Mallacoota chandaniae Lowry & Springthorpe, 2005

Lowry, J. K. & Hughes, L. E., 2009, Maeridae, the Elasmopus group *, Zootaxa 2260 (1), pp. 643-702 : 677-680

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,

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).

Figures

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).