Which statement best describes the morphological differences between benthic and limnetic sticklebacks?

• A. Benthics have morphological features suited to bottom feeding; limnetics differ in jaw shapes and body proportions adapted for open-water feeding.
• B. Benthics have longer gill raker counts than limnetics.
• C. Benthics feed in open water with elongated jaws.
• D. There is no morphological difference.

Answer: (C)

Morphology in these sticklebacks reflects where they feed. Benthic individuals are adapted to the lake bottom, so their features support grabbing and processing prey on or near the substrate and moving among the bottom substrates. Limnetic individuals, living in open water, show jaw shapes and body proportions that suit feeding in the water column, along with traits like more gill rakers to filter small plankton. So the best description is that benthics have features suited to bottom feeding, while limnetics have jaw shapes and body proportions adapted for open-water feeding. This explains why the open-water feeding with elongated jaws idea doesn’t fit benthics, and why differences in gill raker counts align with plankton feeding in limnetics rather than benthics.