A taxonomic study on the Phtisicidae (Crustacea: Amphipoda) of New South Wales, Australia
Author
Takeuchi, Ichiro
Department of Life Environment Conservation, Faculty of Agriculture, Ehime University, Matsuyama, Japan; & Center of Advanced Technology for the Environment, Faculty of Agriculture, Ehime University, Matsuyama, Japan;
Author
Lowry, James K.
Australian Museum Research Institute, Australian Museum, Sydney, NSW, Australia
text
Journal of Natural History
2015
2015-07-31
50
603
648
journal article
21307
10.1080/00222933.2015.1079338
c700f790-3418-4f26-bccc-cf001dd38057
1464-5262
3985737
975EE532-0FAD-4D4F-8E18-9DF3B790953F
Dodecas hexacentrum
Mayer, 1903
(
Figures 4
–
6
)
Dodecas hexacentrum
Mayer, 1903: 29
–
30
, pl. 1, figs 14
–
15, pl. 6 figs 33
–
34.
–
Stebbing, 1910b: 652
.
–
K.H. Barnard, 1932: 306, fig. 169a.
–
Guiler, 1954: 539
–
542
, figs 8
–
9.
–
McCain and Steinberg, 1970: 49
.
–
Lowry and Stoddart, 2003: 35
.
Type material
Syntypes
. Male
“
a
”
,
AM
G2555
,
33°50.8
ʹ
S, 151°60.7
ʹ
E
, off
Watsons Bay
,
Port Jackson
,
New South Wales
,
May 1887
, host sponge:
Thalassodendrum
rubens
Lendenfeld
; 2 mature females
“
b
”
and
“
c
”
,
AM
P46932,
33°50.8
ʹ
S
, 151°60.7
ʹ
E, off
Watsons Bay
,
Port Jackson
,
New South Wales
,
May 1887
, host sponge:
Thalassodendrum
rubens
Lendenfeld
;
7 males
, 7 mature females,
1 immature
female and
4 juveniles
,
AM
P46933,
33°50.8
ʹ
S
, 151°60.7
ʹ
E, off
Watsons Bay
,
Port Jackson
,
New South Wales
,
May 1887
, host sponge:
Thalassodendrum
rubens
Lendenfeld
;
Many
individuals,
AM
P46934, off
Watsons Bay
,
Port Jackson
,
New South Wales
,
May 1887
, host sponge:
Thalassodendrum
rubens
Lendenfeld
; 140 individuals,
AM
P46935,
33°51
ʹ
S
,
151°16
ʹ
E
, off
Watsons Bay
,
Port Jackson
,
New South Wales
,
May 1887
, host sponge:
Thalassodendrum
rubens
Lendenfeld
.
Figure 4.
Dodecas hexacentrum
Mayer, 1903
from Watsons Bay, Port Jackson, New South Wales. Male, syntype, 14.01 mm, AM G2555; B, female, syntype
‘
b
’
, 10.90 mm, AM P46932. Bar indicates 1.0 mm.
Figure 5.
Dodecas hexacentrum
Mayer, 1903
from Watsons Bay, Port Jackson, New South Wales. Male, syntype, 14.01 mm, AM G2555, A2; G1, P3, P5, ABD (LT); female
‘
b
’
, syntype, 10.90 mm, AM P46932, G2, P6, ABD (V); female
‘
c
’
, syntype, 5.03 mm, AM P46932, P7. Bars in P7, ABD (LT) (M) and ABD (V) (F) indicate 0.20 mm, those in G1, G2 (M), G2 (F), P3, P5, P6 and P7 indicate 0.50 mm and that in A2 indicates 1.0 mm.
Figure 6.
Dodecas hexacentrum
Mayer, 1903
from Watsons Bay, Port Jackson, New South Wales. Male, syntype, 14.01 mm, AM G2555. Bars indicate 0.10 mm.
Additional material examined
1 mature female,
AM
G2564
,
38°32
ʹ
S, 145°22
ʹ
E
,
Griffiths Point
,
Victoria
;
1 male
and
1 female
,
AM
P22827,
33°49
ʹ
S, 151°20
ʹ
E
, east of
North Head
,
Port Jackson
,
New South Wales
,
19.8 m
depth
,
19 February 1973
, host sponge: cf
.
Teichonella labrinthica
, Australian Museum Shelf Benthic Survey (=
AMSBS
);
7 males
and 9 mature females,
AM
P22828,
33°49
ʹ
S, 151°21
ʹ
E
, east of
North Head
,
Port Jackson
,
New South Wales
,
19.8 m
depth
,
19 February1973
, host sponge:
Holopsamma flavus
,
AMSBS
; 1 mature female,
AM
P22829,
33°49
ʹ
S
,
151°20
ʹ
E
, east of
North Head
,
Port Jackson
,
New South Wales
,
19.8 m
depth
,
19 February1973
, host:
Chalinissa elegans
; 6 individuals,
AM
P22831,
33°49
ʹ
S
,
151°20
ʹ
E
, east of
North Head
,
Port Jackson
,
New South Wales
,
21.3 m
depth
,
20 February 1973
, host:
Polymastea
craticia
,
AMSBS
;
3 males
and 1 mature female,
AM
P22832,
33°49
ʹ
S
,
151°20
ʹ
E
, east of
North Head
,
Port Jackson
,
New South Wales
,
21.3 m
depth
, host:
Chalinissa elegans
,
AMSBS
;
2 males
and
5 juveniles
,
AM
P22833,
33°49
ʹ
S
,
151°20
ʹ
E
, east of
North Head
,
Port Jackson
,
New South Wales
,
25.9 m
depth
,
26 February1973
, host sponge:
Polymastia craticia
,
AMSBS
; 643 individuals,
AM
P22834,
33°49
ʹ
S
,
151°20
ʹ
E
, east of
North Head
,
Port Jackson
,
New South Wales
,
25.9 m
depth
,
26 February 1973
, host sponge:
Holopsamma flavus
,
AMSBS
;
1 male
and
1 juvenile
,
AM
P22835,
33°49
ʹ
S
,
151°21
ʹ
E
, east of
North Head
,
Port Jackson
,
New South Wales
,
32.9 m
depth
,
23 May 1973
;
1 male
and
1 juvenile
,
AM
P22836,
33°49
ʹ
S
,
151°21
ʹ
E
, east of
North Head
,
Port Jackson
,
New South Wales
,
30.4 m
depth
,
25 May 1973
,
AMSBS
;
2 males
and 2 mature females,
AM
P22837,
33° 50
ʹ
S
,
151°18
ʹ
E
, east of
South Head
,
Port Jackson
,
New South Wales
,
21 m
depth
,
February 1974
, host sponge:
Holopsamma flavus
,
AMSBS
; 1 individual,
AM
P22838,
33°44
ʹ
S
,
151°20
ʹ
E
, east of
Long Reef
,
New South Wales
,
15.2 m
depth
,
28 April 1972
,
AMSBS
; 2 individuals,
AM
P22843,
33°49
ʹ
S
,
151°18
ʹ
E
, east of
North Head
,
Port Jackson
,
New South Wales
,
25.9 m
depth
,
26 February 1974
,
AMSBS
;
1 male
,
AM
P24371,
33°44
ʹ
S
,
151°22
ʹ
E
, east of
Long Reef
,
Sydney
,
New South Wales
,
32 m
depth
,
28 April 1972
,
AMSBS
; 139 individuals,
AM
P46944,
33°50
ʹ
S
,
151°18
ʹ
E
, east of
South Head
,
Port Jackson
,
New South Wales
,
21 m
depth
,
February 1974
, host sponge:
Holopsamma flavus
,
AMSBS
.
Type locality
Off Watsons Bay
,
Port Jackson
,
New South Wales
.
Other records
New South Wales
:
East of North Head
and east of
South Head
,
Port Jackson
, east of
Long Reef
.
Victoria
: Griffiths Point.
Description
Based on male,
syntype
“
a
”
, body length
14.04 mm
, AM G2555.
Head and pereonite 1
combined length
3.02 mm
;
pereonite 2
,
1.60 mm
;
pereonite 3
,
1.78 mm
;
pereonite 4
,
2.40 mm
;
pereonite 5
,
3.02 mm
;
pereonite 6
,
1.78 mm
;
pereonite 7
,
0.44 mm
.
Head and pereonites
robust
Head
smooth, rounded dorsally; eye large, protruding;
head/ pereonite 1
dorsal margin slightly convex; with anteriorly pointed paired dorsodistal projections.
Antenna 1
slender; slightly shorter than body length; peduncle articles 2 and 3 subequal in length; peduncular article 3 concave along anterior margin; flagellum 0.25 × peduncular length, with seven articles; proximal article result of fusion of three articles.
Antenna 2
slender; 0.33 × antenna 1 length; peduncle without setae; flagellum about 0.5 × peduncular length, with five articles.
Upper lip
notched, forming shallow quadrilateral projections.
Mandible
right side incisor with five teeth; lacinia mobilis a reverse trapezoid plate followed by a smaller plate; palp article 2 with eight lateral setae; palp article 3 setal formula 1
–
9
–
1; left side incisor with five teeth; lacinia mobilis with five teeth, followed by a trapezoid plate; palp article 2 with six lateral setae; palp article 3 setal formula 1
–
10
–
1.
Lower lip
finely setose on inner and outer lobes.
Maxilla 1
outer plate with six stout apical setal-teeth; palp distal margin with five triangular projections, each with one robust seta, with a row of slender setae.
Maxilla 2
inner plate triangular with one apical robust and eight slender setae; outer plate elongate with eight apical setae.
Maxilliped
inner plate (basal endite) quadrilateral, with three stout serriform setae on expanded inner half of distal margin, with one seta on outer half; outer plate (ischial endite) oval, 0.25 × length of inner plate (basal endite), inner margin smooth, with three or four setae on inner margin; palp article 2 setose on inner margin; palp article 3 not expanded, with six lateral to distal setae; palp article 4 weakly falcate.
Pereon.
Pereonite 2
with small anterolateral triangular projection, with midlateral projection, with paired anteriorly curved mid dorsal projections.
Pereonite 5
longest.
Gnathopod 1
propodus triangular, with three rows of submarginal setae near dorsal margin; palm begins 1/4 along posterior margin, smooth, with two robust setae (one large and one small) near corner of palm; dactylus curved.
Gnathopod 2
situated in middle of pereonite 2; gill elongate, about 4 × width, 1.2 × pereonite length; coxa vestigial; basis 2.5 × length of pereonite 2; carpus 1.1 × propodus length; propodus elongate (subrectangular), large, length 2 × width, anterodistal margin straight; palm proximal projection with three robust (one large and two small) setae, palm margin straight, smooth, with broad well developed distal shelf, with one large and one small projections, without sinus.
Pereopod 3
very slender; gill length about as long as corresponding pereonite, straight; basis to carpus straight, cylindrical; basis shorter than other pereopod articles; propodus without distal palm and robust setae; dactylus spatulate, not setose.
Pereopod 4
absent.
Gill 4
length about 1/2 × corresponding pereonite, straight.
Pereopod 5
broad; articulation between articles 1 and 2 oblique; dactylus medium length, falcate, without setae.
Pleon.
Pleopod
one pair, tiny.
Uropod 1
; peduncle elongate, about 6
–
8 × width; ramus about 4
–
5 × width; ramus 0.35 × peduncular length.
Female
(sexually dimorphic characters and pereopods 6 and 7). Based on
syntype
“
b
”
, body length
10.90 mm
, AM P46932 and
“
c
”
, body length
5.03 mm
, AM P46932, for pereopods 6 and 7. Length of
head and pereonite 1
combined
1.20 mm
, and each length of
pereonites 2–7
,
1.50 mm
,
1.55 mm
,
2.10 mm
,
2.30 mm
,
1.50 mm
and
0.55 mm
, respectively. Pereonite 1 lacking paired dorsodistal projections. Posterior end of pereonite 1 slightly convex. Pereonite 2 with anterolateral triangular projection, with anteriorly lateral projection, with anteriorly pointed paired mid-dorsal projections. Antenna 1 2/5 × body length. Basis of gnathopod 2 subequal to pereonite 2 length. Propodus oblong, with convex palm. Pereopod 6 with vestigial coxa; basis shorter than propodus; propodus with one pair of robust setae on proximal margin, with two robust setae along palm; dactylus falcate, not setose.
Pereopod 7
similar to pereopod 6; merus shorter than basis.
Remarks
See remarks of
Dodecas decacentrum
.