Record Details
The symbiotic relationships and morphology of Paravortex sp. nov. (Turbellaria, Rhabdocoelida) a parasite of Macoma nasuta Conrad, 1837
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | The symbiotic relationships and morphology of Paravortex sp. nov. (Turbellaria, Rhabdocoelida) a parasite of Macoma nasuta Conrad, 1837 |
| Names |
Hanson, Alfred Warren
(creator) Pratt, Ivan (advisor) |
| Date Issued | 1969-12-11 (iso8601) |
| Note | Graduation date: 1970 |
| Abstract | Rhabdocoels of the genus Paravortex are parasites of marine molluscs. The bent-nosed clams, Macoma nasuta(Conrad, 1837) of Yaquina Bay, Lincoln County, Oregon are commonly infected with a new species of Paravortex. The morphology of the adult worm has been described and it has been compared to the other three species of this genus. The percent infection increased as the size of the clams increased. Analysis of the size frequency distribution of the clam population suggests at least two age classes. Incidence of infection was substantially lower in the younger of these two classes. Clams less than 14 mm in length were not infected. Possible reasons for this distribution of the parasite population were discussed. A peak in the percent of infection, in the incidence of multiple infection, and in the abundance of immature worms was found during April, May, and June, 1968. These data suggest a seasonal periodicity in the reproduction of Paravortex sp. nov. A correlation between the sex of the bent-nosed clams and the incidence and degree of infection could not be established. Paravortex sp. nov. was found only in the pericardial cavity of Macoma nasuta. It is postulated that the rhabdocoel enters this cavity from the suprabranchial space by passing through the kidney. Possible methods by which this endoparasitic rhabdocoel obtains food were discussed. Physical damage to the host clam could not be shown to be the result of parasitic infections. Multiple infections of as many as 28 worms did not appear to physically impair the clam. Observations of the morphology and behavior of living worms were made and conclusions were reached concerning the nature of the symbiotic relationship between Paravortex sp. nov. and its host. Examination of collections of Macoma nasuta made in Coos Bay, Oregon, and Puget Sound, Washington,produced no rhabdocoels. |
| Genre | Thesis/Dissertation |
| Topic | Clams -- Parasites |
| Identifier | http://hdl.handle.net/1957/37322 |
