Leucon (Alytoleucon) dolichorhinos Gerken, 2016, n. sp.
Creators: name: Gerken, Sarah
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Curculionidae
Leucon
Leucon dolichorhinos

description: Leucon (Alytoleucon) dolichorhinos n. sp.
(Figs 14–18)
Material examined. Holotype— preparatory female, MV J68462, 42°02’12”S, 148°38’42”E, 800 m, 27 July 1986, M.F. Gomon. Paratypes— ovigerous female (dissected), MV J68463, 42°00’12”S, 148°37’42”E, 720 m, 27 July 1986, M.F. Gomon; ovigerous female (dissected), MV J68464, 42°02’12”S, 148°38’42”E, 800 m, 27 July 1986, M.F. Gomon; adult male (dissected), MV J68465, 42°00’12”S, 148°37’42”E, 720 m, 27 July 1986, M.F. Gomon; 1 ovigerous female, 1 subadult male, MV J68466, 42°02’12”S, 148°38’42”E, 800 m, 27 July 1986, M.F. Gomon. Non-type material— 6 ovigerous females, 12 subadult females, 7 subadult males, MV J62350, 42°02’12”S, 148°38’42”E, 800 m, 27 July 1986, M.F. Gomon; 4 ovigerous females, 12 subadult females, 8 subadult males, MV J62355, 42°00’12”S, 148°37’42”E, 720 m, 27 July 1986, M.F. Gomon.
Diagnosis. Female and subadult male. Carapace with strong serrations dorsally from posterior border to anterior border of frontal lobe, with strong teeth parallel to ventral margin on posterior half. Pseudorostrum extending 0.3 times carapace length anterior of frontal lobe, acute, weakly or moderately dorsally directed, without setae. Antennal notch deeply excavate, anteroventral corner acutely produced, with several teeth. Pereopod 1 basis more than half length of all other articles together. Adult male. Carapace similar to female, except dorsoventrally flattened, ventral teeth somewhat dorsal of ventral margin, pseudorostrum shorter. Antennal flagellum broken, expected to be long. Maxilliped 3 to pereopod 4 exopods with expanded bases.
Etymology. The species is named dolichorhinos from the Greek meaning long nose, in reference to the long pseudorostrum.
Description. Preparatory female holotype 5.4 mm, ovigerous female paratype 5.5 mm. Body (Figs 14 A–B). Carapace 1.7 times pereon length, with strong serrations dorsally from apex of frontal lobe to posterior margin, row of strong teeth ventrally on posterior half of ventral surface of carapace, antennal notch strongly excavate, anteroventral acutely produced, with several teeth; eyelobe absent; pseudorostrum acute, 0.3 times length of entire carapace. Pleon 0.5 times total body length.
Antennule (Fig. 14 D) article 1 1.2 times length of article 2, with 2 simple and 3 complex pedunculate setae; article 2 equal to article 3 length, with few simple setae; article 3 with simple seta. Main flagellum of 3 articles, with 1 simple seta and 2 aesthetascs; accessory flagellum of 1 article, much less than half length of article 1 of main flagellum.
Antenna (Fig. 14 E) of 4 articles, articles 1–2 broad; article 2 with pappose setae; article 3 narrower and shorter than article 2; article 4 slender and long, with tiny simple setae terminally.
Mandibles (Fig. 14 F) truncate, lacinia mobilis with 4 cusps, with 2 simple setae medially.
Maxillule (Fig. 15 A) with 2 endites; palp with one microserrate seta.
Maxilla (Fig. 15 B) with 3 endites; broad endite medial row of fine hair-like setae, with simple and pappose setae distally; narrow endites with long simple setae.
Maxilliped 1 (Fig. 15 C) basis with long plumose seta, lobe with few simple and hook setae; carpus with pappose setae medially, without beak like setae.
Maxilliped 2 (Fig. 15 D) basis with plumose seta; brood plate with annulate setae.
Maxilliped 3 (Fig. 15 E) 100:11:15:22:16:13; basis with pappose and plumose setae, distolateral corner with 3 plumose setae; ischium unarmed; exopod fully developed.
Pereopod 1 (Fig. 15 F) 100:12:37:72:66:?; basis with plumose setae; ischium unarmed; merus, carpus with simple setae; propodus unarmed; dactylus broken off.
Pereopod 2 (Fig. 15 G) 100:4:24:33:15:30; basis with simple and plumose setae; ischium with plumose seta; merus with plumose setae; carpus with simple setae; propodus unarmed; dactylus with simple setae.
Pereopod 3 (Fig. 16 A) 100:8:13:17:15:4; basis with simple and plumose setae; ischium with plumose seta; merus with simple setae; carpus with simple and annulate setae; propodus with annulate seta; dactylus small, with 2 simple setae.
Pereopod 4 (Fig. 16 B) 100:9:18:20:13:4; basis with plumose setae; ischium, merus with simple seta; carpus, propodus with simple and annulate setae; dactylus short, with simple seta.
Pereopod 5 (Fig. 16 C) 100:15:24:24:18:6; basis with simple and plumose setae; ischium, merus with simple setae; carpus with simple and annulate setae; propodus with annulate seta; dactylus small, with simple seta.
Uropods (Fig. 16 D) peduncles subequal to pleonite 6 length, with 7 microserrate setae with single setule; endopod biarticulate, article 1 1.8 times length of article 2, with 8 microserrate setae with single setule medially, article 2 with 3 microserrate setae with setule medially, long annulate seta laterally, terminal simple seta fused to article 2; exopod 0.8 times length of endopod, with 10 microserrate setae and 2 long annulate setae terminally.
Adult male paratype 4.6 mm. Body (Fig. 14 C). Carapace 1.3 times pereon length, with strong serrations dorsally from apex of frontal lobe midway to posterior border, row of strong teeth ventrally on posterior half of ventral surface of carapace, antennal notch strongly excavate, anteroventral corner acutely produced, without teeth; eyelobe absent; pseudorostrum extending 0.2 times total carapace length anterior of frontal lobe. Pereon pereonites 1–5 with flattened ventral expansion. Pleon 0.5 times total body length.
Antennule (Fig. 17 A) article 1 longer than articles 2 and 3 together, with pappose setae; article 2 longer than article 3, with simple and pedunculate setae; article 3 shortest, with simple seta. Main flagellum of 4 articles, with simple setae and 2 aesthetascs; accessory flagellum of one articles, more than half length of main flagellum article 1, with simple setae.
Antenna (Fig. 17 B) peduncle articles 2–3 with pappose seta; articles 4–5 with rows of moderate length setae on anterior surface; flagellum expected to be long, broken in observed specimen.
Maxilliped 2 (Fig. 17 C) basis with 1 simple and 1 plumose setae; carpus, propodus with many plumose setae medially.
Maxilliped 3 (Fig. 17 D) 100:6:12:13:11:7; basis with plumose setae, distolateral corner with 3 plumose setae; ischium unarmed; exopod basal article 6.0 times width of flagellum.
Pereopod 1 (Fig. 17 E) basis and exopod only, appendage broken off at distal border of basis; basis with plumose setae; exopod basal article 6.5 times width of flagellum.
Pereopod 2 (Fig. 17 F) 100:5:14:21:9:20; basis with simple and plumose seta; ischium with plumose seta; merus with plumose setae; carpus with simple and microserrate setae; propodus unarmed; dactylus with simple setae; exopod basal article 4.0 time width of flagellum.
Pereopod 3 (Fig. 18 A) 100:5:8:14:8:1; basis with simple and plumose setae; ischium with plumose setae; merus with simple seta; carpus and propodus with annulate setae; dactylus minute, with simple seta; exopod basal article 5.0 times width of flagellum.
Pereopod 4 (Fig. 18 B) 100:5:16:18:9:2; basis with plumose and pappose setae; ischium with plumose setae; merus unarmed; carpus with simple and annulate setae; propodus with annulate seta; dactylus minute, with simple seta; exopod basal article 4.0 times width of flagellum.
Pereopod 5 (Fig. 18 C) 100:20:20:23:17:3; basis, ischium, merus with plumose setae; carpus with plumose and annulate setae; propodus with annulate seta; dactylus minute, with simple seta.
Pleopod 1 (Fig. 18 D) basal article moderate, unarmed; rami with plumo-annulate setae.
Pleopod 2 (Fig. 18 E) basal article moderate, unarmed; rami with plumo-annulate setae.
Uropods (Fig. 18 F) peduncles 1.2 times length of pleonite 6, with 13–14 microserrate setae of variable lengths; endopod biarticulate, article 1 2.0 times length of article 2, with 12–14 microserrate setae, article 2 with 3 microserrate setae medially and 1 microserrate seta laterally, terminal stout simple seta fused to article; exopod 0.9 times length of endopod, with 3–4 plumose and 3 simple setae on margins, with 2 microserrate and 3 simple setae terminally.
Distribution. Continental slope off Tasmania, 720– 800 m.
Remarks. The species most similar to Leucon dolichorhinos is Kontiloleucon australiensis. In L. dolichorhinos the terminal seta is fused to the uropod endopod, while in K. australiensis the terminal seta is clearly articulated. In addition, the males can be easily differentiated by the presence of penial lobes in K. australiensis and the lack of penial lobes in L. dolichorhinos. The females can be differentiated by the pattern of serrations in the dorsal crest, the ventral teeth on the carapace, and the proportions of pereopod 1. In L. dolichorhinos females the entire dorsal crest is serrated, there is a distinct row of teeth parallel to the posterior ventral margin of the carapace, and in pereopod 1 the carpus and propodus are each at least 2/3 the length of the basis, while in K. australiensis females only the anterior ½ of the dorsal crest is serrated, there are no teeth near the ventral margin of the carapace, and in pereopod 1 the carpus and propodus are each less than ½ the length of the basis.
description: Published as part of Gerken, Sarah, 2016, Leuconidae (Crustacea: Cumacea) from the collections of the Museum Victoria, Australia, pp. 251-292 in Zootaxa 4067 (3) on pages 273-279, DOI: 10.11646/zootaxa.4067.3.1, http://zenodo.org/record/263497