Parelasmopus poorei, Hughes, 2009

Hughes, L. E., 2009, Parelasmopus poorei a New Species of Maeridae (Crustacea: Amphipoda) from Southern Australia, Memoirs of Museum Victoria 66 (1), pp. 77-80 : 77-80

Parelasmopus Stebbing, 1888

Parelasmopus poorei sp. nov.

( Figs 1 , 2 )

Type locality. West of Point Ricardo , Victoria, Australia .

Type material. Holotype male, 11.0 mm, 4 slides, MV J 60148 ; paratype female, 13.5 mm, 1 slide, MV J 60147 ; paratypes J25634, 56 specimens, 11.7 km West of Point Ricardo, Eastern Bass Strait , (37° 49' 53" S 148° 30' 08" E), 27 m, February 1991, coll N. Coleman ( MSL-EG 105 ).

Additional material examined. 14 specimens, MV J25632 , 11.7 km west of Point Ricardo , Eastern Bass Strait, (37° 49' 53" S 148° 30' 08" E), 27 m, 4 June 1991, coll. N. Coleman ( MSL-EG 78 ) ; 38 specimens, MV J25633 , 11.7 km west of Point Ricardo , Eastern Bass Strait, (37° 49' 53" S 148° 30' 08" E), 27 m, February 1991, coll. N. Coleman ( MSL-EG 104 ) ; 2 specimens, MV J25635 , 14.3 km west south west of Point Ricardo , Eastern Bass Strait, (37° 50' 44" S 148° 28' 24" E), 32 m, 26 September 1990, coll. N. Coleman ( MSL-EG 46 ) ; 25 specimens, MV J25636 , 11.7 km west of Point Ricardo , Eastern Bass Strait, (37° 49' 53" S 148° 30' 08" E), 27 m, 4 June 1991, coll. N. Coleman ( MSL-EG 77 ) ; 58 specimens, MV J25637 , 11.7 km west of Point Ricardo , Eastern Bass Strait, (37° 49' 53" S 148° 30' 08" E), 27 m, Smith-McIntyre grab, February 1991, coll. N. Coleman ( MSL-EG 103 ) ; 10 specimen, MV J56869 , 8 km south of South East Point , Wilsons Promontory, Eastern Bass Strait, (39° 12' 54" S 146° 27' 18" E), 65 m, epibenthic sled, 18 November 1981, ( BSS 180 ) ; 5 specimens, MV J57018 , Cliff Head , 30 km south of Dongara, (29° 32' 00" S 114° 59' 00" E), 2.0 m, 22 April 1986, ( SWA 85 ) ; 3 specimens, MV J57145 , North Lumps , 2 km off Mullaloo, (31° 47' 18" S 115° 42' 48" E), 8.0 m, 2 May 1986, ( SWA 112 ) ; 3 specimens, MV J57203 , North Lumps , 2 km off Mullaloo, (31° 47' 18'S, 115° 42' 48'E) 7.0 m, 2 May 1985, coll. H. M. LewTon and G.C.B. Poore ( SWA 113 ) ; 6 specimes MV J57199 , north end of Little Beach , Two Peoples Bay, (34° 58' 24's, 118° 11' 42'E), depth unknown, 5 April 1984, coll. H. M. LewTon and G.C.B. Poore ( SWA10 ) .

Description. Based on holotype male, 11.0 mm, 4 slides, MVJ60148.

Head. Head eyes ovate; lateral cephalic lobe broad, truncated, anteroventral margin with notch. Antenna 1 longer than antenna 2; peduncular article 1 subequal to article 2, with

2 robust setae along posterior margin; article 2 longer than article 3; flagellum with 34+ articles; accessory flagellum short with 5 articles. Antenna 2 peduncular article 2 cone gland reaching beyond end of peduncular article 3; article 4 longer than article 5; flagellum with 19 articles. Mandible accessory setal row well developed with 4 setae; molar well developed, triturative; mandibular palp present, 3-articulate; article 1 swollen along entire article, four times as long as broad, longer than article 2; article 2 shorter than article 3; article 3 long (more than six times as long as broad), article 3 subequal in length to article 1, with 2 long slender apical setae.

Pereon. Gnathopod 1 coxa anterior margin concave, anteroventral corner produced, acute; carpus about twice as long as broad, longer than propodus; propodus palm subacute, straight, entire, defined by posterodistal corner, with 2 posterodistal robust setae. Gnathopod 2 subchelate; basis slender; carpus compressed, lobate, projecting between merus and propodus; propodus massive, with clusters of slender setae along posterior margin, palm straight, smooth, about one third length of propodus, with subrectangular distomedial shelf, with 3 robust setae on shelf, palmar margin with groups of robust setae, facial margin forming broad tabular blade (heavily calcified), posteroventral corner defined by 90º angle, without posterodistal robust setae, facial margin with dactylar socket; dactylus with crenulated posteroproximal shelf, reaching end of palm, closing into socket, with apical restriction. Pereopod 4 coxa posteroventral lobe well developed, with rounded posteromedial corner. Pereopods 5–7 basis posterior margin heavily serrate, without long slender setae, merus not broadened. Pereopod 5 basis linear; posterior margin concave, posteroventral corner serrate. Pereopod 6 basis posterior margin straight, posteroventral corner serrate. Pereopod 7 basis posterior margin straight, posteroventral corner produced posterodistally, lobate, with acute serrate process; propodus not expanded posterodistally. Pereonite 7 dorsally bicarinate.

Pleon. Pleonite 1-3 dorsally bicarinate. Epimeron 1-2 posteroventral corner with small acute spine. Epimeron 3 ventral margin serrate distally, posteroventral margin serrate below posteroventral corner, posteroventral corner with strongly produced acute spine. Urosomite 1 bicarinate. Uropod 1 peduncle with basofacial robust seta. Uropod 3 rami distally truncated to subacute, with long and short apical robust setae; inner ramus longer than peduncle, subequal in length to outer ramus; outer ramus three times as long as broad. Telson deeply cleft, as long as broad, lobes divergent, distally truncated, with 4 - 5 long apical robust setae.

Female (dimorphic characters). Based on paratype female, 13.5 mm, MV J60147 .

Pereon. Gnathopod 2 carpus very long about, 2.5 times as long as wide, not lobate, not enclosed by merus and propodus; propodus linear, about four times as long as broad, without distomedial shelf; dactylus without posteroproximal shelf, apically subacute.

Remarks. Parelasmopus poorei sp. nov. can be distinguished from other species of Parelasmopus by the male gnathopod 2 propodus with the calcified straight blade-like palm and the dactylus distal apical constriction which closed into a socket on the medial side of the propodus palm. In male juvenile specimens, about 6 mm, the gnathopod 2 constricted dactylus has not developed.

Parelasmopus poorei sp. nov. male gnathopod 2 propodus palm is defined by a right angle corner similar to P. cymatilis Lowry & Hughes, 2009 , P.setiger Chevreux, 1901 , P.suluensis ( Dana, 1852) , P. suensis ( Haswell, 1879) and P. zelei Ledoyer, 1982 . The combination of pereopods 5 - 7 basis with heavily serrate posterior margin and bicarinate pleonite 3 further distinguishes P. poorei sp. nov. and P. cymatilis from these species. The lack of serrations on the gnathopod 1 coxa separates P. poorei from P. cymatilis .

Distribution. Australia. Victoria: Point Ricardo, Wilsons Promontory. Western Australia: Dongara, Two Peoples Bay, Mullaloo (current study).

Figures

Figure 1. Parelamopus poorei n. sp.: holotype male, 11.0 mm, MVJ60148. Scales for Md, F, Mx1 and LL represent 0.2 mm. Scales for U1-3 and T represent 0.5 mm.

Figure 2. Parelamopus poorei n. sp.: holotype male, 11.0 mm, MVJ60148, paratype female, 13.5 mm, MV J 60147. Scales represent 0.5 mm.