Maeraceterus, Hughes, Lauren E., 2016

Hughes, Lauren E., 2016, New genera, species and records of Maeridae from Australian Waters: Austromaera, Ceradocus, Glossomaera, Hamimaera, Huonella gen. nov., Linguimaera and Maeraceterus gen. nov. (Crustacea: Amphipoda), Zootaxa 4115 (1), pp. 1-81 : 4-5

Key to Linguimaera sensu lato: Austromaera , Glossomaera , Hamimaera , Linguimaera and Maeraceterus gen. nov., species of Australian waters

1. Gnathopod 2 symmetrical in males and females, not greatly enlarged. Uropod 3 rami distally narrowing................ 2

– Gnathopods asymmetrical in males. Uropod 3 rami not greatly narrowing distally, apically truncate or rounded........... 5

2. Gnathopod 1 propodus subovate, palm subacute to acute. Uropod 3 rami narrowing distally, apically acute, apical robust setae small..................................................................................3 (Austraomaera)

– Gnathopod 1 propodus rectilinear, palm near transverse. Uropod 3 rami narrowing, apical robust setae large.............................................................................................. 4 ( Maeraceterus gen. nov.)

3. Male gnathopod 2 propodus length twice breadth.................................... .. A. mastersii ( Haswell, 1879a)

– Male gnathopod 2 propodus length 2.5 times breadth................................ A. brevicaudata (Ledoyer, 1984)

4. Gnathopod 2 ischium distal margin with row of long robust setae............................ M. taaroa gen. et sp. nov.

– Gnathopod 2 ischium distal margin with a few slender setae only........................ M. bramblensis gen. et sp. nov.

5. Epimeron 3 posterior margin smooth. Uropod 3 rami short, length less than twice peduncle length, apically margin broadly truncate................................................................................. 6 ( Hamimaera )

– Epimeron 3 posterior margin serrate or notched. Uropod 3 rami more than twice peduncle length, apically margins narrowly truncate to rounded.................................................................................... 7

6. Male gnathopod 2 dominant propodus palm near transverse. Telson with apical robust setae only.................................................................................................... H. hamigera ( Haswell, 1879b)

– Male gnathopod 2 dominant propodus palm obtuse. Telson with apical and inner margins with robust setae................................................................................................... .. H. thjisseni sp. nov.

7. Epimera 2–3 posterior margin sinusoidal, posterodistal corner with small acute tooth...... G. octodens ( Sivaprakasm, 1969)

– Epimera 2–3 posterior margin serrate or notched.................................................8 ( Linguimaera )

8. Male gnathopod 2 dominant propodus palm obtuse........................................................... 9

– Male gnathopod 2 dominant propodus palm subacute........................................................ 10

9. Uropod 3 rami greatly elongate, length 3.8 times width........................................... L. daveyi sp. nov.

– Uropod 3 rami long, length 2.5 times width........................................ L. zeidleri Krapp-Schickel, 2008

10. Male gnathopod 2 dominant side, basis anterior margin lined with robust setae........................ .. L. mere sp. nov.

– Male gnathopod 2 dominant side, basis anterior margin without row of robust setae................................ 11

11. Telson inner margin with robust setae..................................................................... 12

– Telson inner margin without robust setae.................................................................. 14

12. Epimeron 3 posterior margin serrate...................................................................... 13

– Epimeron 3 posterior margin smooth, posterodistal corner with well-developed notch.............. L. everardensis sp. nov.

13. Telson inner margin lined with 4 pair of robust setae. Mandibular palp article 3 length half of article 2...................................................................................... L. schicklae Lowry & Springthorpe, 2005

– Telson inner margins with 1 pair of robust setae. Mandibular palp article 3 length more than half article 2............................................................................................. L. pirloti Krapp-Schickel, 2003

14. Telson with lateral robust setae......................................................................... 15

– T elson without lateral robust setae....................................................................... 17

15. Telson entire, apically emarginate........................................... L. boecki Lowry & Springthorpe, 2005

– Telson cleft, divided into two distinct lobes................................................................ 16

16. Male gnathopod 2 dominant propodus, palm with evenly spaced teeth.................. L. gartima Krapp-Schickel, 2003

– Male gnathopod 2 dominant propodus, palm with J-shaped excavation.................. L. kellissa Krapp-Schickel, 2003

17. Uropod 3 rami length less than 3.5 times width............................................................ 18

– Uropod 3 rami length more than 3.5 times width....................................... L. leo Krapp-Schickel, 2003

18. Male gnathopod 2 dominant propodus palm lined with several small teeth, palm corner defined by small tooth........................................................................................... L. tias Krapp-Schickel, 2003

– Male gnathopod 2 dominant propodus palm with two well-developed teeth, palm corner defined by large tooth.............................................................................................. .. L. boeckoides sp. nov.