The Life History and Biology of Plagioporus hypentelii Hendrix 1973 (Trematoda: Opecoelidae)

Abstract

Plagioporus hypentelii utilizes the pleurocerid snail, Leptoxis (Mudalia) carinata, as first intermediate host. Effects of snail sex and age are noted on the daughter sporocyst burden. Males, as well as 1- and 2-year-old snails have significantly higher intensities of infection. Cotylomicrocercous cercariae are released from snails after the onset of darkness of an LD 12:12 hr photoperiod. Reversal of the photoperiod causes an almost immediate reversal of the emergence pattern. Cercariae encyst in the alderfly larva, Sialis infumata under natural conditions and in Culex pipiens larvae under ex- perimental conditions. Week-old metacercariae are experimentally infective to swordtails, Xiphophorus helleri, and immature specimens of P. hypentelii recovered agree with young worms taken from the natural fish host, Hypentelium nigricans. A seasonal change in the intensity of infection is noted for adult worms in H. nigricans.