Paraehlersia longichaetosa Fukuda, Centurión, Nogueira & Martín, 2012, sp. nov.
Creators: name: Fukuda, Marcelo Veronesi
name: Centurión, Romina
name: Nogueira, João Miguel De Matos
name: Martín, Guillermo San
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Phyllodocida
Syllidae
Paraehlersia
Paraehlersia longichaetosa

description: Paraehlersia longichaetosa sp. nov.
Figures 1–3; Table 1
Material examined. Brazil, State of Rio de Janeiro, offshore: 1 spec. (MZUSP 00972), coll. 2 Mar 1998, 21°51’S 40°07’W, 110 m; 1 spec. (ZUEC-POL 9692), coll. 16 Feb 1998, 23°17’S 42°42’W, 100 m; 7 specs (MZUSP 00973; MNCN 16.01/13607, paratype 2), coll. 28 Feb 1998, 23°20’S 41°22’W, 110 m; 13 specs (ZUEC-POL 9687; MZUSP 0 0 970, paratype 1), coll. 28 Feb 1998, 23°26’S 41°15’W, 146–150 m; 1 spec. (MZUSP 00974), coll. 16 Feb 1998, 23°46’S 42°28’W, 497 m; 1 spec. (ZUEC-POL 9698), coll. 15 Feb 1998, 23°49’S 43°14’W, 138 m; 1 spec. (ZUEC-POL 9689), coll. 15 Feb 1998, 23°51’S 42°49’W, 254 m; 10 specs (MZUSP 00975; ZUEC-POL 9691, paratype 3), coll. 14 Feb 1998, 24°02’S 43°30’W, 147 m; 1 spec. (ZUEC-POL 9690), coll. 14 Feb 1998, 24°13’S 43°25’W, 476 m. State of São Paulo, offshore: 2 specs (MZUSP 0 0 971, paratype 4; MNCN 16.01/13608, paratype 5), coll. 9 Jan 1998, 24°07’S 45°51’W, 147 m; 1 spec. (ZUEC-POL 9693), coll. 13 Jan 1998, 25°43’S 45°09’W, 511 m; – Caraguatatuba, offshore: 1 spec. (ZUEC-POL 9695), coll. 29 Jul 2001, 23º44’163”S 45º00’714”W, 38.6 m. State of Paraná, offshore: 1 spec. (ZUEC-POL 9694), coll. 14 Mar 1998, 27º10’S 46º46’W, 480 m; 1 spec. (MZUSP 00976), coll. 17 Mar 1998, 28º40’S 47º25’W, 285 m.
Argentina, Banco Sarmiento, offshore: 4 specs (MACN-In 38370, holotype; MACN-In 38371, paratype 6), coll. 27 Oct 2006, 52°29’S 68°08’W, 16.2 m; 3 specs, coll. 27 Oct 2006, 52°26’S 68°08’W, 22.1 m; 1 spec., coll. 27 Oct 2006, 52°35’S 68°05’W, 64.7 m; 1 spec., coll. 28 Oct 2006, 52°38’S 67°60’W, 29.3 m; 1 spec., coll. 28 Oct 2006, 52°40’S 67°55’W, 28.6 m.
Type series. Data on each specimen of the type series are provided in Table 1.
Description. Holotype (MACN-In 38370) complete specimen, with 54 chaetigers, 6.10 mm long, 0.76 mm wide; largest specimen (paratype 3, ZUEC-POL 9691) with 70 chaetigers, 6.55 mm long, 0.60 mm wide (Table 1); body without colour patterns (Fig. 1 A); peristomium and chaetigers throughout with 1–2 transverse rows of cilia dorsally extending to near bases of dorsal cirri (Fig. 2 A–C, E–G). Palps triangular, longer than prostomium (Figs. 1 A, 2A–B), tips frequently bent ventrally. Prostomium subpentagonal to oval, 2 pairs of eyes in open trapezoidal arrangement and 1 pair of anterior eyespots (Fig. 1 A); median antenna inserted between posterior pair of eyes, usually twice as long as prostomium and palps together, with up to 30 articles distally; lateral antennae inserted in front of anterior pair of eyes, similar to median antenna but about two thirds as long, with up to 15 articles distally (Figs. 1 A; 2A–C). Nuchal organs as 1 pair of dorso-lateral ciliary bands posterior to insertion of median antenna (Fig. 2 C). Peristomium dorsally shorter than subsequent chaetigers, frequently covering nuchal organs (Fig. 2 C); dorsal peristomial cirri about as long as lateral antennae, sometimes irregularly articulated distally; ventral peristomial cirri about two thirds to half length of dorsal peristomial cirri, usually smooth (Fig. 1 A; 2A–B). Dorsal cirri alternating long, filiform, distally irregularly articulated ones, longer than median antenna, with short, smooth ones, about as long as ventral peristomial cirri (Fig. 1 A; 2A). Antennae, peristomial and dorsal cirri throughout with short cirrophores (Fig. 2 B–D, H); ventral cirri digitiform, about same length or shorter than parapodial lobes (Fig. 2 G), ventral cirri of chaetiger 1 oval, shorter than others. Parapodia with minute pores dorsally, close to cirrophores (Fig. 2 D, H); anterior parapodia with small, rounded subcirral papilla underneath each dorsal cirrus (Fig. 1 A; 2D–E, G). Anterior parapodia with 2–8 spiniger-like chaetae and 5–15 falcigers each, 2–4 spiniger-like chaetae and 5–9 falcigers on midbody parapodia, 0–3 spiniger-like chaetae and 4–7 falcigers on each posterior parapodium (Table 1). Spiniger-like chaetae with thin shafts, progressively slightly thinner towards posterior body (Figs. 1 B–D; 3A–B); elongate, slender blades, unidentate to indistinctly bidentate, with short spines on margin (Figs. 1 B–D; 3A–B), 90–42 μm long on anterior body, 120–77 μm long on midbody, 110–75 μm long on posterior parapodia, spiniger-like chaetae absent on last chaetigers (Table 1). Falcigers with slightly spinulated shafts subdistally, tips of shafts with slightly more sigmoid distal beaks towards posterior body, especially on ventralmost chaetae (Figs. 1 B–D; 3A–G); bidentate blades, teeth about same size on anterior body (Figs. 1 B–C; 3A, C–D), distal tooth progressively smaller and subdistal tooth progressively stouter towards posterior body (Figs. 1 D; 3E–G); blades with short spines on margin, spines progressively slightly thinner towards posterior body (Figs. 1 B–D; 3A–G); blades 57–11 μm long on anterior body, 37–12 μm long on midbody, 20–11 μm long on posterior body (Table 1). Dorsal simple chaetae present from midbody (Table 1), sigmoid, distally bidentate with teeth about same size and short subdistal spines (Figs. 1 E; 3H). Ventral simple chaetae on posterior segments only (Table 1), sigmoid, bidentate, distal tooth thin, subdistal tooth distinctly stouter, with short subdistal spines (Figs. 1 F; 3I). Anterior parapodia with up to 4 aciculae each, two of which bent almost at right angle and two irregularly inflated subdistally, apparently hollow, with acute tip (Fig. 1 G); number of aciculae per parapodium progressively decreasing towards posterior body to a single acicula, of second type (Fig. 1 H–I). Pygidium with 2 long, thin anal cirri and conical median papilla. Pharynx through 5–9 segments (Table 1), with crown of 10 papillae surrounding its opening and conical central tooth close to anterior margin; proventricle through 5–8 segments, with 22–28 muscle-cell rows (Fig. 1 A; Table 1).
Remarks. The only other species of Paraehlersia presenting bidentate dorsal simple chaetae with teeth about same size, as P. longichaetosa sp. nov., is P. articulata (Kudenov & Harris, 1995). All other known species of the genus have dorsal simple chaetae distally rounded, truncate or bidentate, but in this case with teeth clearly different in size (Table 2).
Paraehlersia longichaetosa sp. nov., resembles P. articulata also in the morphology of compound and ventral simple chaetae, and in having body and pharynx similar in length. However, P. longichaetosa sp. nov., differs from P. articulata by possessing a slightly larger proventricle (5–8 segments with 22–28 muscle-cell rows, against 5 segments with 22–24 muscle-cell rows as in P. articulata); by presenting short subdistal spines in both dorsal and ventral simple chaetae, while those are smooth in P. articulata; and by having dorsal simple chaetae of similar morphology throughout, all bidentate with short subdistal spines, while P. articulata has dorsal simple chaetae of two types, unidentate in the anteriormost chaetigers with this chaetae, and then bidentate. Furthermore, P. articulata has 2 aciculae per parapodia on anterior body, increasing to 3–4 aciculae on posterior parapodia (Kudenov & Harris 1995), while the number of aciculae per parapodium gradually decreases towards posterior body in all remaining species of the genus.
Etymology. From the Latin ‘ longus ’, meaning long, the term ‘ longichaetosa ’ refers to the elongate blades of spiniger-like chaetae found in this species, the longest known in the genus so far.
description: Published as part of Fukuda, Marcelo Veronesi, Centurión, Romina, Nogueira, João Miguel De Matos & Martín, Guillermo San, 2012, Two new species of Paraehlersia San Martín, 2003 (Polychaeta, Syllidae) from the Atlantic Coast of South America, pp. 38-52 in Zootaxa 3264 on pages 40-46, DOI: 10.5281/zenodo.280733