Download or read book Biology of the Sea Lamprey in Its Parasitic Phase written by Phillip Sheridan Parker and published by . This book was released on 1956 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most of the experimental lampreys were mature and rip after 14 to 18 months of parasitic life. They exhibited signs of irreversible physical degeneration which precedes death. Three specimens were immature at 14, 18, and 26 months in aquariums, thus indicating that under certain conditions, lampreys may extend their parasitic phase.