Phyllodoce brasiliensis, Oliveira & Magalhães & Lana, 2021

Oliveira, Verônica Maria De, Magalhães, Wagner F. & Lana, Paulo Da Cunha, 2021, Ten new species of Phyllodoce Lamarck, 1818 (Phyllodocidae, Annelida) from Brazil, Zootaxa 4924 (1), pp. 1-61 : 12-16

Phyllodoce brasiliensis sp. nov.

urn:lsid:zoobank.org:act:84AC04D9-50F0-448B-8589-75B38BA92378

Figures 8–11

Holotype. Atlantic Ocean ; Maciel River, Paranaguá Bay, Paraná, Brazil, 25°33’23”S 48°24’58”W, 14 m, Aug 2008 ( ZUEC–POL 16520 ).

Paratypes. A total of 3 paratypes, length 95 ± 41.5 mm for 270 ± 58.8 segments: Maciel River , Paranaguá Bay , 25°33’23”S 48°24’58”W, 10 m, Aug 2008 (1 paratype, ZUEC–POL 16519 ). Continental slope in the Campos Basin : Hab 8 Foz 06 R2 , 22º19’3.8”S 40º5’28.5”W, 386 m, 30 Jan 2009 (1 paratype, ZUEC–POL 16464 ); AMBES1 Foz 01 R3 , 19º52’21.5”S 39º59’33.5”W, 28 m, 17 Dec 2010 (1 paratype, ZUEC–POL 18603 ), Brazil .

Diagnosis. A pair of sensory cavities on posterior sides of prostomium. Proximal part of proboscis with 12 longitudinal rows of semicircular papillae regularly distributed on dorsal-ventral and lateral areas. Supracicular lobes bilobated, asymmetrical and with dorsal ramus larger than ventral one.

Description. Holotype complete, 63 mm long, 2.5 mm wide at median part of body, including parapodia and excluding chaetae for 236 segments. Body long, dorso-ventrally flattened and tapered posteriorly ( Fig. 8 A–B). Prostomium triangular on posterior margin, longer than wide, with a pair of sensorial cavities on lateral posterior region and deep dorsal incision where nuchal papilla situated ( Fig. 9A ). Paired frontal antennae and palps conical, short, robust and of similar lengths ( Fig. 9C ). Antennae and palps with 1/4 of prostomial length ( Fig. 8B ). A pair of subepidermal black eyes of median length. Proboscis basally with 12 longitudinal rows of rounded papillae and about 10–18 papillae in each row ( Fig. 9C , 2,3). Distal region with six longitudinal rows of prominent tubercles. Terminal ring with 17 oval papillae ( Fig. 9C , 4 ). Segment 1 not visible dorsally. Four pairs of cylindrical tentacular cirri, biarticulated, with short cirrophores and long cirrostyles, situated on first three segments. Tentacular cirri of segment 1 reaching segment 9. Dorsal and ventral tentacular cirri of segment 2 reaching segments 14 and 10, respectively. Dorsal tentacular cirri of segment 3 extending to segment 15. Neuropodia and ventral cirri from segment 3. Dorsal cirri from segment 4, asymmetrical, with well-developed cirrophores, without dorsal expansions. Dorsal cirri of anterior segments rounded with a discrete tip, cirri from median segments rounded, kidney-shaped and posterior ones cordiform. Anterior and median parapodial lobes longer than ventral cirri, with brown aciculae and bundles of chaetae. Prechaetal lobes bilobate, asymmetrical and rounded; supracicular lobes with twice the length of subaciculars with those of median and posterior segments having even more marked asymmetry ( Fig. 10 C–D). Postchaetal lobes rounded. Ventral cirri horizontally oriented in relation to lobes, rounded, distally pointed, asymmetrical, and dorso-ventrally flattened ( Fig. 10 A–D). Compound spinigerous chaetae from segment 2. Rostrum of chaetal shaft surrounded by several denticles and one larger tooth or one larger pair of conical teeth present; articles with serrated outer edges ( Fig. 11 A–C). Pygidium with a pair of cylindrical anal cirri about seven times longer than wider ( Fig. 11D ).

Colour. Preserved animals show distinct black pigmentation in the prostomium, in the anterior part of the eyes, and in the subdistal ends of the tentacular cirri ( Fig. 9A ). The colouration is more distinct in the parapodial dorsal cirri of large individuals ( Fig. 9B ). Living specimens show green pigmentation especially on inter-segmental areas and dorsal cirri ( Fig. 8 ).

Habitat. Sublittoral sandy substrates, shallow subtidal up to 14 m.

Distribution. Atlantic Ocean; south and southeastern regions: Paranaguá Bay in Paraná. Ilha Grande, S„o Paulo. Northeastern region: Bahia state, Brazil.

Etymology. This conspicuous Phyllodoce species is named after the country in which it was collected. It has been collected in northern and southern Brazil and may be widely distributed.

Remarks. Phyllodoce brasiliensis sp. nov. differs from Phyllodoce mucosa Örsted, 1843 , mistakenly recorded for Brazil ( Nonato 1981; Amaral et al. 2010, 2006 –2012), in having a parapodial supracicular lobe asymmetrical with the upper part shorter than the lower one, and in having 12 rows of papillae distributed throughout the proximal part of the proboscis. In P. mucosa , the proboscidial papillae are distributed in six rows on each side, separated by median-dorsal and median–ventral non–papillated areas ( Pleijel 1993a, b; Viéitez et al. 2004). Considering the disjoint geographical distribution, it is unlikely that P. mucosa occurs in the Western Atlantic.

Phyllodoce brasiliensis sp. nov. is part of a small group of morphologically similar species that includes Phyllodoce maculata (Linnaeus, 1767) , Phyllodoce arenae ( Webster 1879) , and P. groenlandica . These are all large Phyllodoce species with similar overall parapodial morphology. P. arenae is distinct from P. brasiliensis sp. nov. mainly by the body pigmentation (brown in P. arenae and green in P. brasiliensis sp. nov.) and shape of the dorsal cirri (cordiform in P. arenae and kidney-shaped in P. brasiliensis sp. nov.). Gathof (1984) recorded P. groenlandica from the Gulf of Mexico and based on the description and illustrations, it is very likely that the author was referring to P. brasiliensis sp. nov. and not P. groenlandica . Both species are large and robust with cordiform prostomia but P. brasiliensis sp. nov. is distinct from P. groenlandica by having rounder dorsal cirri, accentuated asymmetry of the parapodial lobes, rounder ventral cirri, and presence of chaetae from segment 4.

Figures

FIGURE 4. Terminology used for species description of Phyllodoce. Morphology of parapodial cirri in anterior view: A, dorsal cirrus lanceolate; ventral cirrus rounded; B, dorsal cirrus lanceolate with tapered distal end; ventral cirrus elongated; C, dorsal cirrus cordiform; ventral cirrus lanceolate; D, dorsal cirrus quadrangular to rounded; ventral cirrus long and slender; E, dorsal cirrus cordiform; F, dorsal cirrus rounded, supracicular lobe digitiform. Abbreviations: Cir, cirrophore; deCir, dorsal extension of the cirrophore; Dc, dorsal cirrus; Lob, lobe, Vc, ventral cirrus. Scale Bars: A, 0.04 mm; B, 0.05 mm; C, 0.2 mm; D, 0.1 mm; E, 0.1 mm; F, 0.05 mm.

FIGURE 8. A–B, Phyllodoce brasiliensis sp. nov., dorsal view. Scale bars: A, 1.0 mm; B, 0.8 mm.

FIGURE 9. Phyllodoce brasiliensis sp. nov. A, anterior end in dorsal view; B, anterior end, lateral view showing lateral sensorial cavities with a black arrow; C, lateral view of everted proboscis showing: (C1) short and robust antennae; (C2) proximal area of proboscis with rows of papillae; (C3) distal part with tubercles; (C4) terminal ring of probocis. A–C, Holotype. Scale bars: A–C, 1.0 mm; B, 0.7 mm.

FIGURE 10. Phyllodoce brasiliensis sp. nov. Anterior view of the holotype. A, parapodium 5; B, parapodium 10; C, parapodium 118; D, parapodium 211. Scale bars: A–B, 0.8 mm; C–D, 0.2 mm.

FIGURE 11. Phyllodoce brasiliensis sp. nov. A, subacicular chaetae from an anterior parapodium; B, subacicular chaetae from a posterior parapodium; C, subacicular chaetae from a median parapodium; D, Anal cirri. A–D, Holotype. Scale bars: A. 0.02 mm; B, 0.07 mm; C, 0.01 mm; D, 0.5 mm.