Janiralata, Menzies, 1951

Kim, Sung Hoon, Kim, Jong Guk & Yoon, Seong Myeong, 2022, Description of two new janirid isopods (Isopoda, Asellota, Janiridae) from Korean waters, Zootaxa 5178 (6), pp. 532-546 : 544-545

Key to known species of the genus Janiralata in the Northwest Pacific

1. Exopod of pleopod III without plumose setae............................................................... 2

- Exopod of pleopod III with plumose setae.........................................................19 (group D)

2. Pleotelson with either posterolateral points or concavity distally................................................ 3

- Pleotelson without both posterolateral points and concavity distally.................................... 15 (group A)

3. Pleotelson with posterolateral points distally........................................................ 4 (group C)

- Pleotelson without posterolateral points........................................................... 11 (group B)

4. Cephalothorax with a pair of anterolateral projections or none.................................................. 5

- Cephalothorax with 2 pairs of anterolateral projections....................................................... 10

5. Anterolateral projections on cephalothorax absent...................................... J. intermedia Mezhov, 1981

- Anterolateral projections on cephalothorax present........................................................... 6

6. Anterolateral projections on cephalothorax indistinct.................................... J. sarsi ( Richardson, 1905)

- Anterolateral projections on cephalothorax distinct........................................................... 7

7. Anterolateral projections on cephalothorax blunt distally.................................. J. bifurcata Mezhov, 1981

- Anterolateral projections on cephalothorax not blunt distally................................................... 8

8. Cephalothorax with distinct rostrum................................................. J. bisinuata Kussakin, 1972

- Cephalothorax with indistinct and reduced rostrum........................................................... 9

9. Pleotelson concave distally; posterolateral points of pleotelson over distal end of medial lobe of pleotelson............................................................................................... J. pilosa Kussakin, 1962

- Pleotelson convex distally; posterolateral points of pleotelson not reaching distal end of medial lobe of pleotelson..................................................................................... J. occidentalis (Walker, 1898)

10. Anterolateral projections on cephalothorax bifid distally; pleotelson shallowly serrated on lateral margin....................................................................................... J. bilobata Kussakin & Mezhov, 1979

- Anterolateral projections on cephalothorax not bifid distally; pleotelson lateral margin deeply serrated..................................................................................... J. problematica Kussakin & Mezhov, 1979

11. Rostrum in cephalothorax present....................................................................... 12

- Rostrum in cephalothorax absent or reduced............................................................... 14

12. Rostrum not exceeding anterolateral projections.......................................... J. vitjazi Kussakin, 1962

- Rostrum exceeding anterolateral projections............................................................... 13

13. Rostrum long, almost half length of cephalothorax....................................... J. tricornis ( Krøyer, 1847)

- Rostrum relatively short, one-third of cephalothorax.................................... J. kurilensis Kussakin, 1962

14. Anterior margin of cephalothorax slightly pointed in the middle; pleopod II in females convex distally.............................................................................................. J. erostrata ( Richardson, 1899)

- Anterior margin of cephalothorax rounded in the middle; pleopod II in females concave distally.................................................................................................... J. soldatovi ( Gurjanova, 1933)

15. Anterolateral projections in cephalothorax present and distinct...................... J. sagamiensis ( Shimomura, 2006)

- Anterolateral projections in cephalothorax absent or reduced.................................................. 16

16. Anterolateral projections in cephalothorax reduced and indistinct.............................................. 17

- Anterolateral projections in cephalothorax absent........................................................... 18

17. Anterior margin of cephalothorax convex; pleopod Ⅰ of males without distomedial lobes.......... J. modesta Mezhov, 1981

- Anterior margin of cephalothorax not convex; pleopod Ⅰ of males with distomedial lobes.......... J. koreanesis Jang, 1991

18. Anterolateral margin of cephalothorax angled; eyes small and its length less than half of cephalothorax........................................................................................... J. microphthalma Kussakin, 1972

- Anterolateral margin of cephalothorax rounded; eyes relatively large and its length over half of cephalothorax.......................................................................................... J. obliterata Kussakin, 1972

19. Cephalothorax with prominent rostrum................................................................... 20

- Cephalothorax without rostrum......................................................................... 22

20. Rostrum with blunt or round distally....................................... J. aberrantis Kussakin & Mezhov, 1979

- Rostrum with acute tip distally.......................................................................... 21

21. Anterolateral projections of cephalothorax expanding forwardly; posterolateral points of pleotelson reaching distal end of pleotelson.................................................................. J. rhacuraeformis Birstein, 1963

- Anterolateral projections of cephalothorax expanding diagonally; posterolateral point of pleotelson expanding beyond distal end of pleotelson................................................................ J. hexadentata Birstein, 1970

22. Lateral margins of cephalothorax and pleotelson serrated.................................... J. serrata Birstein, 1963

- Lateral margins of cephalothorax and pleotelson smooth..................................................... 23

23. Pleotelson with posterolateral points; distal region of pleotelson concave........................................ 24

- Pleotelson without posterolateral points; distal region of pleotelson rounded and convex............................ 25

24. Anterolateral projections of cephalothorax long and acute distally; its length half of cephalothorax.................................................................................................. J. gurjanovae Kussakin, 1962

- Anterolateral projections short and subacute distally; its length a quarter of cephalothorax...... J. ochotensis Kussakin, 1962

25. Pereonites 2 and 3 deeply bilobed; coxal plates of pereonites 2‒4 invisible dorsally; pleotelson not truncated distally..... 26

- Pereonites 2 and 3 not deeply bilobed; coxal plates of pereonites 2‒4 visible dorsally; pleotelson truncated distally.............................................................................................. J. truncata sp. nov.

26. Carpus of pereopod Ⅰ with 6 robust inferior setae; pleopod II of females concave distally; exopod of pleopod III with 11 plumose distal setae.................................................................... J. chuni ( Thielemann, 1910)

- Carpus of pereopod Ⅰ with 8 robust inferior setae; pleopod II of females convex distally; exopod of pleopod III with 16 plumose distal setae....................................................................... J. shiinoi Kussakin, 1962