Tethygeneia waminda J. L. Barnard 1972

Tethygeneia waminda

DESCRIPTION (of female).—Rostrum large, long, curved down slightly, apically blunt but thinner than in T. elanora, new species, lateral cephalic lobe broad, shallow, quadriform, defined below by weak but sharp incision, anteroventral margin bulbous, rounded; antenna 2 about half as long as body, antenna 1 about seven-eighths as long as antenna 2; eye of medium size, purple core surrounded by 1–2 layers of clear ommatidia in alcohol; flagella of antennae 1–2 each nearly 3 times as long as its own peduncle, flagella thin; accessory flagellum articulate, longer than broad; middle of primary flagellum on antenna 1 with alternate articles slightly swollen or offset, and each swollen article bearing 2, rarely 3, aesthetascs; articles of flagellum of antenna 2 even; mandibular molars triturative, each with ragged seta, spine row on right with 3 main ragged spines, 2 slightly smaller plumose spines, 1 between 2 and 3 and 1 past 3 toward molar, left side with 4 ragged spines and 3 plumose spines, 1 between 2 and 3, 1 between 3 and 4 and 1 toward molar past 4, left lacinia mobilis serrate and clearly distinct, right appearing composed of 3 parts, 2 spines and 1 smooth membrane bearing falcations; mandibular palp approximately like T. elanora, article 3 bearing 2 apical spines of medium size, third spine.larger, then about 10 smaller proximal spines and 3–4 basofacial setae, article 2 with about 9 spines on distal half; lower lip lacking inner lobes, mandibular lobes subtruncate and apically smooth or occasionally with very weak fringe; inner plate of maxilla 1 bearing 1 giant apical seta and 4 smaller medial setae on distal half; inner plate of maxilla 2 apically and subapically fringed with small setae, midmedial margin with 2 enlarged setae in tandem; inner plate of maxilliped with apicolateral spine separated from 2 medioapical spines by gap and hollow (cf. Figure 119S of T. elanora), article 2 of maxillipedal palp not especially broad, outer plate with facial setules irregularly arranged; coxae 1–3 lacking posterior setules, posterior lobe of coxa 4 softly rounded; article 2 of gnathopods 1–2 heavily setose posteroventrally, hands of gnathopods less elongate than in T. elanora, rectangular, palms evenly oblique, article 5 of gnathopods 1–2 about 80 percent the length of article 6, posterior margin of article 5 on gnathopod 1 truncate but weakly triangulate distally, on gnathopod 2 produced to medium lobe slightly guarding posterior proximal third of hand; locking spines of pereopods 1–2 really thin flexible setae; dactyls each with distal constriction, nail, medium sharp inner seta, and shorter facial seta guarding constriction; inner margin of dactyl smooth or in large adults occasionally bearing faint, broadly spaced notches resembling incipient castellations, locking setae increasing in number up to 4 or 5; locking spines of pereopods 3–5 normally stiff and slightly thickened, each with subterminal setular trigger, spines often joined by third to fourth members in form of setules, outer apical margin of article 6 at base of dactyl smooth; coxae 5–6 with elongate posterior quadriform lobe; article 2 of pereopods 3–5 broadly expanded, articles 3–7 slender, article 2 of pereopod 5 bearing facial row of setae and spines posterior to main anterior facial ridge, row anterior to ridge on pereopod 4; epimeron 1 grossly and softly rounded behind but with weak tooth (declivity) forming posteroventral tooth, epimeron 2 with sharp shallow tooth and protruding posteromiddle margin, epimeron 3 similar but protrusion deeper and tooth slightly better defined, ventral margins of epimera lined with pairs (rarely triads) of spines and face of epimeron 2 with facial spines in pairs and singles; no dorsal teeth; uropod 3 with 1 stout peduncular spine, pleonite 6 with row of tiny denticles anterodorsal to base of uropod 3; telson flat, broad, cleft more than halfway, apices broad, somewhat beveled but generally truncate, smooth lateral margins of lobes with pairs of setular sets and other setules; cuticle bearing crescents, especially prevalent on epimera, telson, article 2 of pereopods 3–5, coxae, plus frequent setules on coxae 1–4 especially.

MALE.—Like female except as follows: eyes slightly larger; accessóry flagellum bearing about 5 medium-sized apical setae (not like female, bearing 1 very large and stout seta and 2 regular setae); antennal peduncles developing groups of setules on ventral margin of antenna 1 and dorsal margin of antenna 2 and anthurial calceoli on articles 4–5 of antenna 2, calceoli occurring on all articles (except few terminal) of antenna 1 flagellum, articles alternating in breadth as on female and calceoli occurring in zigzag pattern as result; alternate articles of flagellum on antenna 2 slightly swollen and calceoli occurring on all except distal articles, alternating between a recumbent position and a slightly erect position on basal half or more of flagellum; mandibular palp article 2 slightly more swollen than in female; lobes on article 5 of gnathopods 1–2 slightly more protuberant than on female and gnathopods enlarged; posterior setae on article 6 of pereopods 1–2 becoming strongly plumose and elongate.

JUVENILE (smallest, 2.9 mm).—Differing from adults in absence of facial spines on epimeron 2, presence of only single spines in tandem on ventral margins of epimera, poorly developed facial rows of setae on article 2 of pereopods 4–5 (about 2 setae); otherwise important taxonomic characters such as accessory flagellum, spine on peduncle of uropod 3, and thin locking spines of pereopods 1–2 as in adult.

EXAMPLES OF FLAGELLAR FORMULAE (of males and female; see T. elanora for symbols).—Female antenna 1: (1–2):1:3:2:0:2:0:2:0:2:0:3:0:2:0:2:0:2:0:2:0:3:0:2:0:2:0:2:0:0 (bulge continues) :0:0B:0:0 (terminus).

Male antenna 1 flagellum bearing aethestascs (number), a calceolus (C), and a bulge (B): (1–2):2:2:2CB:C:2CB:C:2CB: (continuing to segment 23, then commencing, as follows, on segment 24)2CB:G(B):2CB:C(B):2CB:0:2CB:0:2CB:0:1GB:0:0:0:0:0:0 (terminus).

Male antenna 2 flagellum bearing calceoli either recumbent (P) or slightly erect (E) with some segments bulging: 0:E:E:E:PB:E:PB:E:PB (continuing to segment 22, then commencing with segment 23 as follows) PB: E (slightly erect, continuing alternately to segment 34, then commencing with segment 35) PB:E:0:E:0:E:0:0:0:0:0:0:0:0(terminus).

HOLOTYPE.—WAM, female, 6.6 mm.

TYPE-LOCALITY.—JLB Australia 4, Sugarloaf Rock, Cape Naturaliste, Western Australia, intertidal, wash of algae, mainly green Caulerpa species, 1 September 1968.

RELATIONSHIP.—This species grossly resembles T. elanora so closely that microscopic examination is required to distinguish the species. In adults (or in specimens larger than 3.0 mm) the main differences appear to be the following: In T. waminda, epimeron 2 bears facial spines, and the ventral epimeral spines occur in pairs; the accessory flagellum is elongate; cuticular crescents occur on the epimera, coxae, and article 2 of pereopods 3–5, but these are often hard to see and may actually be absent on some specimens (unless there is a cryptic species, possibly phenotype, mixed into my identification of T. waminda); the peduncle of uropod 3 bears a large and conspicuous terminal spine; article 2 of pereopods 4–5 has a facial setal row. Minor characters include differences in the spine rows of mandibles (see descriptions), the ornamental formulae on antennae, the irregularly scattered setules on face of outer plate of maxilliped, the heavy posteroventral setosity of article 2 on gnathopods 1–2, the essentially smooth apices of the mandibular lobes on the lower lip, the slightly longer telson and longer denticular rows on its basal face, the slightly thinner rostrum, the larger posterior lobe on coxa 5 in the female, the slightly better developed lacinia mobilis membrane, unserrate but bearing a falcation, the presence of more than 1 basofacial seta on article 3 of the mandibular palp, and the slight differences in the shape of the gnathopods.

MATERIAL.—JLB Australia 14 (17).

DISTRIBUTION.—Southwestern Australia, intertidal.