Two New Species of Quadrisegmentum (Phtisicidae: Amphipoda: Crustacea) from the Central Indo-Pacific, with Notes on the Type Species Q. triangulum Hirayama, 1988 Author Hughes, Lauren Elizabeth Author Takeuchi, Ichiro text Records of the Australian Museum 2016 2016-11-16 68 5 231 244 http://dx.doi.org/10.3853/j.2201-4349.68.2016.1663 journal article 10.3853/j.2201-4349.68.2016.1663 2201-4349 4676871 Quadrisegmentum yirrgay sp. nov. Figs 6–10 Quadrisegmentum triangulum . — Guerra-Garcia, 2003: 104–105 , fig. 9a. — Guerra-Garcia, 2006: 440 , fig. 39. —Guerra-Garcia & Lowry, 2009: 323–325. Type material . Holotype ♂ 9.0 mm, AM P.98563, outer reef slope,Ashmore Reef , Coral Sea , Queensland , Australia ( 10°26'16"S 144°25'47"E ), red calcareous cylindrical algae, 19 January 1993 , coll. S.J. Keable ( QLD 704 ); paratype ♂ 9.0 mm, AM P.98564,outer reef slope,Ashmore Reef,Coral Sea, Queensland , Australia ( 10°26'16"S 144°25'47"E ), red calcareous cylindrical algae, 19 January 1993 , coll. S.J. Keable ( QLD 704 ); many specimens, AM P.61630, outer reef slope, Ashmore Reef, Coral Sea, Queensland , Australia ( 10°26'16"S 144°25'47"E ), red calcareous cylindrical algae, 19 January 1993 , coll. S.J.Keable ( QLD 704 ) . Paratypes : ♀ , 6 mm , AM P.61624,eastern edge of outer reef slope, Ashmore Reef , Coral Sea , Queensland , Australia ( 10°09'10"S 144°34'43"E ) calcareous red tubular algae, 24 January 1993 , coll. S.J. Keable ( QLD 734 ) ; 2 specimens ( 1 ♂ and 1 ♀ ), AM P.61627, eastern edge of outer reef slope Ashmore Reef , Coral Sea , Queensland , Australia ( 10°09'10"S 144°34'43"E ) mixed sponges, 24 January 1993 , coll. S.J. Keable ( QLD 736 ) ; 4 specimens ( 2 ♂♂ and 2♀♀ ), AM P.61629, outer reef slope, Ashmore Reef , Coral Sea , Queensland , Australia ( 10°13'10"S 144°24'53"E ) sponges, 22 January 1993 , coll. S.J. Keable ( QLD 722 ) ; 1 ♂ , AM P.61625, outer reef slope, Ashmore Reef , Coral Sea , Queensland , Australia ( 10°26'16"S 144°25'47"E ) sediment, algae and rubble, 19 January 1993 , coll S.J. Keable ( QLD 705 ) . Figure 5. Quadrisegmentum triangularum Hirayama, 1988 paratypes male habitus 8 mm 145°28'E ), 2 m , mixed algae from bommie, 28 September 1978 , coll. J.K. Lowry ( QLD 1 ); 2 specimens ( 1 ♂ and 1♀ ), AM P.32314, off southern Point of Mermaid Cove, Lizard Island ( 14°39'S 145°27'E ), 3–6.1 m , filamentous algae with stone washings and scrapings from crevices, 8 October 1978 , coll. C. J. Short & P.C. Terrill (QLD–25); 1 ♀ , AM P.32318, fringing reef between Bird Islet and South Island , Lizard Island ( 14°40'S 145°28'E ), 25 m , green algae Halophila sp. and mixed algae from grass beds off reef base, 9 October 1978 , coll. J.K. Lowry ( QLD 29 ); 2 ♂♂ , AM P.32320, reefs at western end of Blue Lagoon , Lizard Island ( 14°40'S 145°28'E ), 3 m , sand near artificial reefs, 5 October 1978 , coll. P.C. Terrill ( QLD 33 ); 16 specimens ( 6 ♂♂ , 9 ♀♀ , 1 juvenile ), AM P.32325, Mermaid Cove , Lizard Island ( 14°40'S 145°28'E ), subtidal to 2 m , mixed algae, coral rubble and silt, 14 October 1978 , coll. J.K. Lowry (QLD–48); 1 ♀ , AM P.32326, off North Point , Lizard Island ( 14°39'S 145°27'E ), 3–6.1 m , red algae ( Galaxaura sp.) and coral rubble from subtidal caves, 14 October 1978 , coll. J.K. Lowry ( QLD 49 ); 9 specimens ( 7 ♂♂ , 1 ♀ , 1 juvenile ), AM P.32327, off North Point , Lizard Island ( 14°39'S 145°27'E ), 3–6.1 m , mixed algae, 14 October 1978 , coll. J.K. Lowry ( QLD 50 ); 7 specimens ( 4 ♂♂ and 3 ♀♀ ), AM P.32328, Lizard Island , off North Point , Lizard Island ( 14°39'S 145°27'E ), 6.1 m , green calcareous alga Halimeda sp., 14 October 1978 , coll. P.C. Terrill ( QLD 52 ); 1 ♂ , AM P.61626, Great Barrier Reef , inside outer barrier, Lizard Island ( 10°34'29"S 143°55'17" E ), 15 m , rubble, 16 January 1993 , coll. S.J. Keable ( QLD 682 ); 1 ♂ , AM P.61712, between Palfrey Island and Lizard Island , western side of Blue Lagoon , Lizard Island ( 14°41'S 145°27'E ), 7 October 2001 ; 5 specimens ( 2♂♂ and 3 ♀♀ ), AM P.61713, between Palfrey Island and Lizard Island , western side of Blue Lagoon , Lizard Island ( 14°41'S 145°27'E ), 7 October 2001 ; 1 ♀ , AM P.61714, between Palfrey Island and Lizard Island , western side of Blue Lagoon , Lizard Island ( 14°41'S 145°27'E ), 2–3 m , coral rubble, 7 October 2001 , coll. J.M. Guerra-García & S.J. Keable ( QLD 1469 ); 8 specimens ( 4 ♂♂ and 4 ♀♀ ), AM P.61715, Coconut Beach , Lizard Island ( 14°41'S 145°27'E ), 6 m , fine live hard coral encrusted with calcareous red algae and filamentous red/green/brown algal turf, 8 October 2001 , coll. J.M. Guerra-García & S.J. Keable ( QLD 1476 ); 3 specimens ( 1 ♀ and 2 juveniles ), AM P.61716, Crystal Beach , Lizard Island ( 14°41'S 145°27'E ), 5 m , thick branching coral rubble encrusted with red algal turf and black sponge half buried in sediment, 9 October 2001 , coll. J.M. Guerra-García & S.J. Keable ( QLD 1483 ); 1 juvenile , AM P.61717, Crystal Beach , Lizard Island ( 14°41'S 145°27'E ), 4 m , thin branching live coral heavily encrusted Island ( 14°41'S 145°27'E ), 25 m , gorgonian (cf. Menella sp.), 14 October 2001 , coll. J.M. Guerra-Garcia & S.J. Keable ( QLD 1544 ); 1 ♂ , AM P.61724, reef slope on south side of South Island , Lizard Island ( 14°41'S 145°27'E ), 20 m , gorgonian (cf. Mopsella sp.), 14 October 2001 , coll. J.M. Guerra-Garcia & S.J. Keable ( QLD 1545 ); 2 ♂♂ , AM P.61725, north–east side of Lizard Island , reef slope south of "Washing Machine" ( 14°41'S 145°27'E ), 18 m , brown sponge cf. Clathria reinwardti , 16 October 2001 , coll. J.M. Guerra-Garcia & S.J. Keable ( QLD 1565 ); 1 ♀ , AM P.61726, north–east side of Lizard Island , reef slope south of "Washing Machine" ( 14°41'S 145°27'E ), 6 m , green calcareous alga Halimeda macroloba , 16 October 2001 , coll. J.M. Guerra-Garcia & S.J. Keable ( QLD 1568 ); 1 ♀ , AM P.61727, north–east side of Lizard Island , reef slope south of "Washing Machine" ( 14°41'S 145°27'E ), 5 m , sediment with green alga Halimeda cylindracea Decaisne 1842 , Udotea and Caulerpa spp., 16 October 2001 , coll. J.M. Guerra-Garcia & S.J. Keable ( QLD 1569 ); 2 specimens ( 1 ♂ and 1 juvenile ), AM P.61728, north–east side of Lizard Island , reef slope south of "Washing Machine" ( 14°41'S 145°27'E ), 6 m , mixed silty filamentous red algae and green alga Caulerpa taxifolia (M.Vahl) C. Agardh 1817 , 16 October 2001 , coll. J.M. Guerra-Garcia & S.J. Keable ( QLD 1573 ); 1 ♂ , AM P.61729, Pidgin Point , Lizard Island ( 14°41'S 145°27'E ), 20 m , sponge cf. Clathria reinwardti , 18 October 2001 , coll. J.M. Guerra-Garcia & S.J. Keable ( QLD 1581 ); 1 ♂ , AM P.61730, reef just south–west of Osprey Island , Lizard Island ( 14°41'S 145°27'E ), 10–12 m , fine–medium sand with some shell, 18 October 2001 , coll. J.M. Guerra-Garcia & S.J. Keable ( QLD 1588 ); 1 mature ♀ , AM P.61731, Granite Bluff , Lizard Island ( 14°40'S 145°28'E ), reef rock, 30 August 1976 , coll. P.A. Hutchings (25–1); 4 ♂♂ , AM P.61732, northern end of Mermaid Beach , Lizard Island ( 14°41'S 145°27'E ), 4 m , brown alga Padina sp., 12 October 2001 , coll. J.M. Guerra- Garcia & S.J. Keable ( QLD 1533 ) . Figure 6. Quadrisegmentum yirrgay sp. nov. , holotype male habitus, 9.0 mm, AM P.98563; paratype female, 6 mm, AM P.61624, Ashmore Reef, Coral Sea, Queensland, Australia. Figure 7. Quadrisegmentum yirrgay sp. nov. , holotype male 9.0 mm,AM P.98563,Ashmore Reef, Coral Sea, Queensland,Australia, scales 0.1 mm. Tasman Sea : 7 specimens ( 6 ♂♂ and 1 ♀ ), AM P.61581, patch reef in lagoon, Middleton Reef , Elizabeth and Middleton Reefs ( 29°27'36"S 159°06'42"E ), prolific coral cover on top of bommie, 6 December 1987 ( Site 12); 1 ♂ , AM P.61582, The Sound , large alcove near lagoon entrance, Middleton Reef , Elizabeth and Middleton Reefs ( 29°27'42"S 159°05'24"E ), rubble wash, 5 December 1987 ( Site 7); 1 ♂ , AM P.61475, reef front south of North Passage , straight out from Signal Point , Lord Howe Island ( 31°31'36"S 159°03'E ) coralline algae, coll. G.D. Fenwick , 11 May 1977 ( LHA 17 ) . Papua New Guinea : ♂ 6.1 mm , whole animal SEM pin mount, AM P.97779, The Quarry , near the village of Bunu 2, Madang ( 4°46'30"S 145°48'E ), coral slope with rubble, sand, ascidian Didemnum molle (Herdmann, 1886) and sponges, 21 January 1990 , coll. J.K. Lowry ( PNG 69); ♀ 6.1 mm , AM P.98565, The Quarry , near the village of Bunu 2, Madang ( 4°46'30"S 145°48'E ), coral slope with rubble, sand, ascidian Didemnum molle and sponges, 21 January 1990 , coll. J.K. Lowry ( PNG 69); 3 specimens ( 2 ♂ and 1 mature ♀ ), AM P.61534, base of reef slope, outer face, Horseshoe Reef , Bootless Inlet ( 9°30'30"S 147°15'30"E ) green calcareous alga Halimeda opuntia (Linnaeus) J.V. Lamouroux 1816 , 28 October 1980 , coll. S.P. Arnam & J.K. Lowry (PNG-23); 1 mature ♀ , AM P.61533, Horseshoe Reef , Bootless Inlet ( 9°30'30"S 147°15'30"E ) coral rubble from reef front slope, 29 October 1980 , coll. S.P. Arnam & J.K. Lowry (PNG-32); 1 ♂ , AM P.61536, Horseshoe Reef , Port Moresby ( 9°36'30"S 147°17'54"E ) gorgonian, 2 November 1980 , coll. A.J. Bruce ( AJB 206 ); 4 specimens ( 3 ♂♂ and 1 damaged juvenile), AM P.61537, Lion Island , Manunouma Islands ( 9°32'17"S 147°06'13"E ), gorgonian, 5 November 1980 , coll. A.J. Bruce (AJB-208); 4 specimens ( 3 ♂♂ and 1 mature ♀ ), AM P.61535, outside Horseshoe Reef, Bootless Inlet ( 9°30'30"S 147°17'30"E ), crinoids from outer reef face, 9 November 1980 , coll. S.P. Arnam & J.K. Lowry (PNG-63); 74 specimens , AM P.61531, The Quarry, near the village of Bunu 2 ( 4°46'30"S 145°48'E ), coral slope with rubble, sand, ascidian Didemnum molle and sponges, 21 January 1990 , coll. J.K. Lowry ( PNG 69); 1 ♂ , AM P.61532, The Quarry , near the village of Bunu 2 ( 4°46'30"S 145°48'E ), coral slope with rubble, sand and black sponge, coll. J.K. Lowry , 21 January 1990 ( PNG 68) . Figure 8. Quadrisegmentum yirrgay sp. nov. , holotype male 9.0 mm, AM P.98563, Ashmore Reef, Coral Sea, Queensland, Australia, scales 0.1 mm. Antenna 1 more than ⅓× body length (broken); peduncle article 2 longest, 2× article 1; article 3 length 0.8× article 2; flagellum with more than 4 articles (broken). Upper lip weakly notched. Mandible right, incisor with 4 teeth, lacinia mobilis with 5 teeth followed by 2 plates; palp 3-articulate; article 2 longest; article 3 with 1 distal and 2 midlateral slender setae, anterodistal margin pubescent. Mandible left, incisor with 5 teeth, lacinia mobilis followed by 2 plates; Lower lip setose on outer lobe. Maxilla 1 outer plate with 6 robust setae; palp 2-articulate, article 2 with 3 long and 2 short robust seate. Maxilliped basal endite (inner plate) larger than ischial endite (outer plate), basal endite with 3 apically serrate robust setae; ischial endite (outer plate) margin with several slender setae; palp 4-articulate; article 2 lateral expanded, with 5 setae; article 3 with sub-triangular distal projection. Type locality . Ashmore Reef, off Great Barrier Reef, Coral Sea, Queensland , Australia ( 10°26'16"S 144°25'47"E ). (The present “Ashmore Reef” is the different “ Ashmore Reef”, Timor Sea, north-west Western Australia , type locality for Q. triangulum ) Etymology . “Yirrgay” is the lost spoken language of a coastal indigenous group in Far North Queensland . Applied as a noun in apposition. Description . (Based on holotype ♂ , body length 9.0mm, AM P.98563 and male, body length, 6.1 mm , SEM AM P.97779 for abdomen). Body Somites sub-slender. Head and pereonite 1 combined, completely fused, suture absent, with pair of apically truncate dorsodistal projections. Pereonite 2 , with small acute anterolateral projection and larger acute mid lateral projection. Pereonite 3 , with minute mid-lateral projection. Pereonites 4–6 without anterior or mid-lateral projections Pereon . Gnathopod 1 basis similar in length to ischium, merus and carpus combined; carpus subequal to merus length, posterior margin with slender setae; propodus triangular; palm defined by prominent, curved, bifid process with 2 apical robust setae; dactylus falcate, inner margin lined with setules. Gill 2 subovate, length 0.6× pereonite 2 length. Gnathopod 2 begins ⅓ along posterior margin of pereonite 2; basis length 1.4× pereonite 2 length, 2.1× ischium, merus and carpus combined; merus subrectangular, distally swollen (length 2× width), longer than to carpus; carpus subrectangular (length 2× width); propodus subovate, longer than wide (length 2.1× width); palm 60% of posterior margin, 3 proximal projections each with robust seta. Gill 3 elongate, length 0.6× pereonite 3. Pereopod 3 basis longest, 0.4× pereopod 3 length; ischium 0.1× basis length; merus 0.7× basis length; carpus 0.25× basis length; propodus 1.1× carpus length with 2 large robust setae along palm, dactylus recurved. Gill 4 subequal to gill 3. Pereopod 4 shorter than pereopod 3, length 0.30× body; basis longest, 0.6× pereopod 3 length; ischium 0.25× basis length; merus 0.6× basis length; carpus 0.3× basis length; propodus longer than carpus, length 1.1× carpus with 4 large robust setae along palm; dactylus recurved. Figure 9. Quadrisegmentum yirrgay sp. nov. , male, 6.1 mm, AM P.97779, Madang, Papua New Guinea, scales habitus 1 mm, all other scales 100 µm. Pereopod 5 article 1 length 0.9× article 2; article 2 longest, 1.1× article 3; dactylus recurved. Pereopod 6 basis longest, 0.37× pereopod 6 length; ischium 0.08× basis length; merus 0.6× basis length; carpus 0.33× basis length, anterior margin without robust setae; propodus 0.6× basis length, anterior margin with 4 groups of long robust setae (proximal group only with paired robust setae); dactylus recurved. Pereopod 7 0.8× pereopod 6; basis 0.27× pereopod 7 length; ischium 0.25× basis length; merus length subequal to basis; carpus 0.65× basis length, anterior margin with 1 robust seta; propodus 0.8× basis length, anterior margin with 3 groups of long robust setae (middle group only with paired robust setae) and distal small robust setae; dactylus recurved. Figure 10. Quadrisegmentum yirrgay sp. nov. , male, 6.1 mm, AM P.97779, Madang, Papua New Guinea, scales Ur 20 µm, all other scales 100 µm. Pleon . Uropod 1 elongate, without setae (broken). Uropod 2 (broken). Telson small, with a pair of setae (Based on SEM AM P.97779). Figure 11. Distribution of world species of Quadrisegmentum Hirayama, 1988 . Female . (based on paratype AM P.61624). Pereonite 2 with small anterolateral and small acute mid-lateral projections. Pereonite 4 with rounded anterolateral projection. Antenna 1 long 0.75× body length; article 2 longest, 2× article 1 length; flagellum with 8 articles. Antenna 2 shorter than antenna 1; flagellum 4-articulated, length ½× antenna 1. Remarks . See remarks for Q. atauro sp. nov. Distribution . Australia : Ashmore Reef, Coral Sea, Lizard Island (current study; Guerra-Garcia, 2006 ; Guerra-Garcia & Lowry, 2009). Lord Howe Island. ( Guerra-García, 2006 ). Elizabeth and Middleton Reef ( Guerra-García, 2006 ). Papua New Guinea : Motupore Island, Manunouma Islands, Port Morseby and Madang ( Guerra-García, 2003 ).