Pylopaguropsis, Alcock, 1905

Key to species of Pylopaguropsis

1. Right cheliped palm fringed with long setae. [Third pereopods not markedly dissimilar]................................................................................................... P. fimbriata McLaughlin & Haig, 1989 (Ryukyu Islands, Guam, east Malaysia and Indonesia)

- Right cheliped palm not fringed with setae................................................................. 2

2. Third pereopods generally similar from right to left, right propodus and dactylus without distinct longitudinal sulci on lateral surface.............................................................................................. 3

- Third pereopods markedly dissimilar, right dactylus and/or propodus having one or more longitudinal sulci............. 14

3. Left cheliped palm with 1 or more rows of spines on dorsal surface.............................................. 4

- Left cheliped palm unarmed or at most with few scattered spinules or spinulose tubercles on dorsal surface............. 10

4. Second pereopods carpi with 1 or more spines on dorsal margin in addition to dorsodistal spine....................... 5

- Second pereopods carpi only with dorsodistal spine.......................................................... 6

5. Right cheliped palm with row of strong spines on dorsolateral margin, dorsal surface with mixture of large blunt spines and coarse granules; carpus dorsolateral margin not angular, unarmed. Telson terminal margins with many spines............................................................................................ P. rahayuae Asakura, 2010 (Bohol Sea, Philippines)

- Right cheliped palm only granular on dorsolateral margin, dorsal surface covered with minute granules; carpus dorsolateral margin angular, armed with row of strong spines. Telson terminal margins unarmed or poorly armed.................................................................................................. P. granulata Asakura, 2000 (Ryukyu Islands)

6. Ocular peduncles 0.6–0.7 times as long as shield. [Right chela without longitudinal groove adjacent to dorsolateral margin]. Second and third pereopods dactyli 1.1–1.4 times as long as propodi; third pereopods propodi each with 5–15 corneous spines on ventral margin................................................................... P. furusei Asakura, 2000 (Izu Ogasawara Arc, and Honshu to Kyushu, Japan)

- Ocular peduncles about 0.9 times as long as shield. Second and third pereopods dactyli 1.5–1.6 times as long as propodi; third pereopods propodi of each with 1–4 corneous spines on ventral margin........................................... 7

7. Right chela with longitudinal groove adjacent to dorsolateral margin; dorsal surface of fingers and palm with blunt tubercles or non-corneous-tipped, subacute spines. Fourth pereopod propodal rasp with 1 partial row of corneous scales.............. 8

- Right chela without longitudinal groove adjacent to dorsolateral margin; dorsal surface of fingers and palm with acute, corneous-tipped spines. Fourth pereopod propodal rasp with 2 rows of corneous scales............ P. similis Rahayu & Komai, 2013 ( Philippines)

8. Many dorsal spines on right chela with tuft of short plumose setae at base, making dorsal surface of palm setose. Telson terminal margin each with 12–16 spines extending onto lateral margin.......... P. laevispinosa McLaughlin & Haig, 1989 (Ryukyu Islands)

- Many dorsal spines on palm of right chela with few short plumose setae at base, dorsal surface of palm not setose. Telson terminal margin each with 1–9 spines not extending onto lateral margin.......................................... 9

9. Left cheliped carpus subequal to or shorter than merus. Second and third pereopods dactyli each with row of bristle-like setae on distal half of dorsal margin.................................................. P. vicina Komai & Osawa, 2004 (Kii Peninsula to Ryukyu Islands, Japan, and Moluccas, Indonesia)

- Left cheliped carpus slightly longer than merus. Second and third pereopods dactyli each with row of stiff setae on dorsal margin, none bristle-like....................................................... P. bellula Osawa & Okuno, 2007 (Ryukyu Islands, Japan)

10. Propodal rasp of fourth pereopods with 2 rows of corneas scales. Right third pereopod propodus with lateral surface flattened .................................................................................................. 11

- Propodal rasp of fourth pereopods with 1 partial row of corneous scales. Right third pereopod propodus with lateral surface convex............................................................................................. 12

11. Right cheliped dactylus with irregular double row of very small blister-like tubercles on dorsomesial margin, and with numerous blister or pimple-like small tubercles or granules on mesial and ventral surfaces; palm with dorsolateral margin delimited by double row of small tubercles only on fixed finger, dorsal surface with few, scattered very tiny tubercles...................................................................................... P. pustulosa McLaughlin & Haig, 1989 ( Somalia and Taiwan)

- Right cheliped dactylus with single row of small spines on dorsomesial margin, and with some tiny, low tubercles on mesial and ventral surfaces; right palm with dorsolateral margin delimited by single row of small blunt or spiniform tubercles on over entire length, dorsal surface with scattered small spines....................................... P. rufilineata sp. nov. (Ryukyu Islands)

12. Right chela with mesial face strongly produced ventrally in proximal half, ventral surface deeply excavated in lateral half. Antennal flagellum setose............................................................................. 13

- Right chela with mesial face not strongly produced ventrally in proximal half, ventral surface not strongly excavated in lateral half. Antennal flagellum not setose........................................... P. garciai McLaughlin & Haig, 1989 (Easter Island, Chile)

13. Antennal acicle slightly overreaching distal corneal margin. Right chela dorsal surface smooth (dactylus) or with only scattered minute tubercles on lateral half of palm. Lateral face of right third pereopod dactylus evenly convex.............................................................................................. P. mollymullerae Lemaitre, 2017 (Lesser Antilles, Caribbean)

- Antennal acicle not reaching distal corneal margin. Right chela dorsal surface with numerous albeit well-spaced small tubercles. Lateral face of right third pereopod dactylus slightly flattened............................... P. teevana ( Boone, 1932) (Pacific coast of Colombia to Ecuador, and Galapagos)

14. Left cheliped palm with 1 or more rows of spines on dorsal surface. Second pereopods carpi each with 1 or more spines on dorsal surface in addition to dorsodistal spine.............................................................. 15

- Left cheliped palm unarmed or at most with few scattered spinules or spinulose tubercles on dorsal surface. Second pereopods carpi each only with dorsodistal spine.................................................................... 18

15. Left chela with row of spines only on dorsomesial margin of palm, otherwise dorsal surface unarmed. Cornea not dilated at all. Antennal acicle falling far short of distal corneal margin. [Propodus of right third pereopod with distinct sulcus on lateral surface]................................................................. P. pygmaeus Rahayu & Komai, 2013 ( Philippines)

- Left chela with spines or granules on dorsal surface of palm in addition to spines on dorsomesial margin. Cornea slightly dilated. Antennal acicle reaching or overreaching distal corneal margin.......................................... 16

16. Right cheliped carpus with dorsolateral margin prominently elevated. Telson with terminal margins concave. [Propodus of right third pereopod with dorsal surface flattened, dorsolateral margin angular, lateral face flattened (large specimens) or with shallow longitudinal sulcus, at least in small individuals]................................... P. atlantica ( Wass, 1963) (Florida to Suriname)

- Right cheliped carpus with dorsolateral surface not particularly elevated. Telson with terminal margins oblique, not concave. .................................................................................................. 17

17. Right cheliped carpus with dorsolateral surface moderately to strongly armed. Right third pereopod dactylus with dorsolateral margin rounded, unarmed; propodus with dorsal surface rounded, lateral surface flattened (males) or evenly convex (females), without longitudinal sulcus................................................... P. magnimanus ( Henderson, 1896) (Bay of Bengal to Sri Lanka, northern Arabian Sea)

- Right cheliped carpus with dorsolateral surface without cosp. novicuous spines. Right third pereopod dactylus with dorsolateral margin distinctly carinate, with row of numerous spinules; propodus with dorsal surface flattened, dorsolateral margin carinate with row of numerous minute spinules, upper half of lateral surface concave, forming longitudinal sulcus.. P. decora sp. nov. ( Japan)

18. Right cheliped dactylus with closely-spaced, low, flattened tubercles on dorsal surface, dorsomesial margin with plate-like tubercles. Left cheliped merus with prominent tubercle at ventromesial proximal angle P. speciosa McLaughlin & Haig, 1989 (Izu Islands to Ryukyu Islands, Japan)

- Right cheliped dactylus with scattered, small, spinulose tubercles, dorsomesial margin with row of acute spines. Left cheliped merus with row of spines on ventromesial margin, but no prominent tubercle..................................... 19

19. Ocular peduncle appreciably broader proximally than at base of cornea. Left cheliped carpus with dorsodistal spine only.. 20

- Ocular peduncle not appreciably broader proximally than at base of cornea. Left cheliped carpus at least with dorsomesial row of spines........................................................................................... 21

20. Right third pereopod propodus with 1 longitudinal sulcus on lateral surface............ P. keijii McLaughlin & Haig, 1989 (Indo-West Pacific and Hawaii)

- Right third pereopod propodus with 3 longitudinal sulci on lateral surface............ P. lemaitrei Asakura & Paulay, 2003 ( French Polynesia)

21. Lateral surface of right third pereopod propodus with longitudinal sulcus on upper half......... P. zebra ( Henderson, 1893) (Indo-West Pacific)

- Lateral surface of right third pereopod propodus deeply concave in upper third, deep concavity in midline and small concavity near ventral margin, producing 3 prominent, longitudinal sulci.................. P. lewinsohni McLaughlin & Haig, 1989 (Gulf of Aqaba, Moluccas, Indonesia, and southern Japan)