Ancistrosyllis groenlandica McIntosh 1878

Ancistrosyllis cf. groenlandica McIntosh, 1878 Figure 2 A–H Ancistrosyllis groenlandica McIntosh, 1878: 502–503, pl. 65, figs 3, 20. Material examined. BRAZIL: Campos Basin: 23º36’14.863”S, 41º21’30.068”W, 142 m, one specimen, 1.iii.2009 (MNRJP-002694); 21º13’38.229”S, 40º14’58.238”W, 417 m, two specimens, 4.ii.2009 (MNRJP- 002695); 23º39’19.742”S, 41º18’28.369”W, 699 m, one specimen, 28.i.2009 (MNRJP-002696); 22º59’52.085”S, 40º47’43.276”W, 708 m, three specimens, 29.i.2009 (MNRJP-002697); 21º56’11.947”S, 39º57’45.083”W, 720 m, one specimen, 7.ii.2009 (MNRJP-002698). Description. Fixed specimens whitish with dorsal dark orange papillae in transversal bands (Fig. 2A, E). Largest specimen with 73 chaetigers, measuring 15 mm length and 0.28 mm width (MNRJP-002698). Body dorsoventrally flattened; body surface and parapodia covered by small papillae (Fig. 2F, G). Prostomium with short lateral and median antennae present (Fig. 2B, F); eyes absent. Two biarticulated palps (Fig. 2C), palpophore large and palpostyle diminutive only ventrally visible. Proboscis small and cylindrical. Peristomium set off from prostomium, with two pairs of tentacular cirri of equal length, 1.6x longer than lateral antennae (Fig. 2F). Parapodia biramous. Dorsal and ventral parapodial cirri with papillae irregularly distributed; dorsal cirri of the first parapodium about two times longer than those following (Fig. 2C); dorsal cirri slightly longer than ventral cirri (Fig. 2H). Notopodial hooks present from the chaetigers 3 or 4 to last completely formed chaetiger (Fig. 2A, B, E, G). Neuropodial lobe tapered, with about four serrated capillaries. Pygidium tapered, with a pair of cirri covered by papillae (Fig. 2D, G). Distribution. Atlantic Ocean—Canada, Gulf of Saint Lawrence (Pettibone 1966); Brazil, specimens examined in this study; Uruguay and Argentina (Salazar-Vallejo & Orensanz 1991); Portugal and Spain (Parapar et al. 2004). Pacific Ocean—Japan, Sagami Bay, Off Oga, Tsukumo Bay, Suruga Bay (Imajima 1987); USA, California, Santa Maria Basin and western Santa Barbara Channel (Blake 1997). Remarks. Ancistrosyllis groenlandica has one of the most extensive distributions of all Pilargidae, with records from the Arctic to Antarctic, and for the temperate and tropical seas of the Atlantic and Pacific Oceans (Salazar- Vallejo & Orensanz 1991). The original description (McIntosh, 1878) is short and not very informative for some diagnostic; for example, it lacks on the presence of a median antenna or the beginning of notopodial hooks and ventral cirri, which limits inferring variation. Several authors have reported differences in the beginning of notopodial hooks in A. groenlandica, for example, chaetiger 4 or 5 (Pettibone 1963), 4–7 (Hartman 1965), 4–6 (Pettibone 1966), and 3–5 (Blake 1997; Imajima 1987; Katzm ann et al. 1974). Therefore, a wide intraspecific variation was observed. The specimens of A. cf. groenlandica examined in this study are similar to the ones described by Blake (1997) from Santa Barbara Basin, California, USA; although they differ in the beginning of the notopodial hooks, which always appear from chaetigers 3 or 4 in the specimens of this study, while they can appear from chaetigers 3–5 in the specimens from Santa Barbara. Due to the large intraspecific variation and wide geographic distribution described for this species, it is probable that A. groenlandica represents a species complex (Salazar-Vallejo & Orensanz 1991). A ncistrosyllis hamata (Hartman, 1960) Figure 3 A–E Pilargis hamatus Hartman, 1960: 88, pl. 7, figs 4–6. Ancistrosyllis hamata Pettibone 1966: 168–169, fig. 5a–d. Material examined. BRAZIL: Campos Basin: 21º12’14.127”S, 40º42’26.060”W, 15 m, one specimen, 7.iii.2009 (MNRJP-002700); 21º40’22.947”S, 40º58’26.414”W, 17 m, one specimen, 11.iii.2009 (MNRJP- 002699); 21º39’30.939”S, 40º31’25.652”W, 28 m, one specimen, 13.iii.2009 (MNRJP-002701); 22º6’21.254”S, 40º43’39.365”W, 47 m, one specimen, 12.iii.2009 (MNRJP-002702); 22º19’11.331”S, 40º5’44.221”W, 403.9 m, one specimen, 8.vii.2008 (MNRJP-002703); 21º50’2.961”S, 40º5’55.938”W, 476 m, four specimens, 7.ii.2009 (MNRJP-002704); 22º59’53.839”S, 40º47’45.022”W, 692 m, one specimen, 29.i.2009 (MNRJP-002705). Description. Fixed specimens whitish with round orange pigments distributed in transversal bands. Largest specimen with 27 chaetigers, 10 mm length and 0.24 mm width (MNRJP-002699). Body dorsoventrally flattened with few papillae on ventral and dorsal surfaces (Fig. 3A). Prostomium with a pair of conical lateral antennae, median antenna absent, eyes absent. Two biarticulated palps (Fig. 3B), palpophore large and palpostyle diminutive. Proboscis not observed. Peristomium indistinctly set off from prostomium, with two pairs of similar tentacular cirri, 1.67x longer than lateral antennae. Parapodia biramous. Dorsal and ventral parapodial cirri short with conical shape. Dorsal cirri of first chaetiger slightly longer than following (Fig. 3B). Ventral cirri present from the third to the last chaetiger, shorter than dorsal cirri. Notopodium with inflated acicular lobes. Notopodial hooks curved starting between chaetiger 4 and 7 (Fig. 3A), present up to the last completely formed chaetiger (Fig. 3 C–E). Neuropodium with conical lobe, with about six simple hair-like capillaries. Pygidium tapered with a pair of cirri covered by papillae (Fig. 3E). Distribution. Pacific Ocean—USA, southern California (Pettibone 1966); Costa Rica, Gulf of Nicoya and Golfo Dulce (Dean 1998). Atlantic Ocean—Brazil, specimens examined in this study. Remarks. The specimens of Ancistrosyllis hamata herein studied resemble those of A. groenlandica from the same study area regarding the colouration, but they differ in the absence of a median antenna and in having the first ventral cirri from chaetiger 3. This species also resembles Ancistrosyllis jonesi Pettibone, 1966 but differs from the latter in having smaller notopodial lobes and in lacking a median antennae (Pettibone 1966). The specimens described herein are similar to the specimens from California (USA) (50–1500 m) used in the redescription of A. hamata by Blake (1997). On the other hand, specimens of A. hamata from Costa Rica differ from specimens of this study in the beginning of the notopodial hooks; which appear from chaetigers 6–7 in Costa Rica specimens (Dean 1998), and from chaetigers 4–7 in the specimens of this study. This is the first formal record of the species for Brazil.

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.