Urothoides waminoa Barnard & Drummond 1979

Urothoides waminoa

DESCRIPTION OF FEMALE.—Rostrum broad from dorsal view, anterior margin weakly sinuous, weakly humped in middle. Eyes absent. Article 1 of antenna 1 about 0.65 times as wide as long; article 2 about 0.8 times as long and 0.6 times as wide as article 1; article 3 about 0.6 times as long as article 2; primary flagellum with 5 long articles; accessory flagellum with 2–3 long articles; peduncle not clearly geniculate between articles 2 and 3. Article 3 of antenna 2 with 2 faciodistal setae; article 4 with 5 alternatively short and long dorsal spines and row of facial setae, ventral margin with 2 main setae; article 5 about 0.9 times as long as article 4, dorsal margin with 3 pairs of spines, one long and one short in each pair, plus 2 long distofacial setal-spines, ventral margin naked but with 2 facial plusetae; flagellum about 1.2 times as long as article 5 of peduncle, composed of 2 long articles, first article with apicofacial cusp.

Prebuccal complex massive, dorsally protruding. Epistome and upper lip amalgamated, ventral margin rounded and protruding. Mandibles huge; incisors blunt, broad; right lacinia mobilis thin, apical bifidation obsolescent, left lacinia mobilis broad, dome-shaped, weakly toothed, raker spines absent; molars large, weakly triturative or fuzzy; palp of medium size, about as long as body of mandible, mostly concealed from oral view, article 1 elongate, article 2 naked, article 3 about 0.8 times as long as article 2, apex oblique and short, bearing 3 setae and one seta on inner margin at M. 60. Lower lip massive, inner lobes fully separate, large, outer plates with ordinary mandibular lobes. Inner plate of maxilla 1 narrow, apex with one seta; outer plate with 9 spines, mostly simple, with tenth apicomedial spine-like cusp; palp article 2 exceeding apex of outer plate, apex with 3 wire-like setae. Inner plate of maxilla 2 narrower than outer plate, plates extending equally or inner slightly shorter (variable). Inner plate of maxilliped with 2 apical spines and short ventrofacial pluseta; outer plate with 9 medial spines and setae; articles 2 and 3 of palp apically produced, article 4 with 2 apical setae.

Coxa 1 broadly expanded distally, almost clavate, anterior margin concave, ventral margin broad, weakly convex, anterodistal corner rounded; coxa 2 expanded distally, anteroventral corner rounded, posteroventral corner subsharp; coxae 3–4 broad, comma-shaped, posterior margins deeply concave; ratios of widths to lengths of coxae 3–4 = 5:9 and 3:4. Long posterior setae on article 2 of gnathopods 1–2 and pereopods 1–2 = 3–3–0–0 (including subdistal corner), short posterior setae = 0–0–0–2, long anterior setae = 1–0–0–0, short anterior setae = 1–1–2–(1–2). Gnathopods 1–2 weakly similar to each other; article 5 elongate, posterior margin flat and extended, subquadrate distally, corner weakly extended on gnathopod 2, distomedial margin of article 5 with comb on gnathopod 1 only, medial faces of articles 5–6 on gnathopod 2 with numerous fan-combs, article 5 more densely setose on gnathopod 1 than on gnathopod 2; article 6 narrowly subovate, not strongly widened in middle, palm and posterior margin blending almost evenly but marked by defining spine; dactyl fitting palm. Pereopod 2 larger than pereopod 1; facial formula of setae on articles 4–5 = 2–2 and 2–1; article 4 of pereopod 1 with midposterior facial spray of setae and 3 other distal setae, pereopod 2 simply with 3 groups of 1–3 posterior setae; main spine of article 5 reaching about M. 70 on article 6, apicolateral face with 2 spines in tandem, apicoposterior margin with 2 short spines; article 6 with distal rows of 3 and 2 spines and one distomedial spine; dactyls elongate, bearing sharp inner acclivity and protrusion, no setule apparent, apex with outer scale. Coxa 5 of ordinary familial form, posterior lobe larger and extending more deeply than anterior lobe; article 2 of pereopods 3–5 broad, only pereopod 4 with anterior facial ridge; articles 4–5 of pereopod 3 broad, of pereopod 4 narrow; ratio of widths of articles 2, 4, 5, 6 of pereopod 3 = 53:50:40:18, of pereopod 4 = 68:32:24:9, of pereopod 5 = 90:20:15:7; ratio of lengths of articles 2, 4, 5, 6 of pereopod 3 = 74:27:40:40, of pereopod 4 = 83:39:41:45, of pereopod 5 = 75:26:29:26.

Epimera 1–2 with convex posterior margins, posteroventral corners with weak tooth; epimeron 2 with 1–2 ventrofacial setae in horizontal tandem; epimeron 3 expanded below, posterior margin weakly concave and oblique, posteroventral corner extended as weakly upturned sharp tooth, bearing seta at notch forming boundary of epimeron to pleonite 3, similar seta on epimera 1–2.

Urosomites largely articulate but urosomites 1–2 apparently partially fused but articulation lines almost complete; urosomite 1 weakly elevated dorsally, flat hump and weak saddle, ventrally with one small seta basolateral to peduncle of uropod 1, with 2 long spines in crotch between uropod 1 peduncles medially (hidden from lateral view), urosomite 1 concealing dorsum of urosomite 2. Peduncle of uropod 1 with 3 lateral spines, apicalmost weakly elongate, medially with 3 spines, apicalmost elongate; rami of uropods 1–2 with apical nails amalgamated and immersed in ramus, almost invisible on uropod 2; rami of uropod 1 each with dorsal spine; rami of uropod 2 naked; peduncle of uropod 2 with 2 lateral spines, spine on midmargin small, medially with one apical spine; peduncles of uropods 1–2 with ragged apical comb. Uropod 3 large; peduncle with one apical spine ventrolaterally, one dorsolaterally, 2 smaller medial spines dorsally and ventrally; rami feminine, inner extending to M. 43 on article 1 of outer ramus; inner ramus tapering to sharp point, bearing one short apical setule and one medial subbasal seta; article 1 of outer ramus with one lateral spine, one dorsofacial spine opposite lateral spine, one apicolateral spine, 2 apicomedial spines, article 2 elongate, thin, tapering to sharp attenuate point bearing 2 short setules. Telson of ordinary dimensions, about 1.35 times as long as wide, deeply cleft, weakly subcordate, lobes rapidly tapering to sharp apex bearing minute lateral acclivity armed with 2 setules, another lateral setule at M. 75, pair of lateral plusetules highly distad at M. 65, dorsal surface with cuticular setules occasionally prominent and irregularly distributed.

Cuticle covered to moderate extent with large bulbar setules, chitinous surface apparently pebbled extremely minutely but part of appearance resulting from agglutinated detritus.

OBSERVATION.—One adult female bearing 2 large eggs fully filling brood pouch; several other females with large pouches but eggs missing.

ILLUSTRATIONS.—One view of dactyl on pereopod 1 in oblique view, other fully flattened.

HOLOTYPE.—NMV, female “a,” 1.87 mm.

TYPE-LOCALITY.—CPBS 31S/769, 15 Jul 1969, Western Port, Victoria, Australia, 15 m, muddy sand.

VOUCHER MATERIAL.—CPBS A1/4, juvenile “j,” 1.52 mm (illus.); CPBS 21S/1, female “t,” 2.1 mm. Male unknown, but see possible male described as Urothoides makoo.

RELATIONSHIPS.—This species differs from Urothoides kurrawa in the following characteristics: (1) the larger and sharper posteroventral tooth extension on epimeron 3; (2) the stronger posteroventral points on epimera 1–2; (3) the apically immersed nails on the rami of uropods 1–2; (4) the naked rami of uropod 2; (5) the larger telson and uropod 3 relative to the size of pleonite 6; (6) the more truncate anterior margin of the head; (7) the stouter articles 4–5 of pereopod 3; (8) the broader article 5 of gnathopods 1–2; (9) the narrower telson; (10) the sparsity of cuticular setules; (11) the shorter article 2 of antenna 1; and numerous minor differences in shapes, numbers, and placement of setae on mouthparts as shown in the illustrations.

MATERIAL.—CPBS, 11 samples from 9 stations (30); WPBES, one sample (2).

DISTRIBUTION.—Victoria, Western Port, 3–15 m, sandy gravel, sand and mud, seagrass.