Elasmopus mcluerensis, Hughes & Lowry, 2011

Hughes, L. E. & Lowry, J. K., 2011, The genus Elasmopus (Crustacea: Amphipoda: Maeridae) in Australian waters, Journal of Natural History 45 (9 - 10), pp. 579-628 : 602-608

Elasmopus mcluerensis sp. nov.

( Figures 10 , 11 )

Type locality

Bommies at northwest end of McCluer Island, Northern Territory, Arafura Sea, Australia (11 ◦ 2 ′ S, 132 ◦ 58 ′ E).

Type material

Holotype male, 4.6 mm, 3 slides, AM P83312 . Paratypes, 2 specimens, AM P.78264, bommies at northwest end of McCluer Island , Arafura Sea, Northern Territory (11 ◦ 02 ′ S, 132 ◦ 58 ′ E), 8 m, solitary tunicates, hand collected on SCUBA, 16 October 1982, coll. J.K. Lowry ( NT 39 ) .

Additional material examined

Northern Territory. 7 specimens, AM P.78275, reef West end Oxley Island (11 ◦ 00 ′ S, 132 ◦ 49 ′ E), 5 m, on algae, hand collected on SCUBA , 21 October 1982, coll. J.K. Lowry ( NT 82 ) ; 1 specimen, AM P.78276, West end East Point, northern end of Fannie Bay , Darwin (11 ◦ 24 ′ 30 ′′ S, 130 ◦ 48 ′ 30 ′′ E), 10 m, encrusting ascidian Didemnum psammatodes , hand collected on SCUBA , 26 October 1982, coll. J.K. Lowry ( NT 97 ) ; 1 specimen, AM P.83313, Stokes Hill Wharf, Darwin Harbour (12 ◦ 28 ′ 12 ′′ S, 130 ◦ 50 ′ 54 ′′ E), 0.3 m at low tide, algal scrapings from pontoon, collected by hand, 22 November 2000, coll. R . A. Peart , ( NT 255 ) ; 2 specimens, MAGNT Cr 015764, Cargo Wharf, Gove Harbour (12 ◦ 12 ′ 0 ′′ S, 136 ◦ 40 ′ 60 ′′ E), wharf pylon, pile scrape, June 2001, coll. K. Neil and party ( JCU / CRC Reef) (A779 G2J) ; 1 specimen, MAGNT Cr 015808, Cargo Wharf, Gove Harbour (12 ◦ 12 ′ 15 ′′ S, 136 ◦ 40 ′ 51 ′′ E), 3 m, wharf pylon, pile scrape, 1 June 2001, coll. K. Neil and party ( JCU / CRC Reef) (A502 G2) ; 2 specimens, MAGNT Cr 015822, Cargo Wharf, Gove Harbour (12 ◦ 12 ′ 15 ′′ S, 136 ◦ 40 ′ 51 ′′ E), 3 m, wharf pylon, pile scrape, 8 June 2001, coll. K. Neil and party ( JCU / CRC Reef) (A684 GDD) ; 1 specimen, MAGNT Cr 015868, Coral Bay, Port Essington (11 ◦ 10 ′ 60 ′′ S, 132 ◦ 3 ′ 24 ′′ E), 6 m, coral reef edge, hand collected on SCUBA , 16 May 1983, coll. N.L. Bruce; 8 specimens, MAGNT Cr 015902, Dawson Rock, Bynoe Harbour (12 ◦ 42 ′ 17 ′′ S, 130 ◦ 35 ′ 33 ′′ E), found in sponge sample, hand collected on SCUBA , 9 June 2003, coll. B. Glasby; 13 specimens, MAGNT Cr 015547, Fort Hill Wharf, Darwin (12 ◦ 28 ′ 17 ′′ S, 130 ◦ 50 ′ 48 ′′ E), wharf pylon, pile scrape, 27 March 1999, coll. MAGNT / CSIRO CRIMP Survey Team ( NTDFHW P1-3 ); 10+ specimens, MAGNT Cr 015551, Fort Hill Wharf, Darwin (12 ◦ 28 ′ 17 ′′ S, 130 ◦ 50 ′ 48 ′′ E), wharf pylon, pile scrape, 27 March 1999, coll. MAGNT / CSIRO CRIMP Survey Team ( NTDFHW P2 -0) ; 5 specimens, MAGNT Cr 015558, Fort Hill Wharf, Darwin (12 ◦ 28 ′ 17 ′′ S, 130 ◦ 50 ′ 48 ′′ E), wharf pylon, pile scrape, 27 March 1999, coll. MAGNT / CSIRO CRIMP Survey Team ( NTDFHW Qual) ; 3 specimens, MAGNT Cr 015559, Fort Hill Wharf, Darwin (12 ◦ 28 ′ 17 ′′ S, 130 ◦ 50 ′ 48 ′′ E), wharf pylon, pile scrape, 27 March 1999, coll. MAGNT / CSIRO CRIMP Survey Team ( NTDFHW P2-3 ) ; 5 specimens, MAGNT Cr 015616, Fort Hill Wharf, Darwin (12 ◦ 28 ′ 17 ′′ S, 130 ◦ 50 ′ 48 ′′ E), wharf pylon, pile scrape, 27 March 1999, coll. MAGNT / CSIRO CRIMP Survey Team ( NTDFHW P1-3 ) ; 25 specimens, MAGNT Cr 015621, Fort Hill Wharf, Darwin (12 ◦ 28 ′ 17 ′′ S, 130 ◦ 50 ′ 48 ′′ E), wharf pylon, pile scrape, 27 March 1999, MAGNT / CSIRO CRIMP Survey Team ( NTDFHW P2 -0) ; 12 specimens, MAGNT Cr 015631, Fort Hill Wharf, Darwin (12 ◦ 28 ′ 17 ′′ S, 130 ◦ 50 ′ 48 ′′ E), wharf pylon, pile scrape, 27 March 1999, coll. MAGNT / CSIRO CRIMP Survey Team ( NTDFHW P1 - 0); 10+ specimens, MAGNT Cr 015640, Fort Hill Wharf, Darwin (12 ◦ 28 ′ 17 ′′ S, 130 ◦ 50 ′ 48 ′′ E), wharf pylon, pile scrape, 27 March 1999, coll. MAGNT / CSIRO CRIMP Survey Team ( NTDFHW P1-7 ) ; 3 specimens, MAGNT Cr 015583, Iron Ore Wharf, Darwin Harbour (12 ◦ 28 ′ 21 ′′ S, 130 ◦ 50 ′ 34 ′′ E), wharf pylon, pile scrape, 28 March 1999, MAGNT / CSIRO CRIMP Survey Team ( NTDIOW P1-3 ) ; 4 specimens, MAGNT Cr 015592, Iron Ore Wharf, Darwin Harbour (12 ◦ 28 ′ 21 ′′ S, 130 ◦ 50 ′ 34 ′′ E), wharf pylon, pile scrape, 28 March 1999, coll. MAGNT / CSIRO CRIMP Survey Team ( NTDIOB P2-3 ) ; 13 specimens, MAGNT Cr 015596, Iron Ore Wharf, Darwin Harbour (12 ◦ 28 ′ 21 ′′ S, 130 ◦ 50 ′ 34 ′′ E), wharf pylon, pile scrape, 27 March 1999, coll. MAGNT / CSIRO CRIMP Survey Team ( NTDIOB Qual ); 10+ specimens, MAGNT Cr 015609, Iron Ore Wharf, Darwin Harbour (12 ◦ 28 ′ 21 ′′ S, 130 ◦ 50 ′ 34 ′′ E), wharf pylon, pile scrape, 28 March 1999, coll. MAGNT / CSIRO CRIMP Survey Team ( NTDIOB P2 -0) ; 2 specimens, MAGNT Cr 015638, Iron Ore Wharf, Darwin Harbour (12 ◦ 28 ′ 21 ′′ S, 130 ◦ 50 ′ 34 ′′ E), wharf pylon, pile scrape, 27 March 1999, coll. MAGNT / CSIRO CRIMP Survey Team ( NTDIOW P3-7 ) ; 3 specimens, MAGNT Cr 015876, Middle Bay, Coral Bay , Port Essington (11 ◦ 10 ′ 60 ′′ S, 132 ◦ 1 ′ 59 ′′ E), sand beach, hand collected on SCUBA , 18 May 1983, coll. N.L. Bruce; 13 specimens, MAGNT Cr 015699, Near Stokes Hill Wharf, Darwin Harbour (12 ◦ 28 ′ 28 ′′ S, 130 ◦ 50 ′ 54 ′′ E), wharf pylon, pile scrape, 18 August 1998, coll. MAGNT / CSIRO CRIMP Survey Team ( NTDSHN Qual) ; 4 specimens, MAGNT Cr 015721, Site 2 Export Wharf , Gove Harbour (12 ◦ 12 ′ 18 ′′ S, 136 ◦ 40 ′ 12 ′′ E), 3 m, wharf pylon, pile scrape, 7 May 2001, coll. K. Neil and party ( JCU / CRC Reef) (A735) ; 3 specimens, MAGNT Cr 015728, Site 2 Export Wharf , Gove Harbour (12 ◦ 12 ′ 18 ′′ S, 136 ◦ 40 ′ 12 ′′ E), 3 m, wharf pylon, pile scrape, 7 May 2001, coll. K. Neil and party ( JCU / CRC Reef) (A773 G2I) ; 8 specimens, MAGNT Cr 015734, Site 2 Export Wharf , Gove Harbour (12 ◦ 12 ′ 18 ′′ S, 136 ◦ 40 ′ 12 ′′ E), 0.7 m, wharf pylon, pile scrape, 7 May 2001, coll. K. Neil and party ( JCU / CRC Reef) (A735 G2E) ; 2 specimens, MAGNT Cr 015898, South Shell Island, East Arm of Darwin Harbour (12 ◦ 29 ′ 48 ′′ S, 130 ◦ 53 ′ 13 ′′ E), 7–11 m, dead and live coral with coarse sand and rubble from rocky reef, hand collected on SCUBA , 19 August 2002, coll. B. Glasby and party.

Queensland. 1 dissected male, 5.7 mm, 4 slides, AM P.83314, western drop off, north side of Hammond Island, Torres Strait (10 ◦ 32 ′ 24 ′′ S, 142 ◦ 11 ′ 20 ′′ E), 15 m, sponge and epiphytic algae, hand collected on SCUBA, 30 September 2006, coll. J.K. Lowry and L.E. Hughes, ( QLD 1893 ); 10+ specimens, AM P.75721, western drop off, north side of Hammond Island, Torres Strait (10 ◦ 32 ′ 24 ′′ S, 142 ◦ 11 ′ 20 ′′ E), 15 m, sponge and epiphytic algae, hand collected on SCUBA, 30 September 2006, coll. J.K. Lowry and L.E. Hughes ( QLD 1893 ); 4 specimens, AM P.75723, nearshore, western side of Hawkesbury Island, Torres Strait (10 ◦ 21 ′ 44 ′′ S, 142 ◦ 07 ′ 04 ′′ E), 5.6 m, coral branches with ascidians ( Didemnum sp.), hand collected on SCUBA, 1 October 2006, coll. J.K. Lowry and M. Capa ( QLD 1903 ); 3 specimens, AM P.75725, reef between Hammond Island and Goodes Island, Torres Strait (10 ◦ 33 ′ 43 ′′ S, 142 ◦ 10 ′ 28 ′′ E), 9 m, sponge and coral Acropora sp., hand collected on SCUBA, 28 September 2006, coll. M. Capa and L.E. Hughes ( QLD 1888 ); 1 specimen, AM P.75726, reef between Hammond Island and Goodes Island, Torres Strait (10 ◦ 33 ′ 43 ′′ S, 142 ◦ 10 ′ 28 ′′ E), 9 m, coarse coral rubble, hand collected on SCUBA, 28 September 2006, coll. M. Capa and L.E. Hughes, ( QLD 1891 ); 1 specimen, AM P.75724, nearshore, western side of Hawkesbury Island, Torres Strait (10 ◦ 21 ′ 44 ′′ S, 142 ◦ 07 ′ 04 ′′ E), 8 m, coral rubble with sponges, hand collected on SCUBA, 1 October 2006, coll. J.K. Lowry and M. Capa ( QLD 1904 ); 1 specimen, AM P.75722, Northwest Islet, Torres Strait (10 ◦ 18 ′ 55 ′′ S, 142 ◦ 05 ′ 26 ′′ E), 1.5 m, hydroids, hand collected on SCUBA, 1 October 2006, coll. M. Capa and L.E. Hughes ( QLD 1919 ) .

Western Australia. 12 specimens, MAGNT Cr 015923, West Lagoon , Ashmore Reef (12 ◦ 13 ′ 12 ′′ S, 123 ◦ 0 ′ 18 ′′ E), 0 m, Off floating buoy covered in black plastic, collected by hand, 7 October 2002, coll. K. Gowlett-Holmes ; 4 specimens, AM P.79853, Neds Camp , inshore limestone reef, Cape Range National Park (21 ◦ 59 ′ S, 113 ◦ 55 ′ E), 1.5 m, green algae Caulerpa sp. and basal rubble, hand collected on SCUBA , 2 January 1984, coll. J.K. Lowry ( WA 374 ) ; 12 specimens, AM P.79304, off jetty at Green Island , near Rottnest Island, (32 ◦ 1 ′ S, 115 ◦ 30 ′ E), 2–3 m, baited trap set overnight, 21 December 1983, coll. H.E. Stoddart ( WA 256 ) .

Etymology

Named from the type locality, McCluer Island , Northern Territory .

Description

Based on holotype male, 4.6 mm, AM P.83312. Head. Eyes subovoid; lateral cephalic lobe broad, truncated, anteroventral margin with notch / slit. Antenna 1 longer than antenna 2; peduncular article 1 subequal in length to article 2, without robust setae along posterior margin; article 2 longer than article 3; flagellum with 11 articles; accessory flagellum minute, bi-articulate. Antenna 2 peduncular article 2 cone gland reaching beyond end of article 3; article 4 subequal in length to article 5; flagellum with six articles. Mandible molar well developed, triturative; accessory setal row with 4 setae; palp tri-articulate; article 1 about as long as broad, shorter than article 2; article 2 longer than article 3, with few long slender setae; article 3 strongly falcate, short (about 2.2 times as long as broad), longer than article 1, with comb of short robust setae along anterodistal margin and three apical setae. Lower lip outer lobes with single pair of ducts; mandibular lobes apically subacute. Maxilla 1 inner plate subtriangular, with two apical plumose setae.

Pereon. Gnathopod 1 coxa anterior margin concave, anteroventral corner produced, rounded; merus without posterodistal tooth; carpus about twice as long as broad, subequal in length to propodus; propodus anterior margin with rows of long slen- der setae, medial surface without setal comb, palm acute, convex, entire, defined by posterodistal corner, with posterodistal robust setae. Gnathopod 2 subchelate; basis slender; merus with subquadrate distoventral corner; carpus compressed, lobate, projecting between merus and propodus; propodus expanded, anterior margin with rows of short slender setae, posterior margin with clusters of a few long slender setae, palm one-third to one-half the length of propodus, convex, sculptured, with midmedial excavation, subtriangular distomedial shelf with group of robust setae on shelf, defined by posteroventral corner, without posterodistal robust setae; dactylus reaching end of palm, closing into socket. Pereopod 4 coxa posteroventral lobe slightly developed, with subacute posteromedial corner. Pereopods 5–7 basis posterior margin without long slender setae; merus and carpus not broadened; dactylar ungues simple. Pereopods 5–6 basis slightly expanded, posterior margin straight, posteroventral corner broadly rounded; carpus and propodus with few long, slender setae along anterior margin. Pereopod 7 basis posterior margin convex, minutely castelloserrate.

Pleon. Epimera 1–3 posteroventral corner with small subacute tooth. Urosomites 1–3 smooth, without carina. Uropod 1 peduncle with one basofacial seta. Uropod 2 outer ramus about as long as peduncle, shorter than inner ramus. Uropod 3 rami distally truncated; inner ramus short, about 0.75 times outer ramus; outer ramus long (twice as long as broad), longer than peduncle. Telson moderately cleft (30–60% cleft), as long as broad, truncated distally, apical margins straight, each lobe with four long and short apical robust setae and with pair of lateral plumose setae.

Remarks

The gnathopod 2 male propodus palm sinus is present on E. mcluerensis sp. nov., E. slatyeri Lowry and Hughes, 2009 and E. pseudinteger Appadoo and Myers 2003 . In E. mcluerensis sp. nov. there are no teeth along the gnathopod 2 male propodus palm, only a distomedial shelf, while E. slatyeri has a subpalmar tooth and E. pseudinteger two teeth. Elasmopus mcluerensis sp. nov. has a minute bi-articulate accessory flagellum, relatively short mandibular palp article 3, on gnathopod 1 propodus there is no medial setal comb and the gnathopod 2 male propodus has a well defined palm corner, this combination of characters further separate it from its congeners.

Distribution

Australia. Northern Territory: McCluer Island, Oxley Island, Darwin Harbour, Bynoe Harbour, Gove Harbour. Queensland: Torres Strait, Hammond Island, Goodes Island, Northwest Islet, Hawkesbury Island. Western Australia: Ashmore Reef, Cape Range National Park, Rottnest Island (current study).

Figures

Figure 10. Elasmopus mcluerensis sp. nov., holotype male, 4.6 mm AM P.83312, McCluer Island, Northern Territory, Arafura Sea.

Figure 11. Elasmopus mcluerensis sp. nov., holotype male, 4.6 mm AM P.83312, McCluer Island, Northern Territory, Arafura Sea.