Euzonus papillatus, Santos & Nonato & Petersen, 2004

Santos, Cinthya S. G., Nonato, Edmundo F. & Petersen, Mary E., 2004, Two new species of Opheliidae (Annelida: Polychaeta): Euzonus papillatus sp. n. from a northeastern Brazilian sandy beach and Euzonus mammillatus sp. n. from the continental shelf of southeastern Brazil, Zootaxa 478 (1), pp. 1-12 : 3

Euzonus papillatus sp. n. ( Figs. 1­3 )

Material examined. Holotype. NE BRAZIL: Sergipe State: Abaís beach, intertidal in sand, 23 Feb. 1996, coll. C. R. G. Parisoto ( MCEM­BPO 1617 ) . — Paratypes. Same data as holotype (3 specimens, MCEM­BPO 1618 ); NE BRAZIL: Sergipe State: Atalaia beach, intertidal in sand, 23 Feb. 1996, coll. C. R . G. Parisoto (1 specimen, MCEM­BPO 1619 ); North BRAZIL: Pará State: Canelas Island , intertidal, medium to coarse sand, May 2002, coll. Kerstin Kober (1 specimen, MCEM­BPO 1620 ) .

Etymology. The specific name refers to the numerous papillae present dorsal to the notopodia of chaetiger 10.

Diagnosis. Euzonus with body weakly divided into three regions; body formula 11a+20b+6a = 37 chaetigers; branchiae bifid; chaetiger 10 with numerous closely apposed papillae in small dorsoventrally oriented oval patch just dorsal to notopodium of each side. Last abranchiate chaetigers biramous and anal cirri of equal size.

Description. Preserved material colorless; color in life unknown. Holotype without recognizable gametes, 9 mm long, with 37 chaetigers; paratypes 5, 7, 8, 11 and 7 mm (Pará State) long. Body wall transparent with gut contents (sand grains) visible; segmentation not clearly defined ( Fig. 1 ). Body soft, flabby, maggot­shaped, with body regions poorly delimited. Prostomium acutely pointed, eyes absent; peristomium achaetous, cephalic region with 2 chaetigers before cephalo­thoracic constriction ( Fig. 1 ); chaetiger 1 biramous. Body formula 11a+20b+6a ( Figs. 1, 2 ). Anterior to pygidium, 6 distinct abranchiate segments forming telescoped anal collar, contracted in holotype ( Fig. 1 ), and extended in one paratype ( Fig. 2 ), with elongate capillary chaetae forming a dorsolateral pygidial cage. Pygidial funnel short, with 6 cirri of equal size on each side. Ventral groove extending from chaetiger 12 to pygidium. Noto­ and neurochaetae all capillaries ( Fig. 1 ), except on posterior abranchiate segments, where capillaries are accompanied by 5–6 special knobbed chaetae ( Fig. 3 ) in both rami. Notochaetae of anteriormost segments and around the pygidial funnel elongate and as long as neurochaetae ( Fig. 1 ). Parapodia poorly developed, chaetae arising from glandular area of body wall. Chaetiger 2 with notochaetae 5­6 times as long as neurochaetae; latter much shorter than those of following segments. Branchiae bifid, with branches of equal size, with tapered tips and folded edges ( Fig. 1 ). Area immediately dorsal to notopodia of chaetiger 10 specialized, with 3 dorsoventral rows of closely apposed lateral papillae (holotype: 7+7+5 papillae; paratypes: 5+5+8; 3+6+6; 2+5+3; 1+4+3+3; 3+4+7) forming a small, dorsoventrally elongate oval patch, reaching less than halfway to middorsum ( Fig. 1 ). Neuropodia with 3 papillae just anterior to neurochaetae on chaetiger 9, 2 papillae on chaetigers 10–11 and 1 on chaetigers 12–15 ( Fig. 1 ).

Pygidium wide at base with equal­sized dorsal anal cirri disposed in a V over pygidium, 6–9 each side.

Records. Abaís and Atalaia beaches, Sergipe State, northeastern coast of Brazil; Canelas Island, Pará State Brazil, northern coast of Brazil.

Figures

FIGURES 1–3. Euzonus papillatus sp. n., NE Brazil: 1. Holotype (MCEM 1617), right lateral view, posterior end contracted, sand grains visible; 2. paratype (MCEM 1620), left lateral view of extended posterior end, real length of chaetae not shown; 3. holotype, detail of subterminal region of chaetae of abranchiate posterior chaetigers showing knob (arrows).