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The diet of an invasive crayfish, Cherax quadricarinatus (Von Martens, 1868), in Lake Kariba, inferred using stomach content and stable isotope analyses

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dc.contributor.author Marufu, Lightone T.
dc.contributor.author Dalu, Tatenda
dc.contributor.author Phiri, Crispen
dc.contributor.author Barson, Maxwell
dc.contributor.author Simango, Rutendo
dc.contributor.author Utete, Beaven
dc.contributor.author Nhiwatiwa, Tamuka
dc.date.accessioned 2019-10-01T14:11:31Z
dc.date.available 2019-10-01T14:11:31Z
dc.date.issued 2018-01-27
dc.identifier.citation Marufu, L. T., Dalu, T., Crispen, P., Barson, M., Simango, R., Utete, B., & Nhiwatiwa, T. (2018). The diet of an invasive crayfish, Cherax quadricarinatus (Von Martens, 1868), in Lake Kariba, inferred using stomach content and stable isotope analyses. BioInvasions Record, 7 (2). en_US
dc.identifier.issn 2242-1300
dc.identifier.uri http://hdl.handle.net/10646/3856
dc.description The following supplementary material is available for this article: Table S1. Location of the study sites in the Sanyati Basin of Lake Kariba, Zimbabwe. Table S2. Results of stable isotope analysis in R of the food source proportions in redclaw crayfish diet. This material is available as part of online article from: http://www.reabic.net/journals/bir/2018/Supplements/BIR_2018_Marufu_etal_SupplementaryTables.xlsx en_US
dc.description.abstract The diet of an invasive crayfish, Cherax quadricarinatus (Von Martens 1868), in Lake Kariba, was investigated using stomach content analysis (SCA) and stable isotope analysis (SIA). The frequency of occurrence of macrophytes and detritus ranged between 63.6–97.1% and 20–45.5%, respectively, and the index of relative importance ranked these as the two most important food items across all size classes. Significant differences in the ranking of fish, macroinvertebrates and crayfish were found between size classes 29–37.9, 38–46.9 and 47–55.9mm. Stomach content analysis showed 16% of crayfish stomachs were empty. Feeding intensity differed significantly between size classes and ranged from 3.46 to 5.21. Stable isotope analysis was done by comparing δ13C, δ15N and C/N ratios in crayfish muscle and potential dietary items in the lake. Macrophytes were the most dominant food item (57%), followed by macroinvertebrates (20%), then detritus, and finally fish and crayfish. Stable isotope analysis revealed that all crayfish size classes analysed were in the same trophic level. Nevertheless, while SCA showed high dietary overlap among all crayfish size classes (>65%), SIA showed that small crayfish (< 28.9mm) had limited overlap with large crayfish (> 56mm), with the former showing a higher proportion of macroinvertebrates in their diet. In Lake Kariba, C. quadricarinatus predominantly feeds on macrophytes, macroinvertebrates and detritus, which may bring about nutrient cycle alterations in the lake. Littoral habitat changes caused by the feeding characteristics of C. quadricarinatus might also lead to competition with, and eventual displacement of, some nativelittoral fishes in this lake. en_US
dc.description.sponsorship Research Council of Zimbabwe The University of Zimbabwe Vice Chancellor’s Data Collection Fund. en_US
dc.language.iso en_ZW en_US
dc.publisher Regional Euro-Asian Biological Invasions Centre (REABIC) en_US
dc.subject detritus en_US
dc.subject dietary shift en_US
dc.subject omnivorous en_US
dc.subject stomach content analysis en_US
dc.title The diet of an invasive crayfish, Cherax quadricarinatus (Von Martens, 1868), in Lake Kariba, inferred using stomach content and stable isotope analyses en_US
dc.type Article en_US
dc.contributor.authoremail lmarufu@science.uz.ac.zw en_US


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