Sunamphitoe batavia, Peart, Rachael A., 2017

Peart, Rachael A., 2017, Analysis of the genus Sunamphitoe Spence Bate, 1857 (Amphipoda: Ampithoidae) with descriptions of eight new species, Zootaxa 4269 (3), pp. 301-345 : 310-315

Sunamphitoe batavia sp. nov.

( Figs 5–8 )

Type material. Holotype: male, 5 mm, WAM C70209, 0.5 m, mixed brown algae on rock platform (mainly Lobophora sp.), south of Greenough River mouth, Cape Burney, south of Geraldton, Western Australia, Australia, 28°51.77’S 114°38.06’E, coll. R. Peart, 30 November 2000 .

Paratypes: four males, 5 females, WAM C70210; WAM C70211, collected with holotype.

Other material examined. Australia, Western Australia: 1 specimen, AM P62570, 0.5 m, from Ecklonia radiata on shallow rocky reef at lowtide, close to shore, Champion Bay, Geraldton , 28°45.88’S 114°36.83’E, coll. R. Peart, 28 November 2000 ; 1 specimen (AM P62571), 1 specimen (AM P62572), 0.5 m, mixed brown algae on rock platform (mainly Sargassum sp. and Cystophora sp.), rock platform south of Greenough River mouth, Cape Burney, south of Geraldton , 28°51.77’S 114°38.06’E, coll. R. Peart, 30 November 2000 .

Type locality. Greenough River mouth, Cape Burney, south of Geraldton , Western Australia, Australia .

Diagnosis. Antenna 2 slightly thicker and shorter in the male antenna 1, slender in the female. Mandible palp with one article. Maxilla 1 inner plate with one slender seta. Maxilla 2 inner plate narrow, outer plate broader. Lower Lip outer plate notched, with outer lobes slightly longer than inner and rounded apically. Gnathopod 2 carpus much shorter than propodus; propodus expanded but longer than wide along whole length; palm extremely acute, entire, with subquadrate midmedial tooth, without posterodistal tooth defining palm, without defining robust setae; dactylus overreaching palm, inner margin denticulate. Pereopod 5 distal articles broad. Pereopods 6–7 distal articles slender. Uropod 3 peduncle with five distal robust setae; outer ramus with patch of small conical lateral denticles, without lateral setal fringe. Telson distally truncate, apical cusps small, with apical and lateral slender setae, denticles absent.

Description. (Based on holotype male, 5 mm, WAM C70209 and paratype female, 6 mm, WAM C70210).

Head. Head as long as deep. Antenna 1 longer than antenna 2; peduncular article 1 longer than article 2 (1.23 ×), article 2 longer than article 3 (3.18 ×), article 3 shorter than article 1 (0.25 ×); primary flagellum with 31 articles. Antenna 2 peduncular article 4 longer than article 5; flagellum with 14 articles. Mandible molar well developed, triturating; with eight robust setae in accessory setal row. Maxilla 1 palp well developed, with apical robust setae. Maxilliped outer plate with developed setation (robust setae large), reaching to midlength of article 3 of palp; article 4 inner margin with row of setules.

Pereon. Gnathopod 1 smaller than gnathopod 2, without densely setose margins; coxa not produced anteroventrally, anteroventral corner rounded, ventral margin with row of slender setae of different lengths, not plumose; basis subequal in length to coxa, with sparse (sometimes plumose) slender setae, anterodistal lobe small and rounded, with two or three marginal slender setae; merus produced to form small, rounded posteroventral lobe, anterior margin with setae absent; carpus longer than merus, subtriangular, shorter than propodus (0.8 ×), carpal lobe rounded, anterior margin with slender setae only; propodus narrow (length 1.8 × width), subrectangular; palm transverse, entire, without midmedial tooth, without posterodistal tooth defining palm, with one defining robust seta; dactylus overreaching palm, inner margin denticulate. Gnathopod 2 without densely setose margins; coxa ventral margin with row of small setules along ventral margin and with tuft of long slender setae in posteroventral corner; basis longer than coxa, with sparse slender setae, anteroventral lobe small and rounded, with one slender seta; merus produced to form short, subacute distoventral lobe, anterior margin with setae absent; carpus subequal to merus, subtriangular, anterior margin with slender setae only; propodus ovoid, not produced into anterodistally setose lobe; palmar margin short, dactylus extending length of posterior margin of propodus, tapering evenly, acute, inner margin denticulate.

Pereopods 3–4 basis and merus expanded. Pereopods 5–7 weakly prehensile. Pereopod 5 basis with marginal robust setae, without medial slender setae; merus subrectangular; propodus slightly expanded distally, subrectangular, with three distal simple striated robust setae; dactylus strongly curved. Pereopod 6 basis posterior margin rounded proximally, straight distally, with marginal robust setae, without medial slender setae; merus subrectangular; propodus subrectangular, slightly expanded distally, with three distal simple striated robust setae; dactylus strongly curved. Pereopod 7 basis with marginal robust setae, without medial slender setae; propodus subrectangular, defined distally by three to five simple robust setae.

Pleon. Epimeron 3 posteroventral corner broadly rounded. Uropod 1, in situ, reachingrami of uropod 2; peduncle with more than five robust setae, and with long setal fringe; inner ramus slightly longer than outer ramus, with three to five marginal robust setae, slender setae absent; outer ramus with three to five marginal robust setae, slender setae absent. Uropod 2 peduncle with three to five robust setae, setal fringe absent; inner ramus slightly longer than outer ramus, with more than five marginal robust setae, slender setae absent; outer ramus with three to five marginal robust setae, slender setae absent. Uropod 3 peduncle longer than broad (1.5 × width), long with respect to rami length (2.1 ×), with marginal robust setae absent, with marginal slender setae present, with more than five distal slender setae; rami broad; outer ramus subequal to inner ramus; inner ramus with three distal robust setae, with more than five distal slender setae.

Female. Antenna 1 longer than antenna 2; article 1 longer than article 2 (1.2 ×), article 2 longer than article 3 (3.5 ×), article 3 shorter than article 1 (0.3 ×); primary flagellum with 26 articles. Antenna 2 slender, similar to but shorter than antenna 1, with sparse setae on ventral margin; peduncular article 4 subequal in length to article 5; flagellum with 13 articles. Gnathopod 1 subequal in size to gnathopod 2; coxa distoventral corner with subacute tooth, ventral margin with row of small setules and with long tuft of slender setae on posteroventral corner; basis anteroventral lobe with setae absent. Gnathopod 2 basis subequal in length to coxa, anteroventral lobe with setae absent; carpus longer than merus, shorter than propodus (0.7 ×); propodus subrectangular; palm transverse, without midmedial tooth, defined by one robust seta.

Etymology. This species name is derived from the name of a ship that was wrecked off the coast of Geraldton, near the type locality, and is used as a noun in apposition.

Remarks. Sunamphitoe batavia sp. nov. forms a group with S. stevesmithi sp. nov., S. fantome , S. kanaka and S. pelagica ( Fig. 1 , clade 26). These species are united by the presence of a process/tooth on the palm at the base of the dactylus. Sunamphitoe batavia can be separated from the rest of the group by having a shorter (in relation to the rami) uropod 3 peduncle.

Sunamphitoe batavia can be distinguished from S. fantome by the antenna 1 peduncular article 1 being longer than article 2 ( S. fantome has article 1 subequal in length to article 2), the gnathopod 1 coxa ventral margin has a row of simple setae of different lengths ( S. fantome gnathopod 1 coxa ventral margin has only a long tuft of slender setae in the posterior corner), gnathopod 1 merus is produced to form a rounded distoventral lobe ( S. fantome gnathopod 1 merus is produced to form a subacute antroventral lobe), gnathopod 1 carpus is shorter than the propodus ( S. fantome gnathopod 1 carpus is subequal in length to the propodus). There are also differences in the structure of gnathopod 2. In S. batavia , gnathopod 2 is without densely setose margins, the basis is longer than the coxa, the merus is produced to form a subacute lobe and the dactylus extends the length of the posterior margin. In S. fantome gnathopod has long simple, slender setae on the margins, the basis is subequal in length to the coxa, the merus is produced to form a rounded lobe. Uropods 1–2 of Sunamphitoe batavia sp. nov. have generally fewer robust setae than S. fantome and S. batavia sp. nov., and uropod 3 has three distal peduncular robust setae (versus one in S. fantome ).

Habitat. Sunamphitoe batavia sp. nov. occurs in shallow water on brown algae such as Sargassum sp. and Lobophora sp.

Distribution. Geraldton, Western Australia, Australia.

Figures

FIGURE 1. One of fifteen most parsimonious trees (length 335 steps, consistency index 0.248, retention index 0.440). Clade numbers correspond to character state reconstructions listed in Appendix C. (p) indicates former placement in Peramphithoe. * indicates species described in this paper.

FIGURE 5. Sunamphitoe batavia sp. nov., holotype male, 5 mm, WAM C 70209, and paratype female, 6 mm, WAM C 70210, south of Greenough River mouth, Cape Burney, Geraldton, Western Australia, Australia.

FIGURE 6. Sunamphitoe batavia sp. nov., holotype male, 5 mm, WAM C 70209, and paratype female, 6 mm, WAM C 70210, south of Greenough River mouth, Cape Burney, Geraldton, Western Australia, Australia. Scales 0.5 mm for antennae 1 – 2 and 0.2 mm for mouthparts.

FIGURE 7. Sunamphitoe batavia sp. nov., holotype male, 5 mm, WAM C 70209, and paratype female, 6 mm, WAM C 70210, south of Greenough River mouth, Cape Burney, Geraldton, Western Australia, Australia. Scales 0.5 mm.

FIGURE 8. Sunamphitoe batavia sp. nov., holotype male, 5 mm, WAM C 70209, south of Greenough River mouth, Cape Burney, Geraldton, Western Australia, Australia. Scales 0.5 mm for pereopods 3 – 7 and 0.2 mm for uropods 1 – 3 and telson.