Fig 1.
A map of the Maldives archipelago located to the southwest of India.
Diagram shows the 26 geographical atolls illustrated in green.
Fig 2.
Images of hitchhiker species used for identification.
(A) black trevally (Caranx lugubris), (B) bluefin trevally (Caranx melampygus), (C) giant trevally (Caranx ignobilis), (D) golden trevally (Gnathanodon speciosus), (E) pilot fish (Naucrates doctor), (F) rainbow runner (Elagatis bipinnulata), (G) sharksucker remora (Echeneis naucrates) (juvenile inset), (H) giant remora (Remora remora), (I) little remora (Remora albescens), (J) cobia (Rachycentron canadum), (K) red snapper (Lutjanus bohar), and (L) Chinese trumpetfish (Aulostomus chinensis). All images © The Manta Trust.
Fig 3.
Total presence of hitchhiker species observed with manta rays.
The total number of sightings where each identified hitchhiker species (n = 12) was observed with Mobula alfredi (black) or M. birostris (grey). A (10+1) transformation was used for better visualisation of the data.
Table 1.
Summary of hitchhiker species observed with manta rays.
Fig 4.
Daily mean number of adult Echeneis naucrates (+SE) observed with Mobula alfredi between category groups.
Each category is coloured as per legend with group name below each bar. Letters above each bar correspond to those in brackets after the group name and indicate the groups with a significant difference (p < 0.001).
Fig 5.
Daily mean number of juvenile Echeneis naucrates (+SE) observed with Mobula alfredi between category groups.
Each category is coloured as per legend with group name below each bar. Letters above each bar correspond to those in brackets after the group name and indicate the groups with a significant difference (p < 0.001).
Fig 6.
Heatmaps coloured by season and percentage of sightings where Echeneis naucrates were present.
Includes feeding areas and cleaning stations with > 10 E. naucrates sightings.
Fig 7.
Time series plot showing Mobula alfredi sightings and Echeneis naucrates presence.
The total monthly number of Mobula alfredi sightings 2008–2019, and the percentage of those that had Echeneis naucrates associations.
Fig 8.
Relationship between hitchhiker species presence and significant explanatory variables (p < 0.05) in terms of odds ratio (OR).
Indicates the likelihood of presence in comparison with the reference category shown in the legend. OR values are plotted with 95% confidence intervals (CI; solid horizontal lines). Where the CI does not span 1, the explanatory variable is significantly more likely when OR > 1, and significantly less likely when OR < 1. (A) Mobula alfredi and Echeneis naucrates, (B) M. alfredi and juvenile E. naucrates, (C) M. alfredi and Lutjanus bohar, (D) M. alfredi and Gnathanodon speciosus presence, and (E) M. birostris and Remora remora.
Fig 9.
Daily mean number of Remora remora (+SE) observed with Mobula birostris between category groups.
Each category is coloured as per legend with group name below each bar. Letters above each bar correspond to those in brackets after the group name and indicate the groups with a significant difference (p < 0.001).