The Tryphosa group (Crustacea: Amphipoda: Lysianassoidea: Lysianassidae: Tryphosinae)
Author
Kilgallen, N. M.
Author
Lowry, J. K.
text
Zootaxa
2014
2014-02-28
3768
5
501
545
journal article
5767
10.11646/zootaxa.3768.5.1
4c0b59ec-84a8-4daa-8467-3ac34e86ecd6
1175-5326
4909684
FACF814C-3221-44CF-9DED-4B808F186C64
Pseudonesimus robustus
(J.L.
Barnard, 1961
)
comb. nov.
(
Figs 6–8
)
Ambasiopsis robustus
J.L.
Barnard, 1961: 30
, fig. 1.
Schisturella robusta
.―J.L.
Barnard, 1966: 71
(key).―
Barnard & Karaman, 1991: 527
.―
Larsen, 2007: 14
(key).
Schisturella robusta robusta
.―J.L.
Barnard, 1967: 72
(key).―
Barnard & Ingram, 1990: 31
(key).―
Barnard & Karaman, 1991: 527
.―
Hendrycks & Conlan, 2003: 2333
, fig. 13.
Types
.
Holotype
, male,
10 mm
,
ZMUC
CRU-1976
.
Type
locality.
Off Fiordland
,
South Island
,
New Zealand
(
44º18'S
166º46'E
), clay,
3580 m
depth
.
Material examined.
1 female
, 9.0 mm,
NMV
J46957
, from off
Freycinet Peninsula
,
Tasmania
,
Australia
(
42°0.20'S
148°37.70'E
),
720 m
, coarse shelly sand,
WHOI
epibenthic sled,
27 July 1986
,
M.F. Gomon
et al,
RV
Franklin
stn slope 46
;
6 specimens
,
NMV
J46958
, from off
Freycinet Peninsula
,
Tasmania
,
Australia
(
42°0.20'S
148°37.70'E
),
720 m
, coarse shelly sand,
WHOI
epibenthic sled,
27 July 1986
,
M.F. Gomon
et al
.,
RV
Franklin
stn slope 46
;
4 specimens
,
NMV
J46959
, from off
Freycinet Peninsula
,
Tasmania
,
Australia
(
42°2.20'S
148°38.70'E
),
800 m
, coarse shelly sand,
WHOI
epibenthic sled,
27 July 1986
,
M.F. Gomon
et al,
RV
Franklin
stn slope 45
;
1 specimen
,
NMV
J46960
, from off
Freycinet Peninsula
,
Tasmania
,
Australia
(
42°2.20'S
148°38.70'E
),
800 m
, coarse shelly sand,
WHOI
epibenthic sled,
27 July 1986
,
M.F. Gomon
et al,
RV
Franklin
stn slope 45
.
Description.
Based on female, 9.0 mm, NMV
J46957
.
Head
lateral cephalic lobe subtriangular, apically subacute; eyes apparently absent.
Antenna 1
peduncular article 1 without anterodistal lobe; article 2 without anterodistal lobe; accessory flagellum present, forming cap partially covering callynophore, terminal article not offset; flagellum with strong 2-field callynophore, robust setae absent from proximal articles; calceoli absent.
Antenna 2
peduncular article 3 short, articles 3 to 5 not enlarged, articles 4–5 with brush setae on the anterior margin; flagellum short, calceoli absent.
Epistome/upper lip
separate; epistome less produced than upper lip, straight;
upper lip produced, rounded apically
.
Mandible
molar with reduced column and convex strongly triturating surface.
Maxilla 1
outer plate setal-tooth 7 present, left and right symmetrical, not cuspidate; palp distal margin with apical robust setae.
Maxilliped
basis without recurved hook; outer plate with 2 long, broad apical robust setae.
FIGURE 6.
Pseudonesimus robustus
(J.L.
Barnard, 1961
)
, female
habitus
, 9.0 mm, NMV
J46957
.
FIGURE 7.
Pseudonesimus robustus
(J.L.
Barnard, 1961
)
, female, 9.0 mm, NMV
J46957
, from off the Freycinet Peninsula, Tasmania, Australia. Scale bars: 0.2 mm.
Pereonites 1–7
dorsally smooth.
Gnathopod 1
slightly chelate; coxa reduced, significantly shorter than coxa 2, subquadrate; basis moderately setose along anterior margin; ischium short; carpus short, subequal in length to propodus, without posterior lobe; propodus small, sparsely setose along posterior margin, slightly obtuse, entire, straight.
Gnathopod 2
propodus palm transverse.
Pereopod 4
coxa without distinct lateral ridge.
Pereopod 5
coxa without distinct lateral ridge, without umbo; basis longer than broad, without photophore, not posteroproximally excavate, posterior margin not serrate, posterior margin without mid-central spine, without posteroventral lobe or spine.
Pereopod 7
basis posterodistally produced less than halfway along merus, not posterodistally excavate.
FIGURE 8.
Pseudonesimus robustus
(J.L.
Barnard, 1961
)
, female, 9.0 mm, NMV
J46957
, from off the Freycinet Peninsula, Tasmania, Australia. Scale bars: 0.2 mm.
Pleonites 1–3
without mid-dorsal carina, not produced dorsodistally.
Epimeron 3 posterior margin smooth, posteroventral corner narrowly rounded
.
Urosomite 1 n
ot projecting over urosomite 2, dorsally straight.
Uropod 2
inner ramus with constriction.
Uropod 3
stout; peduncle without dorsolateral flange; inner and outer rami well developed, outer ramus article 2 short, without plumose setae on rami.
Telson
moderately cleft, with dorsal robust setae per lobe, with 2 tiny apical robust setae on each lobe.
Sexually dimorphic characters.
None known.
Depth range.
720–3580 m
(J.L.
Barnard 1961
; this study).
Remarks.
This is the first record of this species in Australian waters. It has previously been recorded from the west coast of the
New Zealand
South Island.
Distribution
.
South Pacific Ocean.
Tasman
Sea: southwest coast of
New Zealand
(J.L.
Barnard 1961
); east coast of Tasmania (this study).