Mallacoota penelope, Hughes, 2011

HUGHES, L. E., 2011, New species of Hoho, Mallacoota and Parelasmopus (Maeridae: Amphipoda) from Australian waters, Zootaxa 2955 (1), pp. 1-79 : 59

Mallacoota penelope sp. nov.

(Figs 37–39)

Type material. Holotype: male, 8.2 mm, dissected, 4 slides, AM P.85224 . Paratypes: 1 female (masculine phenotype), 6.1 mm, dissected, 1 slide, AM P.85225; 1 male, 10.0 mm, dissected, 1 slide AM P.85226; 1 female (masculine phenotype), 8.6 mm, AM P.85227; 3 hyperadults, AM P.85228; 30+ specimens, AM P.60447, east of Seal Islands , Victoria (38°56'30"S 148°19'18"E), 85 m, 27 August 1994, coll. P. Berents (SS05/94/59) ; 1 female (diminutive phenotype), 8.0 mm, dissected, 4 slides, AM P.85229; 8 males and 4 females (masculine phenotype), AM P.60441, east of Seal Islands (38°59'6"S 148°31'36"E), 125 m, benthic sled, 27 August 1994, coll. P.B. Berents (SS05/94/60) .

Type locality. East of Seal Islands , Victoria (38°56'30"S 148°19'18"E) .

Etymology. Named for the collector Dr Penelope Berents, used as a noun in apposition.

Description. Based on holotype, male, 8.2 mm, AM P.85224.

Head. Eyes ovate; lateral cephalic lobe broad, truncated, anteroventral margin with notch/slit. Antenna 1 longer than antenna 2; peduncular article 1 shorter than article 2, with 3 robust setae along posterior margin; article 2 longer than article 3; flagellum articles longer than broad proximally, broader than long distally, with 20+ articles; accessory flagellum minute, with 3 articles. Antenna 2 peduncular article 2 cone gland not reaching to end of peduncular article 3; article 4 subequal in length to article 5; flagellum with 11 articles. Maxilla 1 inner plate subtriangular, with 2 apical plumose setae. Lower lip outer lobes with two pair of ducts, mandibular lobes apically rounded. Mandible accessory setal row well developed with 3 setae; molar well developed, triturative; mandibular palp well developed, 3-articulate; article 1 twice as long as broad, shorter than article 2; article 2 subequal to article 3, with 1 slender setae; article 3 rectolinear, long (5 times as long as broad), longer than article 1, with 2 medial and 2 apical setae.

Pereon. Gnathopod 1 coxa anterior margin straight, anteroventral corner produced, rounded; carpus about twice as long as broad, subequal in length to propodus; propodus medial surface with comb, palm acute, convex, entire, defined by posterodistal corner, with 2 posterodistal robust setae. Gnathopod 2 subchelate; basis slender, anterodistal corner subquadrate; merus without distoventral corner; carpus compressed, lobate, projecting between merus and propodus; propodus massive, with slender medial setal bunch, palm convex, smooth, about half length of propodus, subrectangular distomedial shelf, with 9 robust setae on shelf, palmar margin with 2 subacute teeth, defined by posteroventral tooth, without posterodistal robust setae, subpalmar surface smooth; dactylus with posteroproximal shelf, apically falcate, closing along palm. Pereopod 4 coxa posteroventral lobe well developed, with rounded posteromedial corner. Pereopods 5–7 slender distally; basis linear, posterior margin straight, weakly serrate, posteroventral corner subquadrate; merus and carpus not broadened; carpus and propodus with long, slender setae along posterior margin; propodus not expanded posterodistally; dactylar ungues simple. Pereonite 7 without carina.

Pleon. Pleonites 1–3 without carina. Epimera 1–2 posteroventral corner with small acute tooth. Epimeron 3 ventral margin smooth, posteroventral margin smooth, posteroventral corner produced acute. Urosomite 1 bicarinate, subtriangular. Urosomites 2–3 without carina. Uropod 1 peduncle with 1 basofacial seta; outer ramus slightly shorter than inner ramus. Uropod 2 outer ramus slightly shorter than inner ramus. Uropod 3 rami distally truncated, apical robust setae long; inner ramus long (length 2.2 times breadth), subequal in length to outer ramus; outer ramus longer than peduncle. Telson deeply cleft, longer than broad, tapering distally, lobes apically truncated, with 4 long apical robust setae.

Female masculine phenotype. (sexually dimorphic characters), based on AM P.85225. Gnathopod 2 propodus palm sculptured, subrectangular distomedial shelf with 11 robust setae, palm margin with 3 subacute teeth, defined by corner with 1 posterodistal robust setae.

Female diminutive phenotype. (sexually dimorphic characters), based on AM P.85229. Gnathopod 2 carpus short, not lobate, enclosed by merus and propodus; propodus linear, palm acute, smooth, without distomedial shelf, without teeth, defined by posteroventral corner with 2 robust setae; dactylus apically subacute.

Remarks. See remarks for M. bulowara sp. nov.

Distribution. Australia. Victoria: Seal Islands (current study)