Sunamphitoe naturaliste, 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 : 329-334

Sunamphitoe naturaliste sp. nov.

( Figs 20–23 )

Type material. Holotype: male, 10 mm, WAM C70223, 0.5 m, on Sargassum sp. on rocks near shore, Canal Rocks , south of Yallingup, south west Western Australia, Australia, 33°40.28’S 114°59.67’E, coll. 6 December 2000 by R. Peart.

Paratypes: female, 11 mm (WAM C70224), 4 specimens (WAM C70225), collected with holotype.

Other material examined. Australia, Western Australia: 22 specimens (females and males) AM P62600 , 22 specimens, 0.5 m, on Sargassum sp. and Cystophora sp. on rocks near shore, Shelley Beach, Bunker Bay, near Cape Naturaliste , south of Busselton , 33°32.56’S 115°01.79’E, coll. R. Peart, 4 December 2000 ; 4 specimens, AM P62601, 0.5 m, on Sargassum sp. on rocks near shore, Canal Rocks, south of Yallingup , 33°40.28’S 114°59.67’E, coll. R. Peart, 6 December 2000 .

Type locality. Canal Rocks , south of Yallingup, south west Western Australia, Australia.

Diagnosis. Antenna 2 slender, similar to antenna 1. Mandibular palp with three articles. Maxilla 1 inner plate with one slender seta. Maxilla 2 inner plate narrow, outer plate broader. Lower lip outer plate notched, medial and lateral lobes of equal size. Gnathopod 2 carpus much shorter than propodus; propodus broad; palm acute, entire, without midmedial tooth, without posterodistal tooth defining palm, without defining robust setae; dactylus longer than palm, inner margin smooth. Pereopod 5 distal articles broad. Pereopods 6–7 distal articles slender. Uropod 3 peduncle with two distal robust setae; outer ramus with patch of small conical lateral denticles, with lateral setal fringe. Telson distally rounded, apical cusps small, with apical and lateral slender setae; denticles absent.

Description. (Based on holotype male, 11 mm, WAM C70223, and paratype female, 11 mm, WAM C70224.) Head. Head as long as deep. Antenna 1 longer than antenna 2; peduncular article 1 longer than article 2 (1.2 ×), article 2 longer than article 3 (2.6 ×), article 3 shorter than article 1 (0.3 ×); primary flagellum with 40 articles. Antenna 2 peduncular article 4 subequal to article 5; flagellum 21 articulate. Mandible molar well developed, triturating; with 11 robust setae in accessory setal row; palp stout, long, apically setose, article 1 shorter than article 2 (0.8 ×), article 2 longer than article 3 (1.2 ×), article 3 longer than article 1 (1.2 ×). Maxilla 1 palp well developed, with apical robust setae. Maxilliped outer plate with developed setation (robust setae large and numerous), narrow and reaching midlength of palp article 3; palp article 4 without setules.

Pereon. Gnathopod 1 smaller than gnathopod 2, with patchy setose margins; coxa not produced anteroventrally, anteroventral corner rounded, ventral margin with row of small setules and with long tuft of slender setae on posteroventral corner; basis longer than coxa, with sparse (sometimes plumose) slender setae, anteroventral lobe small, rounded with two or three slender setae; merus produced to form small, rounded distoventral lobe, anterior margin with setae absent; carpus longer than merus, subtriangular, subequal to propodus, carpal lobe rounded, anterior margin with slender setae only, no robust setae, posterior margin lined with setae; propodus narrow (length 2 × width), subrectangular; palm transverse, entire, 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 and with tuft of long slender setae on posteroventral corner; basis subequal to coxa, with sparse slender setae, anteroventral lobe small, rounded, setae absent; merus produced to form short, setose, 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; dactylus tapering evenly, acute, inner margin smooth.

Pereopods 3–4 basis and merus expanded. Pereopods 5–7 simple. Pereopod 5 basis with marginal robust setae; merus subrectangular; propodus not 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, with 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, with medial slender setae; propodus subrectangular, defined distally by three to five simple robust setae.

Pleon. Epimeron 3 posteroventral corner subquadrate. Uropod 1, in situ, reaching to rami of uropod 2; peduncle with six robust setae, with long setal fringe; inner ramus slightly longer and narrower than outer ramus, with two marginal robust setae; outer ramus with four marginal robust setae. Uropod 2 peduncle with three robust setae; inner ramus slightly longer and narrower than outer ramus, with two marginal robust setae; outer ramus with four marginal robust setae. Uropod 3 peduncle longer than broad (1.4 × width), short in relation to rami length (1.9 ×), marginal robust setae absent, marginal slender setae absent, three to five distal slender setae; rami broad; outer ramus subequal to inner ramus, with two small recurved distal robust setae; inner ramus with two distal robust setae, no distal slender setae.

Female. Antenna 1 primary flagellum with 36 articles. Antenna 2 flagellum with 17 articles.

Gnathopod 1 subequal in size to gnathopod 2; merus produced to form a short, subacute distoventral lobe. Gnathopod 2 basis posterodistal lobe with three slender setae; merus produced to form small, rounded distoventral lobe; carpus longer than merus, shorter than propodus, with prominent setose lobe; propodus narrow, subrectangular; palm transverse, defined by one robust seta; dactylus overreaching palm; inner margin denticulate.

Etymology. The name for this species is derived from a locality (Cape Naturaliste ) near the type locality and is used as a noun in apposition.

Remarks. Sunamphitoe naturaliste sp. nov. has some similarities to species in clade 10 ( Fig. 1 ) united by the presence of a setal fringe on uropod 3 outer ramus. Sunamphitoe naturaliste differs from the other species in this clade by having slender distal articles of pereopod 7 ( S. parmerong , S. guryongensis , and S. bungareei have broadened, to some degree, articles).

Habitat. Sunamphitoe naturaliste sp. nov. occurs on a variety of brown algae, especially Sargassum spp.; recorded at a depth of 0.5 m.

Distribution. Cape Naturaliste , 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 20. Sunamphitoe naturaliste sp. nov., holotype male, 10 mm, WAM C 70223, and paratype female, 11 mm, WAM C 70224, Canal Rocks, south of Yallingup, Busselton, Western Australia, Australia.

FIGURE 21. Sunamphitoe naturaliste sp. nov., holotype male, 10 mm, WAM C 70223, and paratype female, 11 mm, WAM C 70224, Canal Rocks, south of Yallingup, Busselton, Western Australia, Australia. Scales 0.5 mm for antennae 1 – 2 and 0.2 mm for mouthparts.

FIGURE 22. Sunamphitoe naturaliste sp. nov., holotype male, 10 mm, WAM C 70223, and paratype female, 11 mm, WAM C 70224, Canal Rocks, south of Yallingup, Busselton, Western Australia, Australia. Scales 0.5 mm.

FIGURE 23. Sunamphitoe naturaliste sp. nov., holotype male, 10 mm, WAM C 70223, Canal Rocks, south of Yallingup, Busselton, Western Australia, Australia. Scales 0.5 mm for pereopods 3 – 7 and 0.2 mm for uropods 1 – 3 and telson.