Pomatostegus stellatus ( Abildgaard, 1789 )

Sánchez-Ovando, J. Pablo & Bastida-Zavala, J. Rolando, 2021, Redescription of Pomatostegus stellatus (Abildgaard, 1789) and P. kroyeri Mörch 1863 (Polychaeta: Serpulidae) from the Tropical American coasts, Zootaxa 4970 (3), pp. 495-514 : 497-504

Pomatostegus stellatus ( Abildgaard, 1789)

( Figures 1A–D , 2A–F , 5A–B , 6A–C , 8A , 9 )

Terebella stellata Abildgaard, 1789: 142–144 , pl. A, figs. 5A–B (type locality: West Indies, Caribbean Sea).

Pomatostegus macrosoma .— Schmarda, 1861: 31–32, pl. 21, fig. 182 (type locality: South of Jamaica; in corals “madreporen”); Mörch, 1863: 398–399 (comparison with P. stellatus ); Bastida-Zavala & Salazar-Vallejo 2000: 816 (synonymy based on morphometric analyses).

Pomatostegus brachysoma .— Schmarda, 1861: 32, pl. 21, fig. 183 (type locality: Jamaica; in coral reef); Mörch 1863: 400 (comparison with P. stellatus ); Bush 1910: 498–500 ( Dominica Island, Lesser Antilles); Bastida-Zavala & Salazar-Vallejo 2000: 816 (synonymy based on morphometric analyses).

Pomatostegus stellatus tetrapoma .— Mörch, 1863: 397 (type locality: Saint Thomas, Lesser Antilles); Bastida-Zavala & Salazar-Vallejo 2000: 816 (synonymy based on morphometric analyses).

Pomatostegus stellatus fruticosa .— Mörch, 1863: 397–398 (type locality: Saint Thomas, Lesser Antilles); Rullier 1974: 72, fig. 9A–I (Batabanó Bay, Cuba; 2 m; in sponge); Bastida-Zavala & Salazar-Vallejo 2000: 816 (synonymy based on morphometric analyses).

Pomatostegus quadruplicatus .— Krøyer in Mörch, 1863: 398, pl. 11, fig. 13 (type locality: Saint Croix, Lesser Antilles; referred as P. stellatus pentapoma ); Bastida-Zavala & Salazar-Vallejo 2000: 816 (synonymy based on morphometric analyses).

Pomatostegus stellatus .— Mörch 1863: 396–397, pl. 11, fig. 14 ( Saint Croix and Saint Thomas, Virgin Islands); Benedict 1887: 551, pl. 22, figs 32–35, pl. 23, figs 36–37 ( Jamaica and Cura ҫao, Caribbean Sea; shallow water); Ehlers 1887: 296–300 (East Key, Florida; 24 m); Treadwell 1902: 210 (Caballo Blanco Reef, Guanica Bay and Ensenada Honda, Puerto Rico); Augener 1927: 79, text fig. 7 (Spaanse Water and Caracas Bay, Cura ҫao; on coral and mangrove roots); Treadwell 1928: 483 (near to Saba Island, Antilles; 130 m); Augener 1934: 118 (Los Testigos Archipelago, Venezuela, and Tagduga (now Taganga), Santa Marta, Colombian Caribbean; intertidal to 11 m); Rioja 1958: 293–296, figs 92–100 (Chankanaab Lagoon, Cozumel, Mexican Caribbean; on coral); Zibrowius 1970: 13–14, pl. 3, fig. 16–20 (Abrolhos Archipelago, Brazil; 16–48 m; sand and coral debris); Zibrowius 1973: 61–62 (Setté Cama, Gabonese Republic); ten Hove & San Martín 1995: 17 (De la Juventud Island, Cuba; 1–6 m, on mollusk shells, mangrove roots, rocks, corals and wood debris); Perkins 1998: 95 (checklist of shallow-water polychaetes from Florida); Dueñas 1999: 14 (Santa Marta, Tayrona National Park, Providencia Island, Cartagena Bay and Cispatá Bay, Colombia); Bastida-Zavala & Salazar-Vallejo 2000: 815–817, figs 3b, 5g –q, 6a–d (San Juan, Puerto Rico; De la Juventud Island, Cuba; eastern Mexico: Alacranes Reefs, Ría Lagartos and San Felipe, Yucatán; Contoy Island, Nizuc Point, Nichupté Lagoon, Xcacel, Xcayal, Cozumel Island, Xahuayxol and Chinchorro Bank, Quintana Roo; intertidal to 43 m; under rocks with algae, seagrass and sponges, corals and on cement pier covered by Millepora spp. ); Bastida-Zavala 2009: 531 (identification key for Tropical American coasts); Amaral et al. 2013: 111 (Polychaete catalogue from Brazil); Humann et al. 2013: 83 (Florida, Bahamas and Caribbean Sea; in vivo color photograph); Hepburn et al. 2015: 192, Table 2 (Puerto Morelos reef, calcareous encrusters on artificial substrates); Schrieken & Van Leeuwen 2016: 43 (field guide to the marine fauna of St. Eustatius, in vivo color photograph); Bastida-Zavala et al. 2017: 40–42, Table 1 (fouling plate in Biscayne Bay, Florida); Leon et al. 2019: Table 1S, supplementary information in Excel file (checklist from the Caribbean coast of Colombia); Bastida-Zavala & Sánchez-Ovando 2021: 26 (identification key for Tropical American coasts).

Material examined: 39 specimens.

Veracruz: (Total: 3 spec.), UANL 5672 and 5673, 2 spec. (Pájaros Reef, intertidal zone, on coral, February 24, 2002, coll. V. Díaz-Castañeda); UANL 5832 , 1 spec. (Blanca Reef, intertidal zone, on coral, July 21, 2002, coll. V. Díaz-Castañeda) .

Quintana Roo: (Total: 27 spec.), ECOSUR, 6 spec. (Playa Azul, Cozumel , intertidal zone, on rock, March 25, 2001, coll. HA. ten Hove); ECOSUR, 3 spec. (off SEDENA, Cozumel , 2 m, on Millepora sp. , March 24, 2001, coll. HA. ten Hove); ECOSUR, 1 spec. ( Contoy Island , on rock, March 2, 2001, coll. P. Salazar-Silva); ECOSUR, 2 spec. (Cozumel, on coral, June 5, 1996, coll. S.I. Salazar-Vallejo); ECOSUR-P0355, 1 spec. (Mahahual, on coral, March 22, 2000, coll. S.I. Salazar-Vallejo); ECOSUR-P0356, 1 spec. ( Contoy Island , on coral, June 1, 2000, coll. S.I. Salazar-Vallejo & L.F. Carrera-Parra); ECOSUR-P0357, 8 spec., ( Contoy Island , on coral, February 18, 2001, coll. S.I. Salazar-Vallejo et al.); ECOSUR-P0358, 1 spec. ( Contoy Island , on coral, March 18, 2001, coll. S.I. Salazar-Vallejo et al.); ECOSUR-P1236, 1 spec. ( Contoy Island , on coral, February 22, 1999, coll. S.I. Salazar-Vallejo & L.F. Carrera-Parra); ECOSUR, 1 spec. ( Contoy Island , Ixlache Reef, on coral, 2 m, February 25, 2008, coll. S.I. Salazar-Vallejo & L.F. Carrera-Parra, fixed and preserved in alcohol 96%); ECOSUR, 1 spec. ( Contoy Island , on rock, 3 m, February 26, 2008, coll. S.I. Salazar-Vallejo & L.F. Carrera-Parra, fixed and preserved in alcohol 96%); UMML, 1 spec. (north of Arrowsmith Bank , 21°15’N, 86°21’W, R / V ‘Gerda’, cruise 6717, sta. 883, 37 m, September 9, 1967, specimen dried) .

Jamaica: ( Total : 2 spec. + 1 without radiolar crown), UMML, 2 spec. (south of the island, 17°42.9’N, 76°35.3’W, R / V ‘ Pillsbury’ , cruise 7006, sta. 1206, Isaacs-Kidd mid-water trawl, ~ 50–80 m, July 5, 1970); UMML, 1 spec. (south of Old Harbour Bay, 17°36’N 77°03’W, R / V ‘Pillsbury ‘, cruise 7006, sta. 1215, otter trawl, 24 m, on coral, July 5, 1970) .

Honduras: ( Total : 1 spec.), UMML, 1 spec. (west of Trujillo Bay, 15°58’N, 86°09’W, R / V ‘ Pillsbury’, cruise 6802, sta. 629, otter trawl, 40 m, March 21, 1968) .

Nicaragua: ( Total : 1 spec.), UMML, 1 spec. (east of Miskitos Keys, 15°15’N, 81°51’W, R / V ‘ Pillsbury’, cruise 7101, sta. 1358, otter trawl, 18 m, February 1, 1971) .

Lesser Antilles: (Total: 4 spec.), UMML, 2 spec. (east of Caicos Islands, Turks and Caicos, 21°41’N, 71°23’W, R / V ‘ Pillsbury’ , cruise 7106, sta. 1423, 18 m, July 19, 1971) ; UMML, 1 spec. (north of Antigua Island, Antigua and Barbuda, 17°18’N, 61°52’W, R / V ‘ Pillsbury’ , cruise 6907, sta. 968, otter trawl, 18 m, July 20, 1969) ; UMML, 1 spec. (east of Saint Vincent Island, Saint Vincent and the Grenadines, 13°11’N, 61°06’W, R / V ‘ Pillsbury’ , cruise 6907, sta. 878, Blake trawl, 39 m, July 6, 1969.

Redescription. Tube white, with five longitudinal ridges, the middle largest, forming an elevated crest that ends in a horizontal spine protruding from tube aperture, semi-circular in cross-section; some tubes with shallow transverse ridges ( Fig. 8A ). Body yellowish, 35 mm long. Thorax 5 mm long and 4 mm wide, with seven chaetigers. Abdomen with 95 chaetigers. Radioles with 1–3 bands of brown iridescent pigment ( Fig. 1D ). Opercular peduncle maculated with brown pigment, 10 mm long including the opercular plates, and 2.8 mm wide in the basal plate, with wide wings with the wavy edge; inserted in right lobe ( Fig. 1B–C ). Operculum chitinous, 4 mm long with four concentric festooned shallow dish-shaped plates, successive plates widely separated between each one ( Fig. 1A ). Plates joined by a central hollow column; column tip with one circlet of spines; circlets of spines present at the basis of each plate (immediately below each plate; Fig. 1A ). Thoracic membrane short, extending to segment 3. Collar with two kinds of chaetae, Spirobranchus - type serrated in subapical section and with a wide proximal boss (twice wider than distal blade) and capillaries chaetae ( Fig. 2A ). Thoracic chaetigers with two kinds of chaetae, Apomatus - type ( Fig. 2C ) and limbate ( Fig. 2B ). Abdominal chaetae flat narrow geniculate, with long blade ( Fig. 2D ). Thoracic uncini of segment 5 saw-shaped, with 11–12 teeth ( Fig. 2E ). Abdominal uncini similar to thoracic uncini but smaller, with 7–8 teeth ( Fig. 2F ).

Variability. The tube color varies from white to pale-yellowish, some tubes with shallow transverse ridges, semi-circular to circular in cross-section. Body length variable (n=18, r: 3–49, µ=27.6 ±13.8). Thorax of variable length (n=18, r: 0.6–7, µ=4.4 ±1.6) and width (n=18, r: 0.2–4, µ=2.5 ±1.4), with seven chaetigers (only one specimen with six chaetigers). Abdomen with a variable number of chaetigers (n=13, r: 38–110, µ=79.3 ±25.6). Radioles with or without bands of color. Some specimens with uniformly colored (not maculated) opercular peduncle of variable length, including the opercular plates (n=18, r: 1–18, µ=8.4 ±4.1) and width of basal plate (n=16, r: 1.2–4, µ=2.4 ±0.8). Wings of opercular peduncle with smooth or wavy edge ( Fig. 5B ). Peduncle inserted into right (n=10) or left lobe (n=4). Operculum variable in length (n=18, r: 0.3–6, µ=2.9 ±1.5) and number of plates (n=18, r: 2–6, µ=4 ±1). Operculum with shallow dish-shaped plates ( Figs 1A , 5A–B ). Spirobranchus - type chaetae with wide proximal boss (twice wider than distal blade; Fig. 6A–C ), except in one specimen where the proximal boss is as wide as the distal blade ( Fig. 6C ).

Habitat. Littoral to sublittoral (80 m). On mangrove roots, mollusk shells, corals, sponges, under rocks, wood debris and on a pier covered by Millepora spp. (ten Hove & San Martín 1995; Bastida-Zavala & Salazar-Vallejo 2000). Only one record as fouling fauna in Florida ( Bastida-Zavala et al. 2017).

Distribution. Wider Caribbean, from Florida to southern Brazil ( Fig. 9 ); in the Gulf of Mexico P. stellatus is only recorded from Alacranes Reefs ( Ehlers 1887; Zibrowius 1970; ten Hove & San Martín 1995; Bastida-Zavala & Salazar-Vallejo 2000) and in two reefs from Veracruz (this study).

Remarks. Pomatostegus stellatus was described by Abildgaard (1789); however, type specimens were not established (nor found in the collections of the Zoological Museum Copenhagen by Mary Petersen in 2000). Many authors supposed P. stellatus to have a wide, even circumtropical distribution ( Zibrowius 1970, 1973; Imajima 1977, 1982; Imajima & ten Hove 1984, 1986; Nishi 1995; Bastida-Zavala 2008); however, Bastida-Zavala & Salazar-Vallejo (2000) suggested that the geographical distribution of P. stellatus was limited to the Tropical Western Atlantic only. Ten Hove & Kupriyanova (2009) suggested that the genus Pomatostegus contained three species with limited distributions: Pomatostegus kroyeri Mörch, 1863 , from the Tropical Eastern Pacific region; P. stellatus from the Tropical Western Atlantic and P. actinoceras Mörch, 1863 , with a distribution in the Indian and Western Pacific oceans ( Kupriyanova et al. 2015). The fact that the genus only extremely rarely has been recorded as part of the fouling fauna (e.g., Cai et al. 2004; Bastida-Zavala et al. 2017) might illustrate their limited distributional powers. Only one specimen of P. stellatus has been recorded as part of the fouling fauna from Biscayne Bay, Florida, after the revision of hundreds fouling plates deployed in marinas with salinities averaging 20‰, by 14 consecutive years ( Bastida-Zavala et al. 2017: 5–6, 41). Therefore, it probably would be impossible for the Caribbean species to cross the Panamá Canal ( Bastida-Zavala et al. 2016).

Figures

FIGURE 1. Specimen of Pomatostegus stellatus (Abildgaard, 1789) from Contoy Island, Mexican Caribbean. A. operculum with shallow dish-shaped plates, lateral view; B. opercular peduncle maculated with brown pigment; C. peduncle with wide wings with the wavy edge; D. radiolar crown with bands of brown iridescent pigment.

FIGURE 2. Specimen of Pomatostegus stellatus (Abildgaard, 1789) from Contoy Island, Mexican Caribbean. A. Spirobranchus-type chaeta with a wide proximal boss; B. limbate chaeta; C. Apomatus-type chaeta; D. abdominal chaetae: flat narrow geniculate; E. thoracic uncinus; F. abdominal uncinus.

FIGURE 5. Pomatostegus stellatus: Operculum with shallowly dish-shaped plates. A. specimen from Mahahual, Quintana Roo; B. specimen from Contoy Island, Quintana Roo. P. kroyeri: Operculum with deeply dish-shaped plates. C. specimen from Caleritas Beach, Baja California Sur; D. specimen from Caleta de Chón, Guerrero.

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.

FIGURE 8. Tubes of species of Pomatostegus. A. Tube of P. stellatus, anterior view; B. Tube of P. kroyeri; C. Tube of P. actinoceras; D. Pomatostegus stellatus, in vivo, between a coral colony, from Chinchorro Bank, Mexican Caribbean (C. modified from Bailey-Brock et al. 2012; D. photo by Humberto Bahena, September 2000).

FIGURE 9. Distribution of Pomatostegus stellatus and P. kroyeri, including literature records (closed symbols) and specimens revised (open symbols).