Apodopsyllus gwakjiensis, Back & Lee, 2012

Back, Jinwook & Lee, Wonchoel, 2012, Two new species of Apodopsyllus (Copepoda, Harpacticoida) from Jeju Island, Korea, Zootaxa 3368 (1), pp. 128-145 : 143-144

Key to species of the genus Apodopsyllus

Including A. gwakjiensis sp. nov. and A. unisetosus sp. nov., the number of valid species in the genus Apodopsyllus has increased to 28. Since the dichotomous key by Coull & Hogue (1978), 14 species have been newly described in this genus. Wells' (2007) tabular key is very useful to identify Apodopsyllus species. After Wells (2007), A. gabesensis is added in the genus Apodopsyllus . Therefore an updated key including A. gabesensis and the two new species is provided herein. This key does not include A. perplexus which was described only from the male. This species is very difficult to identify without information on the female P5. Unfortunately, Gómez (2002) did not describe the P5 of females. He stated that A. samuelgomezi was unique within an arcuatus - chilensis - cubensis clade as the male P6 carries two long inner setae. It is impossible to identify species without characteristics of the female P 5 in this key. Therefore, this key does not include the species A. samuelgomezi . It is based on females.

1. P1 exp 1-segmented................................................................................... 2

— P1 exp 2-segmented.................................................................................. 7

2. P1 endopod-2 with 3 setae/spines; female A1 9-segmented and male 6-segmented.......................... A. littoralis

— P1 endopod-2 with 2 setae/spines, character not combined.................................................... 3

3. A2 exp 2-segmented....................................................................... A. arenicola ***

— A2 exp 1-segmented.................................................................................. 4

4. A2 exp with 2 setae........................................................................... A. depressus

— A2 exp with 3 setae at least............................................................................ 5 5. P1 enp-2 with 2 claw-like setae; enp and exp of maxillule absent.................................... A. madrasensis

— These characters not combined........................................................................... 6

6. Outer lobe of P5 benp with 4 outer setae proximally, and 1 inner seta (or 1 projection)................... A. camptus ****

— Outer lobe of P5 benp with 3 setae proximally and 1 seta sub-apically.................................. A. lynceorum

7. P5 exp separated...................................................................................... 8

— P5 exp fused......................................................................................... 9

8. P5 exp with 3 setae and benp inner lobe with 1 seta................................................. A. adaptatus

— P5 exp with 2 setae and benp inner lobe without seta.................................................. A. spinipes

9. A2 exp with 1 seta.......................................................................... A. unisetosus

— A2 exp with 3 setae at least............................................................................ 10

10. Enp-1 shorter than exp................................................................................ 11

— Enp-1 longer than exp................................................................................ 15

11. A2 exp with 3 setae............................................................................ A. schulzi

— A2 exp with 4 setae................................................................................... 12

12. P4 basis without inner seta; P5 benp not developed.................................................. A. aberrans

— P4 basis with 1 inner seta; P5 benp developed............................................................... 3

13. Inner lobe of P5 benp not confluent............................................................. A. gabesensis

— Benp plate of left and right P5 confluent.................................................................. 14

14. End of P5 benp rounded; P5 exp represented by small protrusion............................... A. africanus listensis

— End of P5 benp pointed; P5 exp completely fused with benp....................................... A. biarticulatus

15. P1 enp-1 1.3 times longer than exp at least................................................................. 16

— P1 enp-1 1.1 times longer than exp at most................................................................ 20

16. A2 exp with 3 setae.................................................................................. 17

— A2 exp with 4 setae................................................................................... 19

17. P1 enp-1 2.4 times longer than exp; P1 basis with 1 outer seta...................................... A. unguiformis

— These characters not combined......................................................................... 18

18. P5 benp bluntly pointed median plate without seta................................................. A. bermudensis

— P5 benp divided in middle with concave median incision with 2 setae................................. A. gwakjiensis

19. P1 enp-1 1.3 times longer than exp..................................................... A. alejandrovillalobosi

— P1 enp-1 1.7 times longer than exp at least................................................................ 20

20. Inner lobe of left and right P5 confluent, with 2 almost same length setae each....................... A. pseudocubensis

— Inner lobe of left and right P5 completely divided, with 1 shorter inner seta and 1 longer outer seta each........ A. arcuatus

21. A2 exp 2-segmented..................................................................... A. vermiculiformis

— A2 exp 1-segmented.................................................................................. 22

22. A2 exp with 3 setae.................................................................................. 23

— A2 exp with 4 setae................................................................................... 24

23. P4 basis with 1 small inner seta............................................................... A. panamensis

— P4 basis without seta............................................................................ A. melitae

24. Inner lobe of benp P5 developed; P5 benp with 3 setae at middle margin and 1 seta sub-apically............... A. cubensis

— Theses characters not combined......................................................................... 25

25. Lobe of P5 benp triangular shape, with 4 outer and 1 inner setae....................................... A. chilensis

— Lobe of P5 benp rounded shape, with 4 outer setae.................................................. A. africanus