Styloptocuma aurorae, Petrescu, 2018

Petrescu, Iorgu, 2018, On the Family Nannastacidae (Crustacea, Cumacea) from the Australian Museum Collection, Records of the Australian Museum 70 (1), pp. 1-111 : 49-50

Styloptocuma aurorae sp. nov.

Fig. 56

Holotype subadult ♀, 2.92 mm, P.90707, Australia, NSW, northeast of Coffs Harbour , -30.182° 153.538°, 1000 m, baited trap, 59.2% mud, 40.8% sand, 8–9 Sep 1994, J.K. Lowry, K. Dempsey, SEAS Project, MV Carrie Ann, NSW-999, in AM.

Etymology. The species is dedicated to my colleague, Dr Aurora Stănescu, renowned specialist in Heteroptera, Head of Education Department in ”Grigore Antipa” Museum, as a sign of sincere friendship.

Diagnosis. Carapace, 0.34 body length; short, upturned, pseudorostrum, 0.36 carapace length; maxilliped 3 carpus 1.2 merus length, propodus 1.33 carpus length; pereopod 2 merus 2.6 ischium length, dactylus 1.66 propodus length, long robust terminal seta; uropod peduncle 2.04 pleonite 6, 1.46 endopod length.

Description. Carapace, 0.34 body length, 1.76 as long as high, laterally compressed, 1.71 as long as wide; short, upturned, pseudorostrum 0.36 carapace length; large antennal notch; a few setulae on dorsal margin of carapace, mid-dorsal ridge; ocular lobe without lenses; smooth ventral margin ( Fig. 56 A, B ). — Antenna 1 peduncle article 1 0.83 rest of article’s length; article 2 as long as the article 3, with process and 2 pedunculate setae; main flagellum 0.8 article 3; accessory flagellum with 1 article; aesthetascs 2 main flagellum length ( Fig. 56 C ). — Maxilliped 3 basis 0.48 rest of article’s length, with 2 pappose and 2 plumose setae; merus 2 ischium length, with 2 pappose setae; carpus 1.2 merus length, 1 simple and 1 pappose seta; propodus 1.33 carpus length, 3 pappose setae on medial margin, 1 pappose seta on outer margin; dactylus 0.5 propodus length, with terminal seta; with exopod ( Fig. 56 D ). — Pereopod 1, basis 0.7 rest of article’s length, with 1 simple seta; merus2 ischium length, with 2 short simple setae; carpus 2 merus length, 2 short simple setae; propodus 0.7 carpus length, 5 simple setae; dactylus 0.6 propodus length, with 6 simple setae; with exopod ( Fig. 56 E ). — Pereopod 2 basis 0.9 rest of article’s length; merus 2.6 ischium length, with 1 simple seta; carpus 1.69 merus length, with 4 simple setae; dactylus 1.6 propodus length, with 6 setae; with exopod ( Fig. 56 F ). — Pereopod 3 basis 1.11 rest of article’s length, with 1 simple seta; ischium with 1 simple seta; merus 1.66 ischium length, with 1 plumose seta; carpus 2.6 merus length, with 1 simple seta; propodus 0.46 carpus length, with 1 simple seta; dactylus fused with terminal long robust seta ( Fig. 56 G ). — Pereopod 4 basis 1.1 rest of article’s length, with 1 simple seta; merus 2 ischium length, with 1 plumose seta; carpus 2 merus length, with 1 simple seta; propodus 0.46 carpus length, with 1 simple seta; dactylus fused with terminal long robust seta ( Fig. 56 H ). — Pereopod 5 basis 0.6 rest of article’s length, with 1 simple seta; merus 2 ischium length, with 1 simple seta; carpus 1.6 merus length, with 1 simple seta; propodus 0.46 carpus length, with 1 simple seta; dactylus fused with terminal robust seta ( Fig. 56 I ). — Uropod peduncle 2.04 pleonite 6, 1.5 endopod length, with 7 setae; exopod 0.8 endopod length, with 3 simple setae, terminal robust seta 0.87 exopod length; 5 robust simple setae, 1 simple seta terminally, broken, on serrated medial margin, terminal robust seta 0.46 endopod length ( Fig. 56 J ).

Remarks. Styloptocuma aurorae sp. nov. belongs to a group of Australian species without dorsal spines: S. australiense , S. granulosum and S. nodosum (all described by Petrescu, 2006). The new species has a carapace with a short pseudorostrum as in S. granulosum , but without a serrate ventral margin of carapace and scaly abdomen (characters present in the other two mentioned species); it has a shorter dactylus of pereopod 2 than in others, uropodal peduncle/ endopod ratio 1.46 v. 1.3 or 0.8 in those previously mentioned species or 1.4 in S. angelae sp. nov.

Distribution. Australia: NSW—northeast of Coffs Harbour, at 1000 m depth.

Figures

Figure 56. Styloptocumaa aurorae sp.nov. Holotype female (A) body, lateral view; (B) carapace, dorsal view; (C) antenna 1; (D) maxilliped 3; (E) pereopod 1; (F) pereopod 2; (G) pereopod 3; (H) pereopod 4; (I) pereopod 5; (J) uropod. Scales: A,B, 0.5; C, 0.1; D, F, 0.1; E, G–I, 0.1; J, 0.2.