Ampithoe parakava, 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 : 59-64

Ampithoe parakava sp. nov.

( Figs 46–49 )

Type material. Holotype: WAM C 38536, male, 4 mm, S of Nelson Rocks , Dampier Archipelago, WA, 20°27.979’S 116°39.733’E, 7 Sep 1999, 5 m, on Dictyopteris sp. on sand, P. Morrison . Paratypes: WAM C 38537, 1 female, 5 mm, type locality ; AM P61864, 14 specimens, type locality ; AM P61865, 2 specimens, on Padina sp. , W side of Malus Island , Dampier Archipelago, WA, 26°30.612’S 116°38.918’E, 27 Aug 1999, 2.8 m , R. Peart ; AM P61866–P61869, 16 specimens, Tish Point , Rosemary Island, Dampier Archipelago, WA, 20°29.671’S 116°35.894’E, 30 Aug 1999, 0.5 m , R. Peart ; AM P61870, 1 specimen, S of Nelson Rocks , Dampier Archipelago, WA, 20°27.979’S 116°39.733’E, 7 Sep 1999 , 5 m, on brown algae on sand, P. Morrison.

Diagnosis. Antenna 2 robust, better developed than antenna 1, with short, dense setae on ventral margin. Lower lip with lateral lobe longer than medial lobe. Maxilla 1 inner plate with 1 slender seta. Gnathopod 1 carpal lobe rounded; carpus shorter than propodus; palm convex, without midmedial tooth, without posterodistal tooth defining palm; dactylus subequal in length to palm. Gnathopod 2 with long dense, simple setae on margins; basis posterodistal lobe large and rounded, with more than 3 robust setae; carpus shorter than propodus; palm acute, incised, without a midmedial tooth, with a large blunt posterodistal tooth defining palm, without a defining robust seta; dactylus subequal in length to palm. Pereopod 3 basis expanded; merus expanded. Pereopods 5–7 prehensile. Pereopod 5 merus subrectangular. Uropod 3 peduncle with 5 distal robust setae, outer ramus subequal in length to inner ramus, with a patch of small conical lateral denticles, without lateral setal fringe; inner ramus with 3 distal robust setae. Telson distally truncate, apical cusps small. Description. Based on holotype, male, 4 mm, WAM C38536. Head as long as deep. Antenna 1 longer than antenna 2; peduncular article 1 longer than article 2 (1.28 x), article 2 longer than article 3 (2.86 x), article 3 shorter than article 1 (0.27 x); primary flagellum with 23 articles. Antenna 2 peduncular article 4 subequal to article 5; flagellum 9-articulate. Mandible molar with 4 robust setae in accessory setal row; palp 3- articulate, stout, long, setose along posterior margin, article 1 longer than article 2 (0.63 x), article 2 shorter than article 3 (0.86 x), article 3 longer than article 1 (1.84 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 larger than gnathopod 2 coxa, produced distoventrally, distoventral margin rounded, anterior margin straight, ventral margin with a row of small setules; basis subequal to coxa, with sparse (sometimes plumose) slender setae, posterodistal lobe small and rounded, 2 or 3 slender 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 1.53 x width), subrectangular; palm with 1 defining robust seta; dactylus inner margin den- ticulate. Gnathopod 2 coxa ventral margin with a row of small setules; basis subequal to coxa, with fringe of long, slender, plumose setae; merus produced to form a short, subacute distoventral lobe, anterior margin with setae absent; carpus longer than merus, subtriangular, anterior margin with slender setae only; propodus broad (length 1.05 x width), ovoid, produced into an anterodistally setose lobe; dactylus tapering evenly, acute, inner margin denticulate. Pereopod 5 basis without marginal robust setae, without medial slender setae; distal articles slender; propodus slightly expanded distally, subrectangular, with 4 distal simple striated robust setae; dactylus strongly curved. Pereopod 6 basis posterior margin rounded proximally, straight distally, without marginal robust setae, without medial slender setae; merus subrectangular; propodus slightly expanded distally, with 4 distal simple striated robust setae; dactylus strongly curved. Pereopod 7 basis without marginal robust setae, without medial slender setae; propodus defined distally by 4 simple robust setae.

Pleon. Epimeron 3 posteroventral corner broadly rounded. Uropod 1 peduncle with more than 5 robust setae, with a long setal fringe, with small rounded distoventral spur; rami subequal in length; inner ramus with 3–5 marginal robust setae, slender setae absent; outer ramus with 3–5 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 1 or 2 marginal robust setae, slender setae absent. Uropod 3 peduncle longer than broad (1.41 x width), long with respect to rami length (2.02 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 apical and lateral slender setae.

Female. (sexually dimorphic characters). Based on paratype, female, 5 mm, WAM C38537. Antenna 1 primary flagellum with 18 articles. Gnathopod 1 subequal in size to gnathopod 2; coxa subequal in size to gnathopod 2 coxa; basis shorter than coxa, posterodistal lobe with 2 or 3 robust setae; merus produced to form a short, rounded distoventral lobe; propodus broad (length 1.4 x width), ovoid. Gnathopod 2 without densely setose margins; basis shorter than coxa, with sparse (sometimes plumose) slender setae; propodus not produced anterodistally; palm entire, with a rounded midmedial tooth, with small subacute posterodistal tooth defining palm, defined by 1 robust seta. Uropod 1 peduncle distoventral spur absent.

Etymology. This species is named due to its similarity to Ampithoe kava Myers, 1985 .

Remarks. Ampithoe parakava is most similar to A. kava but differs by the more setose antenna 2, with slender setae on the margin of the gnathopod 1 basal lobe and the slender distal articles of pereopod 5.

Habitat. Brown algae: Dictyopteris sp. , Dictyota sp. , Padina sp. , and Sargassum oligocystum .

Distribution. Dampier Archipelago, Western Australia, Australia.

Figures

FIGURE 46. Ampithoe parakava sp. nov., holotype, male, WAM C38536, 4 mm. Paratype, female, WAM C 38537, 5 mm. South of Nelson Rocks, Dampier Archipelago, Western Australia, Australia.

FIGURE 47. Ampithoe parakava sp. nov., holotype, male, WAM C38536, 4 mm. Paratype, female, WAM C 38537, 5 mm. South of Nelson Rocks, Dampier Archipelago, Western Australia, Australia. Scales represent 0.5 mm for antennae 1–2 and 0.2 mm for mouthparts. Female antenna 2 is missing.

FIGURE 48. Ampithoe parakava sp. nov., holotype, male, WAM C38536, 4 mm. Paratype, female, WAM C 38537, 5 mm. South of Nelson Rocks, Dampier Archipelago, Western Australia, Australia. Scales represent 0.2 mm.

FIGURE 49. Ampithoe parakava sp. nov., holotype, male, WAM C38536, 4 mm. South of Nelson Rocks, Dampier Archipelago, Western Australia, Australia. Scales represent 0.2 mm.