Folia Parasitologica 46[2] 111-116 (1999)

Post-cyclic transmission in Pomphorhynchus laevis (Acanthocephala)

Clive R. Kennedy

School of Biological Sciences, University of Exeter, Hatherly Laboratories, Prince of Wales Road, Exeter EX4 4PS, UK

A series of laboratory experiments was conducted to investigate the possibility of post-cyclic transmission in Pomphorhynchus laevis (Müller, 1776). Rainbow trout Oncorhynchus mykiss (Walbaum) were exposed to P. laevis in naturally infected Cottus gobio Linnaeus, Noemacheilus barbatulus (Linnaeus), Phoxinus phoxinus (Linnaeus) and Leuciscus cephalus (Linnaeus) and sacrificed one month after infection. Post-cyclic transmission was possible from all four species even though they came from three families and differed in respect of their status and suitability as hosts of P. laevis. There was no selection for or against either sex of P. laevis, parasites grew in the rainbows and they occupied the same, normal site in the intestine of rainbows irrespective of source host. Post-cyclic transmission of gravid parasites could occur from C. gobio but not from L. cephalus. It is believed that this failure to transmit larger parasites of either sex reflects the age and so development of the proboscis bulb of P. laevis and the extent of the host encapsulation response rather than size or stage of maturity per se. Post-cyclic transmission has the potential to be important in nature.

Keywords: transmission, post-cyclic, Pomphorhynchus laevis

Received: September 28, 1998; Accepted: January 7, 1999; Published: June 1, 1999  Show citation