Occurrence of epibionts associated with meiofaunal basibionts from the world’s largest mangrove ecosystem, the Sundarbans

Abstract

Epibionts–basibionts interaction is an ecological relationship observed across terrestrial and aquatic environments. Ciliate epibionts associated with meiofaunal organisms are ubiquitous throughout marine ecosystems, but their distribution patterns remain largely unknown in mangrove habitats. We studied the occurrence of ciliate epibionts (peritrichids and suctorians) on meiofaunal organisms in the Sundarbans, the world’s largest mangrove ecosystem, during early monsoon of 2015. The present study revealed that 1.13 % of meiofaunal organisms (18 out of 2744 specimens) were infested by ciliate epibionts. The epibionts were found to be adhered to host organisms belonging to free-living nematodes and harpacticoid copepods. Four different species of ciliate epibionts (Cothurnia nova, Pleurophryodendron sp., Thecacineta cothurnioides and Trematosoma rotunda) were associated with four different host meiofaunal species (Chromaspirina parapontica, Dorylaimposis punctata, Stenhelia sp. and Distioculus sp.) as observed in this study. Among them, the epibionts Cothurnia nova and Thecacineta cothurnioides were found in July 2015, while the other epibiont species were encountered in August 2015. The detailed systematic and host frequency and remarks of each ciliate epibiont have been discussed in this study. To the best of our knowledge, this is the first study which reports ciliate epibionts on meiofaunal basibionts from a mangrove ecosystem in India. Our results indicate that the occurrence of epibionts in a mangrove ecosystem (even a human-disturbed site) could be due to habitat heterogeneity and the nature of anthropogenic disturbance.