Which vertebrate feature is not found in ascidians and cephalochordates?
|B)||Gill or pharyngeal slits|
|C)||Dorsal nerve cord|
Both lampreys and hagfishes lack jaws and feed by suction with a muscular mouth and teeth.
Unlike cartilaginous or bony fishes, jawless fishes do not have
Most cartilaginous fishes have smooth skin.
The largest sharks and rays feed on which of these?
Which is not recommended as a way to decrease one's risk of shark attack?
|A)||Stay away from sea lion colonies.|
|B)||Don't go swimming at night.|
|C)||If you see a shark, splash at it vigorously.|
|D)||Don't touch a shark or grab its tail.|
Sharks often have a large upper lobe on their tails primarily to act as a rudder for steering.
|A)||Crush their prey.|
|C)||Use their electric organs in defense against predators.|
|D)||Shock the fish they eat.|
|A)||Have elaborate courtship displays.|
|B)||Give birth to live young.|
|C)||Have stinging spines.|
|D)||Lay egg cases.|
The body of a bony fish often is covered by which of these?
Flatfishes have bodies compressed top-to-bottom as an adaptation for their demersal lifestyles.
A much greater diversity of fin shapes and uses has evolved in the bony fishes than in the cartilaginous fishes.
The lateral line of bony fishes is used to detect weak electrical fields of prey.
Bony, but not cartilaginous, fishes have which of these features?
|A)||Rows of teeth that serve as reserves to replace lost teeth|
|D)||Dorsal and lateral fins|
Cartilaginous fishes, unlike bony fishes, can carry on osmosis by which means?
|A)||Accumulation of high amounts of urea to equalize total solutes to that of seawater|
|C)||Excreting salts by means of chloride cells|
|D)||Retaining salts in their gills|
Structural colors in fishes result from crystals that act like tiny mirrors.
A lionfish has venomous spines. What kind of coloration might it have?
|A)||Cryptic--blending in with rocks and coral|
|B)||Warning--bold stripes on its body and fins|
|D)||Countershaded--dark above, light below|
Eel-shaped fishes often live
|A)||On sandy sea floors.|
|B)||In narrow spaces among rocks.|
|D)||near the surface of the open sea.|
Territoriality behavior in fishes usually involves violent battles between defenders and invaders.
Schooling in fishes may be coordinated by vision, the lateral line, olfaction, and sound.
Schooling in fishes has been hypothesized to serve in which function?
|A)||Provides hydrodynamic efficiency for swimming|
|B)||Allows colonies to form with specialized individuals, as in social insects|
|C)||Assists in regulating body heat|
|D)||Creates shadows that look like giant fish|
North Pacific salmon use primarily chemical cues when they migrate around the oceans as adults.
The migratory behavior of the Atlantic Anguilla eels is essentially the opposite of that of the Pacific salmon.
It can be difficult to identify larval fishes to species because
|A)||They drift far from land.|
|B)||Most larvae remain in an egg case.|
|C)||Development takes a long time.|
|D)||The larvae may not resemble their parents at all.|
Among fishes, eggs are retained in a nest by
Viviparity (live birth) such as found in mammals cannot occur in fishes because they always produce yolky eggs to support embryonic growth.
Special organs called claspers are used for internal fertilization in cartilaginous fishes.
Dams, excess silt, and pollution are destroying Pacific salmon runs in rivers because they reduce the number of adults that return to the oceans after spawning.
Hermaphrodism in some fishes involves males changing into females or vice versa.