Semotilus margarita

In addition to behavior changes, exposure to the alarm odor also has physiological effects. For instance, in pearl dace, Semotilus margarita, the levels of plasma cortisol and glucose increase 15 minutes after the alarm and are back to normal after 5 hours. The brain concentrations of dopamine, norepinephrine, 5-hydroxytryptamine, or tryptophan did not change (Rehnberg et al., 1987). The fish recovered physiologically much sooner than the behavioral activation For example. Von Frisch (1941) observed that minnows avoided the site of their encounter with alarm substance for many hours, even days. 

The pearl or northern dace Semotilus margarita) is a widespread species that is especially important in brown-colored, boggy waters. The fallfish (S. corporalis) occurs in northeastern North America, and can grow as large as 18 in (45 cm), and is sometimes eaten by people. 

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