Which one of the following animals would most likely be defined as a keystone species?
A) sea otter
B) housefly
C) fathead minnow
D) nauplii (a species of zooplankton)

Question

Quizplus · Accepted Answer

A keystone species is one that has a disproportionate effect on the ecosystem compared to its numerical abundance. Sea otters are considered a keystone species because they help maintain the health of kelp forests by keeping sea urchin populations in check. Without sea otters, sea urchins can overgraze kelp forests and destroy the habitat for many other species in the ecosystem.

Which One of the Following Animals Would Most Likely Be