Caecijaera, 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 : 538

Key to known species of the genus Caecijaera

1. Coxal plates of pereonites 2–4 visible dorsally; antennula 5-articled; appendix masculina long and coiled.............................................................................................. 2 (the Caecijaeralla group)

- Coxal plates of pereonites 2–4 invisible dorsally; antennula 6-articled; appendix masculina not coiled................................................................................................... 4 (the Caecijaera group)

2. Second mandibular palp article with 3 serrate setae; pleopod II in males with 1 spiral turned appendix masculina....................................................................................... C. derjugini Kussakin, 1962

- Second mandibular palp article with 2 serrate setae; pleopod II in males with much more than 1 spiral turned appendix masculina........................................................................................... 3

3. Antenna with 10–11-articled flagellum; endopod of pleopod III with 5 plumose setae......... C. mirabilis Kussakin, 1962

- Antenna with 8-articled flagellum; endopod of pleopod III with 15 plumose setae............. C. borealis Kussakin, 1962

4. Pereonite 7 with simple setae in middle of posterior margin; pleotelson proximolaterally angled.......... C. ciliata sp. nov.

- Pereonite 7 without simple setae in middle of posterior margin; pleotelson proximolaterally rounded................... 5

5. Pleopod Ⅰ in males with distinctly elongated distolateral lobes.................................................................................................... Menzies (1951a) ’s type materials of C. horvathi Menzies, 1951

- Pleopod Ⅰ in males with slightly expanded distolateral lobes.................................................... 6

6. Lateral margin of cephalothorax with cleft separating each lobe............................ C. cojimarensis Ortiz, 1993

- Lateral margin of cephalothorax entire without cleft......................................................... 7

7. Lateral margins of pereonites angled................................................ C. kussakini Malyutina, 1994

- Lateral margins of pereonites rounded............................ Cooke (1977) ’s Hawaiian materials of “ C. horvathi ”