Four new species of Paranaitis Southern, 1914 (Phyllodocidae, Annelida) from southern and southeastern Brazil
Author
Oliveira, Verônica Maria De
Author
Jacobsen, Danny Eibye
Author
Lana, Paulo
text
Zootaxa
2018
2018-07-09
4444
2
120
136
journal article
29714
10.11646/zootaxa.4444.2.2
f3de278f-f94c-4170-aa4d-addda0a22766
1175-5326
1309536
1A4D6398-EC3A-4279-9846-54EC268CB3D2
Paranaitis cirriformata
sp. nov.
Figs 8–9
Holotype
.
Margin
of continental shelf,
Campos Basin
,
Brazil
,
Hab
17
Foz
15 R01,
21°10'17.4"S
,
40°45'57.0"W
,
20 m
,
22 Jul. 2009
(ZUEC-POL-16339).
Paratypes
.
2 paratypes
, length ranging from
4–11 mm
for 36–104 segments.
Paranaguá Bay
,
Paraná
,
Brazil
:
In
front of
Port Paranaguá
,
25°30'41.6"S
,
48°29'50.3"W
, intertidal,
Aug. 2011
(
1 paratype
, NHMD-207863).
Continental
shelf of
Campos Basin
:
Hab
17
Foz
15 R1
, 21°10'17.4"S, 40°45'57.0"W,
20 m
,
22 Jul. 2009
(1 paratype, ZUEC-POL-16340). Collected in silt-clay, poorly sorted bottoms on the slope and in coarse sand, sorted bottoms on the continental shelf from the intertidal down to a depth of
52 m
.
Diagnosis.
Presence of a pair of cavities or fissures between prostomium and peristomium. Proximal part of proboscis with lateral papillae and dorsal chitinous papillae; 4 longitudinal rows of tubercles, 2 pairs on each side, gradually forming rows of tubercles, terminal part with proboscideal ring with oval papillae. One pair of long, cirriform pygidial cirri.
Description.
Holotype
complete specimen,
10 mm
long for 61 segments,
1.4 mm
wide at median part of body, including parapodia and excluding chaetae. Body long, dorso-ventrally flattened, of uniform width, tapering at posterior end. Prostomium anteriorly rounded, wider than long, with ligule creating distinct depression in posterior part, where nuchal papilla inseres, resembling a rounded button (
Fig. 8A–B
). Nuchal organs present on each side of prostomium (
Fig. 8B
). Paired frontal, conical and robust antennae and palps, of equal size, postero-laterally positioned on prostomium. Antennae and palps 1/4 as long as prostomium (
Fig. 8A–B
). A pair of brown eyes, subepidermal, with lenses, located at posterior margin of prostomium. Proximal part of proboscis with lateral papillae and dorsal chitinous papillae; four longitudinal rows of tubercles, two pairs of rows on each side, terminal part of proboscideal ring with oval papillae (
Fig. 8C
). Terminal ring of proboscis with oval papillae. First and second segments dorso-ventrally fused as a collar, laterally with pair of cavities at border of prostomium (
Fig. 8B
). Four pairs of cylindrical tentacular cirri, biarticulate, with short cirrophores and long cirrostyles, arranged on first three segments. Cirri of segment 1 reaching segment 6. Dorsal and ventral cirri of segment 2 reaching segments 13 and 5, respectively. Dorsal cirri of segment 3 extending to segment 10. Aciculae not observed in segment 2. Neuropodia and ventral cirri from segment 3. Dorsal cirri symmetrical, with asymmetrical, well-developed cirrophores without external extension, rounded, from segment 4. Dorsal cirri longer than wide in anterior segments, clearly wider than long in median segments, and almost as wide as long in posterior segments. Parapodial lobes shorter than dorsal cirri and longer than ventral cirri, with aciculae and neurochaetae. Prechaetal lobes bilobate, asymmetrical and rounded, supraacicular lobe twice as wide as subacicular lobe. Ventral cirri horizontally oriented in relation to parapodial lobes, asymmetrical, on anterior segments oval with rounded edges, on median and posterior segments longer (
Fig. 8D–F
). Compound spinigerous chaetae from segment 3. Rostrum of chaetal shaft asymmetrical, with large, conical main fang, base of fang surrounded by small cylindrical teeth of unequal length; chaetal articles with serrated outer edges (
Fig. 9A–C
). Pygidium with two pairs of cylindrical anal cirri, cirriform and slender. Cylindrical pygidial papilla present (
Fig. 9D
).
Coloration.
Preserved specimens are opaque.
Distribution.
Atlantic Ocean, Brazilian continental margin; areas of the continental shelf in the Campos Basin. Itiberê River in Paranaguá Bay, Paraná—Brazil.
Etymology.
The name of this species is derived from the Latin word
cirrus
(cirrus) and
formis
(shape) and refers to the morphology of the anal cirri.
Remarks.
The small number of specimens, almost all fragmented, hindered the careful observation of the pygidial region. We observed two pairs of pygidial cirri in the
holotype
(ZUEC-POL-16339), but we do not rule out the possibility that this is a morphological anomaly.
Paranaitis cordiformata
sp. nov.
differs from
P. abyssalis
(
Hartmann-Schröder, 1975
)
,
P. benthicola
,
P. bowersi
,
P. caeca
, and
P. uschakovi
in having eyes, but also in the morphology of the dorsal cirri, which are almost circular in
P. abyssalis
and
P. benthicola
, and reniform in
P. caeca
,
P. bowersi
and
P. usachakovi
.
Paranaitis cirriformata
sp. nov.
shares the rounded median dorsal cirri, wider than long, with
P. speciosa
,
but they differ in the presence of a rounded proboscideal papillae in, asymmetrical dorsal cirrophores and cylindrical anal cirri in the first.
P. cirriformata
sp. nov.
iffers from the other species of
Paranaitis
by the presence of nuchal organ on each side of the prostomium (
Kato & Pleijel, 2003
) and cylindrical and long anal cirri. The anal cirri of
P. kosteriensis
are also cylindrical but much shorter than in
P. cirriformata
sp. nov.