Colurostylis whitireia, Gerken, Sarah, 2015

Gerken, Sarah, 2015, New Zealand Diastylidae and Gynodiastylidae (Crustacea: Cumacea), Zootaxa 4031 (1), pp. 1-77 : 8-14

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.6122495
persistent identifier	https://treatment.plazi.org/id/105D73BC-2520-431B-8F6C-2BC72F3CCB51
taxon LSID	lsid:zoobank.org:act:105D73BC-2520-431B-8F6C-2BC72F3CCB51
treatment provided by	Plazi
scientific name	Colurostylis whitireia
status	sp. nov.

Treatment

Colurostylis whitireia View in CoL n. sp.

( Figs. 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 )

Material examined. Holotype: ovigerous female, NIWA 0 94659, Te Onepoto Bay, Whitireia Park, Porirua, 41.1088°S, 178.8558°E, 0–1 m, 19 February 2011. Paratypes: preparatory female (dissected), NIWA 094661; adult male (dissected), NIWA 094663; two subadult males, NIWA 094660; Te Onepoto Bay, Whitireia Park, Porirua, 41.1088°S, 178.8558°E, 0–1 m, 19 February 2011.

Diagnosis. Female and subadult male. Carapace with 2 oblique ridges, anterolateral corner not serrate. Pseudorostrum acute. Eyelobe without lenses. Antennule peduncle of 2 articles. Uropod peduncles shorter than pleonites 5–6 together, exopod longer than endopod.

Adult male. Carapace with single oblique ridge. Pseudorostrum blunt. Eyelobe with lenses. Antennule peduncle of 2 articles, with small brush of setae. Antenna extending past posterior border of telson . Telson with pair of slender plumose subterminal setae.

Etymology. The species is named whitireia for the locality of collection, Te Onepoto Bay within Whitireia Park, Porirua, New Zealand; used as a noun in apposition.

Description. Ovigerous female holotype 3.2 mm, preparatory female paratype 2.1 mm. Body ( Figs. 1 View FIGURE 1 A–B). Carapace with 2 strong oblique ridges, antennal notch oblique; eyelobe broad, without lenses; pseudorostrum acute. Pleon unornamented.

Antennule ( Fig. 2 View FIGURE 2 A) with 2 peduncle articles; article 1 unarmed, longer than article 2; article 2 with few simple setae. Main flagellum of 3 articles, longer than peduncle article 2, with 2 aesthetascs and few simple setae distally; accessory flagellum of 2 articles, shorter than article 1 of main flagellum, with few simple setae.

Antenna ( Fig. 2 View FIGURE 2 B) of 3 articles, with plumose setae terminally.

Mandibles ( Fig. 2 View FIGURE 2 C) navicular, lacinia mobilis with 3 cusps, with row of 9 microserrate setae medially.

Maxillule ( Fig. 2 View FIGURE 2 D) with 2 endites; palp with 2 microserrate setae.

Maxilla ( Fig. 2 View FIGURE 2 E) with 3 endites; broad endite medial row of setae simple; narrow endites with short simple setae.

Maxilliped 1 ( Fig. 2 View FIGURE 2 F) carpus without beak setae, with simple setae medially; without long plumose setae.

Maxilliped 2 ( Fig. 2 View FIGURE 2 G) ischium visible.

Maxilliped 3 ( Fig. 2 View FIGURE 2 H) 100:9:16:13:17:13; basis produced distolaterally with 3 plumose setae; ischium unarmed; exopod fully developed.

Pereopod 1 ( Fig. 2 View FIGURE 2 I) 100:15:19:37:43:35; dactylus with long, simple setae terminally.

Pereopod 2 ( Fig. 2 View FIGURE 2 J) 100:4:29:31:24:45; exopod longer than basis.

Pereopod 3 ( Fig. 3 View FIGURE 3 A) 100:14:25:20:17:12; ischium, merus, carpus and propodus with annulate setae; dactylus terminal seta microserrate; rudimentary exopod 0.34 times basis length.

Pereopod 4 ( Fig. 3 View FIGURE 3 B) 100:18:40:33:25:18; ischium, merus, carpus and propodus with annulate setae; dactylus terminal seta microserrate; rudimentary exopod 0.48 times basis length.

Pereopod 5 ( Fig. 3 View FIGURE 3 C) 100:16:39:58:23:23; basis, ischium and merus with plumose setae; carpus and propodus with annulate setae; dactylus terminal seta microserrate.

Telson ( Fig. 3 View FIGURE 3 D) unarmed, half as long as pleonite 6.

Uropods ( Fig. 3 View FIGURE 3 D) peduncles with simple setae with a single setule medially; endopod biarticulate, with few simple setae with single setule medially, stout simple seta with single

setule terminally; exopod longer than endopod, with long simple setae.

Adult male paratype 2.3 mm. Body ( Figs. 1 View FIGURE 1 C–D). Carapace with single oblique ridge, antennal notch oblique; eyelobe broad, with 3 lenses; pseudorostrum blunt. Pleon unornamented.

Antennule ( Figs. 4 View FIGURE 4 A–B) with 2 peduncle articles; article 1 with plumose seta, more than twice as long as article 2; article 2 with few simple setae. Main flagellum of 6 articles, basal article expanded with many simple setae, with 2 aesthetascs terminally; accessory flagellum of 3 articles, as long as first two articles of main flagellum, with simple setae terminally.

Antenna ( Figs. 4 View FIGURE 4 C–D) peduncle with brush of setae on article 5; flagellum extending past telson , of 21 articles.

Mandibles – maxilliped 2 not examined.

Maxilliped 3 ( Fig. 4 View FIGURE 4 E) 100:6:12:12:15:11; basis medial margin toothed distally, produced at distolateral corner with 3 plumose setae; exopod basal article twice as wide as flagellum.

Pereopod 1 ( Fig. 4 View FIGURE 4 F) 100:7:18:23:32:23; dactylus with simple setae terminally; exopod basal article three times as wide as the flagellum.

Pereopod 2 ( Fig. 5 View FIGURE 5 A)100:3:17:32:13:25; exopod basal article at least three times as wide as flagellum.

Pereopod 3 ( Fig. 5 View FIGURE 5 B)100:8:21:15:11:11; basis with plumose, pappose and pedunculate setae; ischium, merus, carpus and propodus with annulate setae; dactylus terminal seta simple; exopod basal article at least three times as wide as flagellum.

Pereopod 4 ( Fig. 5 View FIGURE 5 C)100:7:23:23:12:12; basis with plumose, simple and annulate setae; merus, carpus and propodus with annulate setae; dactylus terminal seta simple; exopod basal article at least three times as wide as flagellum.

Pereopod 5 ( Fig. 5 View FIGURE 5 D)100:9:33:30:12:15; basis with plumose setae; ischium, merus, carpus and propodus with annulate setae; dactylus terminal seta simple.

Pleopod 1 ( Fig. 5 View FIGURE 5 E) biramous, with plumo–annulate setae.

Pleopod 2 ( Fig. 5 View FIGURE 5 F) biramous, with plumo–annulate setae, shorter than pleopod 1.

Telson ( Fig. 5 View FIGURE 5 G) with 2 small plumose setae inserted subterminally, shorter than pleonite 6.

Uropods ( Fig. 5 View FIGURE 5 G) peduncles with microserrate setae with long setule medially; endopod biarticulate, article 2 much longer than article 2, with many microserrate setae with long setule medially, terminal seta stout with single setule; exopod longer than endopod, with simple setae.

Distribution. Te Onepoto Bay, Whitireia Park, Porirua, New Zealand, 0– 1 m.

Remarks. This species is unique within the Cumacea in having a 2 article peduncle on the antennule. This character is identical in the male and female specimens examined, and is clearly not an aberration. This state represents either a fusion of two articles or a loss of an article on the peduncle. There is a geniculation about midway in the first article which may represent a site of fusion between two articles.

The most similar species of Colurostylis is C. lemurum , which also has oblique ridges on the carapace. However, C. lemurum has 3 articles in the antennule peduncle, and the uropod endopod is longer than the exopod, unlike C. whitireia with 2 articles in the antennule peduncle and the uropod exopod longer than the endopod.