Pachynus pugilator Lowry, 1984

Lowry, J. K. & Stoddart, H. E., 2012, The Pachynidae fam. nov. (Crustacea: Amphipoda: Lysianassoidea) 3246, Zootaxa 3246 (1), pp. 1-69 : 43-45

Pachynus pugilator Lowry, 1984

( Fig. 28c )

Pachynus pugilator Lowry, 1984: 78 , figs 18–20. ― Barnard & Karaman, 1991: 510. ― Springthorpe & Lowry, 1994: 14. ― Lowry & Stoddart, 2003: 169.

Material examined. 1 female, non-ovigerous with setose oostegites, 3.6 mm, MV J62416 , Crib Point , Western Port, Victoria, Australia, 38°20.94'S 145°13.62’E, 15 m, fine sand and mud, Smith-McIntyre grab, 29 March 1965, stn CPBS 31N. – 1 specimen, MV J13749 , Crib Point , Western Port , Victoria, Australia, 38°21.15’S 145°13.51’E, 15 m, fine sand and mud, Smith-McIntyre grab, Marine Studies Group , Fisheries and Wildlife Department , Ministry for Conservation, Victoria, 8 April 1965, CPBS stn 300 .

Diagnostic description. Head lateral cephalic lobe small, subacute; ventral margin curved. Antenna 1 peduncular article 1 without posterodistal spine; accessory flagellum present, 2-articulate, article 1 short; flagellum with strong 1-field callynophore in female, [male not known]. Mandible lacinia mobilis a simple robust seta; lamina dentata absent; accessory setal row present, not on raised setose ridge; molar absent; palp article 2 slender, as long as article 3; article 3 with subparallel margins. Maxilla 1 outer plate with 8 setal-teeth in 5/3 arrangement, setal-teeth smooth; palp well developed, 2-articulate, with apical robust setae. Maxilliped inner plate small; outer plate small; palp 4-articulate, article 4 small. Gnathopod 1 chelate; ischium smaller than propodus, not swollen posteroproximally; carpus extremely compressed; propodus length about 1.5 × breadth, posterior margin well developed, palm with produced corner, corner of palm with complex robust seta; dactylus reaching to corner of palm. Gnathopod 2 propodus, length slightly more than 2 × breadth, palm minute, obtuse. Pereonite 4 without dorsal spines. Pereonite 5 without dorsal spines. Pereopod 4 merus expanded anteriorly, produced less than halfway along carpus. Pereopod 5 merus with posteroproximal shoulder. Pereopod 6 basis with posteroventral lobe produced beyond ischium; merus as broad as long, with posteroproximal shoulder. Pereopod 7 basis subovate, about as long as wide with posterior margin weakly dentate. Oostegites from gnathopod 2 to pereopod 5. Epimeron 3 posterior margin without projections, posteroventral corner acutely produced. Uropod 3 biramous, inner ramus extending halfway along outer ramus but not reaching base of article 2. Telson longer than broad, entire.

Remarks. The female of this species was not previously known. This specimen has a well-developed callynophore on antenna 1, scattered pale ommatidia forming an oval eye, oostegites on gnathopod 2 to pereopod 5 and gills from gnathopod 2 to pereopod 6.

Distribution. Western Port and Bass Strait, south-eastern Australia; 15–59 m depth.

Figures

FIGURE 28. Posteroventral corner of epimeron 3. a: Pachynus denticulatum Lowry, 1984, holotype, 3.4 mm, AM P.24232, off Malabar, New South Wales, Australia; b: P. denticulatum, female, 2.8 mm, AM P.46676, off Horseshoe, Reef, Bootless Bay, Papua New Guinea; c: P. pugilator Lowry, 1984, female, 3.6 mm, MV J62416, Crib Point, Western Port, Victoria, Australia.