Limnoporeia maranowe Barnard & Drummond 1978

Limnoporeia maranowe

DESCRIPTION OF FEMALE.—Head about 17 percent of total body length, greatest width about 65 percent of length; rostrum long, reaching at least to apex of article 2 on antenna 1, constricted weakly towards apex (from dorsal view), apex somewhat attenuate but rounded. Eyes small, composed of black core in preservative surrounded by occasional small and clear ommatidium. Article 1 on peduncle of antenna 1 about 1.7 times as long as wide, almost twice as wide as article 2, apicoventral region with 4 setules, strongly produced dorsal apex with about 4 setae; article 2 about 0.6 times as long as article 1, ventral apex with 4 setae; flagella extending subequally, primary and accessory flagella each 4-articulate, aesthetascs absent or one alone present on accessory flagellum. Article 3 of antenna 2 with one long, one short facial setae; spine formula of article 4 = 3–3–2, proximal group thin, both proximal groups with accessory setule, dorsal margin with weak notch bearing spine and setae, ventral margin with 2 groups of 2–3 setae and 3 subbasal penicillate setules, ventrodistal margin with 3 short to medium spines; article 5 almost 0.7 times as long as article 4, facial spine formula = 1 plus accessory setule, dorsal and ventral margins straight and smooth, dorsodistal apex with 2 spines, ventrodistal apex with 2 spines and 2 setae; flagellum as long as article 5 of peduncle, 3-articulate. Prebuccal complex convex anteriorly, moderately extended forward, epistome and upper lip articulate, epistomal part small, upper lip with widely spread lateral alae, ventral margin bisinuate from anterior view. Mandibles with weak palpar hump; right incisor with 3 teeth and notch; left incisor with 5 humps in 2 branches; right lacinia mobilis broadly flabellate, minutely and complexly toothed and bearing facial tooth; left lacinia mobilis broadly flabellate, with 5 teeth; right rakers 2, left 3; mandibular molar small, projecting, subconical, heavily setulose, these setules attached to strongly cornified, clear cone on apex of molar; palp article 2 bearing one inner seta subapically, article 3 about 0.85 times as long as article 2, strongly oblique apex with 8 setae. Lower lip with 4 cones on outer lobe, one cone facial and disjunct from others, mandibular lobes of medium length, rounded apically, inner lobes small, fused together for most of their length. Inner plate of maxilla 1 large, elliptical, naked; outer plate with 7 spines, two of these with one cusp each on opposite sides; palp exceeding apex of outer plate, uniarticulate, thin, bearing 2 apical and one subapical setae. Inner plate of maxilla 2 broader and slightly shorter than outer plate, setae sparse, inner and outer plates each with one medial seta. Inner plate of maxilliped with one apical and one medial seta; outer plate with 4 medial spines; palp article 2 sparsely setose medially, article 3 with 2 facial setae, article 4 of medium length, not fully unguiform, bearing one apical spine and 2 accessory setae. Coxa 1 unexpanded distally, setal formula of coxae 1–4 = 5–5–5–2, anterior and posterior margins of coxa 4 parallel, posterodorsal excavation medium, V-shaped, ratio of width to length = 5:6. Gnathopod 1 especially slender, gnathopod 2 as long as but stouter than gnathopod 1; long posterior setae on article 2 of gnathopods 1–2 = 1 and 1, small anterior setae on both members = one middle, one distal; article 3 of both gnathopods, but especially of gnathopod 2, slightly elongate; article 5 on gnathopod 1 long, with flat and free posterior margin, shorter on gnathopod 2, posterior margin somewhat triangulate and almost cryptic; article 6 of both gnathopods long, slightly tapering apically, strongly chelate, apex of palm bearing scale-like protrusion and medium spine, apices of dactyls with especially large apical scale; length ratios of articles 5–6 on gnathopods 1–2 = 69:112 and 55:132, width ratios = 24:36 and 27:49. Pereopods 1–2 generally similar to each other but articles 4–5 of pereopod 2 slightly stouter than on pereopod 1; long posterior setae on article 2 of pereopods 1–2 = 3 and 4, anterior short setae = 2 and 1, articles 4–5 lacking facial armaments; article 4 with 2 groups of sparse simple posterior setae, produced anterodistal apex with 2 setae; article 5 with several posterior setae, one long distal spine reaching to M. 80 on article 6; article 6 with one midposterior seta and apical rows of 3 and 2 spines on pereopod 1, 3 and 3 on pereopod 2, spines mostly long; dactyl extremely short, curved, conical, lacking acclivities, nail absent (unless represented by chitinous internal remnants). Coxae 5–7 posteroventral setule formula = 2–1–3. Articles 4–5 of pereopods 3–4 narrow, facial spines almost absent; width ratios of articles 2, 4, 5, 6 of pereopod 3 = 52:23:18:10, of pereopod 4 = 68:20:15:9, of pereopod 5 = 91:16:13:7, length ratios of pereopod 3 = 68:26:29:30, of pereopod 4 = 90:50:39:42, of pereopod 5 = 100:17:27:22; article 2 of pereopod 5 extending to apex of article 4; medial apex of article 6 combed, lacking digits. Posteroventral corners of epimera 1, 2, 3, = rounded, rounded–quadrate, and quadrate, posterior margins = flat, weakly convex, and almost flat, with 3 setules on epimeron 3, epimeron 2 with 5 facial setae, anteriormost 2 of these horizontal, posteriormost 3 of these vertical. Urosomite 1 naked ventrally. Apicolateral corner on peduncle of uropod 1 smooth, with small spine, medial apex with long spine, medial margin with small spine in middle; each ramus lacking apical nail but with weak scale or tiny apical setule, each ramus with one small dorsal spine, apicolateral corner on peduncle of uropod 2 smooth, with one medium sized apicolateral spine, one smaller apicomedial spine, rami like those of uropod 1 apically, outer ramus with dorsal spine, inner naked. Uropod 3 of medium length, peduncle with one ventrolateral spine, one dorsal setule; rami feminine, inner extending to M. 60 on article 1 of outer ramus, inner ramus broad basally, very slender apically, tapering strongly near base, ramus appearing curved basally, bearing one short apical seta, article 1 of outer ramus bearing 2 lateral spines, one apicolateral spine, one long apicomedial spine-seta, article 2 elongate, 0.37, bearing 2 apical setae. Length-width ratio of telson about 3:2, not fully cleft, each apex narrow but with narrow medial lobe, broad lateral acclivity bearing one short spine and one lateral setule of similar length, middorsal pair of plusetules diverse. Cuticle bearing very sparse but unusual bulbar setules, each setule with short tube-like internal tail (nerve duct?), twin bulb and extremely long spike-like external seta and very short accessory setule. Gills on gnathopod 2 and pereopod 5 vestigial.

DESCRIPTION OF MALE.—Following parts like female: head, prebuccal and upper lip, left mandible, lower lip, maxillae, maxilliped, generalities of gnathopods and pereopods 1–2. Eyes enlarged. Antenna 1 with medial patch of fuzz (stout setules) on article 1; primary flagellum with 5 articles, first 2 each bearing calceolus, basal articles and article 3 of peduncle with stout aesthetascs. Spines and setae on peduncle of antenna 2 shorter than in female, articles 3–4 with dorsomedial fuzz, article 4 facial formula = 3–2–2; article 5 of peduncle relatively longer than in female, ventral margin convex, dorsal margin with one dish-shaped calceolus and 2 sets of male setules; flagellum elongate, bearing 33–35 articles, lacking calceoli. Teeth and facial cusp of right lacinia mobilis much sharper than in female; article 2 of palp with 2 inner apical setae, article 3 with 9 apical setae. Coxae 1–3 each with only 3 long ventral setae, coxa 4 with only one long ventral seta. Long posterior setae on article 2 of gnathopods 1–2 and pereopods 1–2 = 1–1–2–4, short anterior setae = 2–1–2–1. Article 6 of gnathopod 1 slightly more elongate than in female. Article 6 of pereopods 1–2 each with spine rows of 3 and 3. Article 2 of pereopods 3–5 slightly to greatly narrower than in female, pereopod 4 relatively longer than in female. Epimera 1–2 lacking facial ridges, epimeron 2 with only one facial seta, epimeron 3 with 2 posterior setules. Urosomite 1 bearing setule at base of uropod 1; urosomite 3 with stronger dorsal protrusion basally than in female. Spines on uropods 1–3 very small, apical scales of rami slightly larger than in female. Rami of uropod 3 masculine, inner ramus extending almost to apex of article 1 on outer ramus, medial margins of inner ramus and outer ramus setose, outer margin of inner ramus naked. Telson slightly more elongate than in female, apical spine slightly smaller than in female, rudimentary denticle row present on each lobe near proximal end of cleft. Gill present on pereopod 5.

OBSERVATIONS (male).—The poorly developed calceoli, aesthetascs, and denticle rows on the telson suggest that the males at hand are not fully mature.

ILLUSTRATIONS.—Male coxa 1 magnified same dimensions as male coxa 4 after latter balanced to female coxa 4; male coxae 1–4 thus of similar proportions to those of female.

HOLOTYPE.—NMV, female “a,” 3.06 mm.

TYPE-LOCALITY.—CPBS 42S, 1 Nov 1971, Western Port, Victoria, Australia, 15.1 m, sand.

VOUCHER MATERIAL.—Type-locality: male “m,” 2.86 mm (illus.); female “d,” 2.77 mm (illus.); male “c,” 3.15 mm.

RELATIONSHIP.—Because this species is used as a model for the genus, its relationships are discussed in the comparisons made for other species. Limnoporeia maranowe is selected as the model because of its regular phoxocephalid telson in combination with ordinary head, fully developed right lacinia mobilis, and elongate apical setae on the outer ramus of uropod 3. However, L. maranowe is not the perfect model of primitiveness because of its alate upper lip and shortened dactyls of pereopods 1–2. MATERIAL.—CPBS, 23 samples from 15 stations (41); PPBES, 3 samples from one station (5).

DISTRIBUTION.—Victoria: Western Port and Port Phillip Bay, 8–19 m, sand, muddy sand, sand on clay.