Characterization of freshwater as a treatment for amyloodiniosis in red drum
Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item. Includes bibliographical references (leaves...
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fttexasamuniv:oai:repository.tamu.edu:1969.1/ETD-TAMU-1999-THESIS-H373 2023-05-15T18:06:01+02:00 Characterization of freshwater as a treatment for amyloodiniosis in red drum Harris, Courtney Elaine 1999 electronic application/pdf reformatted digital http://hdl.handle.net/1969.1/ETD-TAMU-1999-THESIS-H373 en_US eng Texas A&M University http://hdl.handle.net/1969.1/ETD-TAMU-1999-THESIS-H373 This thesis was part of a retrospective digitization project authorized by the Texas A&M University Libraries in 2008. Copyright remains vested with the author(s). It is the user's responsibility to secure permission from the copyright holder(s) for re-use of the work beyond the provision of Fair Use. wildlife and fisheries sciences Major wildlife and fisheries sciences Thesis text 1999 fttexasamuniv 2015-02-07T23:22:41Z Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item. Includes bibliographical references (leaves 49-53). Issued also on microfiche from Lange Micrographics. The ectoparasitic dinoflagellate Amyloodinium ocellatum is a problem of long standing in marine aquaria and recently has emerged as a cause of mortality also in marine food-sh-production facilities. The parasitic stage (trophont) attaches to the gills, skin, and fins of host fish such as red drum (Sciaenops ocellatus), a euryhaline teleost cultured intensively for seafood in Texas and other Gulf states. Amyloodinium ocellatum has a wide range of tolerance to salinity, but freshwater exposure is considered an effective therapy for infested fish. Bioassays were conducted to determine the intervals of time A. ocellatum-infested red drum need to spend in freshwater to result in various degrees of trophont detachment from the gills. Results resolved the time dependency of trophont detachment on freshwater exposure, but also indicated substantial effects of infestation age and of fish weight and group identity. Freshwater dips were generally effective in causing trophont dislodgment from A. ocellatum-infested red drum at an instantaneous rate of 20% per minute. Within the first 24 h of infestation by a trophont generation, however, effectiveness of a freshwater dip varied markedly with fish group. Fish groups fell into two sets, inferred to be comprised of fish with and without prior exposure to A. ocellatum. In putatively "nav?e'' fish, freshwater dips were not effective in dislodging A. ocellatum trophonts younger than 24 h; in putatively "immune'' fish, trophonts of any age detached from the gills when exposed to freshwater. A computer simulation model was constructed to represent the A. ocellatum life cycle and the effects that freshwater exposure had on this cycle. Experimental results and information from the literature were integrated to model the joint effects of infestation age, the fish's weight, prior exposure to the parasite, and duration of freshwater exposure. The simulation model was most successful in explaining parasite load for red drum with A. ocellatum infestations older than 24 h (R? = 0.63). Model results helped answer questions about what the combination of freshwater exposure and age of trophonts contributed to removal of the parasite from red drum gills. Thesis Red drum Sciaenops ocellatus Texas A&M University Digital Repository |
institution |
Open Polar |
collection |
Texas A&M University Digital Repository |
op_collection_id |
fttexasamuniv |
language |
English |
topic |
wildlife and fisheries sciences Major wildlife and fisheries sciences |
spellingShingle |
wildlife and fisheries sciences Major wildlife and fisheries sciences Harris, Courtney Elaine Characterization of freshwater as a treatment for amyloodiniosis in red drum |
topic_facet |
wildlife and fisheries sciences Major wildlife and fisheries sciences |
description |
Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item. Includes bibliographical references (leaves 49-53). Issued also on microfiche from Lange Micrographics. The ectoparasitic dinoflagellate Amyloodinium ocellatum is a problem of long standing in marine aquaria and recently has emerged as a cause of mortality also in marine food-sh-production facilities. The parasitic stage (trophont) attaches to the gills, skin, and fins of host fish such as red drum (Sciaenops ocellatus), a euryhaline teleost cultured intensively for seafood in Texas and other Gulf states. Amyloodinium ocellatum has a wide range of tolerance to salinity, but freshwater exposure is considered an effective therapy for infested fish. Bioassays were conducted to determine the intervals of time A. ocellatum-infested red drum need to spend in freshwater to result in various degrees of trophont detachment from the gills. Results resolved the time dependency of trophont detachment on freshwater exposure, but also indicated substantial effects of infestation age and of fish weight and group identity. Freshwater dips were generally effective in causing trophont dislodgment from A. ocellatum-infested red drum at an instantaneous rate of 20% per minute. Within the first 24 h of infestation by a trophont generation, however, effectiveness of a freshwater dip varied markedly with fish group. Fish groups fell into two sets, inferred to be comprised of fish with and without prior exposure to A. ocellatum. In putatively "nav?e'' fish, freshwater dips were not effective in dislodging A. ocellatum trophonts younger than 24 h; in putatively "immune'' fish, trophonts of any age detached from the gills when exposed to freshwater. A computer simulation model was constructed to represent the A. ocellatum life cycle and the effects that freshwater exposure had on this cycle. Experimental results and information from the literature were integrated to model the joint effects of infestation age, the fish's weight, prior exposure to the parasite, and duration of freshwater exposure. The simulation model was most successful in explaining parasite load for red drum with A. ocellatum infestations older than 24 h (R? = 0.63). Model results helped answer questions about what the combination of freshwater exposure and age of trophonts contributed to removal of the parasite from red drum gills. |
format |
Thesis |
author |
Harris, Courtney Elaine |
author_facet |
Harris, Courtney Elaine |
author_sort |
Harris, Courtney Elaine |
title |
Characterization of freshwater as a treatment for amyloodiniosis in red drum |
title_short |
Characterization of freshwater as a treatment for amyloodiniosis in red drum |
title_full |
Characterization of freshwater as a treatment for amyloodiniosis in red drum |
title_fullStr |
Characterization of freshwater as a treatment for amyloodiniosis in red drum |
title_full_unstemmed |
Characterization of freshwater as a treatment for amyloodiniosis in red drum |
title_sort |
characterization of freshwater as a treatment for amyloodiniosis in red drum |
publisher |
Texas A&M University |
publishDate |
1999 |
url |
http://hdl.handle.net/1969.1/ETD-TAMU-1999-THESIS-H373 |
genre |
Red drum Sciaenops ocellatus |
genre_facet |
Red drum Sciaenops ocellatus |
op_relation |
http://hdl.handle.net/1969.1/ETD-TAMU-1999-THESIS-H373 |
op_rights |
This thesis was part of a retrospective digitization project authorized by the Texas A&M University Libraries in 2008. Copyright remains vested with the author(s). It is the user's responsibility to secure permission from the copyright holder(s) for re-use of the work beyond the provision of Fair Use. |
_version_ |
1766177580565659648 |