Microbial "Liver"
Microbial symbionts offer various helps to the Host animal or Plant. In the gut and mouth-less flatworm, Paracatenula endosymbiont plays a different role. What is Paracatenula? It is a flatworm that lives in subtidal sediments. Adult worm lacks mouth and gut. It grows to a maximum of 15mm in length and 0.4mm in width. It has a very smaller genome 1.34 Mb when compared to the related members without symbionts- 4Mb. Paracatenula in sediment (Pic courtesy : https://en.wikipedia.org/wiki/File:Paracatenula_sediment_OJ_2015.tif ) What are the symbionts? Candidatus Riegeria. It is a chemoautotrophic bacterium which lives inside the flat worm. Symbiosis The biomass of the bacterium is greater than that of the host. The bacterium lives in a special structure trophosome(tropho in greek is food). The role of the bacteria is to store the nutrients. Unlike some other symbiont the bacteria are not killed to release the nutrients, rather bacteria rel...