Pomatostegus krØyeri Mörch, 1863: 399 Serpula stellata Grube 1859: 113–114 Salazar-Vallejo & Londoño-Mesa 2004: 55 Serpula stellatus Dean 2004: 165 Pomatostegus kröyeri Dean 2004: 165 Pomatostegus krØyeri Hove & Kupriyanova 2009: 78 Pomatostegus kroyeri Bastida-Zavala et al . 2016: 428–429 Pocillopora damicornis (Linnaeus, 1758)) Bastida-Zavala & Sánchez-Ovando 2021: 26 Pomatostegus stellatus Monro 1928: 100 Monro 1933: 1081 Treadwell 1937: 157 Fauvel 1943: 30 Laverde-Castillo 1986: 128 Laverde-Castillo 1988: 91 Salcedo-Martínez et al . 1988: 84 Salazar-Vallejo 1989: 200 Bastida-Zavala 1995: 25 Gómez et al . 1997: 1071 López-García et al . 1997: 66 Hernández-Alcántara et al . 2003: 9 Salazar-Vallejo & Londoño-Mesa 2004: 55 Bastida-Zavala 2008: 34 Bastida-Zavala et al . 2013: 349 Redescription of Pomatostegus stellatus (Abildgaard, 1789) and P. kroyeri Mörch 1863 (Polychaeta: Serpulidae) from the Tropical American coasts Sánchez-Ovando, J. Pablo Bastida-Zavala, J. Rolando Zootaxa 2021 2021-05-17 4970 3 495 514  Bastida-Zavala et al . 2016: 428–429   Bastida-Zavala 2008: 34  4LQXY Morch, 1863 Morch 1863 [151,570,726,753] Polychaeta Serpulidae Pomatostegus Animalia Sabellida 9 504 Annelida species kroyeri  ( Figures 3A–D, 4A–E, 5C–D, 6D–F, 8B, 9)      Pomatostegus krØyeri Mörch, 1863: 399, pl. 11, Fig. 15. Typelocality: Puntarenas, Costa Rica(re-identification of Grube’s material, below).    Serpula stellata(not Abildgaard, 1789).—  Grube 1859: 113–114( Puntarenas, Costa Rica);  Salazar-Vallejo & Londoño-Mesa 2004: 55(Tropical Eastern Pacific, checklist).    Serpula stellatus(not Abildgaard, 1789).—  Dean 2004: 165(referring to Grube 1859, above).    Pomatostegus kröyeri.—  Dean 2004: 165(list of polychaetes from Costa Rica).    Pomatostegus krØyeri.—ten  Hove & Kupriyanova 2009: 78(worldwide serpulid checklist).    Pomatostegus kroyeri.—  Bastida-Zavala et al. 2016: 428–429, fig. 12H (Marina San Carlos, Sonora; Margarita Island, Magdalena Bay and Caleritas Beach, Baja California Sur; Caleta de Chón, Guerrero; 6 m; off CentroMexicano de la TortugaAquarium, Mazunte, San Agustinillo, Camarón Beach, Puerto Ángel, San Agustín Beach and Montosa Island, Oaxaca; 2–6 m; on mollusk shell, rocks and coral  Pocillopora damicornis(Linnaeus, 1758));  Bastida-Zavala & Sánchez-Ovando 2021: 26(identification key for Tropical American coasts).    Pomatostegus stellatus(not Abildgaard, 1789).—  Monro 1928: 100(Taboga Island, Panamá, 7–9 m, sand and stones);  Monro 1933: 1081(Balboa, Taboga and Coiba Islands, Panamá, intertidal to 18 m, on docks, pools at low tide and in sand);  Treadwell 1937: 157(Arena Bank, Gulf of California, 23°29’N, 109°23’30”W; 91 m);  Fauvel 1943: 30(Cabo Pulmo, Baja California Sur);  Laverde-Castillo 1986: 128(Málaga Bay, Colombian Pacific);  Laverde-Castillo 1988: 91(Curichichi Island, Málaga Bay, on dead coral and rocks);  Salcedo-Martínez et al. 1988: 84(Zihuatanejo, Guerrero);  Salazar-Vallejo 1989: 200(Mexican coasts, checklist);  Bastida-Zavala 1995: 25(Cabo Pulmo Reef, Baja California Sur, on coral; 4–17 m);  Gómez et al. 1997: 1071(Tangolunda and La Entrega beaches, Oaxaca; rocks and coral);  López-García et al. 1997: 66(Coiba Island, Panamá; under rocks);  Hernández-Alcántara et al. 2003: 9(checklist; erroneously cited from Cedros Island, Baja California; misquote of Treadwell’s record of 1937, above);  Salazar-Vallejo & Londoño-Mesa 2004: 55(Tropical Eastern Pacific, checklist);  Bastida-Zavala 2008: 34, fig. 7S (Cabo Pulmo Reef and Loreto Marina, Baja California Sur; 0–17 m); Bastida-Zavala 2009: 531 (identification key for Tropical American coasts);  Bastida-Zavala et al. 2013: 349(Oaxaca, checklist).   Material examined. 11 specimens.    Baja California Sur:( Total: 3 spec.), UMAR-Poly 789, 2 spec., ( Margarita Island, Magdalena Bay,  February 23, 1989, coll. R. Bastida-Zavala); UMAR-Poly 790, 1 spec., ( Caleritas Beach, on coral,  March 10, 2006, coll. D. Herrero-Pérezrul et al., fixed and preserved in alcohol 96%).    Guerrero:( Total: 1 spec.), UMAR-Poly 791, 1 spec.( Caleta de Chón,  6 m, on coral  Pocillopora damicornis,  December 2, 2010, coll. S. Guendolain).  Oaxaca:(Total: 6 spec.), UMAR-Poly 792, 1 spec.(off Centro Mexicanode la Tortuga Aquarium, Mazunte,  2 m, on rock,  June 11, 2013, coll. T. Peregrino & C. Valeriano); UMAR-Poly 793, 1 spec.(San Agustinillo, on mollusk shell,  May 11, 2013, coll. A. Gerónimo et al.); UMAR-Poly 794, 1 spec.(Camarón Beach, on coral,  April 27, 2013, coll. R. Xavier & V. Alvarado); UMAR-Poly 795, 1 spec.(Puerto Ángel, on rocks,  May 3, 2010, coll. H. Sánchez& A. Pineda); UMAR-Poly 796, 1 spec.(San Agustín Beach, 5.8 m, on coral  Pocillopora damicornis,  February 23, 2010, coll. R. Granja & S. Guendolain); UMAR-Poly 797, 1 spec.( Montosa Island,  6 m, on  P. damicornis,  February 22, 2010, coll. R. Granja& S. Guendolain).   FIGURE 6.Variability of  Spirobranchus-type chaetae.  Pomatostegus stellatus: A–B. specimens from Cozumel, Quintana Roo; C. specimen from Contoy Island, Quintana Roo.  P. kroyeri: D. specimen from Margarita Island, Magdalena Bay, Baja California Sur; E. specimen from Caleta de Chón, Guerrero; F. specimen from Camarón Beach, Oaxaca.    Costa Rica:( Total: 1 spec.), UMAR-Poly 835, 1 spec.( Cabo Blanco, Puntarenas, intertidal zone, between basalts,  November 10, 2012, coll. T. F. Villalobos-Guerrero, fixed and preserved in alcohol 96%).   Redescription.Tube with five longitudinal ridges, the middle largest, forming an elevated crest, outer tube surface of brown color, inner surface of white color, semi-circular in cross-section ( Fig. 8B). Body yellowish, 40 mmlong ( Fig. 3D). Thorax 5 mmlong and 3.1 mm wide, with seven chaetigers. Abdomen with 106 chaetigers. Radioles with 1–3 bands of black-blue iridescent pigment ( Fig. 3B). Opercular peduncle maculated with black-blue pigment, 10 mmlong including opercular plates and 3 mmwide in the basal plate; with wide wings; inserted into right lobe ( Fig. 3B–C). Operculum chitinous, 4 mmlong; with three concentric festooned deep dish-shaped plates, successive plates barely separated, connected to a hollow column with a tip with one “free” circlet of spines without accompanying plates; circlets of small spines present at the basis of each plate (immediately below each plate; Fig. 3A–D). Thoracic membrane short, extending to segment 3. Collar chaetae missing at both sides in examined specimen ( Costa Rica, UMAR-Poly 835); other specimens with  Spirobranchus- typechaetae with a narrow proximal boss. Thoracic chaetigers with two kinds of chaetae,  Apomatus- typeand limbate ( Fig. 4A–B). Abdominal chaetae flat narrow geniculate, with long blade ( Fig. 4C). Thoracic uncini of segment 5 saw-shaped, with 10–11 teeth ( Fig. 4D). Abdominal uncini similar to thoracic uncini but smaller, with 7–8 teeth ( Fig. 4E).  Variability.Tubes brown to white, with five longitudinal ridges. Body length variable (n=10, r: 2.1–40, µ=21.3 ±11.8). Thorax with different length (n=9, r: 0.4–5, µ=3.4 ±1.5) and width (n=10, r: 0.2–3.1, µ=1.8 ±0.9). Variable number of abdominal chaetigers (n=6, r: 55–106, µ=69.3 ±19.2). In some specimens, radioles with 1–3 bands of brown iridescent pigment and opercular peduncle without pigmentation. Peduncle, including opercular plates, varying in length (n=10, r: 0.8–10, µ=5.6 ±3), inserted into right (n=6) or left lobe (n=4). Operculum variable in length (n=10, r: 0.2–4, µ=1.9 ±1.1) and number of plates (n=9, r: 3–8, µ=5 ±1). All opercular plates deeply dish-shaped. On the specimen used for this description (UMAR-Poly 835) the opercular plates are more widely separated than in other reviewed specimens ( Figs 3A–D, 5C–D). All specimens with seven thoracic chaetigers. Collar with  Spirobranchus- typechaetae with a narrow proximal boss (1.3:1 wider than distal blade) with many teeth; denticulate capillaries present as well ( Fig. 6D–F).  Habitat.Littoral to sublittoral ( 64 m, Treadwell 1937). Below rocks, on live or dead coral (  Pocillopora verrucosa(Ellis & Solander, 1786)and  P. damicornis), oysters and pier piles ( Bastida-Zavala 2008). Occasionally part of fouling fauna ( Bastida-Zavala et al.2016).   Distribution.Tropical Eastern Pacific, from the Gulf of California to Colombia( Bastida-Zavala 2008).   Remarks. Mörch (1863: 399, pl. 11, Fig. 15) described the species from the Pacific of Costa Ricaas  Pomatostegus krØyeri; however, here the spelling was corrected because the ICZN Art.32.5.2.1 explicitly states that an “o slash” (ø), as in Mörch’s original  krØyeri, should be corrected to an “o” without slash. The typespecimens are not in the Zoologisk Museum, Copenhagen, and are presumably lost. The records of  Pomatostegus stellatusfrom the Tropical Eastern Pacific region are questionable, as was mentioned in the previous species. In this work, we demonstrate that  P. kroyeridiffers from  P. stellatusin the shape of the opercular plates and  Spirobranchus- typechaetae:  Pomatostegus kroyerihas deep dish-shaped opercular plates and the  Spirobranchus- typechaetae have a narrow proximal boss, while  P. stellatushas shallow dish-shaped plates and a wide proximal boss in the  Spirobranchus- typechaetae. 3127696312 1989-02-23 R Bastida-Zavala Total Bay Margarita Island 9 504 5 Baja California Sur 3127696325 2006-03-10 D. Herrero-Perezrul Caleritas Beach 9 504 1 Magdalena 3127696309 2010-12-02 de Chon & S. Guendolain 6 Caleta de Chon Total 9 504 2 Guerrero 3127696317 2010-02-22 2013-06-11 2010-02-22 T, R, V T. Peregrino & C. Valeriano Haiti Montosa Island 2 Mexicano Mazunte 9 504 6 Centre 3127696304 2010-02-22 2013-06-11 2010-02-22 T, R, V A. Geronimo Haiti Montosa Island 2 Mexicano Mazunte 9 504 6 Centre 3127696330 2010-02-22 2013-06-11 2010-02-22 T, R, V R. Xavier & V. Alvarado Haiti Montosa Island 2 Mexicano Mazunte 9 504 6 Centre 3127696311 2010-02-22 2013-06-11 2010-02-22 T, R, V H. Sanchez & A. Pineda Haiti Montosa Island 2 Mexicano Mazunte 9 504 6 Centre 3127696321 2010-02-22 2013-06-11 2010-02-22 T, R, V R. Granja & S. Guendolain Haiti Montosa Island 2 Mexicano Mazunte 9 504 6 Centre 3127696322 2010-02-22 2013-06-11 2010-02-22 T, R, V R. Granja & S. Guendolain Haiti Montosa Island 2 Mexicano Mazunte 9 504 6 Centre 3127696323 2012-11-10 T F. Villalobos-Guerrero Costa Rica Cabo Blanco Total 11 506 2 Puntarenas