Cabira incerta Webster, 1879

Ribeiro, Rannyele Passos, Barbosa, Aline Da Cruz, Freitas, Roberta, Zanol, Joana, Glasby, Christopher J. & Ruta, Christine, 2020, Pilargidae (Annelida: Phyllodocida) from coastal and deep waters of the Southwestern Atlantic, with descriptions of two new species, Zootaxa 4878 (1), pp. 56-76 : 63-64

Cabira incerta Webster, 1879

Figure 5 A–E

Cabira incerta Webster, 1879: 67 , pl. 11, figs 155–157. – Pettibone 1966: 178, figs 11a–c, 12a–e.

Ancistrosyllis incerta Fauvel 1920: 211 .

Material examined. BRAZIL: Campos Basin : 21º40’23.730”S, 40º58’23.765”W, 18 m, one specimen, 19.vii.2009 (MNRJP-002716); 21º55’50.186”S, 40º25’59.434”W, 47 m, one specimen, 23.vii.2009 (MNRJP-002717); 21º59’3.751”S, 40º25’10.170”W, 52 m, two specimens, 25.ii.2009 (MNRJP-002718); 22º45’49.603”S, 41º45’34.188”W, 53 m, two specimens, 16.vii.2009 (MNRJP-002719); 22º7’43,550”S, 40º18’47,006”W, 72 m, one specimen, 5.vii.2009 (MNRJP-002720); 21º23’37.611”S, 40º15’38.642”W, 89m, two specimens, 21.vii.2009 (MNRJP-002721); 21º42’54.432”S, 40º10’14.096”W, 98 m, one specimen, 7.vii.2009 (MNRJP-002722); 23º6’52.268”S, 41º55’13.122”W, 110 m, one specimen, 15.vii.2009 (MNRJP-002723). State of Espírito Santo: Peroá Cangoá : 19°32’00”S, 39°35’00”W, one specimen ( IBUFRJ0421 ) .

Description. Fixed specimens whitish. Largest individual with 92 chaetigers, 30 mm length and 0.40 mm width (at widest point, including parapodia) (MNRJP-002720). Body cylindrical with smooth surface. Prostomium conical with lateral antennae diminutive inserted on the posterior region ( Fig. 5A, C, E ); median antenna and eyes absent. Two biarticulated palps, palpophore large and palpostyle diminutive ( Fig. 5C ). Proboscis with spines distributed in longitudinal series, on the anterior end. Peristomium distinctly set off from prostomium; with two pairs of tentacular cirri 1.3x longer than lateral antennae ( Fig. 5E ). Parapodia inconspicuous. Dorsal and ventral cirri short, papilliform, equal in length. Ventral cirri from third to last chaetiger. Notopodial hook from seventh to last chaetiger ( Fig. 5A, B, D ). Neurochaetae with bidentate tips, from chaetigers 2–4. Pygidium bilobed; cirri absent.

Distribution. Atlantic Ocean—USA, Chesapeake Bay, ( Pettibone 1966); Off Florida and Texas, Gulf of Mexico ( Wolf 1984); Brazil, specimens examined in this study ( Muniz et al. 1996; Paiva 1993); Uruguay ( Salazar-Vallejo & Orensanz 1991). Pacific Ocean—Costa Rica, Gulf of Nicoya ( Dean 1998).

Remarks. Cabira has five described species: Cabira bohajensis Britaev & Saphronova, 1981 from Japan; Cabira brevicirris ( Rangarajan 1964) , from India; Cabira pilargiformis ( Uschakov & Wu 1962) , from the Yellow Sea, China; Cabira rangarajani Mandal, Harkantra and Salazar-Vallejo, 2007 , from India; and Cabira incerta , from the Gulf of Mexico, USA. Cabira incerta is the only species of the genus recorded from the Atlantic and Pacific coasts of the American continent. No morphological differences were found among examined specimens. Differences were observed between the present specimens and those from the Gulf of Mexico ( Wolf 1984). Those specimens have notopodial hooks from chaetigers 7–9 and neurochaetae unidentate, while specimens of this study have the first notopodial hooks from chaetiger 7 and neurochaetae bidentate. However, all characters observed in our specimens match the redescription of Cabira incerta by Pettibone (1966).

Figures

FIGURE 5. Cabira incerta. A.Anterior body showing prostomium, dorsal view. B. Parapodial detail showing notopodial hook, dorsal view. C. Hook in detail, dorsal view. D.Anterior body showing palp and palpostyle in detail, lateral view. E.Anterior end, dorsal view. Abbreviations. La: lateral antenna, Nh: notopodial hook, Pp: palp, Prb: proboscis, Ps: palpostyle, Pt: prostomium, Py: pygidium, Tdc: tentacular dorsal cirrus. Scale bars: 200 µm (A, B, E), 100 μm (C, D).