Tubicolous polychaete worms (Annelida) from Bahia de Chamela Islands Sanctuary, Mexico, with the description of a new bamboo worm Author Yanez-Rivera, Beatriz CONACYT- Centro de Investigacion en Alimentacion y Desarrollo A. C. (CIAD), Unidad Mazatlan en Acuicultura y Manejo Ambiental, Mazatlan, Mexico https://orcid.org/0000-0002-3192-2142 beyariv@ciad.mx Author Tovar-Hernandez, Maria Ana Universidad Autonoma de Nuevo Leon, Facultad de Ciencias Biologicas, Laboratorio de Biosistematica, San Nicolas de los Garza, Nuevo Leon, Mexico https://orcid.org/0000-0002-5263-2830 maria_ana_tovar@yahoo.com Author Galvan-Villa, Cristian Moises Universidad de Guadalajara, Centro Universitario de Ciencias Biologicas y Agropecuarias, Departamento de Ecologia, Zapopan, Mexico https://orcid.org/0000-0003-1927-2500 Author Rios-Jara, Eduardo Universidad de Guadalajara, Centro Universitario de Ciencias Biologicas y Agropecuarias, Departamento de Ecologia, Zapopan, Mexico text Biodiversity Data Journal 2020 8 57572 57572 http://dx.doi.org/10.3897/BDJ.8.e57572 journal article http://dx.doi.org/10.3897/BDJ.8.e57572 1314-2828-8-e57572 CE3CFA74ABAA48A49EB22776C731837F 9627C5A06E285DBFB389A57DFEE8433F Idanthyrsus sp. Idanthyrsus sp. considered as new to science by Chavez-Lopez 2019 : 37-45, figs 9-10. Materials Type status: Other material . Occurrence: catalogNumber: LEMA-PO159 ; recordedBy: Irving Ramirez-Santana ; individualCount: 6 ; Location: higherGeographyID: Pacific Ocean; higherGeography: Tropical Eastern Pacific; continent: America; islandGroup: Islas de Chamela; island: Isla Cocinas; country: Mexico ; countryCode: MX; stateProvince: Jalisco; municipality: La Huerta; minimumDepthInMeters: 3; maximumDepthInMeters: 4; verbatimLatitude: 19°32 '57'' N ; verbatimLongitude: 105°06 '20'' W ; Identification: identifiedBy: Maria Ana Tovar-Hernandez ; Event: samplingProtocol: Snorkel ; eventDate: April 23, 2009 ; year: 2009; month: 4; day: 23; habitat: Rock; fieldNumber: Site 1; Record Level: language: Spanish; institutionID: Universidad de Guadalajara; collectionID: Coleccion Biologica del Laboratorio de Ecosistemas Marinos y Acuicultura; institutionCode: UDG ; collectionCode: LEMA Description Gregarious worms commonly known as "honey comb worms" (as well as I. cretus and I. mexicanus ). Tubes constructed with sea shells fragments (Fig. 8 A). Complete specimens 14.1-14.5 mm long, 1.3-1.5 mm wide, with 26-32 abdominal chaetigers and a caudal peduncle 4-6 mm long. Body divided into four specialised regions: operculum, parathorax (with three segments), abdomen and caudal region where there is a long peduncle (Fig. 8 B). Operculum composed by a crown and a peduncle, forming two not fused lobes (Fig. 8 C). Outer paleae with straight blades basally, then slightly curved towards tips (Fig. 8 F); lateral denticles long, narrow and straight, those from the distal area longer than basal half (Fig. 8 F-G). Inner paleae with straight blades, transversal thecae not easily seen and pointed tips (Fig. 8 H). Two nuchal hooks with limbate area in concave sides (Fig. 8E). Abdominal uncini with seven teeth in side view (Fig. 8 D). Ecology Found in colony mixed with Idanthyrsus cretus . Taxon discussion Chavez-Lopez (2019) recorded this species to Guerrero and Oaxaca and the formal description of the species is under construction ( Chavez-Lopez pers. com. 2020). Specimen from Bahia de Chamela fits the description provided by Chavez-Lopez (2019) , except for the presence of inner paleae with pointed tips versus blunt by Chavez-Lopez (2019) . Judging from her Figure 9D, we considered that the tip is pointed instead of blunt. In addition, in her Figure 10G, an inner palea from a juvenile has a blunt tip, but it seems broken.