Key:  Family Crangonidae

Phylum Arthropoda
 Subphylum Crustacea
  Class Malacostraca
    Subclass Eumalacostraca
     Superorder Eucarida
      Order Decapoda
        Suborder Pleocyemata
         Infraorder Caridea

Taken primarily from  Kozloff, 1987, 1996  p. 400 (Copyright 1987, 1996, University of Washington Press.  Used in this web page by permission of University of Washington Press)

An excellent alternate, up to date key can be found in Wicksten, 2009 page 147

Here is a crangonid species captured from the Sea of Okhotsk off Kamchatka, NW Pacific (not in key):
  Argis ochotensis
 
 
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1a  Rostrum more than half as long as the rest of the carapace; with only 4 pairs of legs Paracrangon echinata
1b Rostrum, if present, less than half as long as the rest of the carapace (photo); with 5 pairs of legs 2
2a Dactyl of leg 5 broad and flattened; eyestalks parallel and shielded by a hood that consists of the antennal spines, postorbital spines, and rostrum 3
2b Dactyl of leg 5 not broad and flattened (photo); eyestalks not parallel and not shielded by a hood consisting of spines 7
3a Carapace with 2 median spines in addition to the spine that forms the rostrum 4
3b Carapace with 3 or 4 median spines in addition to the spine that forms the rostrum 5
4a Longitudinal dorsal ridges (carinae) on abdominal segment 6 extended beyond the posterior edge of the segment as spines Argis dentata
4b Longitudinal dorsal ridges on abdominal segment 6 not extended beyond the posterior edge of the segment as spines Argis lar
5a Longitudinal dorsal ridges (carinae) on abdominal segment 6 extended beyond the posterior edge of the segment as spines Argis alaskensis
5b Longitudinal dorsal ridges on abdominal segment 6 not extended beyond the posterior edge of the segment as spines 6
6a Abdominal segments 1-4 with a longitudinal dorsal ridge; pleuron of abdominal segment 4 with a small posteroventral spine Argis crassa
6b Abdominal segments 1-4 without a longitudinal dorsal ridge; pleuron of abdominal segment 4 without a posteroventral spine Argis levior
7a Carapace with a median dorsal spine or spines (photo) 8
7b Carapace without median spines Lissocrangon stylirostris
8a Submedian spines present on carapace 9
8b Submedian spines absent on carapace 13
9a Carapace with 2 submedian spines on both sides Mesocrangon munitella
9b Carapace with 1 submedian spine on both sides (photo) 10
10a Pleura of abdominal segments 1-3 with ventrally directed spines Metacrangon spinosissima
10b Pleura of abdominal segments 1-3 without ventrally directed spines 11
11a Anterior median carapace spine extending beyond the bases of the orbits of the eyes, and larger than the posterior median carapace spine Metacrangon acclivis
11b Anterior median carapace spine not extending beyond the bases of the orbits of the eyes, and not larger than the posterior median carapace spine (photo) 12
12a Abdominal segments 3-5 with a prominent longitudinal dorsal ridge (carina); spine of scale of antenna 2 reaching to or beyond the tip of the lamella Metacrangon variabilis
12b Abdominal segments 3-5 without a prominent longitudinal dorsal ridge; tip of the lamella of the scale of antenna 2 reaching beyond the spine (photo) Metacrangon munita
13a Carapace obviously sculptured 14
13b Carapace smooth 15
14a Carapace with 1 or 2 median spines; outer margin of scale of antenna 2 (antennal scale) concave Rhynocrangon alata
14b Carapace with 3 or 4 median spines; outer margin of scale of antenna 2 (antennal scale) convex Sclerocrangon boreas
15a Carapace with 2 median spines 16
15b Carapace with 1 median spine (photo) 18
16a Rostrum ascending at an angle of about 45 degrees and extending beyond the eyes; rostrum, in adult, with a large ventral expansion Neocrangon resima
16b Rostrum ascending at an angle of 30 degrees or less and not extending beyond the eyes; rostrum without a ventral expansion 17
17a Tip of rostrum rounded; eyes not contiguous Neocrangon communis
17b Tip of rostrum acute; eyes large and contiguous Neocrangon abyssorum
18a Dorsal surface of abdominal segment 6 with 2 prominent lateral ridges (carinae) Crangon dalli
18b Dorsal surface of abdominal segment 6 without londitudinal ridges (photo) 19
19a Abdominal segment 5 with a spine on the upper posterolateral margin of both sides 20
19b Abdominal segment 5 without spines on the upper posterolateral margins (photo) 21
20a Dactyl of leg 1 reaching the base of the fixed finger when the chela is closed; propodus of leg 1 of male 4.5 times as long as wide Crangon franciscorum
subspecies franciscorum
20b Dactyl of leg 1 crossing the base of the fixed finger when the chela is closed; propodus of leg 1 of male 5.5 times as long as wide Crangon franciscorum
subspecies angustimana
21a Ventral surface of abdominal segment 6 with a median groove (sulcus) (photo) 22
21b Ventral surface of abdominal segment 6 without a median groove Crangon alba
22a Flagella of antenna 1 equal in length; scale of antenna 2 (antennal scale) not more than twice as long as wide (not known to occur north of California) Crangon handi
22b Inner flagellum of antenna 1 longer than the outer flagellum; scale of antenna 2 more than twice as long as wide (photo) 23
23a Spine of scale of antenna 2 (antennal scale) extending beyond the tip of the lamella, which is narrow (photo); scale of antenna 2 as long as, or longer than, the telson Crangon alaskensis
23b Spine of scale of antenna 2 reached or exceeded by the tip of the lamella, which is a rounded lobe; scale of antenna 2 shorter than the telson Crangon nigricauda



Taxonomic Levels Represented in This Key:
  Crangon alaskensis
  Crangon alba
  Metacrangon munita
  Neocrangon communis
  Paracrangon echinata



Page created by Dave Cowles, 2005
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