Tell Me a Little About Yourself
The origins of marine fish date back to
500 million years
Sea squirt
_______________ million of years ago, the ocean was dominated with jawless fishes
100
What are the three types of cartilaginous fish?
Sharks, skates, rays
Feel slimy to the touch because their skin, which is living, secretes a protective ___________ coating over their scales.
mucous
How many species of fish are there?
25,000 or more
A tiny, transparent fish-like animal lives half-buried in the sand, with its head sticking out to filter plankton from the water
Lancelet
Most _______________________ of the vertebrates
primitive
Cartilaginous fish are the first _________________ fish.
jawed
The skin serves two functions
Barrier against infection
Reduces friction to move more easily through water
Flexible rod-like structure that supports the spinal cord
Notochord
It retains dorsal nerve cord, notochord, and gill slits
Lancelet
Lamprey and hagfish
What is different about the gill slits of cartilaginous fish versus bony fish?
Their gill slits are visible
This organ helps fish float.
Swim bladder
In vertebrate embryos, what does the notochord develop into?
A backbone
Superficially, the animal looks like any other invertebrate, since it resembles a worm, yet it has a dorsal nerve cord and gill slits (but no notochord)
Acorn worm
It feeds by using its teeth and rasping tongue to make a hole in the body of another fish, then it sucks out the blood and tissues of the host.
Sea lamprey
Why have sharks survived so long? Name three out of four reasons.
Very sensitive receptors
Sense sound and vibrations over great distances
Sense of smell - blood up to 5 miles away. ⅔ of its brain is devoted to its sense of smell
Detect electric fields
During external fertilization, gametes are released in a process called _____________.
spawning
Has a hollow dorsal nerve cord and notochord.
Protochordate
Study of the acorn worm, lancelet, and sea squirt is important because these protochordates represent an ___________________________ link between invertebrates and vertebrates
evolutionary
A hagfish lives as what?
parasite
Why are sharks well equipped to catch prey. Name three out of four reasons.
Streamlined body
Powerful muscles
Speedy acceleration
Hundreds of razor sharp teeth
Why are fish very sensitive to changes in the environment? Name three out of five reasons.
Well developed nervous system to carry out their responses
Good sense of hearing
Swim bladder sensitive to vibrations
Excellent sense of smell
Good vision