Paragrubia apoorei, 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 : 71-74

Paragrubia apoorei sp. nov.

(Figs. 44, 45)

Type material. Holotype male, 8.3 mm, dissected, 4 slides, WAM C52214, Rockingham Point, Western Australia (32°16’S 115°44’E), depth unknown, 1 December 2010, coll. Tina Bell.

Additional material examined. Western Australia: Male, dissected, 2 slides, AM P. 41208, 350 m east southeast of Penguin Island, Warnbro Sound (32°18’30”S 115°41’36”E), 3 m, seagrass Posidonia sinuosa , 7 November 1990, coll. P.A. Hutchings and party (Stn P); 2 specimens, AM P. 82620, 350 m east southeast of Penguin Island, Warnbro Sound (32°18’30”S 115°41’36”E), 3 m, seagrass Posidonia sinuosa , 7 November 1990, coll. P.A. Hutchings and party (Stn P).

South Australia: Male, SAMA C6670, creek mouth tributary, 5 km north northwest of Port Davis, Port Pirie (33°15’S 137°49’E), seagrass Posidonia sp., March 1980, coll. T. Ward.

Type locality. Rockingham Point, Western Australia (32°16’S 115°44’E).

Etymology. Named for A.G.B. Poore in recognition of his work on the ecology of Ampithoidae .

Diagnosis. Antenna 1 primary flagellum with more than 36 articles; accessory flagellum 1-articulate. Mandible accessory setal row with 7 robust setae. Lower lip outer plates notched, forming a medial excavation; lateral lobe subequal to medial lobe, without apical ducts. Maxilla 1 outer plate palp broad, article 2 with 5 robust setae. Gnathopod 1 larger and stouter than gnathopod 2; coxa 1 subequal to coxa 2, anterior margin straight, anteroventral corner weakly produced, subacute; basis with single anterodistal lobe large, rounded, with 2 slender setae; ischium anterior margin with large, rounded lobe; propodus subovoid, palm subacute, deeply excavate, defined by posterodistal tooth, subquadrare corner and 1 robust seta, palm length 0.7 times posterior margin. Gnathopod 2 basis anterodistal lobe large, rounded, margin scalloped, corner with 3 slender setae; ischium anterior margin bilobate; propodus subrectangular, palm subacute, convex, defined by rounded corner with small subacute tooth and 2 robust setae. Telson apically rounded, 3 pair of lateral setae and 1 pair of apical setae.

FIGURE 44. Paragrubia apoorei sp. nov. holotype male, 8.3 mm, WAM C52214, Rockingham Point, Western Australia.

Description of holotype. Head. Antenna 1 simlar to Antenna 2; article 1 length 0.9 times article 2; article 2 length 4 times article 3; article 3 length 0.27 times article 1; primary flagellum incomplete, with more than 36 articles; accessory flagellum 1-articulate. Antenna 2 article 4 subequal to article 5; flagellum with 12 articles. Mandible accessory setal row with 7 robust setae; palp 3-articulate; article 2 with 2 slender setae; article 3 length 2.5 times width. Lower lip outer plates notched, forming a medial excavation; lateral lobe subequal to medial lobe, without apical ducts; mandibular lobes with straight margins, rounded apically. Maxilla 1 inner plate with 2 slender setae; outer plate palp broad, article 2 with 5 robust setae.

Pereon. Coxae 1–4 longer than broad. Gnathopod 1 larger and stouter than gnathopod 2; coxa 1 subequal to coxa 2, as broad as deep, anterior margin straight, anteroventral corner weakly produced, subacute; basis subequal to coxa length, with single anterodistal lobe large, rounded, with 2 slender setae; ischium anterior margin with large, rounded lobe; merus posterodistal corners subacute; carpus subtriangular length 1.1 times width, subequal in length to propodus, anterior margin with 2 clusters of robust setae; propodus subovoid, length subequal to width, palm subacute, deeply excavate, defined by posterodistal tooth, subquadrare corner and 1 robust seta, palm length 0.7 times posterior margin; dactylus subequal in length to palm, apically subacute, tapering evenly, inner margin crenate. Gnathopod 2 basis subequal in length to coxa, posterior margin with sparse slender setae, with single anterodistal lobe large, rounded, not reaching beyond ischium, margin scalloped, corner with 3 slender setae; ischium anterior margin bilobate; merus posterodistal corners subacute; carpus subtriangular, length 1.7 times width, 0.9 times propodus length, anterior margin with a few slender setae; propodus subrectangular, length 1.8 times width, palm subacute, convex, defined by rounded corner with small subacute tooth and 2 robust setae, palm length 0.4 times posterior margin; dactylus subequal in length to palm, apically acute, tapering evenly, inner margin crenate.

Pleon. Epimera 1–3 posterior margin convex, posterodistal corner broadly rounded. Uropod 1 long, reaching end of uropod 2 rami; peduncle with 4 robust setae, with large, acute distoventral spine; inner ramus longer than outer ramus, with 5 marginal robust setae; outer ramus with 4 marginal robust setae. Uropod 2 peduncle with 4 robust setae; inner ramus longer than outer ramus, with 5 marginal robust setae; outer ramus with 6 marginal robust setae. Uropod 3 peduncle length 1.9 times width, 2.1 times rami length, with 2 distal robust setae, without marginal robust setae; inner ramus length 1.9 times width, subequal to outer ramus with 2 distal robust setae, 8 distal slender setae and 3 lateral robust setae; outer ramus shorter than inner ramus, with 2 large recurved distal robust setae. Telson subtrapezoidal, apically rounded, with small apical cusps, 3 pairs of lateral setae, 2 pairs of lateral plumose setae and 1 pair of apical setae.

Remarks. The uni-articulate accessory flagellum of antenna 1 in P. apoorei sp. nov. is similar to P. mahafalensis . In P. apoorei sp. nov. the gnathopod 1 closes along the palm whereas in P. mahafalensis the dactylus overreaches the palm.

The enlarged gnathopod 1, which islarger than gnathopod 2 aligns P. apoorei with P. dongara sp. nov., P. dwyeri sp. nov., P. latipoda and P. vorax . The gnathopod 2 propodus palm is convex in P. apoorei sp. nov. and P. latipoda , concave in P. dongara , P. dwyeri , and straight in P. vorax . The gnathopod 1 carpus projection and deeply excavate propodus palm defined by a subacute tooth distinguishes P. apoorei sp. nov. from P. vorax and all other Paragrubia species.

Distribution. Western Australia: Rockingham Point, Warnbro Sound (current study). South Australia: Port Pirie (current study).