Revision of Austrosignum Hodgson and Munnogonium George & Strömberg (Paramunnidae) with descriptions of eight new genera and two new species, (Crustacea: Isopoda: Asellota)
Author
Just, Jean
Author
Wilson, George D. F.
text
Zootaxa
2007
1515
1
29
journal article
10.5281/zenodo.177291
f56cdaa1-a402-4512-af2f-04da945e3b75
1175-5326
177291
Austrosignum glaciale
Hodgson, 1910
Figs 2–4
Austrosignum glaciale
Hodgson, 1910
:68
, pl.X, fig.2;
Menzies, 1962
:50
.
Austrosignum grande
Hodgson, 1910
:66
, pl.X, fig.1;
Menzies, 1962
:50
.
Munnogonium grande
(
Hodgson, 1910
)
. —
Bowman & Schultz, 1974
:266
.
Austrosignum grande
Hodgson, 1910
. —
Kussakin, 1982
:94 (senior synonym of
A. glaciale
)
Austrosignum grande
Hodgson, 1910
. —Junior synonym of
A. glaciale
. Corrected synonymy, herein. Not
Paramunna antarctica
(
Richardson, 1906
)
of
Hale (1937)
. —
Menzies, 1962
:52
Type
fixation
.
Lectotype
, Ψ, NHM 1910.3.18.147. — Here designated
Material examined.
Lectotype
. Ovigerous Ψ,
2.1 mm
, Winter Quarters, McMurdo Bay, Ross
Island
,
Antarctica
,
77°51'S
166°36'E
, inside 20-fathom line [
36.5 m
],
January 1902
, 'Discovery' coll., NHM 1910.3.18.147.
Paralectotypes
. 1 preparatory Ψ, 1 young Ψ, same data as
lectotype
, NHM 1910.3.18.148–149.
Other material
. 1 large terminal ɗ (
2.8 mm
), 1 small ɗ, 1 preparatory Ψ, (
syntypes
of
Austrosignum grande
Hodgson, 1910
), Winter Quarters, McMurdo Bay, Ross
Island
,
Antarctica
,
77° 51'S
166° 36'E
, inside 20-fathom line [
36.5 m
],
February and March 1902
, 'Discovery' coll., NHM 1910.3.18.144–146.
1
specimen, North Bay off Cape Evans, McMurdo Sound, Ross
Island
,
Antarctica
,
77° 38.17'S
,
166° 24.5'E
, on sponge,
18 m
, G.D. Wilson and T.E. DeLaca by hand on
SCUBA
,
20 December 1976
, AM P64142. 12 ɗ, 1 Ψ, Davis Station,
Antarctica
,
68o 34.5'S
,
77o 53'E
, M. Tucker, site C,
25 January 1982
,
NMV
J4765. 1 spent Ψ, Davis Station,
Antarctica
,
68o 34.5'S
,
77o 7'E
, M Tucker, site 9,
1 January 1982
,
NMV
J4776. 1 spent Ψ, Davis Station,
Antarctica
,
68o 38'S
,
77o 48'E
, M. Tucker, site 9,
21 December 1981
,
NMV
J4778.
Description
.
Body
ovate; width 0.55 length in female, width 0.47–0.51 length in male (larger value - terminal male), widest at pereonites 3.
Head
longer in male than female, length 0.44–0.50 width (larger value subterminal male), length 0.42 width; length posterior to eyestalks 1.1 anterior length in female, 1.5 anterior length in male.
Frontal margin
without angular lateral margins adjacent to antennae, shallow convex, almost straight medially.
Eyestalks
in female length 4.0 width, male length 3.5–6.3 width (larger value terminal male), apex rounded, long axis angling forward at approximately 30° in female, 40° in male.
Pereonites
1–4 lateral margins not projecting, coxae visible in dorsal view (coxae II-IV not visible in adult females). Pereonite 1 of terminal male greatly enlarged. Pereonite 1 sagittal length in female 1.8 pereonites midline length, in male 1.9 pereonites midline length. Pereonite 1–7 lateral margin rounded.
FIGURE 2
.
Austrosignum glaciale
Hodgson, 1910
.
A
, terminal male.
B
, young male.
C
, female, (A, B and C: syntypes of
A. grande
Hodgson, 1910
).
D
, lectotype, female.
up
, uropod. Scale bar for all habitus figures: 0.5 mm.
FIGURE 3
.
Austrosignum glaciale
Hodgson, 1910
.
A
, terminal male.
B
, young male.
C
, female; (A, B and C: syntypes of
A. grande
Hodgson, 1910
).
D
, lectotype, female.
p1
, pereopod I;
p2
, pereopod II.
Pleon
length 1.90 width in female, 1.60 width in male (n=2).
Pleonite 1
width 0.86–0.91 distance between uropods (largest non-terminal male, n=3), length 0.4 width.
Pleotelson
laterally rounded, lacking inflection between lateral and proximal margins; length in ventral view proximal to pleopod insertion 0.26 total pleotelson length; lateral margin with proximal neck before convex margin; lateral margins smooth; posterior margin forming 80° angle, evenly curving into lateral margin, apex more broadly rounded in terminal male.
Antennula
articles 1–2 combined extending beyond eyestalk apex; article 1 shorter than 2, width subequal to 2, tubular; 4–6 of subequal length, shorter than 3 (3 nearly as long as 4–6 combined).
Antenna
article
3 in
ventral view tubular, width 0.44 length, 5 only slightly longer than article 4; flagellum with 6 articles, proximal article subequal to next article.
Pereopod I
basis anterior margin smooth, length 2.6–3.5 width (largest value female); carpus distal width 0.72–0.96 posterior margin length (largest value terminal male), posterior margin robust setae shafts straight, posterior margin with single spine proximal to robust setae, with crenate ridges (cuticular combs) on square spine between main robust setae; propodus narrowing distally to insertion of dactylus, with crenate ridge on opposing margin.
FIGURE 4
.
Austrosignum glaciale
Hodgson, 1910
.
A
, terminal male.
B
, young male.
C
, female; (A, B and C: syntypes of
A. grande
Hodgson, 1910
).
a
, antenna;
au
,
antennula
;
cv
, head ventral view;
md
, mandible;
mp
, maxilliped;
mx
1 and 2, maxilla 1 and 2;
op
, female operculum;
pl
1 pleopod I;
pt
, pleotelson;
vv
, ventral view. Asterisk, apical setae broken off.
Male
pleopods I
lateral lobes distinctly projecting from midlateral margin, width 0.4 distance to midline; distal projection length 0.31 pleopod total length, forming acute angle, with pointed apices.
Female operculum
ovoid, width 0.67 length.
Uropods
dorsal and directly adjacent to lateral margin of pleotelson.
Size
. Largest ɗ,
2.8 mm
; largest Ψ,
2.2 mm
.
Distribution
. McMurdo Sound to Adelie Land,
Antarctica
. 18– ca.
36 m
.
Remarks
. The following reports with illustrations of
Austrosignum glaciale
and
A. grande
represent incorrect identifications.
Austrosignum glaciale
,
Vanhöffen (1914)
: we have examined Vanhöffen’s material and have found that none of the specimens belong in
Austrosignum
. The bulk of the specimens represent an undescribed species that does not fit
Cryosignum
, either. A few specimens represent other undescribed species.
A. glaciale
, Monod
(1931; not seen, see
Cryosignum
gen. nov.
below),
A. glaciale
,
Nordenstam
(1933; see
Cryosignum
gen. nov.
below),
A. grande
,
Menzies
(1962; see
Cryosignum
gen. nov.
below);
Menzies (1962, caption for his fig. 11)
stated that the specimen illustrated by him is the
holotype
of
Austrosignum grande
. This is incorrect; the only specimen examined by Menzies was the male from southern
Chile
listed in his ‘Material examined’.