Phoxocephalus burleus

Phoxocephalus burleus

DESCRIPTION OF FEMALE.—Head about 18 percent of total body length, greatest width about 55 percent of length, rostrum nearly reaching middle of article 2 on antenna 1, unconstricted, weakly tapering, apically rounded. Eyes of medium size, dark core surrounded by one partial layer of clear ommatidia in preservative. Article 1 on peduncle of antenna 1 about 1.8 times as long as wide, 1.8 times as wide as article 2, apicoventral margin with several setules, strongly produced dorsal apex with 6 setules; article 2 about 0.42 times as long as article 1, apicoventral surface with 4 setae; article 3 essentially attached terminally to article 2; accessory flagellum shorter than primary flagellum, 3-articulate; primary flagellum 5-articulate, aesthetascs absent. Spine formula on article 4 of antenna 2 = 3–4–3, proximal sets with 1–2 accessory setules, spines thin, dorsal margin with one short spine, one long seta, ventral margin with 3 subbasal penicillate setules and 10 long or short setae, apex with 4 spines; article 5 less than 0.6 times as long as article 4, facial spine formula = 2–2, with one proximal accessory setule, dorsodistal corner with one spine-seta, apex with one spine, ventral margin with 2 pairs of long-short setae, ventrodistal apex with one long, one short setae; flagellum about as long as article 4 of peduncle, 5-articulate. Palpar hump of mandible small; right incisor weakly tridentate, with weak accessory tooth between teeth 2 and 3; left basically bidentate, distal branch weakly tridentate; right lacinia mobilis flabellate, distal branch poorly defined, margin toothed; left lacinia mobilis flabellate, irregularly toothed; right rakers 2, left 3; molar triturative, on long pedicle; palp article 2 with 5 long medial setae on distal half, article 3 about as long as article 2, oblique apex with 10 setae. Mandibular lobes of lower lip of medium length, weakly attenuate and apically rounded, inner lobes fused together for most of their length but with distinct raphe. Inner plate of maxilla 1 large; elliptical, naked, outer plate with 7 spines; palp scarcely exceeding apex of outer plate, bearing 2 apical and one apicolateral setae. Inner plate of maxilla 2 scarcely broader than and extending equally with outer plate, medial margin of inner plate with 2 setae, apical margin with 3 setae; outer plate with 2 apicolateral, 3 apical and 3 medial setae. Inner plate of maxilliped with one mediofacial seta, 2 apical spines; outer plate with 4–5 spines; article 2 of palp with sparse medial setae, article 3 with 2–3 facial setae, article 4 of medium length, apical spine long, bearing 2 accessory setules. Coxa 1 distally expanded and narrowly rounded anteroventrally; long setal formula of coxae 1–4 = (8–10)–(9–10)–(8–10)–(5–8), posteriormost seta of coxae 1–3 shortened (= elongate setule); anterior and posterior margins of coxa 4 divergent, posterior margin weakly convex, posterodorsal corner subsharp, posterodorsal excavation of medium size and V-shaped, ratio of width to length = 73:86. Gnathopod 2 much stouter than gnathopod 1; long posterior setae on article 2 of gnathopods 1–2 = 2 and 5, short anterior setae = 1 and 3; article 3 short, only gnathopod 2 weakly eusirid, article 6 broadened but elongate, rectangular, palm oblique, defining hump large on both pairs, dactyl fitting palm, apices of dactyls with flake, posterior margin of article 5 on gnathopod 1 free, on gnathopod 2 cryptic; length ratios of articles 5–6 on gnathopods 1–2 = 34:77 and 35:126, width ratios = 22:43 and 18:66. Pereopod 2 slightly thinner than pereopod 1; long posterior setae on article 2 of pereopods 1–2 = 2–3 and 3, short anterior setae = 2 and 1; article 4 of pereopods 1–2 with 6 and 2 subapical anterior setae, posterior margins of article 4 moderately setose, of article 5 more densely so, article 5 with 3 and 2 anterofacial setae, with long posterodistal spine reaching to M. 95 on article 6, with small contiguous spine at base, article 6 with one long posterior setal-spine and rows of 3 and 3 spines and setae, plus middistal spine, some stout, some thin, dactyl lacking apical flake, inner margin with acclivity and tooth bearing setule appressed in wide groove, apical nail fused almost fully to dactyl. Coxae 5–7 posteroventral setule formula = 1–1–1. Width ratios of articles 2, 4, 5, 6 of pereopod 3 = 55:25:21:12, of pereopod 4 = 72:26:18:10, of pereopod 5 = 89:21:17:8, length ratios of pereopod 3 = 76:24:26:26, of pereopod 4 = 98:57:56:47, of pereopod 5 = 112:20:28:22; article 2 of pereopod 5 slightly exceeding apex of article 4, posterior margin with accessory tightly packed group of dorsoposterior setules; apex of article 6 finely combed. Epimera 1–2 with facial ridge, each with rounded-quadrate posteroventral corner and convex posterior margin, epimeron 3 with rounded posteroventral margin, posterior margin broadly convex, bearing long setae set in notches, margins between notches inflated, setae extending onto postroventral margin, epimeron 1 with one posteroventral seta, epimeron 2 with 5–7 facial setae in horizontal row. Urosomite 1 bearing 2 short lateral setae at base of uropod 1; urosomite 2 with one such seta; urosomites dorsally truncate; urosomite 3 with 2 long setae at ventral base of uropod 3. Peduncle of uropod 1 with one setule not strongly basal, lateral apex of peduncle with one spine, medial margin with 4 spine-setae; rami of uropods 1–2 with apical nails scarcely articulate but conspicuous, outer ramus of uropods 1–2 with 2 dorsal spines (elongate), inner ramus of uropod 1 with one spine, of uropod 2 naked, inner ramus of both uropods 1–2 with mediobasal spinule (unusual for uropod 2), outer ramus of uropod 1 slightly longer than inner, of normal dimensions and shape; lateral apex of peduncle on uropod 2 with stout spine, margin with 4 long setae, apicomedial corner of peduncle with long spine-seta: comb on apices of peduncles of uropods 1–2 obsolescent. Uropod 3 long, rami feminine, peduncle with 4 long ventrolateral spine-setae, dorsolaterally with tiny spinule, dorsomedially with tiny spinule, inner ramus extending to M. 60 on article 1 of outer ramus, apex with one seta, article 2 of outer ramus elongate, 0.37, bearing 2 long apical setae, outer margin of article 1 with 3 acclivities, elongate spine-seta formula = 1–1–1–3, medial apex with one spine-seta. Telson slightly elongate, length-width ratio about 14:11, apices scarcely tapering, each with medial protrusion and lateral acclivity bearing one long spine-seta and one short lateral setule, dorsal pair of plusetules diverse. Cuticle armed sparsely with bulbar setules and densely covered with fingerprint striations heavily cornified and thickened.

DESCRIPTION OF MALE (male “n,” 4.54 mm, unique specimen).—Eyes enlarged but only of medium size. Article 1 of antenna 1 with medial patch of fuzz; articles 1–2 of primary flagellum each with calceolus and one large aesthetasc. Antenna 2 enlarged, elongate; dorsomedial margins of articles 3 and 4 with fuzz; facial spine formula of article 4 = 3–3–3 plus 3 other apical spines, only one accessory setule with each proximal spine group, setae of articles 4–5 fewer and shorter than in female, article 5 with 3 dorsal sets of male setae and one calceolus; flagellum elongate, flagellar formula = (20), 1–2 3, 5, 7…19. Long posterior setae on article 2 of gnathopods 1–2 and pereopods 1–2 = 1–2–2–3, short anterior setae = 1–1–1–1. Article 2 of pereopods 4–5 narrower and more elongate than in female. Epimera 1–3 broadened anteroposteriorly, (epimeron 1 poorly preserved but of dimensions commensurate with epimeron 2, presence of one seta undetermined); epimeron 2 with 5 facial setae; setae on epimeron 3 shorter than in female. Setules on urosomites 1–2 at bases of uropods elongate, urosomite 1 bearing only one setule. Spines and setae on uropods 1–2 shorter than in female, peduncle of uropod 2 with 9 short lateral spines not divisible into size classes, medial margin with 3 spines, peduncle of uropod 1 with 2 apicolateral spines, otherwise spine formula of uropods 1–2 same as in female. Uropod 3 masculine, inner ramus extending to apex of outer ramus on article 2, both rami setose on both margins, lateral margin on article 1 of outer ramus with 4 acclivities, formula of long setae = 1–1–1–1–1, formula of short setae = 1–1–1–1–2; article 2 of outer ramus shorter than in female, spines on peduncle shortened, apicomedial margin of peduncle with 3 setules in 2 groups. Telson of dimensions similar to female, apical spines short, each lobe dorsomedially with row of denticles.

VARIATIONS.—Female “h,” 4.53 mm, much smaller than other females analyzed, with 7 setae on epimeron 2 and 5 setae plus one spine on lateral margin of peduncle on uropod 1, highest counts found in females of the species.

HOLOTYPE.—AM, female “f,” 5.93 mm.

TYPE-LOCALITY.—SBS CXS4, 22 May 1972, off Malabar, New South Wales, Australia, 92 m, sandy gravel.

VOUCHER MATERIAL.—Type-locality, female “g,” 5.31 mm; SBS D3S3, male “n,” 4.54 mm (illus.); SBS C7S4, female “h,” 4.53 mm.

RELATIONSHIP.—This species has its closest affinities with P. rupullus, new species. The latter is based on a giant, perhaps senile female. Some of the character differences between the two species may be based on the senilic condition of P. rupullus but the extraordinary difference between the cuticles of the two species confirms their distinction. Phoxocephalus rupullus has villi organized into polygons whereas P. burleus has thickened striations lacking a pattern. Phoxocephalus rupullus has more setae and spines in certain places and fewer in other places than does P. burleus; because senile individuals may both gain or lose armaments selectively we leave the reader to compare our illustrations for these differences.

Phoxocephalus regium K. H. Barnard, 1930 (see Hurley, 1954), from New Zealand, is in the species group of P. burleus because of equally extending rami on uropod 1 but otherwise is remote morphologically; among numerous distinctions of P. regium from P. burleus and P. rupullus we emphasize the following: the confinement of facial setae on epimeron 2 to the far anterior region, the shortness of posterior setae on epimeron 3, the absence of posterior setae on article 2 of pereopod 4, and the absence of a dorsal spine on the inner ramus of uropod 1.

MATERIAL.—SBS, 3 samples (4).

DISTRIBUTION.—New South Wales, off Malabar, 71–92 m, sandy gravel, medium fine sand.