Marine Vertebrates Flashcards
Elasmobranch development
Viviparity
Oviviparity
Oviparity
Viciparity
Parents provide nutrients during development
Oviviparity
Nutrients provided from eggs retained within the body
Oviparity
Development occurs within egg cases which are laid
Gonochoristic
Separate sexes
Wrasse polygyny
Male maintains a harem of females, when male dies biggest female becomes male
Phocid seals
Side to side movement
85-90% of time submerged
Otariid seals
Can walk on land or move like a tripod
Population change eqn
Mortality + emigration
Lack’s hypothesis
Density dependent mortality, only major importance factor is food
Ashmole’s hypothesis
Based on tropical birds with a constant food supply
Density dependent food competition during breeding season
Wynn-Edwards hypothesis
Birds regulate their numbers due to social interactions
Prudential restraint due to competition
Very unlikely hypothesis
Periarterial venous retes in fins
Blood changes which veins it flows through to conserve heat
Diadromous migrations
Between the sea and freshwater
Phocid seals spines
Transverse
Otariid seals spines
Neural
Sea snake respiration
Cutaneous
Cetacean blowholes
External nares
Baleen
Strong flexible material made of keratin
Forms plates that han from rostrum
Mysticeti whales use it to filter prey
Ghost fishing
Nets are lost at sea but continue to entrap marine organisms
Echolocation
Used by odontocetes for navigation and foraging
Animals emit calls and listen to the echoes of returning calls
Seahorse reproduction
Male becomes pregnant
Female deposits eggs into males pouch where he fertilises them
Cetaceans
Whales dolphins and porpoises
Odontoceti v Mysticeti whales
Toothed v baleen
Pinniped eyes
Extensive pupillary contraction
Forms v narrow slits or possibly a pinhole
