Data from: Aquatic hitchhikers: examining the phoretic associations between blackfly (Diptera: Simuliidae) and mayfly (Ephemeroptera: Heptageniidae, Tricorythidae) larvae in Kenyan river ecosystems

The interaction known as phoresy, where one organism (the phoront) utilises another (the host) primarily for transport or access to food resources, has been observed among various aquatic invertebrates in Afrotropical rivers. Although documented in multiple species, phoresy’s underlying causes, ecological dynamics, and evolutionary pathways remain poorly understood, and its broader implications are still under investigation. In this study, we collected and analysed macroinvertebrate samples from seven locations along the Gura River and nine locations along the Mara River in Kenya. We explored phoretic dynamics within a diverse range of macroinvertebrate taxa. We identified a consistent phoretic association between Simuliidae larvae and pupae, and Heptageniidae larvae, at four Gura River sites, noting that the prevalence of these interactions varied with the river’s longitudinal gradient. In the Mara River, we detected phoretic interactions between Simuliidae pupae and Tricorythidae larvae, although this was limited to a single site. These findings expand our understanding of phoresy within tropical river systems and highlight the need for more comprehensive research. # Data from: Aquatic hitchhikers: examining the phoretic associations between blackfly (Diptera: Simuliidae) and mayfly (Ephemeroptera: Heptageniidae, Tricorythidae) larvae in Kenyan river ecosystems Dataset DOI: [10.5061/dryad.k3j9kd5nc](doi.org) ## Description of the data and file structure We collected data from seven sites in the Gura River and nine sites in the Mara River, Kenya. We inspected for evidence of phoresy between the macroinvertebrate taxa.  ### Files and variables #### File: Phoresy_Benjamin-et-al._-2025.html **Description:** This is the HTML file for the phoresy analysis #### File: phoresy.gura.csv **Description:** This is a csv file containing the phoresy data for the Gura River ##### Variables * site: The names of the sampling sites  * sim.abund:  The number of Simuliidae abundance.  * hept.abund:The number of Heptageniidae abundance.  * tot.phor: The total number of phoresy noted.  * pct.phor: The perecentage of phoresy in the Gura River  * elevation (m.a.s.l): The elevation/altitude for each site. The units of measurements are (m.a.s.l) * discharge (m^3^/s) (: The discharge data for Gura sites. The units of measurement are (m^3^/s) * velocity (m/s): The velocity of the Gura River sites. The units of measurement are (m/s) * slope: The slope calculated for each site #### File: Mara_River_macros_2023.csv **Description:** This dataset contains macroinvertebrates data collected in the Mara River during 2023 ##### Variables * Site : These are Mara River sites  * Baetidae: Dominant Mayfly taxa * Chironomidae:Dominant Diptera taxa  * Hydropsychidae:Dominant Trichoptera taxa  * Simuliidae :Dominant Diptera taxa * Tricorythidae :Dominant Mayfly taxa #### File: Gura_River_macros_2018.csv **Description:** This dataset contains macroinvertebrates data collected in the Gura River during 2018 ##### Variables * Site:These are Gura River sites  * Heptageniidae:Dominant Mayfly taxa * Simuliidae:Dominant Diptera taxa  * Hydropsychidae:Dominant Trichoptera taxa  * Chironomidae :Dominant Diptera taxa  * Baetidae:Dominant Mayfly taxa #### File: Mara_river_July_2022_macros.csv **Description:** This dataset contains macroinvertebrates data collected in the Mara River during July 2018 ##### Variables * Site:These are Mara River sites  * Baetidae:Dominant Mayfly taxa * Chironomidae:Dominant Diptera taxa  * Hydropsychidae:Dominant Trichoptera taxa  * Simuliidae:Dominant Diptera taxa  * Tricorythidae:Dominant Mayfly taxa #### File: Phoresy_Benjamin_et_al.__2025.Rmd **Description:** This is the R makrdown file for all the anayses for the phoresy paper.  #### File: Gura_River_Oct_2018_macros_sampling.csv **Description:** This dataset contains all macroinvertebrates data collected in the Gura River during Oct, 2018.  ##### Variables * Date: This column shows the date of sampling  * Altitude(m): This is the elevation/ altitude for each site. The units of measurements are (m.a.s.l) * Site Name: This refers to the site name  * Site code:This referes to the site code  * Order :The macroinvertebrate order  * Family : The macroinvertebrate family  * Count: The total count of the macroinvertebrates.  * Abundace(ind/m): The total number of individual per metre.  * FFGs codes: The functional feeding guilds codes  * FFGs:The functional feeding guilds.  * Genus: The macroinvertebrate genus.  * Description: Any further information regarding the taxa.  #### File: Gura_River_Nov_2018_macros_sampling.csv **Description:** This dataset contains all macroinvertebrates data collected in the Gura River during Nov, 2018. ##### Variables * Date: This column shows the date of sampling  * Altitude(m): This is the elevation/ altitude for each site * Site Name: This refers to the site name  * Site code:This referes to the site code  * Order :The macroinvertebrate order  * Family : The macroinvertebrate family  * Count: The total count of the macroinvertebrates.  * Abundace(ind/m): The total number of individual per metre.  * FFGs codes: The functional feeding guilds codes  * FFGs:The functional feeding guilds.  * Genus: The macroinvertebrate genus.  * Description: Any further information regarding the taxa.  #### File: Gura_River_Dec_2018_macros_sampling.csv **Description:** This dataset contains all macroinvertebrates data collected in the Gura River during Dec, 2018. ##### Variables * Date: This column shows the date of sampling  * Altitude (m): This is the elevation/ altitude for each site. The units of measurements are (m.a.s.l) * Site Name: This refers to the site name  * Site code:This referes to the site code  * Order :The macroinvertebrate order  * Family : The macroinvertebrate family  * Count: The total count of the macroinvertebrates.  * Abundace(ind/m): The total number of individual per metre.  * FFGs codes: The functional feeding guilds codes  * FFGs:The functional feeding guilds.  * Genus: The macroinvertebrate genus.  * Description: Any further information regarding the taxa.  #### File: Mara_River_June_2023_macros_sampling.csv **Description:** This dataset contains all macroinvertebrates data collected in the Mara River during June, 2023. ##### Variables * Date :This column shows the date of sampling  * Site name :This refers to the site name  * Site code:This referes to the site code  * Elevation (m):This is the elevation/ altitude for each site * Order :The macroinvertebrate order  * Family :The macroinvertebrate family  * Genus :The macroinvertebrate genus.  * Species : The macroinvertebrate species * Count:The total count of the macroinvertebrates.  #### File: Mara_River_July_2022_macros_sampling.csv **Description:** This dataset contains all macroinvertebrates data collected in the Mara River during July, 2022. ##### Variables * Date :This column shows the date of sampling  * Site name :This refers to the site name  * Site code:This referes to the site code  * Elevation (m):This is the elevation/ altitude for each site. The units of measurements are (m.a.s.l) * Order :The macroinvertebrate order  * Family :The macroinvertebrate family  * Genus :The macroinvertebrate genus.  * Species : The macroinvertebrate species * Count:The total count of the macroinvertebrates.  #### File: Mara_River_June_2022_macros_sampling.csv **Description:** This dataset contains all macroinvertebrates data collected in the Mara River during June, 2022. ##### Variables * Date :This column shows the date of sampling  * Site name :This refers to the site name  * Site code:This referes to the site code  * Elevation (m):This is the elevation/ altitude for each site. The units of measurements are (m.a.s.l) * Order :The macroinvertebrate order  * Family :The macroinvertebrate family  * Genus :The macroinvertebrate genus.  * Species : The macroinvertebrate species * Count:The total count of the macroinvertebrates.  NB: The empty cells throughout the dataset indicate that the information is not available