Graduate Thesis Or Dissertation
 

The morphology and sexual maturation of Philometra americana Ekbaum, 1933 (Dracunculoidea:Philometridae)

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/dr26z214j

Descriptions

Attribute NameValues
Creator
Abstract
  • The female Philometra americana Ekbaum, 1933 is a common subcutaneous parasite of the starry flounder, Platichthyes stellatus (Pallas) of Yaquina Bay, Lincoln County, Oregon. Maturation of this worm produces noticeable red cysts subcutaneously between the fin and tail rays and similarly on the operculum. The gravid female penetrates the epidermis and leaves the fish. In sea water, the female bursts to release thousands of larvae which are presumably then ingested by an intermediate host. One thousand two hundred twenty-four starry flounders were examined and 280 fish were found to be infected. Three hundred forty-three female P. americana were collected and studied. No male was found. The percent of infection decreased as the size of the flounders increased. This suggests that the intermediate host for P. americana is primarily in the diet of the smaller fish. Collection data indicates that there is no seasonal occurrence of the infection in this locality, but no conclusion was reached as to the time required for the parasite to become gravid and leave the host fish. The digestive and reproductive systems of P. americana change drastically as the animal matures. There is a multiplication of cells in the intestinal wall during maturation. There is an atrophy of the anus, vagina and vulva by the time the animal has become pink in color with worm-like embryos in the uterus. The growth of the embryos in the uterus causes the worm to become two to three times larger than the immature worm.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi using Capture Perfect 3.0 on a Canon DR-9050C in PDF format. CVista PdfCompressor 5.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items