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dc.contributor.authorBeck, Kevin Moranen_US
dc.date.accessioned2014-03-14T20:37:43Z
dc.date.available2014-03-14T20:37:43Z
dc.date.issued2001-05-10en_US
dc.identifier.otheretd-05202001-211659en_US
dc.identifier.urihttp://hdl.handle.net/10919/33017
dc.description.abstractFeeding selectivity by the rainbow mussel (Villosa iris) was examined for three age groups; 2-3 days old, 50-53 days old, and 3-6 years old. The mussels were fed an algal diet consisting of Scenedesmus quadricauda (22.3 - 44.5 Æ Ã m), Nannochloropsis oculata (2.8 ¡V 8.1 Æ Ã m), and Selenastrum capricornutum (3.6 ¡V 8.5 Æ Ã m) in equal cell densities. The change in relative abundance of each algal species within feeding chambers over a 5 hr feeding trial was used to discern selectivity. At the conclusion of the feeding trials, the gut contents of mussels were analyzed for preferential ingestion. The mussels selected for N. oculata and S. capricornutum over S. quadricauda (p < 0.05). This may be an indication of particle size-dependent selection. Feeding trials also suggest that selectivity by the rainbow mussel does not change with age. Gut content analyses showed a preferential ingestion of algae, in the sequence N. oculata, S. capricornutum, then S. quadricauda. The suitability of two algal diets, S. quadricauda and N. oculata, for rearing captive juveniles of V. iris in 145-L recirculating culture systems was compared. Juveniles were fed their assigned diet at a density rate of approximately 30,000 cells/ml for 42 days, and sampled weekly for percent survival and shell length. Regardless of diet, juvenile survival decreased rapidly after 21 days, and growth did not exceed approximately 450 Æ Ã m. High mortality rates and slow growth of juveniles was likely due to inadequate diets. Juveniles that were fed S. quadricauda lacked chlorophyll coloration in their guts, indicating that the juveniles did not ingest this species of algae. Colonies of S. quadricauda were likely too large for the juveniles to ingest. The gut content of juveniles fed N. oculata showed chlorophyll coloration, indicating that the juveniles ingested this species, but N. oculata may have been difficult for the juveniles to assimilate. Under the culture conditions provided, survival and growth did not compare favorably to those of other studies with V. iris. Newly metamorphosed juveniles of V. iris were reared in 145-L recirculating culture systems containing sediment (< 600 Æ Ã m) of two depths, 5 mm and 15 mm. Mussels were fed a bi-algal diet of Nannochloropsis oculata and Neochloris oleoabundans. Survival differed significantly between treatments (p=0.04), and was higher for juveniles reared in 5 mm of sediment over a 40-day period. Growth was not significantly different between treatments. After 40 days, juveniles achieved a mean length of approximately 578 Æ Ã m in both treatments. Survival and growth of juveniles compared favorably to those of other culture studies using juveniles of V. iris. A shallow layer of sediment is recommended for the culture of juvenile mussels.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartThesis.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectfreshwater musselen_US
dc.subjectsediment depthen_US
dc.subjectVillosa irisen_US
dc.subjectalgaeen_US
dc.subjectselectivityen_US
dc.subjectjuvenile cultureen_US
dc.titleDevelopment of an Algal Diet for Rearing Juvenile Freshwater Mussels (Unionidae)en_US
dc.typeThesisen_US
dc.contributor.departmentFisheries and Wildlife Sciencesen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineFisheries and Wildlife Sciencesen_US
dc.contributor.committeechairNeves, Richard J.en_US
dc.contributor.committeememberBerkson, James M.en_US
dc.contributor.committeememberParker, Bruce C.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-05202001-211659/en_US
dc.date.sdate2001-05-20en_US
dc.date.rdate2002-05-29
dc.date.adate2001-05-29en_US


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