Leptostylis wisniewskiae, Gerken, Sarah, 2015

Gerken, Sarah, 2015, New Zealand Diastylidae and Gynodiastylidae (Crustacea: Cumacea), Zootaxa 4031 (1), pp. 1-77 : 54-59

publication ID	https://doi.org/ 10.11646/zootaxa.4031.1.1
publication LSID	lsid:zoobank.org:pub:19E72EB1-B55C-40C0-AD11-23BA6E97D438
DOI	https://doi.org/10.5281/zenodo.6122574
persistent identifier	https://treatment.plazi.org/id/C70EEC59-6E10-FFF8-FF24-190EFE4D7E12
treatment provided by	Plazi
scientific name	Leptostylis wisniewskiae
status	sp. nov.

Treatment

Leptostylis wisniewskiae View in CoL n. sp.

( Figs. 30–32 View FIGURE 30 View FIGURE 31 View FIGURE 32 )

Material examined. Holotype: subadult female, NIWA 0 93198, TAN0707/29, 38.6177°S, 168.9428°E – 38.6258°S, 168.9490°E, 480–482 m, 29 May 2007. Paratypes: ovigerous female (dissected), NIWA 0 93175, TAN0707/29, 38.6177°S, 168.9428°E – 38.6258°S, 168.9490°E, 480–482 m, 29 May 2007; adult male (dissected), NIWA 0 94178, TAN0707/29, 38.6177°S, 168.9428°E – 38.6258°S, 168.9490°E, 480–482 m, 29 May 2007. Nontype material: 4 specimens, NIWA 0 94980, TAN0707/29, 38.6177°S, 168.9428°E – 38.6258°S, 168.9490°E, 480– 482 m, 29 May 2007.

Diagnosis. Female and subadult male. Carapace globular, unornamented. Eyelobe without lenses. Pleonites long, especially pleonite 6 distinctly much longer than telson . Pereopod 1 propodus shorter than basis.

Adult male. Eyelobe very broad, with lenses. Antennule greatly expanded. Antenna extending just past posterior border of pleonite 1.

Etymology. The species is named for Dr. Helena Wisniewki, in honor of her commitment to funding scientific research at the University of Alaska, Anchorage.

Description. Subadult female holotype 3.2 mm, ovigerous female paratype 3.2 mm. Body ( Figs. 30 View FIGURE 30 A–B). Carapace with no ornamentation. Pleon unornamented, pleonites long, pleon at least twice length of carapace and pereonites together.

Antennule ( Fig. 30 View FIGURE 30 C) long, article 1 longest, with plumose seta and simple seta; article 2 shortest, with simple setae; article 3 with few small simple setae. Main flagellum of 3 articles, with 2 aesthetascs and few small simple setae terminally; accessory flagellum of 2 articles, not as long as first article of main flagellum, with few simple setae.

Antenna not examined.

Mandibles ( Fig. 30 View FIGURE 30 D) navicular, lacinia mobilis with 3 cusps, with row of 9–10 microserrate setae medially.

Maxillule ( Fig. 30 View FIGURE 30 E) with 2 endites, palp with 2 short microserrate setae.

Maxilla ( Fig. 30 View FIGURE 30 F) with 3 endites; broad endite medial row of setae pedunculate; narrow endites short, with microserrate setae.

Maxilliped 1 ( Fig. 30 View FIGURE 30 G) merus and carpus lateral margins serrate, carpus without beak setae, with pappose setae medially and short plumose setae laterally.

Maxilliped 2 ( Fig. 30 View FIGURE 30 H) basis short, serrate at distolateral corner; ischium visible.

Maxilliped 3 ( Fig. 30 View FIGURE 30 I) 100: 17:15:17:broken; basis expanded distolaterally, with 3 plumose setae, medial margin with plumose setae.

Pereopod 1 not examined, broken off.

Pereopod 2 ( Fig. 31 View FIGURE 31 A) 100:3:18:56:23:31; basis, merus, carpus with short simple setae; carpus with group of stout setae distally; propodus with group of stout setae distally; dactylus terminal seta broken off; exopod longer than basis.

Pereopod 3 ( Fig. 31 View FIGURE 31 B) 100:13:21:28: broken; basis to carpus with simple setae; rudimentary exopod 0.18 times basis length.

Pereopod 4 ( Fig. 31 View FIGURE 31 C) 100:12:21:29:15:8; basis, ischium and merus with simple setae; carpus and propodus with annulate setae; dactylus terminal seta simple; rudimentary exopod 0.17 times basis length.

Pereopod 5 ( Fig. 31 View FIGURE 31 D) 100:17:30:60:20:13; basis with few simple setae; carpus and propodus with simple and annulate setae; dactylus terminal seta simple.

Telson ( Fig. 31 View FIGURE 31 E) 0.6 times length of pleonite 6, with 1 seta with single setule laterally, terminal setae stout and simple.

Uropods ( Fig. 31 View FIGURE 31 E) peduncles with few setae with single setule medially; endopod triarticulate, with few setae with single setule medially, broken at article 3; exopod shorter than endopod, with few simple setae, terminal seta long, stout and simple.

Adult male paratype 3.6 mm.

Body ( Fig. 30 View FIGURE 30 J). Carapace more globular than in female. Pleon unornamented, long, 1.5 times length of carapace and pereonites together.

Antennule ( Fig. 32 View FIGURE 32 A) stout, all peduncle articles broad; article 1 longest, with plumose seta and simple seta; article 2 with few simple setae; article 3 short, with rows of many simple setae terminally. Main flagellum of 5 articles, article 1 expanded as broad as peduncle, with rows of many simple setae, with 2 aesthetascs and few simple setae terminally; accessory flagellum of 3 articles, extending nearly to distal margin of main flagellum article 3, with few simple setae terminally

Antenna ( Fig. 32 View FIGURE 32 B) peduncle articles 1–2 with plumose seta each, peduncle article 5 with few ranks of short setae distally; flagellum of 22 articles extending past posterior border of pleonite 1.

Mandibles –maxilliped 2 not examined.

Maxilliped 3 ( Fig. 32 View FIGURE 32 C) 100:7:13:15:15:13; basis expanded weakly distolaterally, with 3 plumose setae, with pappose setae medially.

Pereopod 1 ( Fig. 32 View FIGURE 32 D) 100:13:15:48:63:28; basis with many plumose setae; merus to dactylus with simple setae.

Pereopod 2 ( Fig. 32 View FIGURE 32 E) 100:8:22:65:22:41; with simple setae throughout; carpus with long simple setae distally; propodus with group of stout setae distally; dactylus with short simple setae, terminal seta short.

Pereopod 3 ( Fig. 32 View FIGURE 32 F) 100:10:20:15:10:8; basis expanded, with plumose and pappose setae; ischium with plumose seta; merus with simple setae; carpus and propodus with annulate setae; dactylus terminal seta simple.

Pereopod 4 ( Fig. 32 View FIGURE 32 G) 100:12:18:30:9:6; basis expanded, with plumose and pedunculate setae; ischium and merus with simple setae; carpus and propodus with annulate setae; dactylus terminal seta simple.

Pereopod 5 ( Fig. 32 View FIGURE 32 H) 100:17:28:56:11:11; basis narrow, with plumose eane simple setae; merus with simple setae; carpus and propodus with annulate setae; dactylus terminal seta simple.

Pleopod 1 ( Fig. 32 View FIGURE 32 I) basal article slender, basal article and rami with plumose setae.

Pleopod 2 ( Fig. 32 View FIGURE 32 J) shorter than pleopod 1, basal article slender, basal article without plumose setae, rami with plumose setae

Telson ( Fig. 32 View FIGURE 32 K) 0.7 times length of pleonite 6, dorsally produced; with 1 seta with single setule laterally, terminal setae stout and simple.

Uropods ( Fig. 32 View FIGURE 32 K) peduncles with setae with single setule medially; endopod triarticulate, with few setae with single setule medially, terminal seta simple; exopod shorter than endopod, with few setae with single setule, terminal seta long with single setule.

Distribution. Challenger Plateau, New Zealand, 480– 482 m.

Remarks. Females of Leptostylis wisniewskiae are easily differentiated from females of Austroleptostylis recalvastra by the smooth ventral margin of the carapace, the lack of an antennal notch and the lack of setae throughout the carapace, pereon and pleon, whereas in A. recalvastra the ventral margin of the carapace is serrate, the antennal notch is distinct, and there are setae throughout the carapace, pereon and pleon. Males are readily differentiated by A. recalvastra having one pair of pleopods while males of L. wisniewskiae have two pairs of pleopods.

Leptostylis wisniewskiae can be easily differentiated from L. zealandiensis by body size and pereopod 1 proportions. Leptostylis wisniewskiae is smaller than L. zealandiensis , with ovigerous females just over 3 mm and adult males about 3.5 mm, while in L. zealandiensis ovigerous females are 4.5–5 mm and adult males are 5.9–6.5 mm. In L. wisniewskiae the propodus of pereopod 1 is shorter than the basis, while in L. zealandiensis the propodus is much longer than the basis.