Parelasmopus cymatilis, Lowry & Hughes, 2009

Lowry, J. K. & Hughes, L. E., 2009, Maeridae, the Elasmopus group *, Zootaxa 2260 (1), pp. 643-702 : 691-695

Parelasmopus cymatilis sp. nov.

( Figs 27 , 28 )

Parelasmopus echo . — Berents, 1983: 136, fig. 27. — Lowry & Stoddart, 2003: 186 (in part).

Type material. Holotype, male, 10.5 mm (3 slides), AM P30155, fringing reef between Bird Islet and South Island, Lizard Island (14°40'S 145°28'E), Halophila , mixed algae and sediment from seagrass beds on reef base, 27.6 m, J.K. Lowry & P.C. Terrill, 9 October 1978 ( QLD 28 ) . Paratypes: 1 unsexed, AM P30154 (76 LIZ B) ; 1 unsexed, AM P78552 ( QLD 28 ); 1 unsexed, AM 30156 ( QLD 30 ); 4 unsexed, AM 30157 ( QLD 50 ); 2 unsexed, AM 30158 ( QLD 52 ) .

Additional material examined. 1 unsexed, AM P78064 ( JDT / LIZ 3j); 1 unsexed, AM P78063 ( JDT / LIZ 5d); 1 unsexed, AM P78062 ( JDT / LIZ 14c); 1 unsexed, AM P78057 ( QLD 1833); 1 unsexed, AM P78197 ( QLD 1869); 1 unsexed, AM P78061 ( QLD 1886); 2 unsexed, AM P78056 ( QLD 1888); 1 unsexed, AM P78059 ( QLD 1891); 10 unsexed, AM P78046 ( QLD 1893); 2 unsexed, AM P78060 ( QLD 1897); 6 unsexed, AM P78045 ( QLD 1902); 2 unsexed, AM P78050 ( QLD 1903); 1 unsexed, AM P78047 ( QLD 1904); 1 unsexed, AM P78049 ( QLD 1905); 4 unsexed, AM P78052 ( QLD 1909); 11 unsexed, AM P78048 ( QLD 1914); 1 unsexed, AM P78058 ( QLD 1915); 11 unsexed, AM P78054 ( QLD 1916); 2 unsexed, AM P78053 ( QLD 1917); 4 unsexed, AM P78055 ( QLD 1918); 1 unsexed, AM P78051 ( QLD 1920); 3 unsexed, AM P75764 ( QLD 1950); many unsexed, AM P75761 ( QLD 1981); 2 unsexed, AM P75762 ( QLD 1982); 2 unsexed, AM P75748 ( QLD 1994); 2 unsexed, AM P75865 ( QLD 1994); 2 unsexed, AM P78301 ( NT 324); 1 unsexed, AM P78302 ( NT 327); 1unsexed, AM P78304 ( NT 345) 3 unsexed, NTM Cr001106 ( MAGNT 1); 10+ unsexed, NTM Cr004907 ( MAGNT 3); 10+ unsexed, NTM Cr004961 ( MAGNT 4); 3 unsexed, NTM Cr015915 ( MAGNT 4); 1 unsexed, NTM Cr005030 ( MAGNT 5); 5+ unsexed, NTM Cr007810 ( MAGNT 6); 3 unsexed, NTM Cr011666 ( MAGNT 8); 1 unsexed, NTM Cr011656 ( MAGNT 11); 6 unsexed, NTM Cr015566 ( MAGNT 14); 6 unsexed, NTM Cr015701 ( MAGNT 15); 12 unsexed, NTM Cr015662 ( MAGNT 15); 5 unsexed, NTM Cr015695 ( MAGNT 16); 1 unsexed, NTM Cr015548 ( MAGNT 17); 1 unsexed, NTM Cr015560 ( MAGNT 17); 3 unsexed, NTM Cr015624 ( MAGNT 17); 19 unsexed, NTM Cr015648 ( MAGNT 17); 3 unsexed, NTM Cr015597 ( MAGNT 17); 2 unsexed, NTM Cr015637 ( MAGNT 17); 2 unsexed, NTM Cr015641 ( MAGNT 17); 7 unsexed, NTM Cr015539 ( MAGNT 18); 1 unsexed, NTM Cr015553 ( MAGNT 18); 1 unsexed, NTM Cr015577 ( MAGNT 18); 5 unsexed, NTM Cr015587 ( MAGNT 18); 8 unsexed, NTM Cr015608 ( MAGNT 18); 5+ unsexed, NTM Cr015666 ( MAGNT 18); 3 unsexed, NTM Cr013559 ( MAGNT 22); 1 unsexed, NTM Cr013570 ( MAGNT 23); 2 unsexed, NTM Cr015903 ( MAGNT 24); 3 unsexed, NTM Cr013916 ( MAGNT 25); 1 unsexed, NTM Cr016758 ( NS 055); 12 unsexed, NTM Cr015894 ( WA location); 9 unsexed, NTM Cr015911 ( WA location). 3 unsexed, NTM Cr016752 ( MAGNT 38); 5 unsexed, NTM Cr016760 ( MAGNT 36); 7 unsexed, NTM Cr016759 ( MAGNT 39); 3 unsexed, NTM Cr016757 ( MAGNT 6); 3 unsexed, NTM Cr016755 ( MAGNT 33).

Type locality. Fringing reef between Bird Islet and South Island, Lizard Island (14°40' S 14528'E) .

Etymology. Named from the Latin ‘cymatilis’ meaning sea-coloured, blue. This is in reference to the type locality which is near the Blue Lagoon.

Description. Based on holotype, male, 10.5 mm, AM P30155.

Head. Head eyes ovate; lateral cephalic lobe broad, rounded, anteroventral margin with notch/slit, anteroventral corner rounded. Antenna 1 longer than antenna 2; peduncular article 1 slightly shorter than article 2, without robust setae along posterior margin; article 2 longer than article 3; flagellum with 37+ articles. Antenna 2 peduncular article 4 longer than article 5; flagellum with 9 articles. Mandible incisor a smooth cutting edge with 2 apicomedial cusps; accessory setal row with 4 setae; palp reduced, 3-articulate; article 1 at least 3 x as long as broad, longer than article 2, inner margin article 1 curved, swollen distally; article 2 shorter than article 3; article 3 long (more than 3 x as long as broad), rectolinear, shorter than article 1.

Pereon. Gnathopod 1 coxa anteroventral corner produced, acute, anterior margin concave, ventral margin serrate; merus with posterodistal tooth; carpus about 2 x as long as broad, subequal in length to propodus (length 1 x propodus), setae in anterodistal bunches along posterior margin; propodus palm acute, slightly convex, entire, defined by posterodistal corner, with posterodistal robust setae. Gnathopod 2 coxa posteroventral corner notch present; basis slender; merus acutely produced distoventrally; carpus compressed, not enclosed by merus and propodus, length 1 x breadth; propodus expanded, with slender setae along posterior margin, palm nearly transverse, concave, sculptured, palm about half length of propodus with straight distomedial shelf, with group of 3 robust setae on shelf, with midmedial excavation, palmar margin with sparse robust setae along palm, with 4 subacute teeth along margin, subpalmar surface smooth, defined by posteroventral corner, without posterodistal robust setae; dactylus reaching end of palm, closing along palm, without setae on anterior margin, without posteroproximal shelf, apically subacute. Pereopod 4 coxa posteroventral lobe absent, posterior margin concave. Pereopod 5 basis slightly expanded, posterior margin slightly concave, without long slender setae, posteroventral corner serrate; carpus and propodus with few long, slender setae along anterior margin. Pereopod 6 basis posterior margin slightly concave, without long slender setae, posteroventral corner slightly serrate; carpus and propodus with many long, slender setae along margins; merus and carpus not broadened; propodus not expanded posterodistally. Pereopod 7 basis posterior margin subsigmoidal, serrate, without long slender setae, not produced posterodistally, posteroventral corner with acute or subacute process; merus and carpus not broadened; capus and propodus with long slender setae; propodus not expanded posterodistally. Pereonite 7 with pair of dorsal spines.

Pleon. Pleonites 1–2 each with pair of dorsal spines. Pleonite 3 dorsally bicarinate. Epimeron 1 posteroventral corner with small acute or subacute spine. Epimeron 3 ventral margin serrate distally, posteroventral margin serrate below posteroventral corner, posteroventral corner with small 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; outer ramus longer than peduncle, long (length 3 x breadth), 1-articulate. Telson deeply cleft (more than 66%), lobes truncated with apical cusps, apical conical extension reaching scarcely one third along longest seta, without dorsal robust setae, each lobe with 4 long and short apical robust setae, without robust setae on inner or outer margins.

Habitat. Marine, epibenthic, living in Halophila , mixed algae and sediment from seagrass beds on reef base at about 27 m depth.

Remarks. Parelasmopus cymatilis sp. nov. was originally identified by Berents (1983) as P. echo J.L. Barnard, 1972a . It differs most obviously from P.echo by the shape of the palm of gnathopod 2. In P. cymatilis sp. nov. it is broadly rounded with four distinct cog-like spines whereas P. echo is spine-less. As specimens mature the corner of the palm becomes a rigid plateau and the cog-like spines become less pronounced. The dactylus closes onto a flat, heavily calcified platform. Parelasmopus suensis , which also occurs on the GBR, can by distinguished from C. cymatilis by its transverse palm. Parelasmopus cymatilis sp. nov. is apparently endemic to tropical Australia.

Distribution. Australia. Northern Territory: Darwin Harbour (current study). Queensland: Lizard Island

( Berents 1983, current study); One Tree Island (current study).

Figures

FIGURE 27. Parelasmopus cymatilis sp. nov., holotype, male, 10.5 mm, AM P30155, Lizard Island, Great Barrier Reef.

FIGURE 28. Parelasmopus cymatilis sp. nov., holotype, male, 10.5 mm, AM P30155, paratype, female, 5.0 mm, AM P30155, Lizard Island, Great Barrier Reef.