Novel compounds isolated from the bile of male sea lampreys are described, in particular, 7α,12α,24-trihydroxy-5α-cholan-3-one-24-sulfate and 7α,12α-dihydroxy-5α-cholan-3-one-24-oic acid and an ELISA for detecting the compounds. The bile compounds act as pheromones which attract female sea lampreys in water to the point in the water where the compounds had been introduced. The bile compounds are useful in lamprey population management programs where it is desirable to control the locomotion and distribution of lampreys and in food operations where it enhances the efficiency of catching lampreys for food.