Paragrubia dongara, Hughes, Lauren E. & Peart, Rachael A., 2013

Hughes, Lauren E. & Peart, Rachael A., 2013, New species and new records of Ampithoidae (Peracarida: Amphipoda) from Australian Waters, Zootaxa 3719 (1), pp. 1-102 : 77-82

Paragrubia dongara sp. nov.

( Figs. 48–51 )

Type material. Holotype male, 16 mm, dissected, 4 slides, WAM C52215, Eagle Beach, near Cape Naturaliste, southwest of Busselton, Western Australia (33°33’41”S 115°03’53”E), 0.5 m, fine brown alga Sargassum sp., 5 December 2000, coll. R.A. Peart (WA 734); paratype female, 1 slide, WAM C52216, rocks near shore, Shelley Beach, Bunker Bay, near Cape Naturaliste, south of Busselton, Western Australia (33°32’34”S 115°01’47”E), 0.5 m, mixed brown algae, 4 December 2000, coll. R.A. Peart (WA 731); 2 paratype specimens, AM P.82628, rocks near shore, Shelley Beach, Bunker Bay, near Cape Naturaliste, south of Busselton, Western Australia (33°32’34”S 115°01’47”E), 0.5 m, mixed brown algae, 4 December 2000, coll. R.A. Peart (WA 731).

Additional material examined. South Australia: Male, dissected, 4 slides, NMV J64949 , point at north end of Little Beach, Two Peoples Bay (34°58’12”S 118°10’48”E), 5 m, 18 May 1986 (SWA 72); 9 specimens, NMV J57020 , point at north end of Little Beach, Two Peoples Bay (34°58’12”S 118°10’48”E), 5 m, 18 May 1986 (SWA 72); 3 specimens, NMV J57111 , Cliff Head, 30 km south of Dongara (29°32’00”S 114°59’00”E), 2 m, 22 April 1986 (SWA 85); 1 specimen, NMV J57110 , northern sided of West Island (35°37’00”S 138°36’00”E), 5 m, 21 March 1985 (SA 43).

Type locality. Eagle Beach, near Cape Naturaliste, southwest of Busselton, Western Australia (33°33’41”S 115°03’53”E).

Etymology. The species name is derived from the Western Australian township of Dongara , applied as a noun in apposition.

Diagnosis. Antenna 1 accessory flagellum 6-articulate. Mandible accessory setal row with 2 robust setae (3 on left). Lower lip outer plates notched; lateral lobes and medial lobes subequal in size; mandibular lobes with curved margins, rounded apically. Maxilla 1 outer plate palp slender, article 2 without robust setae. Gnathopod 1 similar to gnathopod 2; coxa 1 subequal to coxa 2, anterior margin concave, anteroventral corner produced subacute; basis shorter than coxa, posterior margin lined with slender setae, with single anterodistal lobe small, rounded, with 4 slender setae; ischium without well-developed lobe; propodus subovoid to subrectangular, length twice width, palm subacute, deeply excavate, palm defined by subquadrate corner with single robust seta. Gnathopod 2 basis subequal in length to coxa posterior margin with sparse slender setae, with single anterodistal lobe large, rounded, not reaching beyond ischium with 4 slender setae; propodus subrectangular, palm subacute, deeply excavate, palm defined by subquadrate corner with single robust seta. Telson subtriangular, apically rounded, oblique medial rows of slender setae and 4 pairs of short lateral slender setae.

Description of holotype. Head. Antenna 1 longer than antenna 2; peduncular article 1 length 1.2 times article 2; article 2 length 3.66 times article 3; article 3 length 0.23 times shorter than article 1; primary flagellum incomplete, more than 77 articles, accessory flagellum 6-articulate. Antenna 2 slender, similar to antenna 1; peduncle article 4 subequal in length to article 5; flagellum 34 articles. Mandible accessory setal row with 2 robust setae (3 on left); palp 3-articulate; article 2 with 2–3 slender setae; article 3 length 2.9 times width. Lower lip outer plates notched; lateral lobes and medial lobes subequal in size; mandibular lobes with curved margins, rounded apically. Maxilla 1 inner plate with 1 slender seta; outer plate palp slender, article 2 without robust setae. Maxilla 2 inner plate more narrow than outer plate. Maxillaped inner plate with small robust setae.

Pereon. Coxae 1–4 longer than broad. Gnathopod 1 similar to gnathopod 2; coxa 1 subequal to coxa 2, anterior margin concave, anteroventral corner produced subacute, posteroventral corner with tuft of long slender setae; basis shorter than coxa, posterior margin lined with slender setae, with single anterodistal lobe small, rounded, with 4 slender setae; ischium without well-developed lobe; merus anterodistal corner acute; carpus length twice width, 0.9 times propodus length; propodus subovoid to subrectangular, length twice width, palm subacute, deeply excavate, palm defined by subquadrate corner with single robust seta, palm length 0.5 times posterior margin; dactylus subequal in length to palm, apically acute, tapering evenly, inner margin crenate. Gnathopod 2 coxa posteroventral corner with tuft of long slender setae; basis subequal in length to coxa posterior margin with sparse slender setae, with single anterodistal lobe large, rounded, not reaching beyond ischium with 4 slender setae; merus anterodistal corner rounded; carpus subtriangular, length 1.5 times width, 0.9 times propodus length; propodus subrectangular, length 1.5 times width, palm subacute, deeply excavate, palm defined by subquadrate corner with single robust seta, palm length 0.5 times posterior margin; dactylus subequal in length to palm, apically acute, tapering evenly, without unguis, inner margin crenate.

Pleon. Epimeron 1 subquadrate, posterior margin straight, posterodistal corner rounded. Epimera 2–3 subquadrate, posterior margin straight, posterodistal corner with small acute tooth. Uropod 1 reaching end of uropod 2 rami; peduncle length 2.5 times width, with 8 robust setae, without slender setal fringe, with large, acute distoventral spine; inner ramus 1.1 times length of peduncle, slightly longer than outer ramus, with 8 marginal robust setae; outer ramus with 10 marginal robust setae. Uropod 2 peduncle with 3 robust setae, with small distoventral spine; inner ramus subequal to outer ramus, with 8 marginal robust setae; outer ramus with 7 marginal robust setae. Uropod 3 peduncle length 1.41 times width, 1.58 times rami length, with 4 marginal robust setae, with 7 distal robust setae; inner ramus length twice width, with 4 lateral robust setae, 5 distal robust setae and 5 distal slender setae; outer ramus subequal in length to inner ramus with 2 small, distal robust setae, without recurved robust setae, with 3 lateral robust setae and lateral setal fringe. Telson subtriangular, apically rounded, with small apical cusps, oblique medial rows of slender setae, 4 pairs of short lateral slender setae and 2 pairs of lateral plumose setae.

Remarks. Paragrubia dongara sp. nov. and P. mahafalensis can be separated from all other Paragrubia by the deeply excavate propodus palms of both gnathopods 1 and 2, with the palms of P. dwyeri sp. nov. similar although more shallowly excavate and considered as concave. Paragrubia dongara sp. nov. can be distinguished from P. mahafalensis by a number of characters including: the coxa 1 anterior margin more produced; mandible accessory setal row with only 3 setae and the rounded telson shape, where the latter species has coxa 1 weakly produced, 8 accessory setae and a trapezoidal shaped telson, respectively.

Paragrubia dongara sp. nov. is also similar to P. edgari in the gnathopod 1 propodus palm quadrate excavation but can be separated by the antenna 2 peduncle with less setose margins, and the coxa 1 anterior margin strongly produced. Overall the gnathopod 1 is only slightly larger than gnathopod 2 for P. dongara sp. nov., while in P. e d g a r i the gnathopod 1 dominates gnathopod 2 by a greater ratio.

Distribution. Australia. Western Australia: Dongara ; Two Peoples Bay; Busselton (current study). South Australia: West Island (current study).

Figures

FIGURE 48. Paragrubia dongara sp. nov., holotype male, 16 mm, WAM C 52215, Eagle Beach, near Cape Naturaliste, Western Australia.

FIGURE 49. Paragrubia dongara sp. nov., holotype male, 16 mm, WAM C 52215, Eagle Beach, near Cape Naturaliste, Western Australia, scales represent 0.5 mm for antennae 1 – 2 and 0.2 mm for mouthparts.

FIGURE 50. Paragrubia dongara sp. nov., holotype male, 16 mm, WAM C 52215, Eagle Beach, near Cape Naturaliste, Western Australia, scales 0.5 mm.

FIGURE 51. Paragrubia dongara sp. nov., holotype male, 16 mm, WAM C 52215, Eagle Beach, near Cape Naturaliste, Western Australia, scales 0.5 mm.