New species of Bairdioidea (Crustacea, Ostracoda) from the Southern Ocean and discussions on Bairdoppilata simplex (Brady, 1880),? Bairdoppilata labiata (Müller, 1908) and Bythopussella aculeata (Müller, 1908) *
Author
Brandão, Simone N.
text
Zootaxa
2008
1866
373
452
journal article
10.5281/zenodo.183820
287b1420-5c7c-4a05-ae95-e4c9121b51a6
11755326
183820
Bythocypris praerenis
sp. nov.
(Figs. 22–26)
Etymology
. For its resemblance to
B. reniformis
Brady, 1880
.
Material
: 6 live specimens, 318 V.
Holotype
:
1 A F (SNB 0388), ANDEEP III # 133–2–E,
ZMH
K
41356.
Paratypes
:
1 A F (SNB 0387), 1 (A1) (SNB 0209), 5 RV, 7
LV
, 1 RLV, ANDEEP III # 133–2–E,
ZMH
K
41328; 23 RV, 26
LV
, 20 RLV, 157 V, ANDEEP II, # 132–2–S,
ZMH
K
41329; 3 (A1) (SNB 0275 7),
51 V
, 2 RLV, ANDEEP II, # 133–3–E,
ZMH
K
41330; 2 RLV, 1
LV
, ANDEEP II, # 133–3–S,
ZMH
K
41357.
Distribution.
NW Weddell Sea, Southern Ocean (Atlantic Sector),
1123 to 2084
m
.
FIGURE 22.
Occurrence of
Bythocypris reniformis
informal group (published information) and
Bythocypris praerenis
sp. nov.
Legend: —
type
locality of
B. reniformis
, from
Brady (1880)
and
Puri and Hulings (1976)
; —other localities from
Brady (1880)
; ♢—
Briggs (1978)
; —
Chapman (1941)
; —
Dingle (2003)
; —
Maddocks (1969)
; —
Bythocypris praerenis
sp. nov.
, ANDEEP II # 133; —
Bythocypris praerenis
sp. nov.
, ANDEEP II # 132.
Measurements (
Fig. 23
)
.
Holotype
, LV, L
1.60mm
, H
0.77mm
; RV, L
1.60mm
, H
0.72mm
.
Paratypes
, LV, A L
1.60–1.81mm
, H
0.77–0.90mm
; (A1) L
1.32–1.44mm
, H
0.64–0.71mm
; (A2) L 1.00–
1.14mm
, H
0.53– 0.58mm
; (A3) L
0.84mm
, H
0.44mm
.
FIGURE 23.
Length: height scatter plot of the valves of
Bythocypris praerenis
sp. nov.
Diagnosis
. Carapace very large, subreniform; maximum height anterior to midlength; with numerous, straight, short marginal pore canals. Podomere VI of AII with 1 anterodorsal, tiny seta, 1 long claw, 1 mediumsized, posterodorsal, fused claw, and 2 mediumsized, posterodistal setae. Podomere IV of Md palp with 4 mediumsized setae and 3 mediumsized claws. Vibratory plate of Mx I with 7 strahlen and 25 feathered setae. Fu with 3 to 6 tiny, proximal setae and 3 mediumsized, finely feathered, distal setae. Genital lobe ovatesubtriangular, with a scoopshaped internal process attached to short tube.
Description.
Carapace very large, subreniform, maximum height anterior to midlength, posterior angle obtuse. Lateral surface smooth. RV with anterodorsal margin straight, ventral margin concave. LV outline less sinuous, more evenly rounded, with arched dorsal margin. Calcified inner lamella wide; zone of concrescence fairly narrow, with numerous straight, short radial pore canals. Radial pore canals simple, with or without rim. Three anterior plus one posterior adductor muscle scars. In dorsal view, carapace elongate, maximum width at midlength.
FIGURE 24.
Bythocypris praerenis
sp. nov.
,
Bythocypris polarsterni
sp. nov.
and
Bythocypris
sp. aff.
B. polarsterni
sp. nov.
Legend:
Bythocypris praerenis
sp. nov.
:
A, B
, subfossil paratypes, ANDEEP II # 132 (ZMH K41329);
C–L
; subfossil paratypes, ANDEEP II # 133(ZMH K41330).
Bythocypris polarsterni
sp. nov.
, ANDEEP II, # 134:
N, O,
holotype, A F (ZMH K41314, SNB 0137);
R, S
, paratype (A1) (SNB 0246),
V, W
, paratype (A2) (SNB 0384), (ZMH K 41315).
Bythocypris
sp. aff.
B. polarsterni
sp. nov.
: ANDEEP III, # 80:
P, Q
, A F (SNB 0269),
Y, Z
, (A2) (SNB 0270) (ZMH K41319);
M, X (
ZMH K41318);
T, U
, (A1) (ZMH K41316, SNB 0266).
A, C, F, J, N, P, R, T, V, Y,
RV ev;
B, D, G, K, O, Q, S, U, W, Z
, LV ev;
E
, adductor muscle scars from
I
;
H
, RV iv;
I, X
, LV iv;
M
, adductor muscle scars from
X; L
, RLV dv. Scale bars:
A–D, F–L, N–Z
, 500µm;
E, M
, 20 µm.
FIGURE 25.
Bythocypris praerenis
sp. nov.
Legend:
A, B
, paratype (A1) (ZMH K41330, SNB 0275);
C–G
, holotype, A F (ZMH K41356, SNB 0388).
A,
RV ev;
B
, LV ev;
C
, AI;
D
, AII;
E
, Md;
F
, MxI;
G
, vibratory plate of MxI. Scale bars:
A, B,
500µm;
C, D
, 100 µm;
E–G
, 50µm.
FIGURE 26.
Bythocypris praerenis
sp. nov.
Legend:
A–D, G
, holotype, A F (ZMH K41356, SNB 0388);
E
, paratype, A F (ZMH K41328, SNB 0387);
F
, paratype, (A1) (ZMH K41330, SNB 0275).
A, B
, ApV;
C
, ApVI;
D
, ApVII;
E
, Fu and genital lobes;
F
, Fu;
G
, genital lobe. Scale bars: 100µm.
AI robust, with short and thick podomeres, with not very long setae; suture between podomeres II and II incomplete; chaetotaxy 1(0/0), 2(0/.1); 3(0/.12); 4(.1/0); 5(.2/.2); 6(.2/.23), 7(0/0:45). AII robust, with short and thick podomeres; exopodite with 1 short and 2 long setae; podomere VI with 1 anterodorsal, very short seta, 1 long claw, 1 mediumsized posterodorsal fused claw, and 2 mediumsized posterodistal setae; chaetotaxy 1(0/0:
2i
), 2(1/0), Exopodite(0/0:3), 3(0/.3.2), 4(.2r,2./0), 5(.1.1c./.1r.1c,1), 6(1r,1c,2,1fc). Base of Md with 1 anterodorsal seta, masticatory process with 1 dorsal, bifurcate tooth, 4 trifurcate teeth, plus several short setae; exopodite with 1 very long and 2 long feathered setae; podomere IV of palp with 4 mediumsized setae and 3 mediumsized claws; chaetotaxy of palp 1(0/.1.:
1i
), 2(.1.2./1:
1i
), 3(.5./.1:
2i
), 4(.2./0:3c,2). Vibratory plate of Mx I with 7 strahlen and around 25 setae; palp with 3 long, dorsal, setae 2 long, ventral setae and 1 distal, mediumsized, finely feathered claw. ApV robust, with short and thick podomeres; vibratory plate with 4 strahlen and 9 or 10 feathered setae; chaetotaxy 1(.1.2.23/0:
1i
), 2(.2/0), 3(.1/0), 4(.1/0), 5(0/0:1r,1c,1r). Chaetotaxy of ApVI and
VII 1
(.1.1.2/0), 2(.2/0), 3(.1/0), 4(.1/0), 5(0/0:1r,1c,1r). Fu with 3 to 6 tiny proximal setae, and 3 mediumsized feathered distal seta. One short seta between Fu rods. Genital lobe ovatesubtriangular, with scoopshaped process attached to coiled tube.
Remarks.
Bythocypris praerenis
sp. nov.
is similar to
B. reniformis sensu
Puri and Hulings, 1976
, but the former species presents: (1) larger height to length ratio; (2) larger size (
1.60 to 1.76mm
instead of
1.09mm
); (3) more concave ventral margin; (4) and wider calcified inner lamella, with straight, short marginal pore canals (instead of ramified).
The only three species of
Bythocypris
recorded from the high
Antarctic
region of the Southern Ocean (
B. eltanina
Maddocks, 1969
,
B. spiriscutica
Maddocks, 1969
and
B. promoza
Maddocks, 1973
) plus
B. elongata
Brady, 1880
,
B. mozambiquensis
Maddocks, 1969
,
B. prolata
Maddocks, 1969
are more subtriangular than
B. praerenis
.
Bythocypris affins affins
Brady, 1886
(
sensu
Brady & Norman 1889
: 242, Fig.) is smaller and has a more rounded, less sinuous RV in lateral view, and is also wider, more ovate in dorsal view.
Bythocypris affins madagascarensis
Maddocks, 1969
is higher in relation to length with the maximum height of LV at midlength instead of conspicuously anterior to it.