New records for associations between peritrich protozoan ciliates (Ciliophora, Sessilida) and polychaete worms (Annelida) from off the southeastern coast of India Author Bharathidasan, Veeraiyan Center ofAdvancedStudyin MarineBiology, Faculty ofMarineSciences, Annamalai University, Parangipettai- 608 502, Tamilnadu, India Laboratório de Poliquetologia (LaPol), Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, Brazil nogueira @ ib. usp. br; https: // orcid. org / 0000 - 0002 - 8450 - 4294 Author Sarathy, Palanivel Partha 0000-0003-2282-4652 Center ofAdvancedStudyin MarineBiology, Faculty ofMarineSciences, Annamalai University, Parangipettai- 608 502, Tamilnadu, India Laboratório de Poliquetologia (LaPol), Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, Brazil nogueira @ ib. usp. br; https: // orcid. org / 0000 - 0002 - 8450 - 4294 & partha 7915 @ gmail. com; https: // orcid. org / 0000 - 0003 - 2282 - 4652 partha7915@gmail.com Author Murugesan, Perumal 0000-0002-1829-9261 Center ofAdvancedStudyin MarineBiology, Faculty ofMarineSciences, Annamalai University, Parangipettai- 608 502, Tamilnadu, India Laboratório de Poliquetologia (LaPol), Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, Brazil nogueira @ ib. usp. br; https: // orcid. org / 0000 - 0002 - 8450 - 4294 & pmurugesaan 74 @ gmail. com; https: // orcid. org / 0000 - 0002 - 1829 - 9261 pmurugesaan74@gmail.com Author Nogueira, João Miguel De Matos 0000-0002-8450-4294 nogueira@ib.usp.br text Zootaxa 2021 2021-11-25 5071 4 492 504 journal article 3303 10.11646/zootaxa.5071.4.2 28f6ffd4-f126-4a8b-8a6e-0b666adecc8e 1175-5326 5726361 030319C1-62CE-4EFE-807A-1A8365026856 1. Terebella (Annelida, Terebelliformia) and Epistylis sp.1 (Ciliophora, Sessilida) Most if not all specimens of Terebella sp. collected at Vellar estuary were severely infested with ciliate epibiont protozoans Epistylis sp.1 . The ciliates were found all over the worms’ bodies, on the buccal tentacles, lips, branchiae and dorsal and ventral body surfaces, but with clear preference for grooved regions on the body wall, such as between neuropodia and along the mid-ventral groove ( Fig. 2A–C ), possibly because these regions are more sheltered. Partially contracted individuals of Epistylis sp.1 are 52.56 µm long, in average, in 50 individuals measured, and were only found in solitary form ( Fig. 2A–E ), ~300–350 individuals per worm, in average, in 10 worms counted. Nevertheless, the tissues of the worm did not show lesions of any type at attachment points, suggesting that the ciliates are more likely ectocommensals, rather than parasites.