Catalyzes the conversion of biologically active 11beta-hydroxyglucocorticoids (11beta-hydroxysteroid) such as cortisol, to inactive 11-ketoglucocorticoids (11-oxosteroid) such as cortisone, in the presence of NAD(+) (PubMed:22796344, PubMed:23042946, PubMed:27927697, PubMed:33387577). Cortisol is the primary glucocorticoid in teleosts and is released to increase glucose bioavailability in order to meet the increased energy demands in response to stress (PubMed:23042946). Functions as a dehydrogenase (oxidase), thereby decreasing the concentration of active glucocorticoids, regulating the hypothalamus-pituitary-interrenal (HPI) axis function in adult fish (PubMed:23042946). Decreasing the excess glucocorticoids may be of relevance to brain function and neural proliferation (PubMed:23042946). Plays a key role by catalyzing the oxidation of 11beta-hydroxytestosterone (11beta,17beta-dihydroxyandrost-4-ene-3-one) to 11-ketotestosterone (17beta-hydroxyandrost-4-ene-3,11-dione), the major fish androgen, that activates androgen receptor transcriptional activity (PubMed:22796344, PubMed:27927697). Catalyzes the conversion of 11beta-hydroxyandrostenedione (11beta-hydroxyandrost-4-ene-3,17-dione) to 11-ketoandrostenedione (androst-4-ene-3,11,17-trione), which can be further metabolized to 11-ketotestosterone (PubMed:27927697). Exerts a dual role in fish by inactivating glucocorticoids and activating androgens (PubMed:22796344, PubMed:27927697). an 11beta-hydroxysteroid + NAD(+) = an 11-oxosteroid + H(+) + NADH cortisol + NAD(+) = cortisone + H(+) + NADH corticosterone + NAD(+) = 11-dehydrocorticosterone + H(+) + NADH 11beta,17beta-dihydroxyandrost-4-ene-3-one + NAD(+) = 17beta-hydroxyandrost-4-ene-3,11-dione + H(+) + NADH 11beta-hydroxyandrost-4-ene-3,17-dione + NAD(+) = androst-4-ene-3,11,17-trione + H(+) + NADH Steroid metabolism. Broadly expressed in peripheral (brain, gill, eye, heart, liver, head kidney, posterior kidney, and gut). As zebrafish lack the enzyme catalyzing the reverse reaction (HSD11B1), cortisone cannot be recycled, it is metabolized and excreted (PubMed:27927697). To maintain glucocorticoid signaling a new cortisol molecule must be synthesized (PubMed:27927697). Belongs to the short-chain dehydrogenases/reductases (SDR) family.