Philocheras Stebbing, 1900

Han, Qingxi & Keesing, John K., 2018, A new species of Philocheras (Decapoda: Caridea: Crangonidae) from Western Australia, with a key to all species of this genus worldwide, Zootaxa 4382 (1), pp. 175-184 : 179-182

Key to species of Philocheras Stebbing, 1900

1 Antennal scale armed with 1 tooth or serrate on lateral margin.................................................. 2

- Antennal scale unarmed on lateral margin................................................................. 17

2 Outer margin of antennal scale serrate..................................................................... 3

- Outer margin of antennal scale armed with 1 tooth........................................................... 8

3 Denticulation on outer margin of antennal scale very minute and inconspicuous; carapace adorned with 2 tubercles on middor- sal line instead of teeth.................................................... P. gaillardi (Crosnier, 1971) (Congo)

- Denticulation on outer margin of antennal scale normal and conspicuous.......................................... 4

4 Carapace without any tooth at middorsal line.................. P. wilkinsae De Grave, 2000 (Pupua New Guinea, 6–12 m)

- Carapace with at least one tooth, tubercle on middorsal line.................................................... 5

5 Carapace adorned with 2 tubercles instead of teeth on middorsal line............................................................................................ P. nikiforovi (Burukovsky, 1990) (Sala-y-Gomez Ridge, East Pacific)

- Carapace with one tooth on middorsal line.................................................................. 6

6 Carapace with both median tooth and lateral teeth............................................................ 7

- Carapace with/without a small median tubercle on middorsal line, but no lateral teeth................................................... P. lowisi ( Kemp, 1916) ( Andaman Sea , Timor Sea, South China Sea, Japan, WA of Australia, 0–120 m)

7 Only 3 teeth, including median tooth and lateral teeth on carapace.......................................................................................... P. prionolepis (Holthuis, 1952) (Cape Verde Islands, Congo, 100–225 m)

- Five teeth, including median, submedian and lateral teeth on carapace................................................................................... P. japonicus (Doflein, 1902) ( Philippines, Japan, and WA of Australia, 42-522)

8 Carapace with three or more tooth or tubercles on middorsal line................................................ 9

- Carapace with one or two tooth on middorsal line........................................................... 11

9 Rostrum triangular in dorsal view, terminating in acuminate tip......... P. triangulus Komai, 2006 (NT of Australia, 7.3 m)

- Rostrum broad or narrow, but not triangular in dorsal view.................................................... 10

10 Carapace armed with 3 teeth in dorsal midline, including 2 gastric teeth and 1 cardiac tooth................................................................................. P. vanderbilti (Boone, 1935) (Lesser Sunda Islands, 256 m)

- Carapace armed with 1 strong tooth in dorsal midline, and another 3 tubercles............................................................ P. incisus ( Kemp, 1916) (Gulf of Oman to Philippines, Japan, WA of Australia, subtidal to 153 m)

11 Carapace with two tooth on middorsal line................................................................. 12

- Carapace with one tooth on middorsal line................................................................. 13

12 Only one spine on outer edge of distal end of merus of first pereopod................................................................................ P. sculptus (Bell, 1847) (British Islands to South Africa, Mediterranean, 0–230 m)

- No spine present on outer edge of distal end of merus of first pereopod................................................................... P. parasculptus Burukovsky, 1991 [Southwestern Indian Ocean (33°16′N, 45°53′E), 415–460 m]

13 First pereopod with distolateral propodal tooth (“thumb”) fixed, not articulated at base.............................. 14

- First pereopod with distolateral propodal tooth (“thumb”) articulated at base...................................... 15

14 Pleonal somites 3–5 carinated dorsally..................... P. kempii (de Man, 1918) (Flores Sea, Indonesia, 300–400 m)

- Pleonal somites 3–5 smooth dorsally......................... P. bidens (Holthuis, 1951) (Guinea to Angola, 30–100 m)

15 Cornea large, maximum width of cornea exceeds 0.4 of carapace length, all pleonal somites devoid of conspicuous middorsal carina, but visible trace of elevation on somites 3–5.................................................................................................... P. magnioculus Komai & Chan, 2007 (Bohol Sea, Philippines, 145–163 m)

- Cornea normal, maximum width of cornea less than 0.3 of carapace length, pleonal somites usually fairly sculptured with shal- low depressions and/or transverse grooves, with distinct middorsal carina at least on third somite..................... 16

16 Rostrum terminating in convex tip with small lateral horns; carapace with middorsal carina interrupted at midpoint, with 1 middorsal tooth... P. angustirostris (De Man, 1918) (Arabian Sea to Indonesia, South China Sea, WA of Australia 13–120 m)

- Rostrum terminating in slightly concave or truncate tip without lateral horns; carapace with continuous middorsal carina, with- out middorsal tooth.............................................. P. brucei Komai, 2004 (QLD of Australia, 10 m)

17 Rostrum exceedingly small, eyes contiguous........................................................................................ P. parvirostris ( Kemp, 1916) (Gulf of Manaar to Singapore, South China Sea, and Japan, 0–90 m)

- Rostrum well developed, separating eyes.................................................................. 18

18 Carapace unarmed, without any tooth in dorsal midline....................................................... 19

- Carapace armed with 1 or more strong tooth in dorsal midline................................................. 20

19 Hepatic spine present; first pereopod with distolateral propodal tooth (“thumb”) articulated at base........................................................................ P. candidus ( Kemp, 1916) (female) (Andamans, shallow water)

- Hepatic spine absent; first pereopod with distolateral propodal tooth (“thumb”) fixed, not articulated at base......................................................................... P. wolffi (Holthuis, 1951) ( French Guinea, 25–50 m)

20 Carapace armed with 3 or more strong teeth in dorsal midline................................................. 21

- Carapace armed with 1 or 2 strong teeth in dorsal midline..................................................... 29

21 Carapace armed with 4 strong teeth in dorsal midline........................................................ 22

- Carapace armed with 3 strong teeth in dorsal midline........................................................ 23

22 Carapace with longitudinal row of 3 teeth posterior to antennal tooth........................................................................................... P. dimorphus (Fujino & Miyake, 1971) (Sagami Bay, Japan, 75–80 m)

- Carapace with longitudinal row of 4 teeth posterior to antennal tooth............................................................................... P. quadrispinosus (Yaldwyn, 1958) (Southern Ocean, south of New Zealand, 334 m)

23 Third and fourth pleonal somites with middorsal carina....................................................... 24

- Third and fourth pleonal somites 3–4 rounded and smooth dorsally............................................. 25

24 First lateral carina of carapace reaching to near posterior edge; between it and middorsal line another row of very small teeth....................................... P. echinulatus (M. Sars, 1862) ( Norway to Morocco, Mediterranean, 4–137 m)

- First lateral carina reaching only about three fourths length of the carapace backward; no small teeth between it and middorsal line................................ P. victoriensis ( Fulton & Grant, 1902) (SA and Tas. SA, WA of Australia, 0–42 m)

25 Carapace with 2 or 3 teeth posterior to antennal tooth....................................................... 26

- Carapace with longitudinal row of 5 teeth posterior to antennal tooth............................................ 27

26 Carapace with longitudinal row of 2 teeth posterior to antennal tooth............................................................................ P. pilosus ( Kemp, 1916) (Mozambique, Gulf of Manaar, and northern Australia, littoral)

- Carapace with longitudinal row of 3 teeth posterior to antennal tooth.................................................................................... P. yaldwyni (Zarenkov, 1968) (Southern Ocean south of New Zealand, 334 m)

27 Without ventral tooth on merus of first pereopod; with one tooth posterior to branchiostegal tooth........................................................................ P. poorei Komai, 2008 (Albany, southwestern Australia, littoral)

- With a ventral tooth on merus of first pereopod; with two or more teeth posterior to branchiostegal tooth............... 28

28 Two teeth posterior to branchiostegal tooth.......................................................................................... P. acutirostratus (Yaldwyn, 1960) (Tasman Sea, New Zealand and Chatham Islands, 86–732 m)

- Three teeth posterior to brachiostegal tooth.. P. pilosoides (Stephensen, 1927) ( Subantarctic islands of New Zealand, littoral)

29 Carapace armed with 2 strong teeth on dorsal midline........................................................ 30

- Carapace armed with 1 strong tooth on dorsal midline........................................................ 37

30 Third and fourth pleonal somites with middorsal carina...................................................... 31

- Third and fourth pleonal somites rouded dorsally, without middrosal carina....................................... 32

31 Rostrum width longer than length, lateral margin with supraorbital lobe in proximal half, extending to anterior part of carapace as short, parallel carina........................ P. coralliophilus Komai & Kim, 2010 (tropical western Pacific, 0–48 m)

- Rostrum length longer than width, without supraorbital lobe......................................................................................... P. bidentatus (De Haan, 1844) (Yellow Sea, East China Sea and Japan, 33–76 m)

32 Carapace without lateral tooth.......................................................................... 33

- Carapace with one or more lateral teeth................................................................... 34

33 The second median tooth of normal size; numerous minute tubercles arranged in longitudinal series either side of median line........................................................... P. bispinosus bispinosus (Hailstone, 1835) (Atlantic)

- The second median tooth reduced to a tubercle; not any tuberculation either side of median line............................................................ P. bispinosus neglectus (G. O. Sars, 1883) (Northern Atlantic and Mediterranean)

34 Carapace with only one pair of teeth on each side........................................................................................... P. obliquus ( Fulton & Grant, 1902) (SA, Vic., Tas. QLD and WA of Australia, 0–34.2 m)

- Carapace with 5 or 6 lateral teeth........................................................................ 35

35 Two middorsal teeth situated close together on anterior third of carapace; rostrum narrow; pair of dorsolateral carina on sixth pleonal segment............................................. P. australis (Thomson, 1879) ( New Zealand, 0–36 m)

- Two middorsal teeth not situated close, posterior tooth at about mid-point of carapace; rostrum broad; no dorsolateral carina on sixth pleonal segment................................................................................. 36

36 Rostrum bluntly rounded distally; lateral surface of carapace adorned with 6 teeth... P. chiltoni ( Kemp, 1911) (New Zealand)

- Rostrum truncate distally; lateral surface of carapace adorned with 5 teeth...... P. hamiltoni (Yaldwyn, 1971) (New Zealand)

37 Third and fourth pleonal somites with middorsal carina....................................................... 38

- Third and fourth pleonal somites rounded dorsally, without middorsal carina...................................... 41

38 Middorsal carina on carapace indistinct and discontinuous; apex of rostrum bifid................................................................................................ P. anthonyi Taylor, 2010 (WA of Australia, 222 m)

- Middorsal carina on carapace distinct and continuous; apex of rostrum convex or truncate........................... 39

39 Both dorsal and ventral flagellum very short and stout, failing to reach distal margin of antennal scaphocerite............................................................................ P. breviflagella Komai, 2002 (Hawaii, subtidal)

- Flagellum normal, reaching beyond distal end of antennal scaphocerite.......................................... 40

40 The second lateral carina on carapace bearing two teeth; apex of rostrum truncate............................................................................................ P. sabsechota ( Kemp, 1911) (Andaman Islands, littoral)

- No tooth on second lateral carina on carapace, rostrum rounded or convex..... P. vestigialis (Fujino & Miyake, 1971) (Japan)

41 First pereopod with distolateral propodal tooth (“thumb”) fixed, not articulated at base.............................. 42

- First pereopod with distolateral propodal tooth (“thumb”) articulated at base...................................... 50

42 Carapace without lateral tooth........................................................................... 43

- Carapace adorned with at least one pair of lateral teeth....................................................... 48

43 Rostrum with lateral teeth other than distolateral spiniform angles.............................................. 44

- Rostrum without lateral teeth other than distolateral spiniform angles........................................... 45

44 Distal margins of carpus of first pereopod unarmed.............. P. lapillus Wicksten, 1989 (Galapagos Islands, 37–59 m)

- Distal margins of carpus of first pereopod armed................................................................................................. P. gorei (Dardeau, 1980) ( Georgia to Florida, Gulf of Mexico, Uruguay, 9–194 m)

45 Carapace without lateral teeth, but with 5 pairs of well-defined tubercles.... P. opici (Crosnier, 1971) ( Annobon Island, 50 m)

- Carapace without neither lateral teeth nor well defined tubercles............................................... 46

46 Median tooth on carapace blunt; tip of rostrum rounded; lateral margin of antennal scale sinuous and concave.............................................................................. P. aglyptus (Crosnier, 1971) (Congo, littoral)

- Median tooth on carapace acute; tip of rostrum truncate; lateral margin of antennal scale straight...................... 47

47 Two lobe-like folds present on either side off middle line of carapace; no well-defined carina present extending from bran- chiostegal spine.................... P. fasciatus (Risso, 1816) (British Islands to Canary Islands, Mediterranean, 0–60 m)

- No lobe like folds present on either side off middle line of carapace; a well-defined carina extending from branchiostegal spine....................................................... P. gardenensis sp. nov. (Garden Island, WA of Australia)

48 Carapace with 2 pairs of lateral teeth...................... P. intermedius (Bate, 1863) (SA of Australia, shallow water)

- Carapace with 3 or more lateral teeth..................................................................... 49

49 Carapace with 3 pairs of lateral teeth............... P. modestus (de Man, 1918) ( Indonesia, WA of Australia, 296–457 m)

- Carapace with 4 or more lateral teeth.. P. flindersi ( Fulton & Grant, 1902) (SA, Vic., Tas., and NSW of Australia, 18–127 m)

50 Carapace without lateral teeth........................................................................... 51

- Carapace with at least one pair of lateral teeth.............................................................. 53

51 Dactylus of second pereopods about 1.5 times as long as distolateral spine on propodus.......................................................................... P. monacanthus (Holthuis, 1961) ( Portugal, and Mediterranean, 0–23 m)

- Dactylus of second pereopods normal, about as long as distolateral spine on propodus.............................. 52

52 Telson furnished at apex with long and slender tooth, flanked by pair of plumose setae........................................................................................ P. megalocheir Stebbing, 1915 ( South Africa, 45–67 m)

- The apex of telson consists of a triangular plate with minute spinule on either side and two pairs of plumose setae arising from beneath it........................................... P. hendersoni (Kemp, 1915) (India, and South Africa, littoral)

53 Carapace with only one pair of lateral teeth................................................................................................... P. trispinosus (Hailstone, 1835) ( Norway to Canary Islands, Mediterranean, 0–50 m)

- Carapace with more than two pairs of lateral teeth........................................................... 54

54 Three frontal teeth on postorbital carina present..... P. fujinoi Kim & Hayashi, 2000 (South and East China Seas, 80–111 m)

- Frontal teeth on postorbital carina absent.................................................................. 55

55 Carapace with 3 pairs of lateral teeth; tip of rostrum rounded............................................................................................ P. plebs ( Kemp, 1916) (Andaman Islands, and WA of Australia, 3.6–101 m)

- Carapace with 2 pairs of lateral teeth; tip of rostrum truncated................................................. 56

56 Rostrum somewhat slender, about 1.30 times as long as width in distal part............................................................................................. P. candidus ( Kemp, 1916) (male) (Andamans, shallow water)

- Rostrum broad, about 1.80 times as long as width in distal part................................................. 56

57 Appendix interna of each of second to fifth pleopod well developed........................................................................................ P. planoculminus Bruce, 1994 (Timor Sea, and WA of Australia, 30–49 m)

- Appendix interna of each of second to fifth pleopod rudimental...... P. gemmaceus Kim & Hayashi, 2000 ( Japan, 15–50 m)