Nekton- Vertebrates Flashcards
nekton can ___ themselves (swim __ the water)
propel
against
____ are jawless fishes like lampreys and hagfish
Agnatha
Chondrichthyes= ____ fishes including ____ and rays
They have:
- _____ skeleton
- replaceable ___ ___
- ___ skeleton
cartilaginous
sharks
cartilaginous
tooth rows (lose their teeth)
dermal
_____ are bony fishes with teeth fixed in jaws (much more diverse than Chondrichthyes)
Osteichthyes
Why aren’t we sure about the phylogenetic tree of hagfishes/ lampreys?
really hard to find eggs/ young/ DNA of hagfish
- hagfish could be an outgroup, or might be sister taxa to lampreys
hagfish have an eel-like body, and ___ but no ___
teeth but no jaws
what are 3 distinguishing characteristics of hagfish?
- scavengers: they eat dead animals etc in deep waters- they burrow into the animal and eat it inside-out
- rough skin, can absorb nutrients through the skin (absorb from the dead animals they’re inside of)
- secrete immense amounts of slime for defense (hydrated collagen material, clogs gills of predators to deter them)
There are ~____ fish species in all habitats
30, 000
The form of fishes is related to their ___ and ____ ecology
What are the 5 forms? Give examples
locomotion and feeding ecology
- Rover- predators like tuna
- surface oriented- eat plankton (eg flying fish)
- Bottom fish- ie flat fish: eat small fish/ snails & create burrows
- Deep bodied- herbivores/ coral specialists eg butterfly fissh
- Eel-like
-
-
give an example of each
- acceleration eg barracuda (predator)
- cruising eg tuna (predator)
- maneuvering eg butterflyfish (herbivore)
most fish are ____, meaning they’re __-blooded
Some have evolved ___ to allow hunting in cooler waters (eg tuna)
poikilotherms
cold
endothermy (warm-blooded)
sharks are a ___-specialist, so they rely on their ___ to propel them and swim
cruise
tail
for most fish, swimming usually involves ____ of their entire body (thrust)
undulation
What’s a Mola mola ocean sunfish?
a massive fish (3 species) related to pufferfish
- slow-moving and deep diving- feed on jellyfish
- endangered b/c they’re easy to catch in our nets :(
How do sharks stay buoyant?
- they have cartilage as a skeleton, which is lightweight compared to mineral skeletons
- control buoyancy by fat storage in their liver
*sharks must keep moving to stay buoyant