Show simple item record

dc.contributor.advisorHuffman, David G.
dc.contributor.authorFleming, Byron P. ( )
dc.date.accessioned2020-05-11T15:35:40Z
dc.date.available2020-05-11T15:35:40Z
dc.date.issued2002-12
dc.identifier.citationFleming, B. P. (2002). Downstream spread of the digenetic trematode Centrocestus formosanus, into the Guadalupe River, Texas (Unpublished thesis). Southwest Texas State University, San Marcos, Texas.
dc.identifier.urihttps://digital.library.txstate.edu/handle/10877/9835
dc.description.abstractAn exotic heterophyid trematode, Centrocestus formosanus, was recently determined to have adverse effects on fishes in the Comal River, a tributary of the Guadalupe River. This prompted an investigation to determine if the parasite and its obligate first intermediate host, Melanoides tuberculata, a gastropod snail, was established in the Guadalupe River. O f the 22 species and 529 fish collected, 50 % of the species (n = 11) and 29 % (n = 152) of the individuals were infected between 28 May 2001 and 09 March 2002. The highest single intensity observed was 656 metacercarial cysts in Notropis amabilis. Among the infected species, prevalence ranged from 16-100 %, mean intensities ranged from 46-616 cysts per fish, and relative densities ranged from 9-616 cysts per fish. In addition M. tuberculata were not collected at any site during the course of this one-year study. This prompted a series of fish-cage studies in order to isolate the source of cercariae that infected Guadalupe River fishes. Mean intensity of cysts in blacktail shiners Cyprinella venusta showed a consistent decrease in the Guadalupe River as cages were placed increasingly further downstream from the Comal River and Guadalupe River confluence. However, no infection was observed in caged fish in the Guadalupe River upstream from the confluence. The results of the cage studies and the lack of snails in the Guadalupe River indicate that fish were infected with cercariae released from snails upstream in the Comal River.
dc.formatText
dc.format.extent29 pages
dc.format.medium1 file (.pdf)
dc.language.isoen_US
dc.subjectTrematoda
dc.subjectSnails as carriers of disease
dc.subjectGuadalupe River
dc.subjectComal River
dc.titleDownstream Spread of the Digenetic Trematode Centrocestus Formosanus, into the Guadalupe River, Texas
txstate.documenttypeThesis
thesis.degree.departmentBiology
thesis.degree.grantorSouthwest Texas State University
thesis.degree.levelMasters
thesis.degree.nameMaster of Science
txstate.accessrestricted
txstate.departmentBiology


Download

This item is restricted to the Texas State University community. TXST affiliated users can access the item with their NetID and password authentication. Non-affiliated individuals should request a copy through their local library’s interlibrary loan service.

If this is your thesis or dissertation, you can make it open access. This will allow all visitors to view the document. To request open access, fill out the form linked below:

https://www.library.txstate.edu/research/digital-collections/Request-Open-Access.html

This item appears in the following Collection(s)

Show simple item record