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 Isocirrus tropicus (Monro, 1906) Clymene tropica Monro, 1906 in Monro 1928 : 97-98, figs. 17-18. Isocirrus tropicus .- Salazar-Vallejo 1991 : 275 (syntype re-description and relocation). Euclymene tropica .- Salazar-Vallejo and Diaz-Diaz 2009 : 305 (Key). Materials Type status: Other material . Occurrence: catalogNumber: LEMA-PO154 ; recordedBy: Beatriz Yanez-Rivera ; individualCount: 4 ; Taxon: phylum: Annelida; class: Polychaeta; family: Maldanidae; genus: Isocirrus; Location: higherGeographyID: Pacific Ocean; higherGeography: Tropical Eastern Pacific; continent: America; islandGroup: Islas de Chamela; island: Isla Pajarera; country: Mexico ; countryCode: MX; stateProvince: Jalisco; municipality: La Huerta; maximumDepthInMeters: 4; verbatimLatitude: 19°33 '22'' N ; verbatimLongitude: 105°06 '50'' W ; Identification: identifiedBy: Maria Ana Tovar-Hernandez ; Event: samplingProtocol: Scuba dive ; eventDate: June 25, 2013 ; year: 2013; month: 6; day: 25; habitat: On coral; fieldNumber: Site 21; Record Level: language: Spanish; institutionID: Universidad de Guadalajara; collectionID: Coleccion Biologica del Laboratorio de Ecosistemas Marinos y Acuicultura, Universidad de Guadalajara, Mexico ; institutionCode: UDG ; collectionCode: LEMA Description Incomplete worms 6-36 mm long, 0.5-1.4 mm wide and +12 segments. Cephalic plaque oval with lateral margins notched (Fig. 4 A), basal margin with eight shallow crenulations (Fig. 4 B, E); digitiform palpod in lateral view (Fig. 4 C); nuchal organs straight, parallel, almost full length of plaque. No ocelli, no segmental collars. First segments with acicular spines. Following chaetigers with manubriavicular uncini with three teeth above the main fang with subrostral bristles (hairs or barbules) (Fig. 4 F). Ventral mid-line ridge prominent, from segment 7 to end of body (Fig. 4 H). One pre-anal achaetous segment with tori. Anal funnel present (Fig. 4 D) with 26 distinct alternating triangular cirri: 3-4 long alternated with one short, the longest are 2-3 times the length of short ones (Fig. 4 G). Anus terminal (Fig. 4 G). Taxon discussion Originally described from Taboga (Pacific coast of Panama) to 7-9 m depth in sand at low tide ( Monro 1928 ). It was re-described and transferred to Isocirrus by Salazar-Vallejo (1991) , based on the presence of acicular spines on chaetigers 1-3 and the presence of anal cirri of similar length. According to Salazar-Vallejo (pers. comm. 2020), the inclusion of Euclymene tropica in their key was a mistake ( Salazar-Vallejo and Diaz-Diaz 2009 ); it must be included within Isocirrus , but having subequal anal cirri.