Austroleptostylis recalvastra ( Hale, 1945 ), 2014

Gerken, Sarah, 2014, Eleven New Species and a New Genus of Diastylidae (Crustacea: Cumacea) from Australia and One New Species from Canada, Records of the Australian Museum 66 (1), pp. 1-62 : 9-14

Austroleptostylis recalvastra ( Hale, 1945)

Figs 5–9

Type material. South Australian Museum, C 2762–2763, ovigerous female and subadult male, 4–5 miles off Eden , New South Wales, 60–70 m.

Other material examined. Ovigerous female, dissected, NMV J46861 ; ovigerous female, NMV J46862 ; adult male, NMV J46863 ; adult male, dissected, NMV J46864 ; 8 ovigerous females, 25 subadult females, 27 adult males, 11 subadult males, NMV J45976 ; 39°44'48"S 148°40'36"E, 124 m, R . S. Wilson, 14 Nov. 1981.

Diagnosis. Female and subadult male. Carapace without spines or carinae, toothed on anterior margin; eye lobe without lenses. Telson, shorter than pleonite 6, less than half length of uropod peduncle, terminal setae stout and long. Adult male. Carapace boxy, covered in small pits, folded ventrally, anterior margin and anterior margin of ventral fold crenulate. Telson shorter than pleonite 6, less than half length of uropod peduncle, terminal setae stout and long.

Description

Ovigerous female. Ovigerous female, 4.9 mm, NMV J46861 ; ovigerous female, 4.2 mm, NMV J46862 . Carapace toothed on anterior margin, antennal notch absent; pseudorostral lobes 0.4 × carapace length; eye lobe 0.04 × carapace length, without lenses; carapace 2.4 × length of pereonites together ( Figs 5A–B ). —Antennule peduncle article 1 longest, with 1 simple and 1 plumose setae, fine hair-like setae on distal margin; article 2 0.7 × article 1 length, with 2 simple and 1 pedunculate setae; article 3 1.3 × article 2 length, with 5 simple and 1 plumose setae; main flagellum of 2 articles, with 3 simple setae and 2 aesthetascs; accessory flagellum of 2 articles, 0.8 × length of main flagellum article 1, with 3 simple setae ( Fig. 5C ). —Mandible navicular, with 11–12 microserrate setae medially, lacinia mobilis with 2 cusps ( Fig. 5D ). —Maxillule with 2 endites; outer endite with 2 rows of stout simple setae; inner endite with 3 simple and 1 tridentate setae; palp with 2 microserrate setae ( Fig. 5E ). —Maxilla with 3 endites; broad endite distal margin with plumose seta, row of simple setae and 2 plumose setae, medial margin with row of pedunculate setae, with 2 plumose setae; medial narrow endite with 4 microserrate setae terminally; distal narrow endite with 5 microserrate setae terminally; both narrow endites extending past distal margin of broad endite ( Figs 5F–G ). —Maxilliped 1 basis produced as medial lobe with 1 simple, 6 pappose, 2 hook and 1 very stout setae; ischium absent; merus with plumose seta; carpus 2.3 × merus length, with 5 beak, many simple and 1 pappose setae medially, 2 plumose setae laterally; propodus 0.6 × carpus length, with 3 plumose setae distally, medial margin with fine hair-like setae; dactylus 0.7 × propodus length, with 1 simple and 1 dentate setae ( Fig. 5H ). —Maxilliped 2 basis 0.8 × length of all other articles together, with 4 plumose setae distally; ischium 0.06 × basis length, unarmed; merus 5.3 × ischium length, with plumose seta; carpus 1.3 × merus length, with 5 plumose setae; propodus 0.8 × carpus length, with 4 plumose setae medially, 2 plumose setae laterally; dactylus 0.5 × propodus length, with 3 simple setae terminally ( Fig. 5I ). —Maxilliped 3 basis 1.5 × length of all other articles together, with 7 pappose setae medially, 2 plumose setae laterally, distal corner not produced; ischium 0.08 × basis length, with pappose seta; merus 1.5 × ischium length, with 1 pappose and 1 plumose setae; carpus 1.7 × merus length, with 3 pappose setae; propodus 1.0 × carpus length, with 4 simple and 2 plumose setae; dactylus 0.6 × propodus length, with 4 simple setae terminally; exopod 0.7 × basis length, basal article unarmed, flagellum with plumoannulate setae ( Fig. 6A ). —Pereopod 1 basis 0.5 × length of all other articles together, with 22 simple and 7 plumose setae; ischium 0.09 × basis length, unarmed; merus 1.7 × ischium length, with 2 simple setae; carpus 3.9 × merus length, with 5 simple setae; propodus 1.3 × carpus length, with 10 simple setae; dactylus 0.3 × propodus length, with 8 simple setae and 2 simple setae terminally; exopod basis 0.8 × length, basal article with simple seta, flagellum with plumo-annulate setae ( Fig. 6B ). —Pereopod 2 basis 0.5 × length of all other articles together, with 8 simple setae; ischium 0.08 × basis length, with simple seta; merus 3.3 × ischium length, with 4 simple setae; carpus 2.5 × merus length, with 15 simple setae; propodus 0.4 × carpus length, with 3 simple setae; dactylus 3.0 × propodus length, with 14 simple setae and simple seta terminally; exopod 1.7 × basis length, basal article with 4 simple setae, flagellum with plumo-annulate setae ( Fig. 6C ). —Pereopod 3 basis 1.8 × length of all other articles together, with 10 simple setae; ischium 0.06 × basis length, with 2 simple setae; merus 2.7 × ischium length, with simple seta; carpus 1.5 × merus length, with 3 simple and 2 annulate setae; propodus 0.3 × carpus length, with annulate seta; dactylus 1.0 × propodus length, with 2 simple setae and simple seta terminally; exopod rudimentary, 0.1 × basis length, of 2 articles with 2 simple setae ( Fig. 6D ). —Pereopod 4 basis 1.3 × length of all other articles together, with 13 simple setae; ischium 0.08 × basis length, unarmed; merus 2.7 × ischium length, with simple seta; carpus 1.5 × merus length, with 3 simple and 2 annulate setae; propodus 0.3 × carpus length, with annulate seta; dactylus 1.3 × propodus length, with 2 simple setae and simple seta terminally; exopod rudimentary, 0.1 × basis length, of 2 articles with 2 simple setae ( Fig. 6E ). —Pereopod 5 basis 1.1 × length of all other articles together, with 6 simple setae; ischium 0.07 × basis length, with simple seta; merus 3.5 × ischium length, with simple seta; carpus 1.6 × merus length, with 2 simple and 2 annulate setae; propodus 0.3 × carpus length, with annulate seta; dactylus 1.0 × propodus length, with 2 simple setae and simple seta terminally ( Fig. 6F ). —Telson 0.8 × length of pleonite 6, with 1 pair lateral setae with single subterminal setule, 2 stout simple terminal setae, 0.4 × telson length ( Fig. 6G ). —Uropod peduncles 2.0 × pleonite 6 length, 2.7 × telson length, with 11–12 setae with single subterminal setule medially. Uropod endopod of 3 articles, 0.7 × peduncle length; article 1 with 2 setae with single subterminal setule medially; article 2 0.8 × article 1 length, with 1 simple seta laterally, 1 seta with single subterminal setule medially; article 3 0.8 × article 2 length, with 3–4 simple and 0–1 pedunculate setae and 2 simple with single subterminal setule terminally. Uropod exopod of 2 articles, 0.8 × length of endopod; article 1 0.3 × article 2 length, unarmed; article 2 with 3 simple and 1 simple with single subterminal setule setae, and simple terminal seta( Fig. 6G ).

Adult male. Adult male, 4.5 mm, NMV J46863 ; 4.6 mm, NMV J46864 . Carapace boxy, covered in small pits, anterior margin strongly crenulate, carapace folded ventrally, anterior margin of ventral fold crenulate; pseudorostral lobes 0.4 × carapace length; eye lobe 0.05 × carapace length, without lenses; carapace 3.7–3.9 × length of pereonites together. Pleonite 2 with several stout setae ventrally ( Figs 7A–D ). —Antennule peduncle article 1 longest, with simple seta; article 2 0.4 × article 1 length, unarmed; article 3 wider than long, 1.7 × article 2 length, with multitude of setae terminally; main flagellum of 4 articles, with 3 simple and 2 aesthetasc setae terminally; accessory flagellum of 3 articles, article broadened distally, extending past distal border of main flagellum article 3, article 2 with 5 simple setae distally, article 3 with simple seta terminally ( Figs 7E–F ). —Antenna extending no farther than posterior border of pereonite 5; peduncle of 5 articles; article 5 with few ranks of setae distally, incompletely circling article; flagellum with 22 articles, each with several simple setae ( Fig. 7G ) —Mandible navicular, with 8–9 microserrate setae medially, lacinia mobilis with 3 cusps ( Fig. 8A ). —Maxillule with 2 endites; outer endite with two rows of stout simple setae; inner endite with 2 simple, 2 microserrate and 1 tricuspid setae; palp with 2 microserrate setae ( Fig. 8B ). —Maxilla with 3 endites; broad endite distal margin with row of simple setae, 1 pappose seta, medial margin with row of pedunculate setae, 2 pappose setae; medial narrow endite with 4 microserrate setae terminally; lateral narrow endite with 4 microserrate setae terminally; both narrow endites extending past distal margin of broad endite ( Fig. 8C ). —Maxilliped 1 basis produced as lobe medially, with 5 pappose, 2 hook and 1 very stout pappose setae; ischium absent; merus with plumose seta laterally; carpus 2.1 × merus length, with 5 hook setae, field of simple and 1 pappose setae medially, plumose seta laterally; propodus 0.6 × carpus length, with 3 plumose and 1 dentate setae; dactylus 0.3 × propodus length, with 2 simple setae terminally ( Fig. 8D ). —Maxilliped 2 basis 0.9 × length of all other articles together, with 2 simple and 2 plumose setae distally; ischium 0.06 × basis length, unarmed; merus 4.0 × ischium length, with 2 plumose setae medially, plumose seta laterally; carpus 1.7 × merus length, with 5 plumose setae medially, 2 plumose setae laterally; propodus 0.8 × carpus length, with 4 simple and 1 plumose setae medially, 1 simple and 1 plumose setae laterally; dactylus 0.4 × propodus length, with 3 simple setae terminally ( Fig. 8E ). —Maxilliped 3 basis 1.3 × length of all other articles together, with pappose setae medially, medial margin produced as teeth distally, distal corner with 3 plumose setae; ischium 0.07 × basis length, with pappose seta; merus 1.5 × ischium length, with pappose seta medially, plumose seta laterally; carpus 2.3 × merus length, with 2 pappose setae medially, simple seta laterally; propodus 0.9 × carpus length, with 5 plumose setae medially, simple seta laterally; dactylus 0.8 × propodus length, with simple setae terminally; exopod 1.0 × basis length, basal article with pappose seta, flagellum with plumo-annulate setae ( Fig. 8F ). —Pereopod 1 broken. —Pereopod 2 basis 0.5 × length of all other articles together, with 3 simple and 2 plumose setae; ischium 0.06 × basis length, unarmed; merus 3.7 × ischium length, with 4 simple setae; carpus 3.5 × merus length, with 13 simple setae; propodus 0.3 × carpus length, with 2 simple setae; dactylus 2.1 × propodus length, with 14 simple setae, simple seta terminally; exopod 1.4 × basis length, basal article with 2 pappose setae, flagellum with plumo-annulate setae ( Fig. 8G ). —Pereopod 3 basis 1.5 × length of all other articles together, broad, with 11 simple setae, margin serrate; ischium 0.7 × basis length, with 3 simple setae; merus 2.2 × ischium length, with 3 simple setae; carpus 1.7 × merus length, with 3 simple and 2 annulate setae; propodus 0.2 × carpus length, with annulate seta; dactylus 1.3 × propodus length, with 2 simple setae and simple seta terminally; exopod 1.03 × basis length, basal article with plumose setae, flagellum with plumo-annulate setae ( Fig. 9A ). —Pereopod 4 basis 1.2 × length of all other articles together, with 10 simple setae, margin serrate; ischium 0.1 × basis length, with 2 simple setae; merus 2.0 × ischium length, with 3 simple setae; carpus 1.6 × merus length, with 4 simple and 2 annulate setae; propodus 0.4 × carpus length, with annulate seta; dactylus 0.8 × propodus length, with 2 simple setae and simple seta terminally; exopod 1.2 × basis length, basal article unarmed, flagellum with plumoannulate setae ( Fig. 9B ). —Pereopod 5 basis 1.0 × length of all other articles together, with 6 simple setae; ischium 0.1 × basis length, unarmed; merus 2.0 × ischium length, with simple seta; carpus 2.0 × merus length, with 4 simple and 2 annulate setae; propodus 0.3 × carpus length, with annulate seta; dactylus 1.2 × propodus length, with 2 simple setae and simple seta terminally ( Fig. 9C ). —Pleopod 1 peduncle wide, rami tiny, endopod uniarticulate, with plumose seta, exopod bi-articulate, with 3 plumose setae ( Fig. 9D ). — Telson 1.2 × length of pleonite 6, with 1 pair simple lateral setae with single subterminal setule, two stout simple terminal setae, 0.4 × telson length ( Fig. 9E ). —Uropod peduncles 3.0 × pleonite 6 length, 2.6 × telson length, with 15 or 19 simple setae with single subterminal setule medially. Uropod endopod of 3 articles, 0.7 × peduncle length; article 1 longest, with 3 or 5 simple setae with single subterminal setule medially, 1 simple and 1 pedunculate setae laterally; article 2 0.6 × article 1 length, with 2 simple setae with single subterminal setule medially, 2–3 simple setae laterally; article 3 1.2 × article 2 length, with simple seta with single subterminal setule medially, 0–2 simple setae laterally, terminal seta simple with single subterminal setule. Uropod exopod 0.8 × length of endopod; article 1 unarmed, 0.2 × article 2 length; article 2 with 2 simple and 1 simple with single subterminal setule setae, terminal seta simple with single subterminal setule ( Fig. 9E ).

Remarks. The species placed in the new genus, Austroleptostylis recalvastra ( Hale, 1945) , is easily distinguishable from the only species of Leptostylis known from Australia, Leptostylis vercoi , because L. vercoi has the carapace covered in spines, and in A. recalvastra the carapace has no spines. Hale did not have any adult male material when originally describing the species, and the stout setae present on pleonite 2 in the adult male could be mistaken in the subadult male for a developing pleopod. In addition, the one pair of pleopods present in this species is unusual in that the peduncle is quite large and the rami are minute in the adult male, thus the rami are probably nearly impossible to see in the subadult male, making the males appear more juvenile than they are, based on the apparent pleopod development.

Figures

Figure 5. Austroleptostylis recalvastra (Hale, 1945) n. gen., n. comb., female, 4.9 mm, NMV J46861: (A), lateral view; (C), antennule; (D), mandibles; (E), maxillule; (F), maxilla; (G), maxilla narrow endites; (H), maxilliped 1; (I), maxilliped 2. Female, 4.5 mm, NMV J46862: (B), dorsal view. Scale bars A,B = 1.0 mm, C–I = 0.5 mm.

Figure 6. Austroleptostylis recalvastra (Hale, 1945) n. gen., n. comb., female, 4.9 mm, NMV J46861: (A), maxilliped 3; (B), pereopod 1; (C), pereopod 2; (D), pereopod 3; (E), pereopod 4; (F), pereopod 5; (G), pleonite 6, telson and uropods. Scale bar = 0.5 mm.

Figure 7. Austroleptostylis recalvastra (Hale, 1945) n. gen., n. comb., male, 4.5 mm, NMV J46863: (A), lateral view; (C), dorsal view; (D), ventral view. Male, 4.6 mm, NMV J46864: (B), dorsal view; (E), antennules without setae; (F), antennules with setae; (G), antenna. Scale bars A–D = 1.0 mm, E–G = 0.5 mm.

Figure 8. Austroleptostylis recalvastra (Hale, 1945) n. gen., n. comb., male, 4.6 mm, NMV J46864: (A), mandibles; (B), maxillule; (C), maxilla; (D), maxilliped 1; (E), maxilliped 2; (F), maxilliped 3; (G), pereopod 2. Scale bars = 0.5 mm.

Figure 9. Austroleptostylis recalvastra (Hale, 1945) n. gen., n. comb., male, 4.6 mm, NMV J46864: (A), pereopod 3; (B), pereopod 4; (C), pereopod 5; (D), pleopod; (E), pleonite 6, telson and uropods. Scale bar = 0.5 mm.