Haplodendron buzwilsoni, Just, Jean, 2003

Just, Jean, 2003, Haplodendron buzwilsoni gen. nov., sp. nov., the first record of Haplomunnidae from the southern Indo­Pacific (Isopoda: Asellota), Zootaxa 372, pp. 1-10 : 6-9

Haplodendron buzwilsoni sp. nov.

( Figs 1–3)

Etymology. The species is named for Dr G.D.F. “Buz” Wilson, Australian Museum, in recognition of his significant contribution in creating the family Haplomunnidae and placing its genera and species on a modern descriptive basis.

Type locality. Bass Strait, eastern slope, Australia.

Material examined

Holotype. Copulatory male, 2.8 mm, Bass Strait, south of Point Hicks, Victoria, Australia, 38°25.0’S 149°0.0’E, 1500 m, compacted clay, WHOI epibenthic sled, G.C.B. Poore et al., 22.vii.1986, RV Franklin stn SLOPE 27, NMV J18627 .

Paratypes. Same data as holotype, female A, preparatory, 3.1 mm, NMV J52750 , female B, spent, 1 juvenile female, J52749 . Male M, Bass Strait, S of Point Hicks, Victoria, Australia, 38°24.14’S 149°13.07’E to 38°23.76’S 149°14.50’E, 1220­ 1170 m, clay, WHOI epibenthic sled, G.C.B. Poore et al., 23.vii.1986, RV Franklin stn SLOPE 31, NMV J18628 . Two females, 1 without pleon, Bass Strait, 67 km S of Point Hicks, Victoria, Australia, 38°23.95’S 149°17.02’E to 38°23.78’S 149°15.24’E, 1277– 1119 m, fine mud, WHOI epibenthic sled, G.C.B. Poore et al., 25.x.1988, RV Franklin stn SLOPE 67, NMV J18629 . Two males, 1 crushed female, 2 poor juveniles, Bass Strait, 76 km S of Point Hicks, Victoria, Australia, 38°29.33’S 149°19.98’E to 38°26.81’S 149°20.78’E, 1840­ 1750 m, WHOI epibenthic sled, G.C.B. Poore et al., 26.x.1988, RV Franklin stn 69, NMV J18630 . One female with pleon and both pereopod I, 1 juvenile, 5 damaged specimens, Tasmania, 48 km ENE of Cape Tourville, Freycinet Peninsula, Australia, 42°00.25’S 148°43.55’E to 41°57.77’S 148°42.08’E, 1264­ 1130 m, gravel, lumps of sandy mud, WHOI epibenthic sled, G.C.B. Poore et al., 30.x.1988, RV Franklin stn SLOPE 81, NMV J18631 . Four damaged specimens, continental slope of eastern Australia, 40°45.94'S 149°01.62'E to 40°46.54'S 149°00.27'E, 2500– 2400 m, NMV dredge, P. Hutchings et al., 10.xii.1986, RV Franklin stn FR1086­4, AM P66974.

Description. Head length (clypeus to midposterior margin) equalling pereonite 1 and 2 combined; frons and clypeus bulges equal in lateral view, rounded. Pereon with scattered simple setae, mainly in lateral parts. Pleotelson with cover of long simple setae, in lateral view broadly rounded dorsally, depth equal to 4/5 ventral length, apex acutely pointed in lateral view.

Antennula article 1 bulging in proximal third, longer than antenna articles 1–4 combined in male, equal in female; article 3 as long as 1 and 2 combined in male, subequal to article 1 in female; flagellum with 14 articles in male (holotype), 8 in female (female A), article 1 of equal length and width, article 2 elongate; male with aesthetascs on all but proximal 2 articles, female without aesthetascs. Antenna just over twice head­pereon length, peduncle articles 1–4 short, subequal with simple setae, article 5 the longest, 4 times articles 1–4 combined in male, 3 times in female, article 6 approximately 3/5 of 5, 5 and 6 with long simple setae; flagellum of 24 articles in male (holotype), 17 in female (female A).

Mandible, palp articles 2 and 3 with fine setules on surface and margins, 3 with transverse row of simple setae on truncate apex; left incisor and lacinia mobilis with 4 subequal teeth, setal row of 2 simple setae, right incisor more pointed, with 5 teeth, setal row of 3 simple setae. Maxilliped basis approximately 1.5 times longer than wide, distally tapering towards truncate apex, apically with row of stiff pectinate setae and two simple setae ventrally near margin; epipodite greatest length 1.8 greatest width; palp slender, article 1 shorter than wide, 3 the longest. Maxilla 1 outer plate apex with 10 spine­like setae.

Pereopod I approximately 1.5 times longer than head­pereon length; ischium length 3 times width; merus rounded anteriorly, posterodistally with robust seta; carpus 4.7 times longer than greatest width, anterior margin convex, posterior margin straight with 17–18 robust setae in distal 2/3 successively smaller distally, proximal one on low heel, a single robust setae on lateral surface next to heel; propodus and dactylus combined reaching to carpus heel, propodus length approximately 8 times width, with posterior margin row of more than 20 equal sized triangular robust setae; dactylus with tiny second claw. Pereopod II length nearly 2.5 head­pereon length; ischium length 4.5 width; all articles with cover of long slender setae, more dense distally, setae with reversed microsetules in distal one third.

Male pleopod I distinctly narrowing in proximal third, distolateral corners rounded, hardly protruding, with fringe of short setae, distal margin between corner and apex concave, ventral surface between lateral corners and apices depressed; dorsal surfaces strongly swollen between lateral lobes and apices; entire ventral surface covered with long simple setae. Male pleopod II protopod length 3.5 midwidth, apex curving mediad, extended into acute point, ventral surface and lateral margin with long slender, simple setae; stylet short, thick, length approximately half protopod length, apex with different sized hooked setae. Pleopod III endopod shorter than exopod, broadly rounded laterally, set at right angle to normal plane, reaching up into pleotelson bulge (flattened medially in Fig. 3 pl3), both endopod and exopod fringed with fine setules. Pleopod IV exopod very long and slender, distally tapering (tip broken in Fig. 3 pl4), fringed with setules. Pleopod V single naked lobe. Female operculum ovoid, margins faintly concave distally, ventral surface covered with long simple setae, margins with finer simple setae.

Uropods inserted just dorsal to lateral margin; distal article approximately 9/10 length of proximal one, distally tapering, with single simple seta and several pappose setae.

Size. Largest male, 2.8 mm, largest female, 3.1 mm.

Figures

FIGURE 3. Haplodendron buzwilsoni, gen. nov., sp. nov. Paratype, male (J 18628), except B, paratype, female B (J 52749). pl 1 ­ 5, pleopods I­V; dv, dorsal view; op, operculum; pp, penile papillum with tuft of sperm protruding; vv, ventral view.