Analysis of the genus Sunamphitoe Spence Bate, 1857 (Amphipoda: Ampithoidae) with descriptions of eight new species Author Peart, Rachael A. text Zootaxa 2017 4269 3 301 345 journal article 32995 10.11646/zootaxa.4269.3.1 4f5c4cb2-271c-47b4-8d95-7cc9d5bee766 1175-5326 582419 F2CB1918-F7AA-4C33-9634-53A732A1FCCA Sunamphitoe stevesmithi sp. nov. ( Figs 24–27 ) Type material. Holotype : male, 8 mm , WAM C70226, mixed fine Sargassum sp. on rocks near shore, Canal Rocks , south of Yallingup , South west Western Australia , Australia , 33°40.28’S 114°59.67’E , coll. R. Peart , 6 December 2000 . Paratype: female, 9 mm , WAM C70227, collected with holotype; 6 specimens (males and females), WAM C70228, collected with holotype. Other material examined. Australia , Western Australia : 1 specimen (AM P62604), 42 specimens (AM P62605), 0.5 m , from mixed brown algae on rocks near shore, Shelley Beach , Bunker Bay , near Cape Naturaliste , south of Busselton , 33°32.56’S 115°05.79’E , coll. R. Peart , 4 December 2000 ; 4 specimens , AM P62606, 0.5 m , Sargassum sp. on rocks near shore, Eagle Beach , near Cape Naturaliste , south west of Busselton , 33°33.69’S 115°03.90’E , coll. R. Peart , 5 December 2000 ; 9 specimens (AM P62607), 11 specimens (AM P62608), 12 specimens ( WAM C70229), 5 specimens (AM P62610), 0.5 m , Sargassum sp. on rocks near shore, Canal Rocks , south of Yallingup , 33°40.28’S 114°59.67’E , coll. R. Peart , 6 December 2000 . FIGURE 24 . Sunamphitoe stevesmithi sp. nov. , holotype male, 8 mm, WAM C70226, and paratype female, 9 mm, WAM C70227, Canal Rocks, south of Yallingup, Busselton, Western Australia, Australia. Type locality. Canal Rocks , south of Yallingup , Western Australia , Australia . Diagnosis. Antenna 2 slender, similar to antenna 1, with short, dense setae on ventral margin; Mandibular palp absent. Maxilla 1 inner plate without slender setae. Maxilla 2 inner plate narrow, outer plate broader. Lower lip outer plate notched, with lateral lobe longer than medial lobe. Gnathopod 2 carpus much shorter than propodus; propodus ovoid; palm extremely acute, entire, with subquadrate tooth near the base of the dactylus, without posterodistal tooth defining palm, without defining robust setae; dactylus overreaching palm, extending length of posterior margin of propodus, inner margin smooth. Pereopod 5 distal articles broad. Pereopod 6 basis posterior margin rounded. Pereopods 6–7 distal articles slender. Uropod 3 peduncle with four distal robust setae; outer ramus with patch of small conical lateral denticles, without lateral setal fringe. Telson distally truncate, apical cusps small, with apical and lateral slender setae, denticles absent. FIGURE 25 . Sunamphitoe stevesmithi sp. nov. , holotype male, 8 mm, WAM C70226, and paratype female, 9 mm, WAM C70227, Canal Rocks, south of Yallingup, Busselton, Western Australia, Australia. Scales 0.5 mm for antennae 1–2 and 0.2 mm for mouthparts. FIGURE 26 . Sunamphitoe stevesmithi sp. nov. , holotype male, 8 mm, WAM C70226, and paratype female, 9 mm, WAM C70227, Canal Rocks, south of Yallingup, Busselton, Western Australia, Australia. Scales 0.5 mm for gnathopods 1–2 and 0.2 mm for uropods 1–3 and telson . Description. (Based on holotype male, 8 mm , WAM C70226, and paratype female, 9 mm , WAM C70227.) Head as long as deep. Antenna 1 longer than antenna 2; peduncular article 1 longer than article 2 (1.2 ×), article 2 longer than article 3 (3.3 ×), article 3 shorter than article 1 (0.2 ×); primary flagellum with 16 articles. Antenna 2 peduncular article 4 subequal to article 5; flagellum 12 articulate. Mandible molar well developed, triturating, with eight robust setae in accessory setal row. Maxilla 1 palp well developed, with apical robust setae. Maxilliped outer plate with developed setation (robust setae large and numerous), and reaching midlength of palp article 3; palp article 4 without setules. FIGURE 27 . Sunamphitoe stevesmithi sp. nov. , holotype male, 8 mm, WAM C70226, Canal Rocks, south of Yallingup, Busselton, Western Australia, Australia. Scales 0.5 mm. Pereon . Gnathopod 1 smaller than gnathopod 2, without densely setose margins; coxa not produced anteroventrally, anteroventral corner rounded, ventral margin with row of slender simple setae of different lengths; basis subequal to coxa, with sparse (sometimes plumose) slender setae, anteroventral lobe small, rounded with one slender seta; merus produced to form small, subacute distoventral lobe; anterior margin without setae; carpus longer than merus, subtriangular, shorter than propodus (0.8 ×), carpal lobe rounded, anterior margin with slender setae only; propodus narrow (length 1.9 × width), subrectangular; palm transverse, entire, without midmedial tooth, without posterodistal tooth defining palm, with one defining robust seta; dactylus overreaching palm, inner margin denticulate. Gnathopod 2 coxa ventral margin with row of slender simple setae of varying lengths; basis subequal to coxa, with sparse slender setae, anteroventral lobe small, rounded, setae absent; merus produced to form short, subacute distoventral lobe, anterior margin with setae absent; carpus shorter than merus, subtriangular, anterior margin with slender setae only; propodus ovoid, not produced into anterodistally setose lobe; dactylus tapering evenly, acute, inner margin smooth. Pereopods 3–4 basis and merus expanded. Pereopods 5–7 weakly prehensile. Pereopod 5 basis with marginal robust setae and medial slender setae; merus subrectangular; propodus not expanded distally, subrectangular, with three simple distal striated robust setae; dactylus strongly curved. Pereopod 6 basis with marginal robust setae, without medial slender setae; merus subrectangular; propodus subrectangular, slightly expanded distally, with three simple distal striated robust setae; dactylus slightly curved. Pereopod 7 basis with marginal robust setae, without medial slender setae; propodus subrectangular, defined distally by three to five simple robust setae. Pleon. Epimeron 3 posteroventral corner rounded. Uropod 1, in situ, reaching rami of uropod 2; peduncle with eight robust setae, and short setal fringe; inner ramus slightly longer and narrower than outer ramus, with three marginal robust setae; outer ramus with four marginal robust setae. Uropod 2 peduncle with three robust setae; inner ramus slightly longer and narrower than outer ramus, with five marginal robust setae; outer ramus with four marginal robust setae. Uropod 3 peduncle longer than broad, (1.5 × width), short in relation to rami length (1.9 ×), marginal robust setae absent, but marginal slender setae present in two bundles, with more than five distal slender setae; rami broad; outer ramus longer than inner ramus, inner ramus with two distal robust setae and more than five distal slender setae. Female. Antenna 1 primary flagellum with 36 articles. Antenna 2 peduncular article 4 longer than article 5; flagellum with 21 articles. Gnathopod 1 subequal in size to gnathopod 2; coxa ventral margin with row of small setules and long tuft of slender setae on posteroventral corner; basis shorter than coxa, posterodistal lobe with setae absent. Gnathopod 2 coxal ventral margin with row of small setules and with long tuft of slender setae on posteroventral corner; basis shorter than coxa, posterodistal lobe with one slender seta; carpus longer than merus, shorter than propodus (0.8 ×); propodus narrow (length 1.7 × width), subrectangular; palm transverse, without midmedial tooth, with one defining robust seta; dactylus overreaching palm, inner margin denticulate. Etymology. This species is named for Dr Steve Smith of the National Marine Science Centre , Southern Cross University, Australia , for his encouragement and advice, and assistance in field work during my Ph .D. Remarks. Sunamphitoe stevesmithi sp. nov. resembles another new species from Australia , S. batavia sp. nov. by having a slender antenna 2 that is similar to antenna 1 and lacking the mandibular palp. Sunamphitoe stevesmithi differs from S. batavia by a number of characters: antenna 1 peduncular article 1 longer than article 2 ( S. batavia has peduncular article 1 subequal in length to article 2), maxilla 1 inner plate lacks setation ( S. batavia has one seta), gnathopod 2 palm is sinuous ( S. batavia is straight), the uropod 1 rami inner margins are without robust setae ( S. batavia margins have one robust seta each), weakly setose on the lateral margins of the telson ( S. batavia quite setose on telson lateral margins), and the coxae are without fine setae ( S. batavia has a coating of fine setae). Habitat. Sunamphitoe stevesmithi sp. nov. occurs in shallow water ( 0.5 m ), living in mixed brown algae, particularly Sargassum spp. Distribution. Cape Naturaliste , Western Australia , Australia .