Thoridae, Kingsley, 1878

Wicksten, Mary K., 2012, Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces 3371, Zootaxa 3371, pp. 1-307 : 74-75

Key to Species of Family Thoridae

1. Supraorbital teeth present............................................................................... 2

– Supraorbital teeth absent.............................................................................. 12

2. Two or more supraorbital teeth, third maxilliped with exopod.................................................. 3

– One supraorbital tooth, no exopod on third maxilliped........................................................ 8

3. Carapace with 3–4 supraorbital teeth...................................................................... 4

– Carapace with 2 supraorbital teeth........................................................................ 5

4. Rostrum deep (protruding ventrally below level of antennular peduncle), with 10–26 dorsal teeth on rostrum proper, ventral margin of pleuron of third abdominal somite acute or pointed................................. Spirontocaris prionota

– Rostrum less deep, with 1–3 large dorsal teeth on rostrum proper, ventral margin of pleuron of third abdominal somite broadly rounded........................................................................... Spirontocaris truncata

5. Pleura of abdominal somites 1–3 ventrally acute to pointed............................... Spirontocaris lamellicornis

– Pleura of abdominal somites 1–3 broadly rounded ventrally.................................................... 6

6. Rostrum without distinct terminal projection, dactyls of pereopods 3–5 short, stout, apices bifid....... Spirontocaris snyderi

– Rostrum with distinct terminal projection, dactyls of pereopods 3–5 long, slender, simple............................ 7

7. Distal projection of rostrum with 1 ventral tooth, dorsal teeth extending to or past middle of carapace.. Spirontocaris holmesi

– Distal projection of rostrum without ventral tooth, dorsal teeth not extending as far as middle of carapace.. Spirontocaris sica

8. Rostrum reduced to tooth on frontal margin of carapace. 3 teeth on anterior dorsal midline of carapace..... Lebbeus lagunae

– Rostrum prominent, not reduced to tooth. 1–2 teeth on anterior dorsal midline of carapace............................ 9

9. Epipods on only pereopod 1. Living at 950 m and deeper.............................. Lebbeus vicinus montereyensis

– Epipods on pereopods 1–3. Shallow subtidal to 1808 m ...................................................... 10

10. Antennular peduncle extending nearly to end of scaphocerite. Inhabiting continental slope....... Lebbeus washingtonianus

– Antennular peduncle extending to near middle of scaphocerite. Inhabiting subtidal rocky areas....................... 11

11. Rostrum shorter than eye. Dorsal surface of abdominal somite 2 without furrow, fold.................... Lebbeus zebra

– Rostrum longer than eye. Dorsal surface of abdominal somite 2 with furrow, fold................... Lebbeus speciosus

12. Exopod on third maxilliped............................................................................ 13

– No exopod on third maxilliped.......................................................................... 19

13. No epipod on any pereopod............................................................................ 14

– Epipod at least on pereopod 1......................................................................... 16

14. Rostrum deep, shorter than carapace, eye large........................................... Eualus macrophthalmus

– Rostrum slender, as long as or longer than carapace, eye smaller............................................... 15

15. Posterior margin of abdominal somites 3–6 each bearing median dorsal tooth .......................... Eualus barbatus

– Posterior margin of abdominal somites 3–6 unarmed............................................. Eualus biunguis

16. Rostrum with dorsal margin markedly convex over eye, with 7–14 teeth................................ Eualus avinus

– Rostrum nearly straight over eye, with 2–9 teeth............................................................ 17

17. Pleuron of abdominal somite 4 without ventral tooth. Rostrum with 8–11 dorsal teeth............... Eualus berkeleyorum

– Pleuron of abdominal somite 4 with ventral tooth. Rostrum with 3–6 dorsal teeth.................................. 18

18. First segment of antennular peduncle with more than 1 spine. Pereopod 3 with 2 spines on merus. In life, marked with obvious bands................................................................................... Eualus lineatus

– First segement of antennular peduncle with only 1 spine. Pereopod 3 with 2–5 spines on merus. In life, translucent or with small brown chromatophores................................................................ Eualus subtilus

19. Ventral margin of fourth pleuron without tooth............................................................. 20 – Ventral margin of fourth pleuron with tooth................................................................ 26

20. Epipod absent on third maxilliped..................................................... Heptacarpus tenuissimus

– Epipod present on third maxilliped...................................................................... 21

21. Epipods present on at least pereopods 1, 2. Dorsal surface of abdominal 3 somite forming conspicuous hump............ 22

– Epipods absent from all pereopods. Dorsal surface of abdominal somite 3 evenly rounded, not forming conspicuous hump...................................................................................................... 23

22. Epipods present on pereopods 1–3. Rostrum deep, with 3–7 dorsal teeth, 2–6 ventral teeth......... Heptacarpus carinatus

– Epipods present on pereopods 1, 2 only. Rostrum narrow, with 4–5 dorsal teeth, 5–8 ventral teeth....... Heptacarpus flexus

23. Pterygostomian tooth absent............................................................................ 24

– Pterygostomian tooth present........................................................................... 25

24. Rostrum shorter than carapace, distal ventral half convex................................ Heptacarpus brachydactylus

– Rostrum longer than carapace, distal ventral half not convex or only slightly so................ Heptacarpus franciscanus

25. Scaphocerite shorter than carapace, abdominal somite 6 longer than telson........................ Heptacarpus decorus

– Scaphocerite as long as or longer than carapace, abdominal somite 6 shorter than telson............ Heptacarpus kincaidi

26. Rostrum deep. Epipod on pereopod 1 only. Usually on continental shelf, Oregon northward ............ Heptacarpusmoseri

– Rostrum shallow. Epipods on at least pereopod 1, often pereopod 2. Usually intertidal to subtidal, Alaska to Baja California ..................................................................................................... 27

27. Epipods on pereopods 1, 2 at most....................................................................... 28

– Epipods on pereopods 1–3............................................................................. 30

28. Rostrum barely reaching end of first segment of antennular peduncle.......................... Heptacarpuspugettensis

– Rostrum extending beyond end of first segment of antennular peduncle.......................................... 29

29. Rostrum reaching to end of antennular peduncle or beyond. Often in sea grass beds.............. Heptacarpus paludicola

– Rostrum not reaching end of antennular peduncle. Common in tide pools....................... Heptacarpus sitchensis

30. Dactyls of pereopods 3–5 simple, curved; rostrum slightly ascending over eye, with dorsal teeth most thickly set in proximal half............................................................................... Heptacarpus stimpsoni

– Dactyls of pereopods 3–5 bifid, rostrum not slightly ascending over eye, with dorsal teeth more widely spaced.......... 31

31. Rostrum not reaching as far as cornea of eye, with series of teeth descending from anterior margin of carapace to apex........................................................................................... Heptacarpustaylori

– Rostrum exceeding cornea of eye, rostral teeth more widely spaced, not as clearly descending........................ 32

32. Spine on distal ventral flexor margin of merus of pereopod.............................. Heptacarpus fuscimaculatus

– No spine on distal ventral flexor margin of merus of pereopod 1................................................. 3

33. Rostrum usually with bifid or trifid apex, exceeding cornea, merus of pereopods 3, 4 with 2 spines.... Heptacarpuspalpator

– Rostrum usually with simple apex, not exceeding cornea, merus of pereopods 3, 4 with 1 spine.... Heptacarpus brevirostris