Michelea kalbarri, Poore And D, 2015

Poore And D, Gary C. B., 2015, Micheleidae (Crustacea: Decapoda: Axiidea): new family, generic and species synonymies, three new Australian species, and new records, Memoirs of Museum Victoria 73, pp. 95-105 : 98-101

Michelea kalbarri sp. nov.

Figure 2

Michelea sp. MoV4969.— Poore et al., 2008: 95.

Material examined. Holotype. Western Australia, off Kalbarri (27°48.29'S – 28°29.22'S, 113°17.49'E – 113°25.08'E), 123– 112 m, 04 Dec 2005 (stn SS10/2005/096), NMV J53462 (female, cl 3.4 mm).

Diagnosis. Gills fully developed. Pleopods 2–5 without marginal lamellae. Telson tapering to rounded apex, length 1.2 width. Maxilliped 3 ischium with obsolete crista dentata; merus with mesial tooth.

Description. Cephalothorax 0.37 total length, about 1.7 times as long as greatest depth; rostrum acute, sharply narrowing from broad base, slightly depressed distally, about 0.7 as long as eyestalks; cervical groove weakly defined, reaching 0.7 length of cephalothorax; longitudinal setal-row level with lateral margin of eyestalk, of 5 setae; marginal setal-row of 5 setae at base of eyestalk.

Pleomere 1 without dorsolateral longitudinal setal-row. Pleomeres 3–5 with transverse setal-rows of 6–7 setae near midpoint; all somites also with groups of long simple setae, none with marginal setal-rows. Pleomere 6 with transverse setal-row of 4 setae.

Antennule with elongate waisted article 1, 0.4 length of cephalothorax; articles 2 and 3 subequal, each about 0.25 length of article 1; flagella each of 14 articles, longer than peduncle. Antenna with distinct articulating scaphocerite, about half length of article 2; article 4 reaching to middle of article 3 of antennule; article 5 short; flagellum of 17 articles, more than twice as long as peduncle.

Mandible, maxillules, maxillae, maxillipeds 1 and 2 typical of genus. Maxilliped 3 ischium with obsolete crista dentata; merus with strong mesial tooth; exopod 1.7 times ischium length.

Chelipeds equal; ischium with weak lower tooth; merus twice as long as deep, upper margin convex, with weak tooth on slightly convex lower margin; carpus unarmed; propodus almost cylindrical, 3.5 times as long as deep; fixed finger 0.37 total length of propodus, its cutting edge with 1 obsolete tooth at midpoint; dactylus cutting edge straight, curved distally, equal to fixed finger.

Pereopod 2 merus–propodus with lower marginal rows of long setae; carpus 0.5 length of merus; propodus 1.3 times as long as carpus, with setal-row of 5 short setae; fixed finger cutting edge with 5 short spiniform setae; dactylus longer than fixed finger, with 4 short spiniform setae on distal half of cutting edge; each finger with corneous tip. Pereopod 3 propodus 2.5 times as long as wide, with 2 spiniform setae on distal-upper mesial face, 7 on distal-lower face; and 2 transverse setal-rows of 3 and 4 setae; dactylus with 3 spiniform setae on upper margin. Pereopod 4 propodus 3.5 times as long as wide, with 3 spiniform setae on lower margin, 3 spiniform setae and numerous pectinate distally; with transverse setal-row of 3 setae; dactylus with 4 spiniform setae on upper-mesial margin. Pereopod 5 semichelate; propodus with setae on lower margin transforming to strongly pectinate distally; fixed finger with 4 distal spiniform setae; dactylus without spiniform setae.

Pleopods 2–5 without marginal lamellae; appendix interna sac-like, 3 times as long as wide.

Uropodal endopod ovate, 1.65 times as long as wide, with a minute distal tooth; exopod ovate, almost twice as long as wide, lateral margin with about 20 short spiniform setae. Telson tapering to rounded apex from one-third length; 1.2 times as long as wide.

Branchial formula (f = filamentous; r = rudimentary): Thoracomere 1 2 3 4 5 6 7 Arthrobranch – r 1 2 2 2 2 Epipod 1 1 1 1 1 1 1 Podobranch – – f f f f –

Distribution. Western Australia, 27°S, 113°E, 112– 123 m. 8 – – –

Etymology. The specific name is that of a town near the type locality; noun in apposition.

Remarks. Michelea kalbarri is notable for the absence of pleopodal lamellae on both rami, present on at least one ramus in all other species. While this feature has been treated as a key generic character the numbers of lamellae are highly variable, being absent on exopods of three species ( Sakai, 2011) while the maximum is almost 100 on both rami in M. lamellosa Kensley and Heard, 1991 . In all other respects, general habitus and pereopods, the species is a typical member of Michelea .