THE MORPHOLOGY AND LIFE HISTORY OF THE DIGENETIC TREMATODE, ZOÖGONOIDES LAEVIS LINTON, 1940

Publisher Website
Google Scholar
Abstract
The life history of Z. laevis has been traced at Woods Hole, Mass. in naturally and experimentally infected hosts. Adults occur in the intestine of Tautoga onitis. The eggs are large, without shells, and contain active, ciliated larvae when extruded. The miracidia emerge in sea water, swim rapidly and invade snails, Columbella lunata, where the asexual generations are produced. The cercariae are tailless and develop in sporocyts; they emerge from the snails and encyst in Nereis virens where they become metacercariae. Fishes eat the infected annelids, the meta-cercariae emerge in the intestine, and develop to maturity. The morphology of the successive stages is described. Comparison of the adult with descriptions of Z. viviparus, as given by different authors, indicates possible mistakes in the specific detn. of European specimens.