What are the differences among the three types of skeletal muscle found in fish (red, pink, and white)?
A) speed of contraction
B) susceptibility to fatigue
C) both speed of contraction and susceptibility to fatigue
D) only their color

Question

Quizplus · Accepted Answer

The main differences among the three types of skeletal muscles found in fish (red, pink, and white) are both the speed of contraction and susceptibility to fatigue. Red muscles are slow-twitch (or Type I) fibers that have a high oxidative capacity, which makes them resistant to fatigue and enables sustained contractions. Pink muscles are intermediate-twitch (Type IIa) fibers that have a moderate oxidative capacity, allowing them to contract relatively quickly and resist fatigue to some extent. White muscles are fast-twitch (Type IIb and IIx) fibers that have a low oxidative capacity, making them well-suited for rapid and powerful contractions but also highly susceptible to fatigue. The color of each muscle type is due to the amount of myoglobin and other pigments present, which influences their oxygen-carrying capacity and energy metabolism.

What Are the Differences Among the Three Types of Skeletal