Phragmatopoma caudata Krøyer in Mörch, 1863

Chávez-López, Yessica, 2020, New species and new records of Phragmatopoma (Polychaeta: Sabellariidae) from Tropical America, Zootaxa 4845 (3), pp. 301-330 : 307-308

Phragmatopoma caudata Krøyer in Mörch, 1863

Figures 4 A–K, 12A

Phragmatopoma caudata Krøyer in Mörch, 1867: 442–444 , pl. 11, figs. 27–30. Type locality: Caribbean Sea.

Phragmatopoma caudata .— Hartman 1959: 473 ( West Indies , catalog of the Polychaeta ); Kirtley 1994: 31–36, figs. 2.3.1–2.3.6 ( Brazil; Miami Beach, Florida; Veracruz, Mexico; Venezuela); Occhini et al. 2009: 739–746, figs. 2–8 (Rio de Janeiro, Brazil) ; Dos Santos et al. 2011: 426–427, figs. 2A–B ( Brazil, 7°01’02”S, 34°47’55”W); de Assis et al. 2012: 12, 32 (do Bessa Beach, Brazil) ; Liñero-Arana 2013; 383–384, fig. 2 ( Venezuela).

Phragmatopoma lapidosa Kinberg, 1867 .— Johansson 1926: 2; Hartman 1944: 348–349, pl. 35, figs. 73–75, pl. 36, fig. 79, pl. 40, figs. 102–103 ( Brazil to Miami, Florida); Hartman 1959: 473 ( Brazil, catalog of Polychaeta ); Amaral 1987: 471–474, fig. 1–6 (characterization of P. lapidosa from Brazilian coast); Lana & Bremec 1994: 212–213 (checklist of polychaetes from South America and identification key); Baez & Ardilla 2003: 103 (Colombian Caribbean).

Material examined. 51 specimens. Veracruz: ECOSUR-P3084, one spec. (La Gallega, 19°13’13”N, 96°09’51”W, July 12, 2000, coll. J. R. Bastida-Zavala) ; ECOSUR-P3085, one spec. (La Mancha, 19°35’24”N, 96°22’41”W, January 23, 2004); ECOSUR-P3086, 13 spec. (La Mancha, 19°35’24”N, 96°22’41”W, January 27, 2004); ECO-SUR-P3087, 13 spec. (La Mancha, 19°35’24”N, 96°22’41”W, April 1, 2004); ECOSUR-P3088, five spec. (Monte Pío, 18°38’45”N, 95°05’47”W, April 2, 2004); ECOSUR-P3089, 15 spec. (La Mancha, 19°35’24”N, 96°22’41”W, May 27, 2004); ECOSUR-P3090, one spec. (La Mancha, July 31, 2004); ECOSUR-P3091, one spec. (Monte Pío, 18°38’45”N, 95°05’47”W, August 1, 2004); ECOSUR-P3092, one spec. (La Mancha, 19°35’24”N, 96°22’41”W, September 23, 2004); ECOSUR-P3093, one spec. (La Mancha, 19°35’24”N, 96°22’41”W, September 27, 2004).

Description. Color pattern of preserved specimens. Body pale yellow ( Fig. 4A ). Outer paleae with amber blade and handle; median plume translucent ( Fig. 4D ). Middle paleae, of the mid-dorsal section of the opercular crown, cherry with dark-amber handle ( Fig. 4E ); mid-ventral paleae, cherry to dark amber from the nape toward the tip ( Fig. 4F ). Inner paleae amber ( Fig. 4G ). Opercular papillae pale yellow. Median ridge with brown eyespots ( Fig. 4C ). Tentacles light brown. Building organ and branchiae pale yellow. Parathoracic chaetae translucent ( Fig. 4 H–I). Abdominal neuropodia with a series of brown points; the last neuropodia completely dark brown ( Fig. 4A ). Abdominal neurochaetae and uncini translucent ( Fig. 4J ). Caudal peduncle dark brown to pale yellow toward distal part ( Fig. 4A ).

Body. Complete specimen of 12 mm total length; parathoracic region 1 mm wide; 27 abdominal segments; caudal peduncle 4 mm long ( Fig. 4A ).

Operculum. Opercular crown and opercular stalk completely fused. Opercular crown conic and circular, protruding in lateral view ( Fig. 4A, B, K ). Three rows of paleae, only two visible: ~50 outer paleae, 22 middle and inner paleae. Outer paleae geniculate with a pair of heterodont teeth, one straight and lacerate, and the other curved; flat blade almost twice longer than wide, serrated margin and without visible transversal thecae; median plume long, slightly longer than the blade, acicular, pectinate and branched distally ( Figs. 2I , 4D ). Median plume straight or slightly curved in lateral view. Middle paleae strongly geniculate with straight peak, smooth surface with transversal thecae; sub-circular nape, straight, smooth surface, wider than peak, and large, 1/3 as long as peak in dorsal middle paleae ( Fig. 4E ) and 2/ 5 in ventral paleae ( Fig. 4F ); small chin, longer than wide, with margin slightly serrated; sharp tip strongly curved in dorsal paleae ( Fig. 4E ), blunted tip falcate in the ventral ( Fig. 4F ). Inner paleae strongly geniculate with straight serrated peak, eight times longer than wide; nape smooth; tip with filaments ( Fig. 4G ). Papillae small and oval. Oral tentacles unbranched. Median ridge long, almost 1/3 as long as opercular stalk, with marginal eyespots ( Fig. 4C ). Median organ absent. Building organ with ‘U’ shape.

Thorax. Chaetiger 1 with a pair of neuropodia.

Parathorax. Three parathoracic segments. Chaetigers with a pair of branchiae. Notopodia with lanceolate chaetae interspersed with capillary chaetae ( Fig. 4H ). Neuropodia with lanceolate chaetae interspersed with small lanceolate chaetae ( Fig. 4I ); neurochaetae thinner than notochaetae.

Abdomen. Segments with a pair of branchiae decreasing in size towards posterior segments. Neurochaetae verticillate of different lengths. Notopodia with a series of uncini with eight pairs of teeth ( Fig. 4J ).

Caudal region. Caudal peduncle elastic and smooth ( Fig. 4A ).

Tube. Tubes with thick sand grains and some fragments of shell ( Fig. 12A ).

Variation. Body measurements varied from 5–19 mm total length, parathoracic region 0.5–1.2 mm wide and caudal peduncle 1–4 mm long. Most specimens were incomplete. The number of paleae varied between 43–65 in outer paleae and 16–26 in middle paleae. The abdominal segments varied from 23–31.

Habitat. Phragmatopoma caudata can build aggregations in sublitoral zone, generally shallower than 10 m depth ( Kirtley 1994).

Distribution. Western Atlantic, from Gulf of Mexico to Southern Brazil ( Nunes et al. 2017) ( Fig. 13 ).

Remarks. The specimens of Veracruz coincided with descriptions of P. caudata by Hartman (1944) and Amaral (1987). Phragmatopoma caudata differs from the other species of the genus by having outer paleae with long median plume, acicular and pinnate, and the presence of eight teeth in notopodial uncini of the abdominal region.

Kirtley (1994) synonymized P. lapidosa with P. caudata . Later, Drake (2007) and Nunes et al. (2017) supported Kirtley’s synonymies with molecular phylogenetics. Recently, Nunes et al. (2017) study demonstrated the presence of two distinct populations of P. caudata in the Atlantic Ocean, one in Florida, another in the Caribbean and Brazilia. Phragmatopoma caudata is probably the most abundant of sabellariids in the Atlantic Ocean. On the other hand, the records of P. caudata from Peru ( Johansson 1926, Hartman 1944) are questionable because of the significant distance between this country and the type locality.

Figures

FIGURE 2. Morphology of body, opercular paleae and chaetae. A, Complete body, ventral view. Morphology of outer paleae: B, Phragmatopoma moerchi; C, P. attenuata. Morphology of middle paleae: D, P. villalobosi n. sp.; E, P. attenutata. Morphology of inner paleae: F–G, P. attenuata. Outer paleae: H, P. digitata; I, P. caudata; J–K, P. californica; L, P. virgini. Middle paleae: M, P. carlosi n. sp.; N, P. balbinae n. sp.; O, P. digitata; P, P. peruensis. Q, Inner paleae of P. balbinae n. sp. R, Capillary chaetae. S, Bipinnate chaetae. T, Lanceolate chaetae. U–V, Verticillate chaetae. W, Uncini. Abbreviation: tbl, total body length; mp, middle paleae; op, outer paleae; Pr, parathoracic region; lt, lateral teeth; pl, median plume; plw, plume width; pll, plume length; bl, blade length; bw, blade width; nw, nape width; nl, nape length; peal, peak length; pew, peak width; cl, chin length; cw, chin width. Modified from: A) Kirtley (1994), B-C, E, I-L) Hartman (1944), H) Rioja (1942).

FIGURE 4. Phragmatopoma caudata Krøyer in Mörch, 1867. A, Complete body, dorsal view. B, Operculum, lateral view. C, Median ridge. D, Outer paleae. E–F, Middle paleae. G, Inner paleae. H, Parathoracic lanceolate notochaetae. I, Parathoracic lanceolate neurochaetae. J, Abdominal uncini. K, Opercular crown, top view. Scale bars: A: 1 mm; B: 500 μm; C: 200 μm; D, H: 50 μm; E–G: 100 μm; I: 30 μm; J: 10 μm; K: 300 μm. Abbreviation: pc, peduncle caudal; op, outer paleae; mp, middle paleae; mr, median ridge; pl, median plume; lt, lateral teeth.

FIGURE 12. Morphology of tubes. A, Phragmatopoma caudata. B, P. digitata. C, P. carlosi n. sp. Tubes of P. balbinae n. sp. with: D, Bryozoans; E, Serpulids and F, Syllids associated. Scale bars: A–B, D: 1 mm; C: 2 mm; E: 500 μm; F: 300 μm.

FIGURE 13. Historical and new records of Phragmatopoma species. Empty symbols indicate previous records.