Maeridae, the Elasmopus group * Lowry, J. K. Hughes, L. E. Zootaxa 2009 2009-10-08 2260 1 643 702 3XMZY Lowry & Hughes, 2009 Lowry & Hughes 2009 [151,413,1002,1028] Malacostraca Maeridae Mallacoota Animalia Amphipoda 44 687 Arthropoda species scopulosa sp. nov.  ( Figs 25, 26)   Type material.  Holotype, 1 male, 7.3 mm, 4 slides, AMP78042, Stevesbommie, near Two Trees Islet, outer reef, One Tree Island, Queensland( 23°29.059’S 152°5.452’E), coral rubble with algae,  13.2 m, L.E. Hughes& J.K. Lowry,  27 October 2006( QLD 1974).  Paratype: 1 female, 7.7 mm, 1 slide, AMP78043 ( QLD 1974); 1 unsexed, AMP78044 ( JDT/ LIZ 13); many unsexed, AMP75627 ( QLD 1972); 5 unsexed, AMP75746 ( QLD 1973); 2 unsexed, AMP75757 ( QLD 1974); many unsexed, AMP75747 ( QLD 1974); 7 unsexed, AMP75749 ( QLD 1976); 2 unsexed, AMP75750 ( QLD 1977); many unsexed, AMP75628 ( QLD 1983); 1 unsexed, AMP75759 ( QLD 2001); 12 unsexed, AMP75758 ( QLD 2003).    Typelocality. Stevesbommie, near Two Trees Islet, outer reef, One Tree Island, Queensland( 23°29.059’S 152°5.452’E), coral rubble with algae,  13.2 m.   Etymology. Named from the Latin ‘scopulosa’ for the hard rocky-rubble bottom where it is found.   Description.Based on holotype, male, 7.3 mm, AM P78042.  Head. Headeyes ovate; lateral cephalic lobe broad, rounded, anteroventral margin with notch/slit, anteroventral corner rounded. Antenna 1peduncular article 1 subequal in length to article 2; accessory flagellum minute, with 2 articles. Mandibleincisor a smooth cutting edge with 2 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 longer than article 3; article 3 short (about 3 x as long as broad), rectolinear, longer than article 1.  Pereon. Gnathopod 1coxa anteroventral corner produced, rounded, anterior margin concave; merus without posterodistal tooth; carpus about 2 x as long as broad, carpus subequal in length to propodus (length 1.2 x propodus), setae in anterodistal bunches and along posterior margin; propodus palm acute, straight, entire, defined by posterodistal corner, with posterodistal robust setae. Gnathopod 2coxa posteroventral corner notch absent; basis slender; merus with rounded distoventral corner; carpus compressed, projecting between merus and propodus, length 0.8 x breadth; propodus expanded, without setal bunches along posterior margin, palm acute, convex, sculptured, palm about half length of propodus, with subtriangular distomedial shelf, with group of 6 robust setae on shelf, with midmedial excavation, palmar margin without robust setae, with 2 palmar teeth, subpalmar surface smooth, corner defined by posteroventral tooth, without posterodistal robust setae; dactylus reaching end of palm, closing along palm, without setae on anterior margin, with posteroproximal shelf, apically falcate. Pereopod 4coxa posteroventral lobe slightly developed, with rounded posteromedial corner. Pereopod 5basis expanded, posterior margin subsigmoidal, without long slender setae, posteroventral corner broadly rounded; carpus and propodus with few long, slender setae along anterior margin. Pereopod 6basis posterior margin straight, without long slender setae, minutely castelloserrate, posteroventral corner broadly rounded; carpus and propodus with few long, slender setae along anterior margin; merus and carpus broadened; propodus expanded posterodistally to from a hood-like projection. Pereopod 7basis posterior margin slightly convex, minutely castelloserrate, without long slender setae, not produced posterodistally, posteroventral corner broadly rounded; merus and carpus broadened; propodus expanded posterodistally to from a hood-like projection.   FIGURE 25.  Mallacoota scopulosa  sp. nov., male, 7.3 mm, AM P78042, One Tree Island, Great Barrier Reef.   FIGURE 26.  Mallacoota scopulosa  sp. nov., male, 7.3 mm, AM P78042, female, 7.7 mm, AM P78043, One Tree Island, Great Barrier Reef.  Pleon. Pleonites 1–3dorsally smooth, without setae, spines or carinae. Epimeron 1posteroventral corner with small acute spine. Epimeron 2posteroventral corner strongly produced, acute. Epimeron 3ventral margin smooth, posteroventral margin smooth, posteroventral corner with produced acute spine. Urosomite 1bicarinate, subtriangular. Urosomites 2–3dorsally smooth, without setae, spines or carinae. Uropod 1peduncle with basofacial robust seta. Uropod 3rami distally truncated, apical robust setae long; inner ramus subequal in length to outer ramus; inner ramus short (length 1 to 1.9 x breadth); outer ramus short (length 2 x breadth), subequal to peduncle, 1-articulate.  Telsondeeply cleft (more than 66%), broader than long, slightly tapering distally, apical margins concave, apical conical extension reaching at least halfway along longest seta, without dorsal robust setae, each lobe with 2 short apical robust setae, without robust setae on inner and outer margins.  Female(sexually dimorphic characters). Based on female, 7.7 mm, AM P78043. Gnathopod 2carpus long, length 1.7 x breadth, not enclosed by merus and propodus; straight, one third length of propodus, smooth, without distomedial shelf, with posterodistal robust setae; dactylus apically acute, without posteroproximal shelf.  Habitat.Marine, epibenthic.   Remarks.  Mallacoota scopulosais a large species, nearly twice the size of similar species such as the western Indian Ocean species  M. subinsignis Ledoyer, 1979band  M. magnimerus Appadoo & Myers, 2006. It differs from  M. subinsignisin the coxa of gnathopod 1 which has no posterodistal notch (well developed in  M. subinsignis); in the palm of gnathopod 2 which has a well developed subtriangular shelf (oblique and weakly developed in  M. subinsignis) two palmar teeth and a well developed corner tooth (one palmar tooth, a well developed corner tooth and a notch along the posterior margin in  M. subinsignis); and in the dactylus of gnathopod 2 which is strongly falcate (apically acute in  M. subinsignis).  Mallacoota magnimerusis distinguished from  M. scopulosa Appadoo & Myers, 2006by its immensely broadened meri on pereopods 6– 7. On the GBR only  M. scopulosa,  M. chandaniaeand  M. capricorniahave the corner of the male gnathopod 2 palm defined by a tooth. Of these three species only  M. scopulosahas a falcate tip on the dactylus of male gnathopod 2 and two short apical robust setae on each lobe of the telson.   Distribution.  Australia. Queensland: Lizard Island; One Tree Island (current study). P78042 2006-10-27 AM L. E. Hughes & J. K. Lowry Steves 13 -23.484316 One Tree Island 1 152.09087 Two Trees Islet 44 687 QLD 1974 1 1 Queensland holotype P78043, P78044, P75627, P75746, P75757, P75747, P75749, P75750, P75628, P75759, P75758 AM, JDT 44 687 QLD 1974, LIZ 13, QLD 1972, QLD 1973, QLD 1976, QLD 1977, QLD 1983, QLD 2001, QLD 2003 1 1 Queensland paratype Steves 13 -23.484316 One Tree Island 1 152.09087 Two Trees Islet 44 687 1 Queensland holotype