Ampithoe peronana, 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 : 64-69

Ampithoe peronana sp. nov.

( Figs 50–53 )

Type material. Holotype: WAM C38538, male, 7 mm, reef west of groyne, 2 km south of Cape Peron, WA, 32°16’S 115°41’E, 26 Dec 1983, 3 m, on brown algae, R. T. Springthorpe . Paratype: WAM C38539, female, 9 mm, type locality .

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 4 slender setae. Gnathopod 1 carpal lobe subacute; carpus shorter than propodus; palm excavate, with midmedial tooth, with posterodistal tooth defining palm; dactylus overreaching palm. Gnathopod 2 with long setae on margins (not plumose); basis posterodistal lobe large and rounded, with more than three slender setae; carpus shorter than propodus; palm acute, excavate, without midmedial tooth, with a small subacute posterodistal tooth defining palm, without a defining robust seta; dactylus overreaching palm. Pereopod 3 basis narrow; merus narrow. Pereopods 5– 7 simple. Pereopod 5 merus subrectangular. Uropod 3 peduncle with 7 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 5 distal robust setae. Telson distally rounded, apical cusps small.

Description. Based on holotype, male, 7 mm, WAM C38538. Head as long as deep. Antenna 2 peduncular article 4 longer than article 5; flagellum 18–24 articulate. Mandible molar with 6 robust setae in accessory setal row; palp stout, long, setose along posterior margin; article 1 shorter than article 2 (0.36 x), article 2 longer than article 3 (1.18 x), article 3 longer than article 1 (2.38 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 subequal to gnathopod 2 coxa, produced distoventrally, distoventral margin rounded, anterior margin concave, ventral margin with a row of small setules; basis subequal to coxa, with fringe of long, slender, plumose setae, posterodistal lobe small and rounded, more than three slender setae; merus produced to form a long, subacute distoventral lobe, anterior margin with setae absent; carpus longer than merus, subtriangular, anterior margin with slender setae only; propodus narrow (length 1.69 x width), subrectangular; palm with 1 defining robust seta; dactylus inner margin denticulate. Gnathopod 2 coxa ventral margin with a row of small setules; basis shorter than 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 1.3 x width), ovoid, not produced into an anterodistally setose lobe; dactylus tapering evenly, acute, inner margin denticulate. Pereopod 5 basis with marginal robust setae, with medial slender setae; distal articles slender; propodus not expanded distally, subrectangular, with 2 distal simple striated robust setae; dactylus slightly curved. Pereopod 6 basis posterior margin rounded, without marginal robust setae, with medial slender setae; merus subrectangular; propodus slightly expanded distally, with 3 distal simple striated robust setae; dactylus slightly curved. Pereopod 7 basis without marginal robust setae, with medial slender setae; propodus defined distally by 3–5 simple robust setae.

Pleon. Epimeron 3 posteroventral corner subquadrate. Uropod 1 peduncle with more than 5 robust setae, with a short setal fringe; inner ramus slightly longer than outer ramus, with more than 5 marginal robust setae, slender setae absent; outer ramus with more than 5 marginal robust setae, slender setae absent. Uropod 2 peduncle with more than 5 robust setae, setal fringe absent; inner ramus slightly longer than outer ramus, with more than 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 (1.39 x width), short with respect to the rami length (1.76 x), marginal robust setae absent, marginal slender setae absent, with more than 5 distal slender setae; inner ramus with more than 5 distal slender setae. Telson with apical and lateral slender setae.

Female. (sexually dimorphic characters). Based on paratype female, 9 mm, WAM C38539. Antenna 1 longer than antenna 2, peduncular article 1 longer than article 2 (1.3 x), article 2 longer than article 3 (3.4 x), article 3 shorter than article 1 (0.23 x); primary flagellum with 33 articles; accessory flagellum absent. Antenna 2 slender, similar to antenna 1, with sparse setae on ventral margin; peduncular article 4 longer than article 5; flagellum with 21 articles. Gnathopod 1 subequal in size to gnathopod 2; basis shorter than coxa, with sparse (sometimes plumose) slender setae; merus produced to form a short, subacute distoventral lobe; palm convex, with midmedial tooth, with posterodistal tooth defining the palm; dactylus subequal in length to the palm. Gnathopod 2 without densely setose margins; basis posterodistal lobe small and round, with more than 3 slender setae; palm entire, defined by 1 robust seta; dactylus subequal in length to palm.

Etymology. This species name is derived from the type locality, Cape Peron.

Remarks. Ampithoe peronana sp. nov. is similar to the new species from Coffs Harbour, New South Wales, Ampithoe eremitis sp. nov. The differences are: the shape of gnathopod 1 ( A. peronana gnathopod 1 carpus is shorter than the propodus, the palm is strongly excavate and the dactylus is longer than the palm, whereas A. eremitis gnathopod 1 carpus is subequal in length to the propodus, the palm is only slightly exca- vate and the dactylus is subequal in length to the palm); and uropod 3 ( A. peronana peduncle has 7 distal robust setae, the outer ramus is subequal in length to the inner ramus and does not have a lateral setal fringe, the inner ramus has 5 distal robust setae, whereas A. eremitis uropod 3 peduncle has 6 distal robust setae, the outer ramus is shorter than the inner ramus and has a lateral setal fringe, the inner ramus has seven distal robust setae).

Habitat. Brown algae.

Distribution. Cape Peron, Western Australia, Australia.

Figures

FIGURE 50. Ampithoe peronana sp. nov., holotype, male, WAM C38538, 7 mm. Paratype, female, WAM C 38539, 9 mm. 2 km south of Cape Peron, Western Australia, Australia.

FIGURE 51. Ampithoe peronana sp. nov., holotype, male, WAM C38538, 7 mm. Paratype, female, WAM C 38539, 9 mm. 2 km south of Cape Peron, Western Australia, Australia. Scales represent 0.5 mm for antennae 1–2 and 0.2 mm for mouthparts. Male antenna 1 missing.

FIGURE 52. Ampithoe peronana sp. nov., holotype, male, WAM C38538, 7 mm. Paratype, female, WAM C 38539, 9 mm. 2 km south of Cape Peron, Western Australia, Australia.Scales represent 0.5 mm.

FIGURE 53. Ampithoe peronana sp. nov., holotype, male, WAM C38538, 7 mm. Paratype, female, WAM C 38539, 9 mm. 2 km south of Cape Peron, Western Australia, Australia. Scales represent 0.5 mm for pereopods 3–7 and 0.2 mm for uropods 1–3 and telson. Pereopod 4 identical to pereopod 3.