Wellsopsyllus

Back, Jinwook & Lee, Wonchoel, 2014, Two new species of the genus Wellsopsyllus (Copepoda; Harpacticoida; Paramesochridae) from the Yellow Sea, Zootaxa 3895 (3), pp. 346-366 : 364

Key to species of the genus Wellsopsyllus

The tabular keys reported by Wells (2007) represent the latest key for the genus Wellsopsyllus . The keys to the species of subgenera Scottopsyllus and Intermediopsyllus by Kunz (1962) and Lang (1965) are also available. Since the study by Wells (2007), five species (including the two new species reported here) have been described. In addition, Wells’ key contains an error in the couplets leading to S. (S.) praecipuus ( Veit-Köhler, 2000) . Specifically, Veit-Köhler (2000) described the S. (S.) praecipuus A2 exp as having 5 setae/spines (See Veit-Köhler, 2000, p.11, fig.6A), and not 3 setae/spines as reported in Wells’ key (see Wells, 2007, p.581). Lastly, because of the doubtful nature of the description of W. (S.) minor by T & A Scott (1895), this species is not included in the key. Our key is based on female characters.

1. P4 exp 2-segmented......................................................... (subgenus Intermediopsyllus )... 2

- P4 exp 3-segmented................................................................................... 5

2. P2–P3 exp-3 with 3 setae/spines.............................................................. W. (I.) antoniae

- P2–P3 exp-3 with 2 setae/spines.......................................................................... 3

3. P2–P4 enp represented by small process........................................................ W. (I.) smirnovi

- P2–P4 enp 1–segmented; P4 enp-1 with 1 stout seta.......................................................... 4

4. P5 exp separated from benp, armed with 3 setae; baseoendopodal lobe with 2 small setae.............. W. (I.). intermedius i

- P5 exp fused with benp, armed with 2 setae; baseoendopodal lobe with 1 small seta...................... W. (I.) minutus

5. P4 enp 1-segmented....................................................... (subgenus Wellsopsyllus )....... 6

- P4 enp 2-segmented...................................................... (subgenus Scottopsyllus )....... 10

6. P1 enp-2 with 2 setae................................................................... W. (W.) antarcticus

- P1 enp-2 with 1 seta.................................................................................. 7

7. A2 exp with 3 setae.......................................................................... W. (W.) gigas

- A2 exp with 4 setae................................................................................... 8

8. P2–P3 enp represented by a small process; caudal seta IV and VI bump-like setae; well-developed outer process of P5 benp................................................................................. W. (W.) egregius . sp. nov.

- These characters not combined.......................................................................... 9

9. P5 benp with 1 long inner seta and 1 short outer seta; width:length ratio of caudal rami about 1:2.5....... W. (W.) abyssalis

- P5 benp with 2 short setae; width:length ratio of caudal rami about 3:4................................ W. (W.) runtzi

10. P1 basis with 5 long inner setules........................................................................ 11

- P1 basis without long setules.......................................................................... 15

11. A2 exp with 4 setae................................................................................. 12

- A2 exp with 5 setae................................................................................. 13

12. P5 benp with 1 long inner seta and 2 short outer setae; male P5 exp with 2 setae................. W. (S.) pararobertsoni

- P5 benp with 2 short setae; male P5 exp with 3 setae..................................... W. (S.) koreanus sp. nov.

13. A2 exp with 5 subequal length setae; P5 benp with 1 long inner seta and 1 short outer seta; width:length ratio of caudal rami about 1:3.............................................................................. W. (S.) robertosni

- These characters not combined......................................................................... 14

14. Articulation between P4 exp-1 and exp-2 not clearly demarcated...................................... W. (S.) langi

- P4 exp clearly 3-segmented......................................................... W. (S.) langi continentalis

15. A2 exp with 4 setae...................................................................... W. (S.) herdmani

- A2 exp with 5 setae................................................................................. 16

16. P1 enp-2 with 1 seta..................................................................... W. (S.) praecipuus

- P1 enp-2 with 2 setae..................................................................... W. (S.) depressus