Phyllodoce (Ushakov, 1972)

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 : 50-57

Phyllodoce sp. B.

Figure 35–36

Material examined. Two individuals. Margin of continental shelf in the Campos Basin , Brazil , Hab13 Foz23 R1 , 22º1’9.9”S 40º31’54.4”W, 49 m, 12 Mar 2009 ( ZUEC–POL 16531 ); Hab 13 Foz 23 R1 , 22º1’9.9”S 40º31’54.4”W, 49 m, 12 Mar 2009 ( ZUEC–POL 16532 ), Brazil .

Diagnosis. Prostomium oval to rounded with accentuated anterior protuberance. Posterior prostomial region expanded with a nuchal papilla. Anal cirri cylindrical with inflated bases.

Description. Specimens with length ranging from 2–7 mm, 0.5 mm wide at median part of body, including parapodia and excluding chaetae and for 27–40 segments. Body long, dorso-ventrally flattened and tapered posteriorly. Prostomium oval to rounded, longer than wide, with anterior protuberance and posterior expansion, where nuchal papilla situated ( Fig. 35A ). Paired frontal antennae and palps cylindrical and short with similar lengths ( Fig. 35A ). Antennae and palps with 1/4 of prostomial length ( Fig. 35A ). Eyes absent. Proboscis observed through dissection, basally with longitudinal row of four sclerotized cusp-shaped papillae on each side; papillae large, tough, similar to teeth, surrounded by conical papillae obliquely distributed, and separated by non-papillated median-dorsal and median-ventral areas ( Fig. 35 B–C); distal, with six longitudinal rows of prominent tubercles. Terminal ring with 17 oval papillae. 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 5. Dorsal and ventral tentacular cirri of segment 2 reaching segments 8 and 3, respectively. Dorsal tentacular cirri of segment 3 reaching segment 7. Neuropodia with chaetae from segment 2. Dorsal cirri from segment 4, symmetrical, with well-developed cirrophores and lacking dorsal expansions. Dorsal cirri of anterior segments oval to elongated and those from median and posterior segments rounded. Parapodial lobes shorter than ventral cirri, with light brown median aciculae and bundles of chaetae. Prechaetal lobes bilobated, symmetrical and rounded ( Fig. 36 A–D). Ventral cirri from segment 3, horizontally oriented in relation to lobes, asymmetrical and dorso-ventrally flattened; cirri from anterior segments rounded with tapered distal ends and from median and posterior segments slender and elongated ( Fig. 36 A–D). Compound spinigerous chaetae from segment 2. Rostrum of chaetal shaft surrounded by several denticles; articles with serrated outer edges. Pygidium with a pair of cylindrical anal cirri with inflated bases ( Fig. 36 E–F).

Colour. Preserved animals show opaque pigmentation with discrete brown colour in prostomium and parapodial cirri.

Habitat. Sublittoral sandy substrates at 49 m.

Distribution. Atlantic Ocean; Brazil: Margin of the continental shelf in the Campos Basin–Brazil.

Remarks. Phyllodoce sp. B. differs from P. lamella sp. nov. because the latter presents cylindrical ventral tentacular cirri with lateral lamellae. It also differs from P. micrognatha sp. nov. by the median-dorsal cirri that are subrectangular with rounded edges and rounded in P. ovalis sp. nov. The species P. tamoya sp. nov., P. tupana sp. nov. and P. bipapillosa sp. nov. can be readily distinguished from Phyllodoce sp. B by the presence of cordiform dorsal cirri from anterior segments.

Key to species of Phyllodoce currently known from Brazilian waters

1. Uniramous parapodia; eyes present or absent............................................................... 2

- Biramous parapodia; eyes present; oval to rectangular dorsal cirri; lanceolate ventral cirri; proboscis with chitinous papillae and two median-dorsal rows of chitinous plates........................................ Phyllodoce micrognatha sp. nov.

2. Eyes absent; symmetrical parapodial lobes................................................................. 3

- Eyes present; parapodial lobes symmetrical or asymmetrical................................................... 6

3. Ventral and dorsal cirri rounded...................................................... Phyllodoce ovalis sp. nov.

- Ventral cirri elongated; dorsal cirri oval.................................................................... 4

4. Dorsal cirri oval to quadrangular; ventral cirri elongated; prostomium with U–shaped nuchal bars; proximal proboscis part with cuspidate papillae............................................................... Phyllodoce concava sp. nov.

- Eyes absent; dorsal cirri oval; ventral cirri elongated and slender................................................ 5

5. Proboscis with two median-dorsal and six dorso–lateral rows of papillae.................... Phyllodoce lamella sp. nov.

- Proboscis with papillae obliquely distributed in the proximal part; rows of rigid papillae................ Phyllodoce sp. B.

6. Symmetrical parapodial lobes........................................................................... 7

- Asymmetrical parapodial lobes.......................................................................... 8

7. Dorsal cirri cordiform anteriorly, longer than wide, medially sub-rectangular with truncated distal ends and posteriorly rounded, longer than wide; rounded ventral cirri with distal tapered ends; proximal part of proboscis with non-queued papillae and nonpapillose median-dorsal area....................................................... Phyllodoce tamoya sp. nov.

- Dorsal cirri foliaceous anteriorly with tapered distal ends, medially sub-rectangular with tapered ends; rounded ventral cirri; proximal part of proboscis with irregular rows of papillae in dorso–lateral position and irregularly distributed papillae on the dorsal part.............................................................................. Phyllodoce sp. A.

8. Asymmetrical parapodial lobes, with digitiform supraciculars longer than subaciculars; dorsal and ventral cirri rounded anteriorly; proximal part of proboscis with six dorso-lateral rows of papillae............................ Phyllodoce longipes

- Asymmetrical parapodial lobes with rounded distal ends...................................................... 9

9. Dorsal cirri cordiform................................................................................. 10

- Dorsal cirri lanceolate, sub-rectangular, rounded, or foliaceous................................................ 11

10. Dorsal cirri cordiform anteriorly, wider than long, medialy sub-rectangular with rounded edges, and posteriorly as wide as long, rounded; proximal part of proboscis with irregular rows of conical papillae and distal part with less than half the length of proximal part................................................................. Phyllodoce tupana sp. nov.

- Dorsal cirri cordiform anteriorly, longer than wide; proximal part with conical and rounded papillae unevenly distributed; prostomium cordiform........................................................... Phyllodoce bipapillosa sp. nov.

11. Ventral cirri slender or lanceolated....................................................................... 12

- Ventral cirri rounded................................................................................. 13

12. Dorsal cirri sub-rectangular; ventral cirri slender, subulate, much longer than parapodial lobes; proboscis with two types of papillae in oblique rows in dorso–lateral disposition.................................... Phyllodoce colorata sp. nov.

- Dorsal cirri lanceolated, medially sub-rectangular with tapered distal ends; ventral cirri lanceolated; proximal part of proboscis with a median–dorsal row of papillae and six dorso-lateral rows..................................... P. madeirensis

13. Dorsal cirri foliaceous anteriorly, medially subquadrangular with rounded distal ends; ventral cirri rounded; clusters of dorsolateral papillae and one horizontal row in the median-dorsal part of proboscis.................. Phyllodoce thalia sp. nov.

- Dorsal cirri rounded anteriorly, medialy rounded and elongated and posteriorly cordiform; ventral cirri rounded to oval; proximal part of proboscis with six rows of papillae..................................... Phyllodoce brasiliensis sp. nov.

Figures

FIGURE 35. Phyllodoce sp. B. A, anterior end, dorsal view; B, dissected proboscis; C, cuspidate papillae, ventral view; A–C; Holotype. Scales bars: A, 0.15 mm; B, 0.04 mm; C, 0.05 mm.

FIGURE 36. Phyllodoce sp. B. Anterior view of parapodia. A–B, parapodium 5; C–D, parapodium 11; E–F posterior end with pygidium and anal cirri. Scale bars: A–B, E–F, 0.08 mm; C–D, 0.07 mm.