Ensayara evax, Lowry, James K. & Hughes, Lauren E., 2015

Lowry, James K. & Hughes, Lauren E., 2015, Endevouridae, a review with description of four new species (Crustacea, Amphipoda, Lysianassoidea), Zootaxa 4018 (1), pp. 1-34 : 18-22

Ensayara evax sp. nov.

( Figs 14–16 )

Type material. Holotype ovigerous female (1 egg, no oostegites), 3.0 mm, dissected, 4 slides, AM P.69264, Vancouver Peninsular, near Mistaken Island, King George Sound, Western Australia (35°04'S, 117°56'E), 2 m, sponges, 13 December 1983, coll. J.K. Lowry (WA101). Paratypes, 2 specimens, AM P.69268, Vancouver Peninsular, near Mistaken Island, King George Sound, Western Australia (35°04'S, 117°56'E), 3 m, sea grass bases with detritus, 13 December 1983,coll. J.K. Lowry (WA-112).

Additional material examined. Western Australia. 2 specimens, AM P.69265, near Mistaken Island, Vancouver Peninsula, King George Sound (35°04'S, 117°56'E), 2 m, sponges, 13 December 1983, hand collected on SCUBA, coll. J.K. Lowry (WA 101).

South Australia: 2 specimens, AM P.69266, Muston Point, American River, Kangaroo Island, South Australia (35°48'S, 137°44'E), 4–5 m, clumps of sponge in channel below wharf, 2 February 1979, coll. P. Hutchings ( SA- 56).

Arafura Sea: 1 specimen, AM P.69269, west end of East Point, north end of Fannie Bay, Darwin, Northern Territory (11°24'30"S, 130°48'30"E), 8–10 m, on ascidian Didemnum psammatodes , 26 October 1982, hand collected on SCUBA, coll. J.K. Lowry (NT-97); 2 specimens, AM P.69267, reef, west end of Oxley Island, Northern Territory (11°00'S 132°49'E), 5 m, yellow sponge, 20 October 1982, coll. J.K. Lowry (NT-77).

Etymology. ‘ Evax’, Latin interjection for joy be!

Type locality. Vancouver Peninsular, near Mistaken Island, King George Sound, Western Australia (35°04'S, 117°56'E).

Diagnosis. Head lateral cephalic lobe subacute. Maxilla 1 palp article 2 with 5 nodular and 1 slender seta. Maxilliped inner plate with 5 robust setae. Coxae 1 to 3 ventral margin without fringe of fine setae. Gnathopod 1 basis anterior margin smooth, not cuspidate. Pereopod 3 carpus posterior margin as long as free proximal margin of propodus, posteroproximal margin slightly produced; propodus palm slightly obtuse, margin straight. Epimeron 3 posteroventral corner subquadrate. Uropod 3 outer ramus article 2 length 1.5 × width; inner ramus subequal to article 1 of outer ramus. Telson slightly longer than broad, length 1.3 × breadth.

Description of holotype female. Head lateral cephalic lobe subacute, ventral margin straight. Antenna 1 peduncular article 3 hidden in medial view; accessory flagellum 4-articluate; primary flagellum 7-articulate. Mandible incisor convex, margin broadly serrate; palp attached about midway, just proximal to molar; palp article 2 length 1.4 × article 3. Maxilla 1 inner plate with 1 apical seta; outer plate with 10 setal teeth; palp with 5 nodular robust setae and 1 slender setae across distal margin with one subapical seta on medial margin. Maxilla 2 inner plate subtriangular, much shorter than outer plate; outer plate subrectangular. Maxilliped inner plate with 3 nodular robust setae; outer plate with 9 embedded nodular robust setae; palp article 4 slender, claw-like, unguis present.

Coxae 1–3 ventral margin with dense fringe of fine setae. Gnathopod 1 simple; carpus length subequal to width; dactylus posterior margin smooth. Gnathopod 2 minutely chelate. Pereopod 3 chelate; merus length 2.2 × width, subequal to carpus length; carpus subtriangular, posterior margin as long as free proximal margin of propodus, posteroproximal margin slightly produced; propodus length 1.3 × width, posteroproximal margin not produced, palm slightly obtuse, margin straight. Pereopod 5 basis expanded, posterior margin crenulate. Pereopods 6-7 basis posterior margin expanded, cuspidate.

Epimeron 1 posteroventral corner rounded. Epimera 2–3 posteroventral corner subquadrate. Uropod 1 peduncle with 3 lateral and 2 apical robust setae; outer ramus with 1 robust setae; inner ramus without robust setae. Uropod 2 peduncle with 1 lateral and 2 apical robust setae; outer ramus with 1 robust setae; inner ramus without robust setae. Uropod 3 peduncle with 1 apical robust seta; inner ramus subequal to article 1 of outer ramus; outer ramus 2-articulate, article 2 length 2.1 × width. Telson as long as broad, length 1 × width.

Remarks. Ensayara evax sp. nov. differs from other Ensayara by the 7-articulate flagellum of antenna 1 and the crenulate basis posterior margin along pereopods 5 to 7. Ensayara evax can be separated from Ens. laetum sp. nov. by the more obtuse, chelate propodus palm of gnathopod 1, and the gnathopod 2 propodus palm being less obtuse, comparative to the near transverse palm and well-developed obtuse palm in Ens. laetum .

Ensayara evax sp. nov. is similar to the three New Zealand species Ens. iara Lowry & Stoddart, 1983; Ens. kermadecensis Kilgallen, 2009 and Ens. ursus Kilgallen, 2009 in the form of the pereopod 3 propodus palm angle, however can be distinguished by the pereopod 7 which has a stronger crenate margin and is less posteriorly expanded.

Distribution. Western Australia: Kings George Sound. Nrthern Territory: Oxley Island. South Australia: Kangaroo Island.

Figures

FIGURE 14. Ensayara evax sp. nov., holotype female, 3.0 mm, AM P. 69264, Vancouver Peninsular, near Mistaken Island, King George Sound, Western Australia. Scale 0.1 mm.

FIGURE 15. Ensayara evax sp. nov., holotype female, 3.0 mm, AM P. 69264, Vancouver Peninsular, near Mistaken Island, King George Sound, Western Australia. Scale 0.1 mm.

FIGURE 16. Ensayara evax sp. nov., holotype female, 3.0 mm, AM P. 69264, Vancouver Peninsular, near Mistaken Island, King George Sound, Western Australia. Scale 0.1 mm.