalation to expel
What is true of salt glands in seasnakes?
– Base of tongie
– Empties into the oral cavity
What is true of salt glands in turtles?
– in orbit of eye
– Empties into posterior corner of orbit
What is true of salt glands in Crocodiles?
Distributed over the surface of the tongue
How many species in the order Sphenisciformes ?
17
What is true of the order Sphenisciformes?
- all seabirds
- southern hemisphere
- flightless
- feet –> rudder
- wings –> fins
How many species in the order Procellariiformes ?
125 spp
What is true of the order Procellariiformes?
– All seabirds
– Tubular nostrils
– good sense of smell
How many species in the order Pelecaniformes ?
65
What is true of the order Pelecaniformes?
– All waterbirds
– All seabirds, except anhingas, some pelicans and some cormorants
– All four toes are webbed
– Salt gland enclosed within orbit
– Nostrils are slit like, nearly closed or absent
What are examples of the order pelicaniformes?
Pelicans, frigatebirds, gannets, boobies, cormorants, anhingas
What are examples of the order Procellariiformes?
Albatrosses, petrels, storm-petrels, fulmars and shearwaters
What are examples of the order Sphenisciformes?
Penguins
What is true of the order Charadriiformes?
– Mostly seabirds except shore birds
How many species in the order Charadriiformes ?
128 spp. +~200 shorebirds
What are examples of the order Charadriiformes ?
Skuas, jaegers, gulls, terns, auks, guillemots, puffins, shorebirds & skimmers
What are examples of the order Ciconiiformes?
herons, egrets, storks, ibis, spoonbills
What is true of the order Ciconiiformes?
May feed along the shoreline, but not ‘seabirds’
Why are lungs the key to endothermy?
– To be endothermic you must generate heat and keep it in – e.g. NEED insulation
– Insulated skin prevents gas exchange
– Can’t be bimodal: lungs need to be efficient at CO2 elimination and O2 uptake
– Having efficient lungs is vital for evolution of endotherms
What does flight and endothermy mean for birds?
– HIGH metabolic demands
– insulation
What are some adaptions to life at sea for birds?
– Energy management
– Salt management
– locomotion and feeding
– Colouration
Life history
Why is energy management key in seabirds?
- Weight reducing adaptations
– High MR and endothermy
– Specialised lungs
Why is salt management key in seabirds?
- Feed in salt water
– May avoid saltwater ingestion
– Nasal salt hands (above eye) – connects to nasal cavity
– Preening gland/waterproofing
Why is locomotion and feeding key in seabirds?
– Wings for: Underwater swimming (penguins, cormorants), Flying vast distances (albatrosses), flying fast&agile, close to shore (auks & puffins)
– Bodies can be streamlined for swimming underwater
– Webbed feet
– Bills adapted to prey type and feeding mechanism
Why is life history key in seabirds?
– Form large colonies
– Large, long life, deferred maturity, small clutch size, extended chick period…due to energy limitation?
