Halirages spongiae, Lörz & Nack & Tandberg & Brix & Schwentner, 2024

Lörz, Anne-Nina, Nack, Madita, Tandberg, Anne Helene S., Brix, Saskia & Schwentner, Martin, 2024, A new deep-sea species of Halirages Boeck, 1871 (Crustacea: Amphipoda: Calliopiidae) inhabiting sponges, European Journal of Taxonomy 930, pp. 53-78 : 66-68

Key to described Halirages species amended after d’Udekem d’Acoz, 2012 including Halirages spongiae sp. nov. Lörz, Nack & Tandberg

1. Ep3 with strong posteromedian and posteroventral tooth (posterior border forming an angular protrusion) (Example A) ................................................................................................................... 2

– Ep3 with posteroventral tooth only (posterior border rounded, but can have a minute posteromedian protrusion) (Example B) .................................................................................................................... 4

2. Pereionite 7 with 0–1 posterodorsal tooth; pleonite 1 and 2 with 1 posterodorsal tooth .................. 3

– Pereionite 7 and pleonites 1–2 with 3 posterodorsal teeth ........................... H. nilssoni Ohlin, 1895

3. Telson distally truncated and slightly concave; ventral border of coxae 1–2 smooth; posterior border of basis of P5–7 with very weak crenulations; carpus of Gn1–2 equal to propodus .......................................................................................... H. fulvocinctus (M. Sars, 1859)

– Telson pointed, with large distal tooth flanked by 2 pairs of small lateral subdistal teeth; ventral border of coxae 1–2 and posterior border of basis of P5–7 distinctly serrate; carpus of Gn1–2; distinctly longer than propodus .............................................. H. stappersi d’Udekem d’Acoz, 2012

4. Ventral lobe of head produced into a sharp tooth; carpus of P1–2 about 4× as long as broad or narrower; at least some segments of pleon with posterodorsal tooth; telson pointed; bathyal and abyssal species .................................................................................................................................. 5

– Ventral lobe of head bluntly subquadrate; carpus of P1–2 a bit less than 2× as long as broad; pleon smooth, segments without posterodorsal tooth; telson truncated; infralittoral species ...................... ................................................................................................................ H. mixtus Stephensen, 1931

5. Eyes present ...................................................................................................................................... 6

– Eyes absent ....................................................................................................................................... 8

6. Eye small and subreniform; coxa 1 with anteroventral corner forming a square angle; ventral border of coxa 1 with about 10 weak crenulations; posteroventral corner of basis of P7 bluntly angular; pereionite 7 (but never 6) and pleonites 1–2 with posterodorsal tooth; tip of telson with a single distal tooth ............................................................................................ H. cainae d’Udekem d’Acoz, 2012

– Eye large, tip of telson tridentate ...................................................................................................... 7

7. Eye large and subreniform; coxa 1 with anteroventral corner pointing forwards; ventral border of coxa 1 with about 10 weak crenulations; posteroventral corner of basis of P7 angular; pereionite 7 (but never 6) and pleonites 1–2 with posterodorsal tooth; tip of telson tridentate ............................. .................................................................................... H. spongiae sp. nov. Lörz, Nack & Tandberg

– Eye large and broad; coxa 1 with anteroventral corner pointing anteriorly; ventral border of coxa 1 with about 20 pronounced serrations; posteroventral corner of basis of P7 forming a sharp square angle; pereionite 7 (and often 6) and pleonites 1–2 with posterodorsal tooth; tip of telson tridentat .................................................................................................... H. qvadridentatus G.O. Sars, 1877

8. Ventral border of coxa 1–2 with pronounced serrations ................... H. gorbunovi Gurjanova, 1946

– Ventral border of coxa 1–2 smooth or nearly so ................................. H. caecus Kamenskaya, 1980