Amblyops, G. O. Sars, 1872

Murano, Masaaki, 2012, The Genus Amblyops (Crustacea: Mysida: Mysidae: Erythropinae) from East Asia and Australia, with Descriptions of Ten New Species, Species Diversity 17 (1), pp. 49-85 : 82-84

Key to the species of the genus Amblyops

1. Eyeplate with small, nger-like projection on dorsal surface near mesial line. Antennal scale without terminal lobe. Telson strongly tapered; apex armed with 2 long spines and pair of plumose setae, latter situated at acute apex....... A. tenuicaudus W. M. Tattersall, 1911

– Eyeplate with or without papilliform projection; if present, projection located at about center of anterior margin. Antennal scale with small terminal lobe (except for A. magnus and A. tattersalli ), and distolateral spine not or only slightly extending beyond apex of brade. Telson rounded or truncate posteriorly, with pair of plumose setae usually situated on dorsal surface near apex.... 2

2. Posterior margin of telson rounded................ 3

– Posterior margin of telson more or less truncate.... 17

3. Telson with 1 or 2 minute apical spines............. 4

– Telson without minute apical spines................ 8

4. Telson with spines on posterior half of lateral margin. 5

– Telson with spines on posterior two-thirds to entire length of lateral margin........................... 6

5. Telson with 12 spines on lateral margin.................... A. durbani O. S. Tattersall, 1955

– Telson with 25–26 spines on lateral margin............ A. spiniferus Nouvel and Lagardère, 1976

6. Antennal scale 3.8 times as long as wide......................... A. manazuruensis sp. nov.

– Antennal scale 3.3 times as long as wide............ 7

7. Telson abruptly narrowing near base, then gradually tapering posteriorly, armed with 27–28 spines on posterior four- hs of lateral margin................. A. kempi ( Holt and Tattersall, 1905)

– Telson gradually narrowing posteriorly with no abrupt change near base, armed with 28–30 spines on posterior two-thirds of lateral margin................................ A. izuensis sp. nov.

8. Eyeplate with large triangular lobe on anterior margin....... A. aequispinus Birstein and Tchindonova, 1958

– Eyeplate with small papilliform projection or unarmed on anterior margin.............................. 9

9. Telson width at mid-length less than half of greatest width........................ A. okinawensis sp. nov

– Telson width at mid-length more than half of greatest width......................................... 10

10. Telson with fewer than 30 spines on each lateral margin .............................................. 11

– Telson with more than 35 spines on each lateral margin .............................................. 12

11. Telson with 26–27 spines on posterior two-thirds of lateral margin........ A. abbreviatus (G. O. Sars, 1869)

– Telson with 27–29 spines on less than posterior half of lateral margin........ A. antarcticus O. Tattersall, 1955

12. Antennal scale overreaching antennular peduncle by one-third to two- hs of its length................ 13

– Antennal scale overreaching antennular peduncle by half or more of its length........................ 15

13. Spines on lateral margin of telson strongly increasing in length posteriorly............ A. timorensis sp. nov.

– Spines on lateral margin of telson slightly increasing in length posteriorly............................... 14

14. Eyeplate with distinct papilliform projection on anterior margin. Antennal scale 3.5 times as long as wide. Telson with 33–37 spines on posterior two-thirds to three-fourths of lateral margin.... A. paci cus sp. nov.

– Eyeplate without distinct papilliform projection on anterior margin. Antennal scale 3.0 times as long as wide. Telson with 41–42 spines on posterior two-thirds of lateral margin................ A. sagamiensis sp. nov.

15. Telson with 47–48 spines on posterior two-thirds of lateral margin................ A. kashimensis sp. nov.

– Telson with fewer than 40 spines on lateral margin.. 16

16. Antennal scale 3.5 times as long as wide and gradually narrowing distally in distal half. Telson with 37 spines on posterior four- hs of lateral margin. About 14 mm in body length............... A. amamiensis sp. nov.

– Antennal scale 3.2 times as long as wide and slightly narrowing distally. Telson with 39 spines on posterior three- hs of lateral margin. About 20 mm in body length......................... A. surugensis sp. nov.

17. Telson with spines along entire length of lateral margin........................... A. ewingi Băcescu, 1967

– Telson with spines on posterior half to four- hs of lateral margin.................................... 18

18. Antennal scale without terminal lobe.......... A. magnus Birstein and Tchindonova, 1958

– Antennal scale with terminal lobe................. 19

19. Blade of antennal scale extending far beyond tip of distolateral denticle........... A. tattersalli Zimmer, 1914

– Blade of antennal scale extending to tip of distolateral denticle....................................... 20

20. Posterior margin of telson with 7 pairs of spines..... A. longisquamosus Murano and Mauchline, 1999

– Posterior margin of telson with 3 pairs of spines.... 21

21. Antennal scale less than 3.5 times as long as wide. Lateral margin of telson with spines on posterior fourhs......... A. trisetosus Nouvel and Lagardere, 1976

– Antennal scale about 4 times as long as wide. Lateral margin of telson with spines on posterior less than half............................ A. australiensis sp. nov.