Additional info: |
While testosterone is the primary androgenic male steroid found in mammals, 11-keto testosterone (11-KT) is a second key androgenic steroid found in fish. It occurs in males together with testosterone in amounts which vary from less than 1 ng/ml to as much as 50-100 ng/ml, depending on the species and the stage of the reproductive cycle. In the sea bass, testosterone concentrations are generally higher than 11-KT, with peak levels found after the spawning season. 11-KT, on the other hand, remains at levels less than 1 ng/ml but rises abruptly to 4-6 ng/ml during spermiation at the height of the spawning season. 11-KT also shows individual variations in Arctic char, with dominant males having significantly higher 11-KT levels. |