Marufu, Lighthouse T.Dalu, TatendaPhiri, CrispenBarson, MaxwellSimango, RutendoUtete, BeavenNhiwatiwa, Tamuka2022-11-092022-11-092018-01-27Marufu, L. T., et al. The diet of an invasive crayfish, Cherax quadricarinatus (Von Martens, 1868), in Lake Kariba, inferred using stomach content and stable isotope analyses. BioInvasions Records (2018) Volume 7, Issue 2: 121–132.DOI: https://doi.org/10.3391/bir.2018.7.2.03.<http://hdl.handle.net/11602/2335>.DOI: https://doi.org/10.3391/bir.2018.7.2.03http://hdl.handle.net/11602/2335The 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 47–55.9 mm. 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 native littoral fishes in this lakeenDetritusUCTDDietary shiftOmnivorousstomach content analysisArticleMarufu Lighthouse T, Dalu T, Phiri C, Barson M, Simango R, Utete B, et al. The diet of an invasive crayfish, Cherax quadricarinatus (Von Martens, 1868), in Lake Kariba, inferred using stomach content and stable isotope analyses. 2018; http://hdl.handle.net/11602/2335.Marufu, Lighthouse T., Dalu, T., Phiri, C., 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. http://hdl.handle.net/11602/2335Marufu, Lighthouse T., Tatenda Dalu, Crispen Phiri, Maxwell Barson, Rutendo Simango, Beaven Utete, and Tamuka Nhiwatiwa "The diet of an invasive crayfish, Cherax quadricarinatus (Von Martens, 1868), in Lake Kariba, inferred using stomach content and stable isotope analyses." (2018) http://hdl.handle.net/11602/2335TY - Article AU - Marufu, Lighthouse T. AU - Dalu, Tatenda AU - Phiri, Crispen AU - Barson, Maxwell AU - Simango, Rutendo AU - Utete, Beaven AU - Nhiwatiwa, Tamuka AB - 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 47–55.9 mm. 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 native littoral fishes in this lake DA - 2018-01-27 DB - ResearchSpace DP - Univen KW - Detritus KW - Dietary shift KW - Omnivorous KW - stomach content analysis LK - https://univendspace.univen.ac.za PY - 2018 T1 - The diet of an invasive crayfish, Cherax quadricarinatus (Von Martens, 1868), in Lake Kariba, inferred using stomach content and stable isotope analyses TI - The diet of an invasive crayfish, Cherax quadricarinatus (Von Martens, 1868), in Lake Kariba, inferred using stomach content and stable isotope analyses UR - http://hdl.handle.net/11602/2335 ER -