Lin-Tai Ho and colleagues monitored fish populations in a tide pool in Taiwan. They found that some species were entirely absent from the tide pool at particular times of the year; for example, they did not observe even one ______
Which choice most effectively uses data from the graph to complete the example?
Explanation
Context: Ho and colleagues tracked three fish species in a Taiwanese tide pool and found that some vanished entirely at certain times of year, so the example needs a species seen zero times. The graph gives counts for January, April, July and October of 2001.
Answer: A) Wavy-lined blenny in January, April, and July of 2001.
Why? The wavy-lined blenny line sits at 0 in January, April and July, appearing only in October at 3. It is the one species with any zero readings, so it is the one that was entirely absent at particular times.
Traps:
- B) The Indo-Pacific sergeant is at about 28 in October, its highest count of the year, so it was anything but absent then.
- C) The Indo-Pacific sergeant is at about 22 in July, again far from zero.
- D) The Cocos frillgoby peaks at about 10 in April and is present in all four months, never dropping to zero.