Three new species of Diplocirrus Haase, 1915 (Polychaeta: Flabelligeridae) from Campos Basin in SE Brazil
Author
Teixeira, Juliana Henrique
Author
Rizzo, Alexandra Elaine
Author
Santos, Cinthya Simone Gomes
text
Zootaxa
2015
4027
2
287
295
journal article
10.11646/zootaxa.4027.2.8
8dcb1038-d556-49c8-8649-50202fa770f6
1175-5326
236450
9096376A-C64F-46D7-8E75-55B56E495A4F
Diplocirrus acafi
sp. nov.
(
Figure 3
A–D)
Type
material.
Brasil
.
Atlantic Ocean. Southeastern coast, Campos Basin.
Holotype
: (
UERJ
5573-HAB16 C3 R3),
77 m
, 0
3 July 2009
(
22º 46' 50,350" S
41º 3' 39,080" W
).
Paratypes
: 1
paratype
(
UERJ
5574-HAB8 A6 R2),
400.8 m
, 0
1 February 2009
(
23º 37' 53,970" S
41º 19' 47,574" W
), 1
paratype
(
UERJ
5577-HAB13 FOZ 43 R2),
68 m
,
15 March 2009
(
22º 11' 55,016" S
,
40º 32' 14,086" W
) 1
paratype
(
UERJ
5576-HAB16 B4 R2),
107 m
, 0
2 July
. 2009 (
23º 10' 0,820" S
41º 3' 12,720" W
), 1
paratype
(
UERJ
5575-HAB17 FOZ 43 R2),
97 m
,
24 July 2009
(
22º 12' 26,776" S
40º 14' 14,985" W
).
Diagnosis.
Sediment particles of about the same size and homogeneously distributed throughout body, all papillae of the same length along body, 7 noto- and 5 neurochaetae per bundle throughout body.
Description.
Holotype
complete; body cylindrical, anteriorly tapered, light brown;
5 mm
long,
0.4 mm
wide, cephalic cage 0.7 long, for 29 chaetigers.
Paratypes
with 24–32 chaetigers,
3.2–5 mm
long,
0.3–0.5 mm
wide, cephalic cage
0.5–0.7 mm
long. Tunic with thin layer of fine sediment grains, papillate. Papillae ½ as long as neurochaetae, papillae capitate (longer than wide). Fine sediment particles on papillae basis only, papillae are not distributed homogeneously, more numerous on the anterior and posterior region and chaetal lobes, the same-sized throughout. Four rows of papillae per chaetiger. Cephalic hood not exposed. Anterior region not dissected to avoid damage. Cephalic cage chaetae as long as body width. Only notochaetae of chaetiger 1 form cephalic cage, chaetae directed dorsally. Seven notochaetae per bundle throughout, anterior dorsal margin of first chaetiger papillate, papillae similar to those along body. Some notochaetae twice as long as the others in the same bundle, 5 neurochaetae per bundle along body. Chaetigers all of same size. Ventrolateral gonopores absent. Chaetae emerge from body wall. Median notochaetae about ½ of body width. Notochaetae 1/6 longer than neurochaetae. All notochaetae multiarticulated capillaries. Neurochaetae multiarticulated capillaries only in first chaetiger; from chaetiger 2 to end of body, chaetae thicker and falcate. All articles of noto- and neurochaetae of about same length. Neurochaetae thicker than notochaetae and of same thickness along capillary length. Posterior region tapered; terminal anus.
Remarks.
Diplocirrus acafi
sp. nov.
and
D. octobranchus
(Hartman, 1965)
have fine sediment particles only on the base of the papillae, absence of ventrolateral gonopores, and only notochaetae of chaetiger 1 make up the cephalic cage. However,
Diplocirrus acafi
sp. nov.
has sediment of the same size homogeneously distributed, papillae in greater number in the anterior and posterior regions and in chaetal lobes, all papillae of about the same size along the body, 4 rows per chaetiger, 7 noto- and 5 neurochaetae per bundle throughout the body.
Diplocirrus octobranchus
presents sediment particles composed of a few larger sand grains, especially on the dorsum, papillae of varying lengths, longer dorsally and on chaetal lobes, may be as long as chaetae, shorter in the rest of the body, 4–5 rows per chaetiger, 4–5 notochaetae and 2–8 neurochaetae in the first chaetiger, 7 noto- and 2–5 neurochaetae in the median region.
Etymology.
The species epithet,
acafi
, is a composition from Dr.
A
ntonio
Ca
rlos de
F
re
i
tas, whose species is named, for his friendship and contribution to the world of nature photography, including the new species described herein.
Distribution.
Southeastern Atlantic coast, Campos Basin,
Brazil
, in soft bottom from
5 to 174 m
depth.