Sunamphitoe jonathani, 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 : 320-325

Sunamphitoe jonathani sp. nov.

( Figs 13–16 )

Type material. Holotype: male, 9 mm, WAM C70218, Eagle Beach , near Cape Naturaliste , south west of Busselton , Western Australia, Australia, 33°33.69’S 115°03.90’E, coll. R. Peart, 5 December 2000 .

Paratypes: female, 10 mm (WAM C70219), 26 specimens (males and females) (WAM C70220), collected with holotype.

Other material examined. Australia, Western Australia: 36 specimens (females and males) (AM P62588), 3 specimens ( WAM C70221), 9 specimens (AM P62590), 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 ; 13 specimens (AM P62591), 0.5 m, on Sargassum sp. on rocks near shore, Eagle Beach, near Cape Naturaliste , south west of Busselton , 33°33.69’S 115°03.90’E, coll. R. Peart, 5 December 2000 ; 4 specimens (AM P62592), 14 specimens ( WAM C70222), 12 specimens (AM P62594), 6 specimens (AM P62595), 6 specimens (AM P62596), 7 specimens (AM P62597), 0.5 m, 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. Eagle Beach, near Cape Naturaliste , south west of Busselton, Western Australia, Australia.

Diagnosis. Antenna 2 (male) slightly more robust (but shorter) than antenna 1, not densely setose on ventral margin; Mandible palp with 3 articles. Maxilla 1 inner plate with two slender, plumose setae. Maxilla 2 inner and outer plates narrow. Lower lip outer plate notched, lateral and medial lobes of equal size. Gnathopod 2 carpus much shorter than propodus; propodus broad; palm angle extremely acute, palm excavate, without midmedial tooth, with small subacute posterodistal tooth defining palm, without defining robust setae; dactylus subequal in length to palm, inner margin smooth. Pereopod 5 distal articles broad. Pereopods 6–7 distal articles slender. Uropod 3 peduncle with four distal robust setae; outer ramus with patch of small conical lateral denticles, with lateral setal fringe. Telson distally truncate, apical cusps small, with apical and lateral slender setae; denticles absent.

Description. (Based on holotype male, 9 mm, WAM C70218, and paratype female, 10 mm, WAM C70219).

Head as long as deep. Antenna 1 longer than antenna 2; peduncular article 1 longer than article 2 (1.4 ×), article 2 longer than article 3 (2.6 ×), article 3 shorter than article 1 (0.8 ×); primary flagellum with 41 articles. Antenna 2 peduncular article 4 subequal to article 5; flagellum 15 articulate. Mandible molar well developed, triturating, with eight robust setae in accessory setal row; palp slender, long, apically setose, article 1 shorter than article 2 (0.5 ×), article 2 longer than article 3 (1.3 ×), article 3 longer than article 1 (1.7 ×). Maxilla 1 palp well developed, with apical robust setae. Maxilliped outer plate with developed setation (robust setae large and numerous); outer plate broad, reaching to end of palp article 3; article 4 without setules.

Pereon. Gnathopod 1 smaller than gnathopod 2, without densely setose margins; coxa subequal to gnathopod 2 coxa, not produced anteroventrally, anteroventral corner rounded, ventral margin with row of small setules and long tuft of slender setae on posteroventral corner; basis subequal to coxa, with sparse (sometimes plumose) slender setae, anteroventral lobe small and rounded with 1 slender seta; merus produced to form small, subacute distoventral 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 2.16 x 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 coxa ventral margin with row of small setules and with tuft of long slender setae in posteroventral corner; basis longer than coxa, with sparse slender setae, anterodistal lobe small, rounded, setae absent; merus produced to form short, rounded distoventral lobe, anterior margin with setae absent; carpus subequal to merus, subtriangular, anterior margin with slender setae only, posterior corner with small tuft of setae; 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 on anterior margin, without medial slender setae; merus subrectangular; propodus slightly expanded distally, subrectangular, with three simple distal striated robust setae; dactylus strongly curved. Pereopod 6 basis with marginal robust setae, without medial slender setae; merus subrectangular; propodus subrectangular, slightly expanded distally, with three simple distal striated robust setae; dactylus slightly 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 narrowly rounded. Uropod 1, in situ, reaching rami of uropod 2; peduncle with more than five robust setae, with long setal fringe; inner ramus slightly longer than outer ramus, with one to two 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 and setal fringe absent; inner ramus slightly longer than outer ramus, with one to two marginal robust setae, slender setae absent; outer ramus with three to five marginal robust setae, and slender setae absent. Uropod 3 peduncle longer than broad (1.5 ×width), long in relation to rami length (2.4 ×), marginal robust setae absent, marginal slender setae absent, and with three to five distal slender setae; rami broad; outer ramus subequal to inner ramus; inner ramus with two distal robust setae and with one to two distal slender setae.

Female. Antenna 1 primary flagellum with 33 articles. Antenna 2 slender, similar to antenna 1, with sparse setae on ventral margin; peduncular article 4 longer than article 5; flagellum with 17 articles.

Gnathopod 1 subequal in size to gnathopod 2; carpus shorter than propodus (0.8 ×). Gnathopod 2 without densely setose margins; basis subequal in length to coxa, anteroventral lobe with two or three slender setae; merus produced to form small, subacute distoventral lobe; carpus longer than merus; propodus narrow (length 1.8 ×width), subrectangular; palm transverse, entire, without tooth defining palm, with one defining robust seta; dactylus overreaching palm, inner margin denticulate.

Etymology. This species is named for Jonathan Peart, without whose encouragement and assistance in scanning and labelling the plates, and support throughout this project, this study would not have been completed.

Remarks. Sunamphitoe jonathani sp. nov. is similar to S. lehae sp. nov. and S. mixtura sp. nov. owing to the shape of the gnathopod 2 propodus, which is large and triangular with a strongly acute and excavated palm. Sunamphitoe jonathani differs from S. lehae by having the gnathopod 1 coxa not produced anteriorly (strongly produced in S. lehae ), the lower lip outer plate lateral lobe possesses a beak-like tooth (absent in S. lehae ), pereopods 3–4 bases have medial setae (absent in S. lehae ), uropod 1 peduncle has a short setal fringe (absent in S.

lehae ) and uropods 1–2 inner ramus is narrower than the outer ramus (subequal in width in S. lehae ). Sunamphitoe jonathani differs from S. mixtura by the broadly rounded maxilliped outer plate (narrow in S. mixtura ), the lower lip outer plate medial lobe is apically rounded (apically subacute in S. mixtura ), the gnathopod 1 coxa anteroventral corner broadly rounded, smooth (with nipple-shaped process on corner in S. mixtura ), gnathopod 1 basis subequal in length to the coxa, without setules (basis longer than coxa, setules present in S. mixtura ), gnathopod 2 palm smoothly excavate (with sculpturing present in S. mixtura ), uropod 3 rami subequal in length (inner ramus longer than outer ramus in S. mixtura ), and uropod 3 inner ramus with 2 lateral robust setae (lateral robust setae absent in S. mixtura ).

Habitat. Sunamphitoe jonathani sp. nov. occurs mainly on Sargassum spp., recorded from 0.5 m depth. Distribution. Cape Naturaliste , Western Australia, Australia.

Figures

FIGURE 13. Sunamphitoe jonathani sp. nov., holotype male, 9 mm, WAM C 70218, and paratype female, 10 mm, WAM C 70219, Eagle Beach, Cape Naturaliste, Busselton, Western Australia, Australia.

FIGURE 14. Sunamphitoe jonathani sp. nov., holotype male, 9 mm, WAM C 70218, and paratype female, 10 mm, WAM C 70219, Eagle Beach, Cape Naturaliste, Busselton, Western Australia, Australia. Scales 0.5 mm for antennae 1 – 2 and 0.2 mm for mouthparts.

FIGURE 15. Sunamphitoe jonathani sp. nov., holotype male, 9 mm, WAM C 70218, and paratype female, 10 mm, WAM C 70219, Eagle Beach, Cape Naturaliste, Busselton, Western Australia, Australia. Scales 0.5 mm.

FIGURE 16. Sunamphitoe jonathani sp. nov., holotype male, 9 mm, WAM C 70218, Eagle Beach, Cape Naturaliste, Busselton, Western Australia, Australia. Scales 0.5 mm for pereopods 3 – 7 and 0.2 mm for uropods 1 – 3 and telson.