Pilargidae (Annelida: Phyllodocida) from coastal and deep waters of the Southwestern Atlantic, with descriptions of two new species
Author
Ribeiro, Rannyele Passos
0000-0002-0304-7053
Departamento de Biología, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
Author
Barbosa, Aline Da Cruz
0000-0002-6219-1557
Programa de Pós-Graduação em Ciências Ambientais e Conservação, Instituto de Biodiversidade e Sustentabilidade, Universidade Federal do Rio de Janeiro, 27965 - 045, Macaé, RJ, Brazil.
Author
Freitas, Roberta
0000-0002-2178-791X
Departamento de Zoologia, Universidade Federal do Rio de Janeiro, 21941 - 599, Rio de Janeiro, RJ, Brazil. & freitas. r. roberta @ gmail. com; https: // orcid. org / 0000 - 0002 - 0816 - 761 X
freitas.r.roberta@gmail.com
Author
Zanol, Joana
0000-0002-9464-1938
Museu Nacional, Universidade Federal do Rio de Janeiro, 20940 - 040, Rio de Janeiro, RJ, Brazil.
Author
Glasby, Christopher J.
0000-0002-0816-761X
Museum and Art Gallery of the Northern Territory, PO Box 4646, Darwin NT 0801, Australia.
Author
Ruta, Christine
0000-0001-6412-6751
Departamento de Zoologia, Universidade Federal do Rio de Janeiro, 21941 - 599, Rio de Janeiro, RJ, Brazil. & christineruta @ gmail. com; https: // orcid. org / 0000 - 0001 - 6412 - 6751
christineruta@gmail.com
text
Zootaxa
2020
2020-11-12
4878
1
56
76
journal article
7928
10.11646/zootaxa.4878.1.2
ffe57499-723a-4ade-a574-215e0e1f8742
1175-5326
4574027
29DB126D-4751-433B-89BC-EFDD421368F7
Pilargis falconae
sp. nov.
Figures 7
A–C, 8A–D
urn:lsid:zoobank.org:act:
D4F4E539-27F4-4D16-BBF6-574B031AC761
Material examined.
BRAZIL
:
Campos Basin
:
Holotype
:
21º50’2.96”S
,
40º5’55.938”W
,
476 m
, one specimen,
7.ii.2009
(MNRJP-002731).
Comparative material examined
.
Pilargis verrucosa
Saint-Joseph, 1899
: Northeastern Atlantic Ocean:
syntypes
, two specimens, females (MNHN-IA-TYPE1234-5); one specimen, male (MNHN-IA-TYPE1236).
Diagnosis.
Body surface sparsely papillate. Dorsal tentacular cirri 1.5x longer than ventral ones. All dorsal cirri similar in length. Parapodial glands from first chaetiger on dorsal surface and from the sixth chaetiger on ventral surface. Neurochaetae smooth capillaries, limbate with limbus smooth, unidentate.
Description.
Fixed specimen whitish with dark parapodial glands on dorsal and ventral surfaces (
Fig. 7
A–C; 8A, B). The following description is based on the
holotype
: size
20.89 mm
long,
0.90 mm
wide at widest point (including parapodia), 92 chaetigers. Body dorsoventrally flattened (
Fig. 7A
,
8A
). Body surface with papillae minute and sparse, papillae abundant on cirrophores of tentacular and dorsal cirri, antennae and parapodial cirri (
Fig. 8D
). Prostomium with lateral antennae inserted on posterior margin; median antenna and eyes absent (
Fig. 7B
,
8D
). Two biarticulated palps conical (
Fig. 7B
,
8D
), palpophore large and palpostyle diminutive. Proboscis not observed. Peristomium dorsally distinct from prostomium with two pairs of tentacular cirri. Dorsal tentacular cirri 1.5x longer than ventral ones and 2.2x longer than lateral antennae. Parapodia sub-biramous and inflated; all parapodia have ventral and dorsal cirri in conical shape (
Fig. 8B
). Dorsal cirri of first chaetiger 1.2x longer than second one, and as long as following cirri (
Fig. 7B
); ventral cirri shorter than dorsal cirri. Cirrophores of dorsal cirri thick and globose, twice as long as cirrostyles. Parapodial glands darkly pigmented, some brownish to reddish, concentrated in elliptical clusters, present on dorsal surfaces of all parapodia, and on ventral surface from the chaetiger 6 and some absent between chaetigers 30 and 35 (
Fig. 7
A–C), ventral glands smaller than dorsal ones. Neuropodial lobes conical, smaller than dorsal cirri. Neurochaetae smooth capillaries variable in length, limbate with limbus smooth and unidentate tips; up to seven neurochaetae per fascicle (
Fig. 8C
). Posterior end abruptly tapering due to posterior regeneration, 12 regenerating segments; parapodial glands barely visible in regenerated segments (
Fig. 7C
). Pygidium with small papillae present on the posterior margin; anal cirri absent (
Fig. 7C
).
FIGURE 7.
Pilargis falconae
sp. nov.
A. Whole body. B. Anterior end. C. Posterior body showing regeneration. All images in dorsal view. Abbreviations. Dc: dorsal cirrus, La: lateral antenna, Pgl: parapodial gland, Pp: palp, Pt: prostomium, Py: pygidium, Reg: regeneration, Tdc: tentacular dorsal cirrus, Tvc: tentacular ventral cirrus. Scale bars: 2 mm (A), 200 µm (B, C).
Distribution.
Atlantic Ocean—Brazil, Campos Basin, specimen examined in this study.
Remarks.
There is no doubt that the specimen examined belongs to the genus
Pilargis
, due to the absence of notochaetae. Among species with papillae small and sparsely distributed,
P
.
falconae
sp. resembles
P
.
angeli
Salazar-Vallejo & Harris, 2006
,
P
.
berkeleyae
Monro, 1933
,
P
.
maculata
Hartman, 1947
, and
P
.
modesta
Intes & Le Loeuff, 1975
(see
Table 2
). However,
P
.
angeli
is different in lacking parapodial glands either on the dorsal or ventral surface, and in having dorsal tentacular cirri 1.2x longer than ventral ones, while
P
.
falconae
sp. nov.
has dorsal and ventral parapodial glands, and dorsal tentacular cirri 1.5x longer than ventral ones.
Pilargis berkeleyae
differs from
P
.
falconae
sp. nov.
in having parapodial glands only in the most posterior segments and limbate chaetae bidendate, while
P
.
falconae
sp. nov.
has parapodial glands from anterior chaetigers and limbate chaetae unidentate. Both
P
.
maculata
and
P
.
modesta
have dorsal parapodial glands from the first chaetiger. However,
P
.
maculata
differs from
P
.
falconae
sp. nov.
in having bidentate capillaries, sub-spherical glands on the tentacular segment (peristomium), ventral glands from the first or second chaetigers, while
P
.
falconae
has limbate chaetae unidentate, lacks glands in the peristomium, and has ventral glands from the sixth chaetiger. On the other hand,
P
.
modesta
differs in having spherical-shaped glands located in the cirrophore, and cirrostyles one-fifth the length of cirrophores, while
P
.
falconae
sp. nov.
has glands in elliptical clusters on the base of parapodia and cirrostyles half the length of cirrophores.
Etymology.
Name is in honour of Ana Paula da Costa Falcão, marine biologist and member of the PETRO- BRAS technical staff who collaborated in the HABITATS Project.