Why do bony fish have an Operculum?
it closes while water is let into the gills through the mouth, preventing back flow, ensuring the counter current system of the gills
What is anadromous behavior?
A life cycle in which the creatures are hatched in fresh water and migrate to salt water when adults and return to fresh water to reproduce
What is the opercula?
in boney fish a protective covering for the gills, it helps control water flow over the gills
What do gill rakers do?
In filter feeding fish they catch the plankton the fish eats, in other fish they prevent bits of food from getting in the gills.
What are chromatophores?
suface pigment cells that expand and contract to create various colors
What are dental plates, what fish has them and why?
They are hard calcified plates in the mouth. Rays have them instead of teeth, they suction their food into their mouth and crush the hard shells with them
Which lobe of the brain is oversized in a fish?
Olfactory lobe (smelling)
name the sensory organs in a cartilaginous fish and what they sense. (4)
1. Eyes-light, 2.nostrils –smells, 3.lateral line- vibrations in the water, 4 ampulla of Lorenzinii – small electrical currents.
Explain the difference between 1.oviparous, 2.ovoviviparous, 3.viviporous.
1.Eggs are hatched outside the body 2.Eggs hatched inside the females body,live birth3.Young obtain their nutrition directly from the mother, live birth
What are denticles?
placoid scales made from the same material as teeth, and are covered with enamel.
Describe the counter current blow flow system and why is it beneficial?
blood in the gills flows in the opposite direction to that of the oxygenated water. It allows for diffusion over a long area
What do fish in the Agnatha class, lack? Can you name 4 structures?
Jaws, also called Jawless fish Also paired fins, scales and true bones
name the four types of coloration in fishes and what they are used for.
What characteristics do Rays have in common?
The are flat,(camouflage, easy movement across the bottom) their mouths are on their ventral side (convenient feeding), eyes are on their dorsal side.
Name three ways boney fish are different that cartilaginous fish.
1.Swim bladder, 2.terminal mouth, 3.bones, 4.larger scales (cycloid), 5.fins are boney spines covered in a membrane, operculum