Ampithoe roly, Peart, 2007

Peart, Rachael A., 2007, A review of the Australian species of Ampithoe Leach, 1814 (Crustacea: Amphipoda: Ampithoidae) with descriptions of seventeen new species, Zootaxa 1566 (1), pp. 1-95 : 74-77

Ampithoe roly sp. nov.

( Figs 58–61 )

Type Material. Holotype: WAM C38542, male, 5 mm, W side of Malus Island , Dampier Archipelago, WA, 26°30.612’S 116°38.918’E, 27 Aug 1999, 2.3 m, on fine Sargassum sp. on sand, R. A. Peart . Paratypes: WAM C38543, female, 5 mm, type locality ; AM P61887, 1 specimen, Tish Point , Rosemary Island, Dampier Archipelago, WA, 20°29.671’S 116°35.894’E, 30 Aug 1999, 0.5 m, on Dictyota sp ., R. Peart ; AM P61888, 12 specimens, S side of Kendrew Island , Dampier Archipelago, WA, 20°28.987’S 116°32.549’E, 30 Aug 1999, 4 m, on brown algae , R. Peart ; AM P61889, 1 specimen, south side of Kendrew Island , Dampier Archipelago, WA, 20°28.987’S 116°32.549’E, 30 Aug 1999, 4.5 m, on Sargassum sp ., R. Peart ; AM P61890, 2 specimens, Roly Rock , Dampier Archipelago, WA, 20°29.741’S 116°30.184’E, 1 Sep 1999, 16 m, under rocks, M. Hewitt .

Diagnosis. Antenna 2 slender, similar to antenna 1, not densely setose on ventral margin. Lower lip with lateral lobe longer than medial lobe. Maxilla 1 inner plate with 1 slender seta. Gnathopod 1 carpal lobe subacute; carpus shorter than propodus; palm convex, with midmedial tooth, without posterodistal tooth defining palm; dactylus subequal in length to palm. Gnathopod 2 without densely setose margins; basis posterodistal lobe large and rounded, with more than 3 robust seta; carpus much shorter than propodus; palm transverse, entire, with a subacute midmedial tooth, with a small subacute posterodistal tooth defining palm, with 1 defining robust seta; dactylus subequal in length to palm. Pereopod 3 basis narrow; merus narrow. Pereopods 5–7 simple or weakly prehensile. Uropod 3 peduncle with 5 distal robust setae, outer ramus subequal in length to inner ramus, with patch of small conical lateral denticles, without lateral setal fringe; inner ramus with 3 distal robust setae. Telson distally truncate, apical cusps expanded to form large hooks.

Description. Based on holotype, male, 5 mm, WAM C38542. Head as long as deep. Antenna 1 longer than antenna 2; peduncular article 1 subequal to article 2 (0.95 x), article 2 longer than article 3 (3.23 x), article 3 shorter than article 1 (0.33 x); primary flagellum with 24 articles. Antenna 2 peduncular article 4 subequal to article 5; flagellum 15 articulate. Mandible molar with 4 robust setae in accessory setal row; palp slender, long, setose along posterior margin, article 1 shorter than article 2 (0.36 x), article 2 subequal to article 3 (1.05 x), article 3 longer than article 1 (2.68 x). Lower lip mandibular lobe with curved margins, rounded apically. Maxilla 1 palp with apical robust setae. Maxilla 2 inner plate narrow, outer plate broader. Maxilliped outer plate with developed setation (robust setae large).

Pereon. Gnathopod 1 without densely setose margins; coxa smaller than gnathopod 2 coxa, produced distoventrally, distoventral margin rounded, anterior margin concave, ventral margin with a row of small setules; basis subequal to coxa, with sparse (sometimes plumose) slender setae, posterodistal lobe large and round, 2 or 3 robust setae; merus produced to form a small, subacute distoventral lobe, anterior margin with setae absent; carpus longer than merus, subtriangular, anterior margin with 1 robust seta and slender setae; propodus narrow (length 1.79 x width), subrectangular; palm with 1 defining robust seta; dactylus inner margin denticulate. Gnathopod 2 without densely setose margins; coxa ventral margin with a row of small setules; basis longer than coxa, with fringe of long, slender, plumose setae; merus produced to form a short, subacute distoventral lobe, anterior margin with setae absent; carpus subequal to merus, subtriangular, anterior margin with more than 4 robust setae, much shorter than propodus (0.37 x); propodus broad (length 1.09 x width), subrectangular, produced into an anterodistally setose lobe; dactylus tapering evenly, acute, inner margin denticulate. Pereopod 7 basis without marginal robust setae, without medial slender setae; propodus defined distally by 3–5 simple robust setae.

Pleon. Epimeron 3 posteroventral corner narrowly rounded. Uropod 1 peduncle with more than 5 robust setae, with a long setal fringe; inner ramus slightly longer than outer ramus, with 3–5 marginal robust setae, slender setae absent; outer ramus with more than 5 marginal robust setae, slender setae absent. Uropod 2 peduncle with 1 or 2 robust setae, setal fringe absent; inner ramus slightly longer than outer ramus, with 3–5 marginal robust setae, slender setae absent; outer ramus with more than 5 marginal robust setae, slender setae absent. Uropod 3 peduncle longer than broad (1.67 x width), short with respect to rami length (1.86 x), marginal robust setae absent, marginal slender setae absent, with more than 5 distal slender setae; inner ramus with 3–5 distal slender setae. Telson with lateral slender setae.

Female. (sexually dimorphic characters). Based on paratype, female, 5 mm, WAM C38543. Antenna 1 primary flagellum with 19-articulate. Antenna 2 flagellum 11-articulate. Gnathopod 1 subequal in size to gnathopod 2; coxa subequal in size to gnathopod 2 coxa; basis shorter than coxa, posterodistal lobe small and round, with 2 or 3 slender setae; merus produced to form a short, rounded distoventral lobe; carpal lobe truncated; palm without midmedial tooth. Gnathopod 2 basis shorter than coxa, with sparse (sometimes plumose) slender setae, posterodistal lobe small and round, with 2 or 3 slender setae; carpus longer than merus, shorter than propodus (0.69 x), anterior margin with slender setae only; propodus ovoid, not produced anterodistally; palm acute, without a midmedial tooth.

Etymology. This species name is derived from Roly Rock, near the type locality.

Remarks. Ampithoe roly sp. nov., with a strongly subrectangular propodus of gnathopod 2, most closely resembles A. hyalos sp. nov. Characters distinguishing A. roly from A. hyalos are outlined under the account of the latter.

Habitat. Brown algae; 0.5–16 m.

Distribution. Dampier Archipelago, Western Australia, Australia.

Figures

FIGURE 58. Ampithoe roly sp. nov., holotype, male, WAM C38542, 5 mm. Paratype, female, WAM C 38543, 5 mm. Dampier Archipelago, Western Australia, Australia.

FIGURE 59. Ampithoe roly sp. nov., holotype, male, WAM C38542, 5 mm. Paratype, female, WAM C 38543, 5 mm. Dampier Archipelago, Western Australia, Australia. Scales represent 0.5 mm for antennae 1–2 and 0.2 mm for mouthparts.

FIGURE 60. Ampithoe roly sp. nov., holotype, male, WAM C 38542, 5 mm. Paratype, female, WAM C 38543, 5 mm. Dampier Archipelago, Western Australia, Australia.Scales represent 0.5 mm.

FIGURE 61. Ampithoe roly sp. nov., holotype, male, WAM C38542, 5 mm. Dampier Archipelago, Western Australia, Australia.Scales represent 0.5 mm for pereopods 3–7 and 0.2 mm for uropods 1–3 and telson. Pereopods 5–6 missing.