Coral Reef: A City That Never Sleeps

According to the article, why do some parrotfishes make a cocoon?

• to attract other fishes to their hiding place

• to show other fishes they are asleep

• to create a safe place for their eggs

• to hide themselves from predators

Why are some diurnal fishes harder to see in the evening than in the daytime?

• The movement on the reef blurs their shapes.

• Their predators can only detect outlines.

• The light casts shadows that hide them.

• Their skin color changes to blend in.

What statement best summarizes the information in lines 1 through 9?

• Daytime fish who live in the coral reef generally generally stop feeding at dusk.

• Fish have the natural ability to become less visible at night in the coral reef.

• Predatory fish hide in the coral reef so they can feed on the diurnal fish.

• Fish in the coral reef have remarkably better vision during the day.

Which sentence from the article best explains why some fishes may be dangerous to humans?

• "Though twilight predators are not very good at distinguishing colors, they can detect shape, outlines, and movement well." (lines 25 and 26)

• "Many predators that have been quietly waiting in the background all day become more active at dusk and dawn." (lines 28 and 29)

• "The crepuscular hunters have ingenious ways of picking off their prey." (lines 29 and 30)

• "By thrusting out its lower jaw, its mouth becomes big enough to swallow almost any prey." (lines 31 and 32)

What does the phrase "zero in on" in line 40 mean?

• to locate

• to look

• to threaten

• to smell

The author develops a central idea about how fishes adapt to their environment by focusing mostly on the

• light in the water

• depth of the reef

• currents in the water

• shape of the reef

Which detail is most important to include in a summary of the article?

• "Because fishes don't have eyelids to close, it's impossible to tell whether or not most fishes are really sleeping." (lines 15 and 16)

• "Many predators that have been quietly waiting in the background all day become more active at dusk and dawn." (lines 28 and 29)

• "It has been rumored that giant groupers (which may weight up to 1,000 pounds) have been known to swallow divers whole!" (lines 32 and 33)

• "Many daytime fishes move into deeper water, rise to the surface, or spawn during outgoing tides..." (lines 49 and 50)