Eusyllis nonatoi, Fukuda, Marcelo V., Nogueira, João M. M. & Martín, Guillermo San, 2015

Fukuda, Marcelo V., Nogueira, João M. M. & Martín, Guillermo San, 2015, Eusyllinae and “ Incertae sedis ” syllids (Annelida: Syllidae) from South America, with a new species from Brazil and a new combination for a Peruvian species, Zootaxa 3936 (4), pp. 507-537 : 521-525

Eusyllis nonatoi sp. nov.

Figures 9–10 ; Table 1

Material examined. Project ' BIOTA '. Ubatuba—Praia da Fazenda (23°21'25"S 44°51'55"W), on rocky shore: 1 spec., 16 Oct 2001; Praia de Picinguaba (23°22'31"S 44°50'21"W), on rocky shore: 1 spec. (ZUEC-POL 16210), 9 May 2001; 2 specs (ZUEC-POL 16213), 17 Oct 2001; on Sargassum : 27 specs (ZUEC-POL 16211–16212), 8 Jun 2001; 68 specs (holotype, MUSP 2346; paratype 1, ZUEC-POL 16090; paratype 2, MZUSP 2347; 13 paratypes, MZUSP 2348; remaining specs, MZUSP 2494), 18 Oct 2001. Caraguatatuba—Praia Martim de Sá (23°37'34"S 45°22'31"W), on Sargassum : 11 specs (ZUEC-POL 16209), 16 Mar 2001; 52 specs (paratype 3, ZUEC-POL 16091; paratype 4, MZUSP 2354; 2 paratypes, USNM 1273435; remaining specs, MZUSP 2493), 27 Sep 2001. São Sebastião—Praia da Baleia (23°46'48"S 45°39'51"W), on rocky shore: 1 spec. (ZUEC-POL 16208), 8 Apr 2001; on Sargassum : 2 specs (paratypes, MNCN 16.01/13188), 10 Apr 2001; 31 specs ( MZUSP 2492), 14 Nov 2001.

Project ' BIOPOL'. Ubatuba—Praia do Félix (23°23'34"S 44°58'19"W): 1 spec. (ZUEC-POL 16205), 4 Nov 2002; Praia de Domingas Dias (23°30'00"S 45°08'38"W): 1 spec. ( MZUSP 2489), 2 Nov 2002. São Sebastião—Praia da Baleia (23°46'48"S 45°39'51"W): 12 specs ( MZUSP 2487), 23 Jul 2005; 2 specs (ZUEC-POL 16204), 17 Oct 2005; Praia de Toque-Toque Grande (23°50'12"S 45°30'40"W): 13 specs ( MZUSP 2490), 21 Jul 2005. Guarujá—Praia de Pernambuco (23°58'20"S 46°11'02"W): 7 specs ( MZUSP 2491), 22 Jun 2005; 8 specs (ZUEC- POL 16207), 4 Oct 2005. Itanhaém—Praia do Sonho (24°11'44"S 46°48'05"W): 2 specs ( MZUSP 2488), 14 Jun 2003; 1 spec. (ZUEC-POL 16206), 26 Aug 2003.

Type series. All type specimens collected by the Project ' BIOTA ' team. Holotype ( MZUSP 2346), paratypes 1–2 (ZUEC-POL 16090 and MZUSP 2347, respectively) and thirteen paratypes ( MZUSP 2348) collected at Praia de Pincinguaba (23°22'31"S 44°50'21"W), Ubatuba, State of São Paulo, Brazil, intertidal, on assemblage of algae, 18 Oct 2001. Paratypes 3–4 (ZUEC-POL 16091 and MZUSP 2354, respectively) and two other paratypes ( USNM 1273435) collected at Praia Martim de Sá (23°37'34"S 45°22'31"W), Caraguatatuba, State of São Paulo, Brazil, intertidal, on Sargassum , 27 Sep 2001. Two paratypes ( MNCN 16.01/13188) collected at Praia da Baleia (23°46'48"S 45°39'51"W), São Sebastião, State of São Paulo, Brazil, intertidal, on Sargassum , 10 Apr 2001. Morphological data of selected specimens of the type series are provided in Table 1 .

Description. Relatively small bodied, largest specimen examined paratype 2 (MZUSP 2347), 5.56 mm long, 0.33 mm wide, with 41 segments ( Table 1 ). Pigmentation as 2 transverse, dark stripes dorsally per segment, one at each margin, anterior and posterior, usually more evident on midbody chaetigers ( Figs 9 A; 10A). Palps distally rounded, fused along basal 1/3, occasionaly only with tip to distal half bent ventralwards ( Figs 9 A; 10B, D). Prostomium ovate, nearly rounded, with 2 pairs of eyes in open trapezoidal arrangement and 1 pair of small, anterior eyesposts ( Figs 9 A; 10A); lateral antennae inserted slightly anteriorly to anterior pair of eyes, extending slightly beyond palps; median antenna inserted centrally, between eyes or slightly backwards, up to 2.5 times longer than lateral antennae ( Figs 9 A; 10A–B); nuchal organ as a transverse, discontinuous row of cilia around posterior margin of prostomium ( Fig. 10 B). Peristomium dorsally short; dorsal peristomial cirri approximately as long as median antenna or slightly longer, ventral peristomial cirri ~1/4 length of dorsal ones ( Figs 9 A; 10B). Dorsal cirri of chaetiger 1 longer than dorsal peristomial cirri; dorsal cirri of chaetigers 2–6 irregularly alternating in length, between those of dorsal and ventral peristomial cirri; from chaetiger 7 onwards, dorsal cirri alternating in length, longer cirri slightly longer than ventral peristomial cirri, usually directed upwards, shorter cirri approximately same length as ventral peristomial cirri or slightly shorter, usually directed laterally ( Figs 9 A; 10A–B, E). Lateral antennae, ventral peristomial cirri and shorter dorsal cirri spindle-shaped; antennae and cirri throughout smooth to wrinkled, antennae and longer cirri on anterior body frequently distally articulated; cirrophores present ( Figs 9 A; 10A–B, D–E). Ventral cirri ovate, as long as or slightly longer than parapodial lobes ( Fig. 10 D). Parapodial lobes dorsally with 2 tufts of cilia, one close to bases of cirrophores, another near tips of lobes ( Fig. 10 E). Anterior parapodia with 9–10 falcigers each, midbody with 7–13, posterior parapodia with 3–7 falcigers each ( Table 1 ); shafts of falcigers distally spinulated ( Figs 9 B–C; 10C, H–I); blades unidentate, some chaetae on anterior body chaetigers with finely spinulated blades, remaining falcigers with smooth blades; blades with dorso-ventral gradation in length and shape, dorsalmost blades shorter and more strongly falcate, specially on mid- and posterior body, blades ~7–15 µm long ( Figs 9 B–C; 10C, H–I; Table 1 ). Dorsal simple chaetae usually present from anterior body, almost straight, slightly bent distally, spinulated, distally rounded ( Fig. 9 D) to bifid, with nearly inconspicuous teeth ( Fig. 10 I); ventral simple chaetae only present on posteriormost parapodia, bidentate to subbidentate, subdistal tooth smaller than distal one ( Fig. 9 E; Table 1 ). Anterior parapodia with 2 aciculae each, one of which straight, distally tapering, another distally irregularly expanded and spinulated ( Fig. 9 F); mid- and posterior parapodia with 1 acicula each, of the second type ( Fig. 9 G). Pharynx though 3–3.5 segments, opening surrounded by 10 large, rounded papillae, internally with fringe of cilia ( Figs 9 A; 10D, F–G; Table 1 ); central tooth relatively small, slightly conical, in anterior third of pharynx; trepan incomplete, with ~16 small teeth more conspicuous on ventral half, dorsal half frequently just subtly serrated ( Fig. 10 F); proventricle wider than pharynx, relatively short, through 2.5–3 segments, with ~25–30 muscle cell rows ( Fig. 9 A; Table 1 ).

Remarks. Eusyllis nonatoi sp. nov. has falcigers with unidentate blades, as in E. kupfferi and E. maxima ( Monro, 1930) . However, E. kupfferi has blades longer than E. nonatoi sp. nov. (up to 27 µm long) and the characteristic bayonet-shaped dorsal simple chaetae ( San Martín & Hutchings 2006). Eusyllis maxima is a conspicuously larger species, with 80–100 falcigers in each anterior parapodium, dorsalmost falcigers with bidentate blades, and proventricle through 4–10 segments, with ~120 muscle cell rows ( Jiménez et al. 1995).

Etymology. The species is named in honor of Prof. Edmundo Ferraz Nonato, the scientific father, grandfather and great-grandfather of all polychaetologists in Brazil, who recently passed away at the age 93.

Figures

FIGURE 9. Eusyllis nonatoi sp. nov., holotype (MZUSP 2346). (A) anterior body, dorsal view; (B) falcigers, anterior body; (C) falcigers, mid- and posterior body; (D) dorsal simple chaeta; (E) ventral simple chaeta; (F) aciculae, anterior body; (G) acicula, posterior body. Scale bars: A = 230 µm; B – G = 10 µm.

FIGURE 10. Eusyllis nonatoi sp. nov. (A) Anterior and midbody, dorso-lateral view (pharynx everted); (B) anterior body, dorsal view; (C) ventralmost falcigers, anterior body; (D) anterior end, ventral view; (E) midbody parapodia, dorso-lateral view (arrows pointing to tufts of cilia); (F) detail of everted pharynx, dorso-lateral view (to: pharynx central tooth; tre: trepan); (G) detail of pharynx opening; (H) intermediate falcigers, anterior body; (I) dorsalmost falcigers and dorsal simple chaeta, posterior body. Scale bars: A = 100 µm; B = 70 µm; C, H = 2.4 µm; D = 40 µm; E = 32 µm; F = 25 µm; G = 10 µm; I = 4 µm.

Tables

TABLE 1. Morphological variation among selected specimens of the type series of Eusyllis nonatoi sp. nov.

Eusyllis nonatoi sp. nov. HOLOTYPE	PARATYPE 1	PARATYPE 2	PARATYPE 3	PARATYPE 4
MZUSP 2346	ZUEC-POL 16090	MZUSP 2347	ZUEC-POL 16091	MZUSP 2354
Number of chaetigers 44	29	41	41	38
Total length x width at 4.93 x 0.3 proventricle (mm)	2.81 x 0.25	5.56 x 0.33	4.0 x 0.31	3.73 x 0.38
Length of blades of falcigers (Μm) / number of falcigers per parapodium
Anterior body 7–15 / 9–12	7–12 / 9	6–12 / ~10	7–15 / ~9	7–13 / ~10
Midbody 6–12 / 9–12	7–12 / 7–8	7–12 / ~10	7–15 / ~13	7–13 / 13
Posterior body 7–10 / 3–6	7–12 /3–6	7–11 / 3–6	7–12 / 5–7	8–11 / 4–7
Dorsal simple chaetae / 10 / 43 ventral simple chaetae starting from (chaetiger)	22 / 25	13 / 38	32 / 38	31 / 39
Length of pharynx ~4 (chaetigers)	~3	~3	~3 (evert.)	~4 (evert.)
Length of proventricle 2.5–3 (chaetigers)	2.5	3	~3	~4