Nannastacus inconstans Hale, 1945

Petrescu, Iorgu, 2018, On the Family Nannastacidae (Crustacea, Cumacea) from the Australian Museum Collection, Records of the Australian Museum 70 (1), pp. 1-111 : 35-36

Nannastacus inconstans Hale, 1945

Fig. 40

Nannastacus inconstans Hale, 1945: 150 . Hale, 1953: 73. Petrescu, 1997a: 137. Petrescu, 1997b: 127. Petrescu, 2001b: 107. Petrescu, 2003: 104. Stoddart & Lowry, 2003: 416.

Material examined: 2♂♂, P.90687; 1♂, P.64590; 22♀♀, 5♂♂, P.90689; 8♀♀, P.64592; 2♂♂, P.90682; 3, P.90684; 1♀, P.64618; 2♀♀, P.64620; 1♀, P.90686; 1♂, P.90679; 14♀♀, 3♂♂, P.64791; 2♀♀, P.90678; 2♀♀, P.90683; 1♀, P.64838; 1♂, P.64844; 1♀, 3♂♂, P.64845; 1♀, P.64848; 1♀, P.65009; 1♀, P.90688; 2♀♀, 1 subadult ♂, P.65300; 4♀♀ (1 fully diss.), 1♂, P.65301; 1♀, P.65302; 3♀♀, P.65306; 1♀, P.65322; 2♀♀, P.65352; 2♀♀, P.65363; 4♀♀, 3♂♂, P.65595; 1♀, P.65597; 1♀, 1♂, MGAB CUM 1673 ; 4♀♀, 2♂♂, P.65093.

Description. Female, cristate form according to Hale description (1945). Body: 1.6 mm. —Carapace with numerous small, distally dilated granules, closely beset, 0.4 entire body length, 1.7 as long as high, seen from above it is widest across the branchial regions which are more inflated; small elevation on basis of frontal lobe; anterolateral margin with 1 toothed process, with serrate margins; anterolateral margin anteriorly serrate; pseudorostral lobes upturned, coarsely serrate, 0.3 carapace length ( Fig. 40 A, B ). — Pereon and pleon with 1 double dorsal row of denticles and 1 lateral row. — Antenna 1 peduncle article 1 1.3 rest of article’s length, with 3 simple setae; article 2 with 2 simple setae and 1 process, 1.3 article 3 length; main flagellum 0.8 article 3; accessory flagellum with 1 article; aesthetascs 2.5 main flagellum length ( Fig. 40 C ). — Maxilliped 1 basis with 2 simple, 4 plumose and 2 hook setae; carpus 1.25 merus length, with 6 comb-like setae medially; propodus 1.6 carpus length, with 3 simple and 1 plumose seta; dactylus as long as propodus, with 2 simple setae ( Fig. 40 D ). — Maxilliped 2 basis with 1 simple plumose seta; merus 1.6 ischium length, with 1 plumose seta; carpus 0.8 merus length, with 3 pappose setae; large propodus, 0.9 carpus length, with 1 plumose, 3 simple and 2 pectinate setae; dactylus with 1 strong terminal seta ( Fig. 40 E ). — Maxilliped 3 basis 0.7 rest of article’s length process, long process, with 4 plumose setae; merus 2.2 ischium length, with 1 simple and 1 plumose seta; carpus 1.25 merus length, as long as propodus, with 2 simple setae; propodus 0.9 carpus length, with 1 simple and 3 pappose setae; dactylus 0.6 propodus length, with 2 simple and 2 pectinate setae; with exopod ( Fig. 40 F ). — Pereopod 1 basis 0.3 entire length, with 3 simple setae; ischium with 4 simple setae; merus 1.4 ischium length, with 3 simple setae; carpus 1.6 merus length, with 4 simple setae; propodus as long as carpus, with 5 simple setae; dactylus 0.5 propodus length, with 4 setae; with exopod ( Fig. 40 G ). — Pereopod 2 basis 0.6 rest of article’s length, with hyaline margins; merus 5 ischium length, with simple setae; carpus 1.6 merus length, with simple setae; dactylus 2.4 propodus length, with 6 simple setae; with exopod ( Fig. 40 H ). — Pereopods 3–5 with decreasing basis and increasing carpus; dactylus fused with terminal robust simple seta ( Fig. 40 I–K ). — Uropod peduncle 0.45 pleonite 6 length, 0.46 of endopod length, with serrate margins; exopod 0.4 of endopod length, with terminal robust simple seta; serrate endopod with 2 simple medially and 1 terminal simple seta ( Fig. 40 L ).

Remarks. The species was described by Hale (1945) based only on males from South Australia, without referring to maxillipeds, females being unknown. Our females have similar elevations on frontal lobe and same type of tubercles. Petrescu (1997a, 2001) mentioned the species from Indonesia and Tanzania and gave a short description of a female presumed to be N. inconstans . Petrescu (1997b) also found the species in Malaysia and redescribed the male. Australian female specimens from the Australian Museum differ from the Indonesian and Tanzanian females, material that I consider to belong to different species.

Distribution. Australia: WA and SA, 16 m ( Hale, 1945, 1953), Indonesia (?), Malaysia, Madagascar and Tanzania (?), 10–18 m ( Petrescu, 1997a,b, 2001, 2003). The species is also found in NSW, TAS, QLD and the NT, 0– 38 m.

Figures

Figure 40. Nannastacus inconstans Hale, 1945 Female (A) body, lateral view; (B) body, dorsal view; (C) antenna 1; (D) maxilliped 1; (E) maxilliped 2; (F) maxilliped 3; (G) pereopod 1; (H) pereopod 2; (I) pereopod 3; (J) pereopod 4; (K) pereopod 5; (L) uropod. Scales:A,B 0.3 mm; C,F,L 0.1 mm; D 0.05 mm; E 0.1 mm; G–K 0.2 mm.