Studies have found significant amounts of thraustochytrids in the stomach contents and feces of Lytechinus variegatus, a sea urchin. This discovery could be due to either ingestion of detritus, containing thraustochytrids or it could potentially be a regular component of the sea urchin species’ stomach. A species of thraustochytrid, Ulkenia visurgensis have also been found in healthy cnidarians in Indian tidal pools using immunofluorescence. Large amounts of the protist have also been discovered in the feces of the salp Pegea confoederata. These discoveries suggest that there is a relationship between thraustochytrids and the invertebrates mentioned, as well as potentially others in marine environments. Barnacle larvae were also found to survive and grow on substrates where thraustochytrids lived compared to surfaces without, potentially indicating a relationship between the two.
