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The formation of breeding tubercles and a mucus-secreting dorsal pad in male and female fathead minnows is induced by 17α-methyltestosterone. Neither lactotrophic hormone (LTH) nor human chorionic gonadotropin induced dorsal pad or tubercle formation in the dosages used. LTH (with androgen) may delay loss of mucus cells at the end of the breeding season.
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R. J. F. Smith (1974) studied this question.
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