Eudorellopsis mykteros, Gerken, Sarah, 2016

Gerken, Sarah, 2016, Leuconidae (Crustacea: Cumacea) from the collections of the Museum Victoria, Australia, Zootaxa 4067 (3), pp. 251-292 : 263

Eudorellopsis mykteros n. sp.

( Figs 7–8 )

Material examined. Holotype— subadult female (dissected), MV J62356 , 42°00’15”– 41°57’46”S, 148°43’33”– 148°42’05”E, 1130–1264 m, 30 Oct 1988, G.C.B. Poore.

Diagnosis. Female and subadult male. Carapace with 2 strong teeth dorsally, 1 dorsal of the frontal lobe/ pseudorostral lobe suture corner, the other at the anterior end of the frontal lobe. Pseudorostrum directed dorsally, anterior margin with strong teeth. Antennal notch present, carapace anterior margin with several strong teeth ventral to antennal notch. Uropod endopod article 2 0.7 times length of article 1.

Adult male. Unknown.

Etymology. The species is named from the Greek mykteros meaning upturned nose, in reference to the upturned pseudorostrum.

Description. Subadult female holotype 4.1 mm. Body ( Fig 7 A) robust. Carapace 1.3 times length of pereon, with 2 strong teeth dorsally, antennal notch present; eyelobe absent; pseudorostrum blunt, with strong teeth on anterior margin. Pleon 0.6 times total body length.

Antennule ( Fig. 7 B) article 1 longer than articles 2–3 together, with pappose and simple setae; article 2 subequal to article 3, with pappose and simple setae; article 3 with simple setae. Main flagellum of 3 articles, with simple setae and 2 aesthetascs; accessory flagellum of 1 articles, with simple setae, attached to main flagellum article 1 distally.

Antenna -maxilliped 2 not examined.

Maxilliped 3 ( Fig. 7 C) 100:13:23:25:21:17; basis with pappose setae medially, distolateral corner with 1 very stout and 2 slender plumose setae; ischium unarmed.

Pereopod 1 ( Fig. 7 D) basis and exopod only, appendage broken off at distal border of basis.

Pereopod 2 ( Fig. 7 E) 100:8:24:32:16:46; basis with pappose and plumose setae; ischium present, unarmed; merus and carpus with simple and plumose setae; dactylus with simple setae.

Pereopod 3 ( Fig. 7 F) 100:8:20:30:13:3; basis with plumose setae; ischium with plumose and annulate setae; merus and carpus with plumose and annulate setae; propodus with annulate seta; dactylus with tiny simple setae.

Pereopod 4 ( Fig. 7 G) 100:19:26:35:19:3; basis with plumose setae; ischium with annulate and simple setae; merus and carpus with plumose and annulate setae; propodus with annulate seta; dactylus with tiny simple setae and terminal annulate seta.

Pereopod 5 ( Fig. 8 A) 100:14:23:45:27:5; basis with plumose setae; ischium with plumose and annulate setae; merus with plumose seta; carpus with plumose and annulate setae; propodus with annulate seta; dactylus with tiny simple seta and terminal annulate seta.

Uropods ( Fig. 8 B) peduncles 1.2 times length of pleonite 6, with 5 setae with subterminal setule medially; endopod biarticulate, article 1 1.5 times length of article 2, with 6 microserrate setae with subterminal setule medially, article 2 with 5 microserrate setae with subterminal setae medially, pedunculate seta laterally, with stout seta with subterminal setule terminally; exopod broken.

Distribution. Continental slope off Tasmania, 1130–1264 m.

Remarks. This is the only species in the genus known from Australian waters, and can readily be distinguished from the only similar species in the Australian fauna, Eudorella rochfordi , by the pseudorostrum extending dorsally above the dorsal margin of the carapace, whereas in E. rochfordi the pseudorostrum does not extend dorsally above the carapace.

Figures

FIGURE 7. Eudorellopsis mykteros n. sp., paratype subadult male (MV J 62356): A, side view; B, antennule; C, maxilliped 3; D, pereopod 1 basis; E, pereopod 2; F, pereopod 3; G, pereopod 4.

FIGURE 8. Eudorellopsis mykteros n. sp., holotype subadult male (MV J 62356): A, pereopod 5; B, pleonite 6 and uropods.