Deep-sea Rhachotropis (Crustacea: Amphipoda: Eusiridae) from New Zealand and the Ross Sea with key to the Pacific, Indian Ocean and Antarctic species Author Lörz, Anne-Nina text Zootaxa 2010 2482 22 48 journal article 10.5281/zenodo.195450 a7230d4e-1bc8-49ce-a928-8a7a4f8e6ba9 1175-5326 195450 Key to Indo-Pacific and Antarctic species of Rhachotropis 1. Telson incised or cleft ................................................................................................................................................... 3 - Telson entire.................................................................................................................................................................. 2 2. Pereonites laterally smooth, coxa 1 anteroventrally rounded ..................................................................... R. glorisae - Pereonites lateral process, coxa 1 anteroventrally pointed .................................................... R. chathamensis sp. nov. 3. Eyes present .................................................................................................................................................................. 4 - Eyes absent ................................................................................................................................................................. 15 4. Pereonites 6 and 7 with dorsal and dorsal lateral teeth............................................................................................... 26 - Pereonites 6 and 7 lacking dorsolateral teeth, urosomite 2 smooth.............................................................................. 5 5. Epimeral plate 3 with middorsal tooth.......................................................................................................................... 6 - Epimeral plate 3 lacking middorsal tooth ..................................................................................................................... 7 6. Pereonite 7 with carinae, telson cleft about 10% ................................................................................ R. boreopacifica - Pereonite 7 smooth or very small carinae, telson cleft about 50% ............................................................. R. macropus 7. Urosomite 1 with tooth ................................................................................................................................................. 8 - Urosomite 1 lacking tooth............................................................................................................................................. 9 8. Telson cleft about one third; dorsal protrusion on urosomite 1 not reaching end of urosomite 2 ............ R. antarctica - Telson apically notched, about one tenths; dorsal protrusion on urosomite 1 extending length of urosomite 2 ............ .................................................................................................................................................................... R. barnardi 9. Pereonite 7 with middorsal tooth ................................................................................................................................ 10 - Pereonite 7 lacking middorsal tooth ........................................................................................................................... 11 10. Pereopods 3 and 4 dactylus long; inner margin uropod 3 setose................................................................... R. oculata - Pereopod 3 and 4 dactylus short; uropod 3 inner margin spinose ................................................................. R. minuta 11. Pleonite 1 and 3 with strong dorsolateral teeth and ridge............................................................................... R. inflata - Pleonite 1 and 3 lacking strong dorsolateral teeth and ridge ...................................................................................... 12 12. Epimeron 1 with carinae or tooth ............................................................................................................................... 13 - Epimeron 1 dorsally smooth, lacking teeth or carinae................................................................................................ 14 13. Pereopod 5 and 6 posterior margin of basis double or triple toothed. Antenna 1 shorter than antenna 2 ...................... ................................................................................................................................................................... R. luculenta - Pereopod 5 and 6 posterior margin of basis smooth; Antenna 1 same length than antenna 2............ R. schelllenbergi 14. Telson longer than uropod 3: gnathopods 1 and 2 propodi slender ............................................................... R. elliotta - Telson shorter than uropod 3: gnathopods 1 and 2 propodi rounded ......................................................... R. conlanae 15. Urosomite 1 with tooth or carinae .............................................................................................................................. 16 - Urosomite 1 lacking tooth or carinae.......................................................................................................................... 20 16. Epimeral plate 3 distinct dorsal tooth ......................................................................................................................... 17 - Epimeral plate 3 lacking dorsal tooth ......................................................................................................................... 18 17. Dorsolateral teeth present on epimeral plates 1 and 2 ............................................................................. R. kergueleni - Epimeral plates laterally smooth................................................................................................................................27 18. Telson notch shallow .................................................................................................................................... R. clemens - Telson deeply cleft ...................................................................................................................................................... 19 19. Epimeral plates laterally smooth; no calceoli on antenna............................................................................... R. ludifer - Epimeral plates with lateral process; calceoli on antenna 1 and antenna 2 .............................................. R. calceolate 20. Epimeral plate 3 with tooth......................................................................................................................................... 21 - Epimeral plate 3 lacking dorsal tooth ........................................................................................................ R. anoculata 21. Head and pereonites 1–7 smooth ............................................................................................................................... 22 - Head and pereonites 1–7 bumpy.................................................................................................................. R. grimaldi 22. Rostrum shorter than head .......................................................................................................................................... 23 - Rostrum long, same length as head ........................................................................................................................... 25 23. Epimeral plates 2 and 3 bearing lateral process, telson cleft to at least one-third ...................................................... 24 - Epimeral plates 2 and 3 laterally smooth, no distinct processes; telson cleft to less than one-quarter R. rossi sp. nov. 24. Dorsal process of epimeral plate 2 twice as long as process from epimeral plate 1 and 3 ...................... R. multesimus - Dorsal process of epimeral plate 2 longer than dorsal process of epimeral plate 1 and 3 ...................... R. americana 25. Antenna with calceoli; urosomite 1 bearing lateral ridge; uropod 1 outer ramus shorter than inner ramus................... ...................................................................................................................................................................... R. levantis - Antenna lacking calceoli; urosomite 1 laterally smooth; uropod 1 rami subequal in length...................................... 28 26. Mid-dorsal carinae of epimeron 1 and 2 with double hooks; pereopod 7 basis strongly expanded posteriorly, smooth, rounded ...................................................................................................................................................... R. aculeanta - Mid-dorsal carinae of epimeron 1 and 2 simple; pereopod 7 basis with distinct tooth midposteriorly...... R. gubilata 27. Coxa 1 expanded; pereopod 7 basis strongly notched ................................................................. R. abyssalis sp. nov. - Coxa 1 not expanded; pereopod 7 basis smooth......................................................................................... R. distincta 28. Gnathopod 2 basis expanded; posterolateral corners of epimeral plates 1 and 2 subquadrate ...... R. delicata sp. nov. - Gnathopod 2 basis parallel; posterolateral corners of epimeral plates 1 and 2 broadly rounded ................. R. sibogae