Sunamphitoe tjibaoui, Peart & Hughes, 2013

Peart, R. A. & Hughes, L. E., 2013, Ampithoid amphipods from the South Pacific: Papua New Guinea, French Polynesia and New Caledonia, Journal of Natural History (J. Nat. Hist.) 48 (13 - 14), pp. 739-861 : 851-857

Sunamphitoe tjibaoui sp. nov.

( Figures 83–86 )

Type material

Holotype male, 5 mm, dissected, three slides, AM P.84621, Entrance of Baie de Citron , New Caledonia (22 ◦ 18.17 ′ S, 166 ◦ 26.07 ′ E), 1.5 m, brown alga Sargassum sp. , 13 November 1995, coll. I. Takeuchi (NCL-81) . Paratype female, 6 mm, dissected, one slide, AM P.84622; paratypes five specimens, AM P.84623, same location as holotype .

Type locality

Baie de Citron , New Caledonia (22 ◦ 18.17 ′ S, 166 ◦ 26.07 ′ E) .

Etymology

Named for Tjibaoui, a historic cultural leader of the indigenous Kanak people of New Caledonia.

Diagnosis

Antenna 2 slender, similar to antenna 1; peduncular article 4 longer than article 5; flagellum with 12 articles. Mandible accessory setal row with seven robust setae. Maxilla 1 inner plate with one plumose seta; outer plate palp well-developed, slender; article 2 with four apical robust setae. Gnathopod 1 coxa anteroventral corner rounded, posteroventral corner with a long tuft of slender setae; basis subequal in length to coxa, with sparse slender setae, with one rounded anterodistal lobe; carpus subtriangular; propodus subrectangular, palm transverse, entire, defined by subquadrate corner with one robust seta; dactylus overreaching palm. Gnathopod 2 coxa posteroventral corner rounded with tuft of long slender setae; basis subequal in length to coxa, with sparse slender setae, anterodistal lobe small, subquadrate; merus anteroventral corner subquadrate; carpus compressed, cup-shaped; propodus subovoid to subrectangular, palm subacute, weakly subsigmoidal, defined by weak rounded corner with one robust seta, palm length 0.3 times posterior margin; dactylus overreaching palm, apically acute, tapering evenly, posterior margin denticulate. Pereopods 3–4 basis and merus anteriorly expanded. Pereopods 5–7 merus subrectangular; propodus slightly expanded distally; dactylus recurved. Pereopod 5 propodus length three times width. Telson trapezoidal, apically convex with one pair of apical slender and one pair of medial slender setae.

Description

Based on holotype male, 5 mm, AM P. 84621.

Head. Antenna 1 longer than antenna 2; peduncular article 1 length 1.2 times article 2; article 2 length 2.5 times article 3; article 3 length 0.27 times article 1; primary flagellum with 17 articles; accessory flagellum absent. Antenna 2 slender, similar to antenna 1; peduncular article 4 longer than article 5; flagellum with 12 articles. Upper lip distally setose, lateral margins each with midlateral notch. Epistome and upper lip angle directed nearly straight down, around 90 degrees. Mandible molar well-developed, triturating; accessory setal row with seven robust setae; palp absent. Lower lip outer plate notched; inner lobes subequal to outer lobes; mandibular lobe with curved margins, apically subacute. Maxilla 1 inner plate with one plumose seta; outer plate, palp welldeveloped, slender; article 2 with four apical robust setae. Maxilla 2 inner plate slightly narrower than outer plate. Maxilliped outer plate with large robust setae.

Pereon. Coxae 1–4 longer than broad. Gnathopod 1 smaller than gnathopod 2; coxa 1 subequal to coxa 2, anterior margin straight, not anteroventrally produced, anteroventral corner rounded, ventral margin with a row of small setules along margin, posteroventral corner with a long tuft of slender setae; basis subequal in length to coxa, with sparse slender setae, with one rounded anterodistal lobe; merus anteroventral corner truncate; carpus subtriangular, length twice breadth, length slightly shorter than propodus; propodus subrectangular, length 2.7 times width, palm transverse, entire, defined by subquadrate corner with one robust seta; dactylus elongate, overreaching palm, apically subacute, tapering evenly, posterior margin denticulate. Gnathopod 2 coxa ventral margin with a row of small setules, posteroventral corner rounded with tuft of long slender setae; basis subequal in length to coxa, with sparse slender setae, anterodistal lobe small, subquadrate; merus anteroventral corner subquadrate; carpus compressed, cup-shaped, length subequal to width, 0.4 times propodus; propodus subovoid to subrectangular, length twice width, palm subacute, weakly subsigmoidal, defined by weak rounded corner with one robust seta, palm length 0.3 times posterior margin; dactylus overreaching palm, apically acute, tapering evenly, posterior margin denticulate. Pereopods 3–4 basis and merus anteriorly expanded. Pereopods 5–7 merus subrectangular; propodus slightly expanded distally; dactylus recurved. Pereopod 5 propodus length 3 times width.

Pleon. Epimera 1–3 subquadrate, posteroventral corner rounded. Uropod 1 not reaching past uropod 2 rami; peduncle length 3 times width, setal fringe three-quarters length of peduncle, with five robust setae, distoventral spine large, acute; inner ramus 0.8 times length of peduncle, slightly longer than outer ramus, with one marginal robust seta; outer ramus with two marginal robust setae. Uropod 2 peduncle with two robust setae, with small distoventral spine; inner ramus slightly longer than outer ramus, with three marginal robust setae; outer ramus with three marginal robust setae. Uropod 3 peduncle length 1.9 times breadth, with four distal robust setae, length 2.1 times rami; inner ramus length 1.1 times as long as broad, with two distal robust setae; outer ramus subequal to inner ramus, with two large recurved distal robust setae, with patch of lateral denticles. Telson trapezoidal, apically convex, subsubapical cusps absent, with one pair of apical and dorsal slender setae.

Female (sexually dimorphic characters).

Description based on paratype female, 6 mm, AM P.84622

Pereon. Gnathopod 1 subequal to gnathopod 2. Gnathopod 2 propodus length 1.8 times width, palm transverse.

Remarks

Sunamphitoe tjibaoui sp. nov. has gnathopod 2 propodus palm subacute, defined by a rounded palm corner. The gnathopod 2 propodus is also evenly expanded proximally and distally with the propodus anterior and posterior margins parallel. In all other species of Sunamphitoe the gnathopod 2 palm is acute and the propodus is proximally expanded and distally more narrow. Sunamphitoe tjibaoui sp. nov. is similar to juvenile S. fantome where the gnathopod 2 propodus palm is less proximally expanded. It can be distinguished from this species by the acute palm without a defined corner. See also the remarks for S. kanaka sp. nov.

Habitat

Living on brown alga Sargassum sp.

Distribution

New Caledonia (current study).

Figures

Figure 83. Sunamphitoe tjibaoui sp. nov., holotype male 5 mm, AM P.84621; paratype female 6 mm, AM P.84622, New Caledonia.

Figure 84. Sunamphitoe tjibaoui sp. nov., holotype male 5 mm, AM P.84621; paratype female 6 mm, AM P.84622, New Caledonia. Telson scale 0.1 mm, all other scale bars 0.2 mm.

Figure 85. Sunamphitoe tjibaoui sp. nov., holotype male 5 mm, AM P.84621; paratype female 6 mm, AM P.84622, New Caledonia. Scale bars 0.2 mm.

Figure 86. Sunamphitoe tjibaoui sp. nov., holotype male 5 mm, AM P.84621, New Caledonia. Scale bars 0.2 mm.