Exampithoe waratah, Hughes, Lauren E. & Peart, Rachael A., 2015

Hughes, Lauren E. & Peart, Rachael A., 2015, Three new species of Exampithoe from Australia and New Zealand (Ampithoidae: Amphipoda: Crustacea), Zootaxa 3918 (4), pp. 559-570 : 566-569

Exampithoe waratah sp. nov.

( Figs. 7–9 )

Type material. Holotype: male, 10 mm, dissected, 4 slides, AM P.88425, Walkerville, Victoria, Australia, coll. A.G.B. Poore, date not recorded. Paratypes: 4 females, AM P.88416, same location as holotype. Type locality. Walkerville, Victoria, Australia.

Etymology. Named waratah from the township near the collection location, applied as a noun in apposition.

Diagnosis. Antenna 1 longer than antenna 2; peduncular article 1 longer than article 2; article 2 longer than article 3, length 3 times article 3; article 3 shorter than article 1; primary flagellum with 36 articles. Mandible accessory setal row with 7 robust setae; palp 3-articulate, apically setose and marginally setose; article 1 shorter than article 2; article 2 subequal in length to article 3; article 3 long, length twice article 1. Labium outer plates notched or slit, forming a deep distal cleft, lateral lobe distinctly longer than medial lobe, with an apical duct; mandibular lobes with straight margins, rounded apically. Maxilla 1 palp with apical slender setae, without apical robust setae. Maxilliped outer plate with reduced row of small robust setae along medial margin. Coxae 1–4 as long as broad. Gnathopod 1 subequal in size to gnathopod 2; coxa distinctly larger than coxa 2, anteroventral corner produced, anterior margin straight, with sparse long slender setae, anteroventral corner rounded; basis longer than coxa, anterodistal lobe absent; carpus elongate, rectilinear, twice as long as broad, shorter than propodus, anterior margin with slender setae; propodus narrow, subrectangular, palm acute, excavate, with weak posterodistal shelf, posterodistal corner subquadrate, with 1 robust seta defining palm; dactylus subequal in length to palm. Gnathopod 2 basis longer than coxa, anterodistal lobe large and rounded, not reaching beyond ischium, anterodistal corner with 1 slender seta; carpus subtriangular, shorter than propodus, anterior margin with slender setae; propodus narrow, subrectangular, palm acute, entire, posterodistal corner subquadrate, with 1 robust seta defining palm; dactylus subequal in length to palm. Epimera 1–3 posteroventral corner subquadrate. Uropod 1 inner ramus longer than outer ramus, without lateral robust setae; outer ramus length 3 times width, with 3 lateral robust setae.

Description of holotype. Head as long as deep. Antenna 1 longer than antenna 2; peduncular article 1 longer than article 2, length 1.1 times article 2; article 2 longer than article 3, length 3 times article 3; article 3 shorter than article 1, length 0.25 times article 1; primary flagellum with 36 articles; accessory flagellum absent/vestigial. Antenna 2 robust, distinctly stouter than antenna 1; peduncle article 4 longer than article 5; flagellum longer than peduncular article 5, with 17 articles. Labrum directed nearly straight down, lateral margins without midlateral notches. Mandible molar well developed, triturating, accessory setal row with 7 robust setae; palp 3-articulate, apically setose and marginally setose; article 1 length 1.1 times width, shorter than article 2, length 0.5 times article 2; article 2 subequal in length to article 3, with 5 marginal setae; article 3 long, length 2.5 times width, longer than article 1, length twice article 1, with 11 apical setae. Labium outer plates notched or slit, forming a deep distal cleft, lateral lobe distinctly longer than medial lobe, with an apical duct; mandibular lobes with straight margins, rounded apically. Maxilla 1 inner plate unknown; palp well developed, with apical slender setae, without apical robust setae. Maxilla 2 inner and outer plates subequal in width; inner plate without oblique setal row. Maxilliped outer plate with reduced row of small robust setae along medial margin.

Pereon. Coxae 1–4 as long as broad. Gnathopod 1 subequal in size to gnathopod 2; coxa distinctly larger than coxa 2, anteroventral corner produced, anterior margin straight, with sparse long slender setae, anteroventral corner rounded; basis longer than coxa, length 4.2 times width, anterodistal lobe absent; ischium anterior margin without lobe; merus anterodistal lobe subacute, posterodistal corner subquadrate or rounded; carpus elongate, rectilinear, twice as long as broad, longer than merus, shorter than propodus, length 0.8 times propodus, anterior margin with slender setae; propodus narrow, subrectangular, length 2.1 times width, palm acute, excavate, with weak posterodistal shelf, posterodistal corner subquadrate, with 1 robust seta defining palm; dactylus subequal in length to palm, inner margin crenate. Gnathopod 2 basis longer than coxa, length 3 times width, anterodistal lobe large and rounded, not reaching beyond ischium, anterodistal corner with 1 slender seta; ischium anterior margin bilobate; merus margin without lobe; carpus subtriangular, shorter than propodus, length 0.9 times propodus, anterior margin with slender setae; propodus narrow, subrectangular, length 1.8 times width, palm acute, entire, posterodistal corner subquadrate, with 1 robust seta defining palm; dactylus subequal in length to palm, tapering evenly, apically acute, inner margin crenate.

Pleon. Epimera 1–3 posteroventral corner subquadrate. Uropod 1 reaching end of uropod 2 rami; peduncle with 6 robust setae, without slender setal fringe, distoventral spur absent; inner ramus longer than outer ramus, without lateral robust setae, with 4 apical robust setae, slender setae absent; outer ramus length 3 times width, with 3 lateral and 5 apical robust setae. Uropod 2 peduncle with 5 robust setae, slender setae fringe absent; inner ramus, damaged; outer ramus marginal robust and slender setae absent. Uropod 3 peduncle longer than broad, length 1.5 times width, with 1 marginal robust seta, and marginal slender setae present, with 5 distal peduncular robust setae, and distal slender setae present; rami short, length 1.1 times breadth; outer ramus subequal in length to inner ramus, with 2 large recurved distal robust setae, with patch of small lateral denticles, without lateral setal fringe; outer ramus with 4 distal robust setae, without lateral robust setae and with distal slender setae present. Telson (paratype female) with 1 pair of apical and lateral slender setae and two pairs of lateral plumose setae.

Remarks. Exampithoe waratah sp. nov. has the propodus longer than the carpus in both gnathopods 1 and 2, distinguishing it from other Exampithoe species. The clavate article 3 of the mandibular palp further distinguishes E. waratah , from E. taylori and E. natalensis K.H. Barnard, 1925 , which are the only other Exampithoe species to have all three mandibular palp articles present or where the third article is narrow and rectilinear.

Distribution. Known only from the type locality.

Figures

FIGURE 7. Exampithoe waratah sp. nov., holotype male, 10 mm, AM P. 88425, Walkerville, Victoria, Australia.

FIGURE 8. Exampithoe waratah sp. nov., holotype male, 10 mm, AM P. 88425, Walkerville, Victoria, Australia (scales 0.1 mm).

FIGURE 9. Exampithoe waratah sp. nov., holotype male, 10 mm, AM P. 88425, Walkerville, Victoria, Australia (scales 0.1 mm).