Maeridae, the Elasmopus group *
Author
Lowry, J. K.
Author
Hughes, L. E.
text
Zootaxa
2009
2009-10-08
2260
1
643
702
https://www.biotaxa.org/Zootaxa/article/view/zootaxa.2260.1.33
journal article
10.11646/zootaxa.2260.1.33
1175-5326
5361655
Mallacoota chandaniae
Lowry & Springthorpe, 2005
(
Figs 19
,
20
)
Mallacoota chandaniae
Lowry & Springthorpe, 2005: 257–260
, figs. 17–19.
Material examined.
24 unsexed,
AM
P75622 (
QLD
1846); 2 unsexed,
NTM
Cr001801 (
MAGNT
2); 5 unsexed,
NTM
Cr011627 (
MAGNT
7); 1 unsexed,
NTM
Cr011717 (
MAGNT
10); 1 unsexed,
NTM
Cr011700 (
MAGNT
12); 1 unsexed,
NTM
Cr011703 (
MAGNT
13); 7 unsexed,
NTM
Cr015660 (
MAGNT
15); 2 unsexed,
NTM
Cr015561 (
MAGNT
17); 1 unsexed,
NTM
Cr015617 (
MAGNT
17); 1 unsexed,
NTM
Cr015646 (
MAGNT
17); 2 unsexed,
NTM
Cr015603 (
MAGNT
17); 3 unsexed,
NTM
Cr015642 (
MAGNT
17); 4 unsexed,
NTM
Cr015555 (
MAGNT
18); 8 unsexed,
NTM
Cr015578 (
MAGNT
18); 10 unsexed,
NTM
Cr015591 (
MAGNT
18); 10+ unsexed,
NTM
Cr015607 (
MAGNT
18); 2 unsexed,
NTM
Cr015665 (
MAGNT
18); 1 unsexed,
NTM
Cr015729 (
MAGNT
19); 2 unsexed,
NTM
Cr015736 (
MAGNT
19); 3 unsexed,
NTM
Cr015765 (
MAGNT
20); 3 unsexed, Cr015771 (
MAGNT
20); 2 unsexed, Cr015750 (
MAGNT
20); 1 unsexed,
NTM
Cr015751 (
MAGNT
20); 2 unsexed,
NTM
Cr015752 (
MAGNT
20); 1 unsexed,
NTM
Cr015927 (
MAGNT
21); 1 unsexed,
NTM
Cr015490 (
MAGNT
29); 10+ unsexed,
NTM
Cr015491 (
MAGNT
29); 4 unsexed,
NTM
Cr015496 (
MAGNT
29); 2 unsexed,
NTM
Cr016744 (
MAGNT
32); 11 unsexed,
NTM
Cr016741 (
MAGNT
36); 2 unsexed,
NTM
Cr016747 (
MAGNT
3); 1 unsexed,
NTM
Cr016740 (
MAGNT
37); 6 unsexed,
NTM
Cr016746 (
MAGNT
15); 1 unsexed,
NTM
Cr016742 (
MAGNT
35); 4 unsexed,
NTM
Cr016743 (
MAGNT
16); 3 unsexed
NTM
Cr016745 (
NS
056); 7 unsexed,
AM
P78293 (NT 1); 2 unsexed,
AM
P78296 (NT 89); 19 unsexed,
AM
P78294 (NT 326); 9 unsexed,
AM
P78295 (NT 345).
Type
locality.
At
end of sugar loading jetty,
5 km
long,
Lucinda
,
Queensland
,
Australia
(~
18°31’S
146°19’E
)
.
Description
. Based on
holotype
, male,
11 mm
, AM P59021.
Head.
Head
eyes ovate; lateral cephalic lobe broad, truncated, anteroventral margin with notch/slit, anteroventral corner rounded.
Antenna 1
longer than antenna 2; peduncular article 1 subequal in length to article 2, with 4 or more robust setae along posterior margin; article 2 longer than article 3; accessory flagellum short, with 4 articles; flagellum with about 26 articles.
Antenna 2
peduncular article 4 longer than article 5; flagellum with about 11 articles.
Mandible
incisor a smooth cutting edge with many small apicomedial cusps; accessory setal row with 3 setae; palp reduced, 3-articulate; article 1 about twice as long as broad, shorter than article 2, inner margin article 1 not produced distally; article 2 subequal to article 3; article 3 long (more than 3 x as long as broad), rectolinear, longer than article 1.
Pereon.
Gnathopod 1
coxa anteroventral corner produced, rounded, anterior margin concave; merus without posterodistal tooth; carpus about 2 x as long as broad, carpus shorter than propodus, setae in anterodistal bunches and along posterior margin; propodus palm acute, convex, entire, without posterodistal corner, with posterodistal robust setae.
Gnathopod 2
coxa posteroventral corner notch absent; basis broad; merus with subquadrate distoventral corner; carpus compressed, projecting between merus and propodus,
FIGURE 19.
Mallacoota chandaniae
Lowry & Springthorpe, 2005
, holotype, male, 11 mm, AM 59021, Lucinda, Queensland (After
Lowry & Springthorpe, 2005
).
FIGURE 20.
Mallacoota chandaniae
Lowry & Springthorpe, 2005
, holotype, male, 11 mm, AM 59021, paratype, female, 9.1 mm, Lucinda, Queensland (After
Lowry & Springthorpe, 2005
).
length 0.5 x breadth; propodus massive, with 2 robust setae on anterior margin, with slender medial setal bunch, palm nearly transverse, sculptured, palm about half length of propodus, with rounded distomedial shelf, with group of 6 robust setae on shelf, with midmedial excavation, palmar margin without robust setae, with 1 subacute tooth, subpalmar surface smooth, corner defined by posteroventral tooth, without posterodistal robust setae; dactylus reaching end of palm, closing along palm, with 1 seta on anterior margin, without posteroproximal shelf, apically blunt.
Pereopod 4
coxa posteroventral lobe well developed, with subrectangular posteromedial corner.
Pereopod 5
basis slightly expanded, posterior margin straight, without long slender setae, posteroventral corner broadly rounded; carpus and propodus without long, slender setae along anterior margin.
Pereopod 6
basis posterior margin straight, without long slender setae, posteroventral corner broadly rounded; merus and carpus not broadened; carpus and propodus without long, slender setae along anterior margin; propodus not expanded posterodistally.
Pereopod 7
basis posterior margin straight, minutely castelloserrate, without long slender setae, produced posterodistally lobate, posteroventral corner narrowly rounded; merus and carpus not broadened; propodus not expanded posterodistally.
Pleon.
Pleonites 1–3
dorsally smooth, without setae, spines or carinae.
Epimeron 1
posteroventral corner with small acute or subacute spine.
Epimeron 2
posteroventral corner acute.
Epimeron 3
ventral margin smooth, posteroventral margin smooth, posteroventral corner with strongly produced acute spine.
Urosomite 1
bicarinate, subtriangular.
Urosomites 2–3
dorsally smooth, without setae, spines or carinae.
Uropod 1
peduncle with basofacial robust seta.
Uropod 3
rami distally truncated, apical robust setae long and short; inner ramus subequal in length to outer ramus, long (length more than 2 x breadth); outer ramus long (length 2.4 x breadth), longer than peduncle, 1-articulate.
Telson
deeply cleft (more than 66%), as long as broad, tapering distally, apical margins concave, apical conical extension reaching at least halfway along longest seta, without dorsal robust setae, with apical/subapical robust setae, each lobe with 6 long apical robust setae, without robust setae on outer or inner margins.
Female
(sexually dimorphic characters).
Based on
paratype
, female,
9.1 mm
,
AM
P62996.
Gnathopod 2
basis slender; merus acutely produced distoventrally; length 1 x breadth, not enclosed by merus and propodus; propodus expanded, with setae along posterior margin, palm acute with well defined corner, convex, smooth, without distomedial shelf, with sparse robust setae, without teeth along margin, without posteroventral corner, with posterodistal robust setae; apically acute, without posteroproximal shelf.
Pereopods 5–7
carpus broadened
.
Habitat.
Marine, epibenthic, living among algae.
Remarks.
These are the first records of the distinctive species
M. chandaniae
since the original description (
Lowry & Springthorpe 2005
) and indicate that
M. chandaniae
occurs throughout tropical
Australia
. The species is distinguished from all other species of
Mallacoota
by the massive second gnathopod of the male with the nearly transverse palm, large palmar teeth and extensive setal bunch.
Distribution
.
Australia
.
Northern Territory
: Darwin; Beagle Gulf; Gove Harbour; Bynoe Harbour; Shell Islands (current study).
Queensland
: Lucinda; Weipa (
Lowry & Springthorpe, 2005
); Torres Strait: Number One Reef, north of Horn Island (current study).