Dulichiella pacifica, Lowry & Springthorpe, 2005

Lowry, JK & Springthorpe, RT, 2005, New and Little-known Melitid Amphipods from Australian Waters (Crustacea: Amphipoda: Melitidae), Records of the Australian Museum 57, pp. 237-302 : 292-294

Dulichiella pacifica n.sp.

Figs. 54–57

Dulichiella appendiculata .–Berents, 1983: 111, fig. 9.–Ledoyer, 1986: 187, fig. 9S.

Type material. HOLOTYPE, ♂ “a”, 4.4 mm, AM P61112 ; 1 PARATYPE, ♀, 5.9 mm, AM P61113 ; 9 PARATYPES, 1♂, 5 ovigerous females, 3 nonovigerous females, AM P61117 , between Tandai Point and Koilo Point , Guadalcanal , Solomon Islands , 9°22.5'S 159°52.2'E, coral rubble, 10 m, R.T. Springthorpe, 24 September 1991, SI-3; 1 PARATYPE, ♂ “b”, 4.1 mm, AM P61114 ; 4 PARATYPES, males, AM P61115 , Tandai Point , Guadalcanal , Solomon Islands, 9°23'S 159°52.5'E, sand with low algal turf, 20 m, hand dredge, R.T. Springthorpe, 11 October 2001, SI-36; 1 PARATYPE, ♂, AM P61116 , same locality, black finger sponges from rubble bottom, 16 m, R.T. Springthorpe, 11 October 2001, SI-38 .

Additional material examined. Queensland: 1 specimen, AM P30123, outer slope, Yonge Reef, 14°36'S 145°38'E, reef rock with Halimeda and Lithothamnion , 36 m, P.B. Berents & P.A. Hutchings, 9 January 1975, stn 75 LIZ D–1. 6 specimens, AM P30124, Watsons Bay, Lizard Island, 14°40'S 145°28'E, Halophila , Caulerpa, Udotea & drift algae, 7 m, J.K. Lowry & P.A. Hutchings, 29 September 1978, stn LI-2. 5 specimens, AM P30125, fringing reef between Bird Islet and South Island, Lizard Island, 14°40'S 145°28'E, Halophila , mixed algae, sediment from grass beds off reef, 24 m, J.K. Lowry, 9 October 1978, stn LI-27. 2 specimens, AM P30126, same locality, P.C.Terrill, 9 October 1978, stn LI-28. New Caledonia: 1 specimen,AM P47550, off Ilot Maitre, New Caledonia, 22°19.35'S 166°25.85'E, dead branching coral, 21 m, ORSTOM divers, 10 November 1995, stn NCL-72. 3 specimens, AM P47556; 7 specimens, AM P47563, same locality, large sea fan covered in sponges & other epiflora & epifauna, air lift, 21 m, J.K. Lowry, 10 November 1995, stn NCL-65. 1 specimen,AM P47522, Ilot Maitre, New Caledonia, 22°19.61'S 166°24.07'E, Padina -like alga, 10.5 m, G. Bargibant, ORSTOM, 14 November 1995, stn NCL-98. Several specimens, AM P47528, same locality, coralline algal “reef”, 10.5 m, G. Bargibant, ORSTOM, 14 November 1995, stn NCL-99. 5 specimens, AM P48322, Ilot Maitre, New Caledonia, 22°20.57'S 166°25.43'E, red alga, 20 m, I. Takeuchi, 7 November 1995, stn NCL-38. 3 specimens, AM P48332, same locality, dead coral, 20 m, ORSTOM divers, 7 November1995, NCL-40. 10 specimens, AM P47334; 2 specimens, AM P47347, between Ilot Maitre and Croissant reef, New Caledonia, 22°19.7'S 166°23.3'E, Sargassum sp. , 10 m, I. Takeuchi, 6 November 1995, stn NCL-28, 30. 1 specimen, AM P47506, between Ilot des Goelands and Grand Recif Abore, New Caledonia, 22°24.10'S 166°20.90'E, Halimeda sp. fine red alga, 10 m, J.K. Lowry, 16 November 1995, stn NCL-111. 1 specimen, AM P47590, between Ile Ngé & Sèche Croissant, New Caledonia, 22°19.41'S 166°20.89'E, purple bryozoan, Iodyctium buchneri , 20 m, ORSTOM divers, 9 November 1995, stn NCL- 57. 1 specimen, AM P47967, same locality, sediment sample (sand), 20 m, J.K. Lowry, 9 November 1995, stn NCL-56. 1 specimen, AM P48354, 200 m off Poé Plage, New Caledonia, 21°36.41'S 165°22.73'E, Sargassum , 1–2 m, J.K. Lowry, 19 November 1995, stn NCL-212.4 specimens,AM P48379, fringing reef Thio, New Caledonia, dead coral, 1 m, A.A. Myers, 20 November 1995, stn NCL-217. Several specimens, AM P48460, same locality, “felt like” alga, 1 m, A.A. Myers, 20 Nov 1995, NCL-218. Singapore: 1♂, AM P61135, Pulau Sakia, Singapore, [approx. 01°16'N 103°42'E], Smith-McIntyre grab, C.S.C. Lee, University of Singapore, 23 May 1991, stn E, ZRC–1991–16108.Many specimens,AM P61136, Changi Floating Fish Farm, Singapore, [approx. 01°24'N 103°58'E], 1 m, J.B. Sigurdsson, 7 May 1997, associated with biofouling.

Type locality. Between Tandai Point & Koilo Point , Guadalcanal , Solomon Islands, (9°22.5'S 159°52.2'E), coral rubble.

Description. Based on holotype male “a”, AM P61112, paratype female, AM P61113, and paratype male “b”, AM P61114.

Head. Lateral cephalic lobes broad, truncated, lacking notch or slit, anteroventral corner subquadrate. Antenna 1 slightly longer than antenna 2; peduncular article 1 shorter than article 2, with 3 robust setae along posterior margin; flagellum with about 28 articles; accessory flagellum with 4 articles. Antenna 2 peduncular article 2 cone gland reaching at least to end of peduncular article 3; article 4 subequal to article 5; flagellum with 12 articles. Mandible palp article 3 rectolinear, setae along both margins and terminal, longer than article 1; article 2 subequal to article 3; article 1 produced distally, shorter than article 2, about as long as broad. Maxilla 1 inner plate with setae mainly terminal.

Pereon. Gnathopod 1 coxa anteroventral corner not produced, posteroventral corner notch present; merus without posterodistal spine; propodus palm acute, convex, without posterodistal corner, defined by posterodistal robust setae. Gnathopod 2 sexually dimorphic; left and right gnathopods unequal in size; coxa posteroventral corner notch present; (larger) chelate; merus with rounded posteroventral corner; carpus compressed; propodus, distolateral margin with 4 acute distinct spines; palm angle obtuse, straight, posterodistal spine absent, without robust setae; dactylus apically blunt; (smaller) subchelate; merus with sharp posteroventral spine; carpus long; propodus palm straight, without posteroventral spine. Pereopod 5 basis posterior margin straight, posteroventral corner narrowly rounded or subquadrate; dactylus unguis anterior margin with accessory spine. Pereopod 6 coxa anterior lobe ventral margin slightly produced, rounded; basis posterior margin slightly concave, posteroventral corner narrowly rounded or subquadrate; dactylus unguis anterior margin with accessory spine. Pereopod 7 basis posterior margin straight, with posterior margin smooth or minutely castelloserrate, posteroventral corner narrowly rounded or subquadrate; dactylus unguis anterior margin with accessory spine.

Pleon. Pleonites 1–3 with dorsal serrations, with dorsodistal spine. Epimeron 1 posteroventral corner with small acute spine. Epimera 1–2 posteroventral margin without spines above posteroventral corner. Epimeron 3 posterior margin smooth, posteroventral corner with strongly produced acute spine. Urosomite 1 with broad dorsal midline gape, rarely bearing midline spines, dorsally bicarinate. Urosomite 2 posterior margin serrate. Uropod 3 inner ramus scale-like, much shorter than outer ramus; outer ramus much longer (more than 2× length) than peduncle, 2-articulate. Telson without apical robust setae, apical conical extension absent.

Female (sexually dimorphic characters). Gnathopod 2 subchelate; merus with sharp posteroventral spine; carpus long; propodus without medial depression, palm acute, concave, smooth, with sparse robust setae, defined by posterodistal robust setae, defined by posteroventral corner; dactylus apically acute/subacute. Pereopod 7 basis posterior margin subsigmoidal.

Habitat. Marine; littoral; coral rubble, sponges, sand with low algal turf, 10 to 20 m depth.

Etymology. Named for its widespread distribution in the Pacific Ocean.

Remarks. This distinctive species was illustrated from Senegal by Ledoyer (1986). It is common in Singapore and occurs along the archipelago that runs from New Guinea to Fiji.A closely related, undescribed species has been reported from Florida and Bermuda by LeCroy (2000). See remarks under D. australis for differences between these species.

Distribution. Queensland: Yonge Reef, Great Barrier Reef; Lizard Island (Berents, 1983; AM).

Extrinsic distribution. Senegal, Singapore, New Guinea, Solomon Islands, New Caledonia.

Australian geographic areas. Northeastern Australia.

Figures

Fig. 54. Dulichiella pacifica n.sp., paratype, male “b”, 4.1 mm, AM P61114, Tandai Point, Guadalcanal, Solomon Islands.

Fig. 55. Dulichiella pacifica n.sp., holotype, male “a”, 4.4 mm, AM P61112, Tandai Point, Guadalcanal, Solomon Islands. Scales for MDp, MX1IP represent 0.1 mm, remainder represent 0.2 mm.

Fig. 56. Dulichiella pacifica n.sp., holotype, male “a”, 4.4 mm, AM P61112, paratype, female, 5.9 mm, AM P61113, Tandai Point, Guadalcanal, Solomon Islands. Scales represent 0.2 mm.

Fig.57. Dulichiella pacifica n.sp., holotype, male “a”, 4.4 mm,AM P61112, paratype, female, 5.9 mm, AM P61113, Tandai Point, Guadalcanal, Solomon Islands. Scales represent 0.2 mm.