• Pasternak Zohar
• Diamant Ariel
• Abelson Avigdor

Parasitology research

• Publish Date: Mar 2007
• ISSN: 0932-0113
• Volume: 100
• Issue: 4
• Pages: 721-7
• Medium: Print
• Language: English
• Citation (JAMA): Pasternak Zohar, Diamant Ariel, Abelson Avigdor, et al. Co-invasion of a Red Sea Fish and Its Ectoparasitic Monogenean, Polylabris Cf. Mamaevi into the Mediterranean: Observations on Oncomiracidium Behavior and Infection Levels in Both Seas.. Parasitol. Res. Mar 2007;100:721-7

Abstract

This study investigated aspects of the biology of the monogenean gill ectoparasite Polylabris cf. mamaevi (Polyopisthocotylea: Microcotyleae) infecting rabbitfish, Siganus rivulatus (Forskal) (Teleostei: Siganidae). Both host and parasite are Lessepsian immigrants that have co-invaded the Mediterranean Sea via the Suez Canal. The infection prevalence and mean intensity of the polyopisthocotylean was examined in both native and immigrant host populations and found to be three times greater in the new biogeographical region. In vitro observations on parasite eggs from both areas indicated that hatching occurred almost exclusively in the dark. The reaction of the larval oncomiracidia to water flow and secreted host chemicals indicated that neither Red Sea nor Mediterranean oncomiracidia exposed to waterborne host metabolites displayed any significant response or change in behavior; however, upon encountering flow, they ceased to swim and drifted passively downstream. Host specificity of P. cf. mamaevi may have co-evolved with temporal synchronization of the parasite with the host’s diurnal activity. Hatching of P. cf. mamaevi eggs was rhythmical and the timing coincided with the known nocturnal resting behavior of the hosts, when their schools lie immobile on the sea bottom. After hatching, abrupt cessation of active swimming by the oncomiracidia upon sensing host inhalant gill-ventilating currents is likely to facilitate rapid, passive entry into the gill chamber of a suitable host. The greater abundance of P. cf. mamaevi in the invading (Mediterranean) populations is probably due to the changed, new environment, possibly impacting host resistance to the parasite and encouraging heavier infections.

This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.

Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.

The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.