Key to Family Paguridae

Phylum Arthropoda
 Subphylum Crustacea
  Class Malacostraca
   Subclass Eumalacostraca
    Superorder Eucarida
     Order Decapoda
      Suborder Pleocyemata
       Infraorder Anomura
        Superfamily Paguroidea
 

Taken primarily from  Kozloff, 1987, 1996 p. 408 (Copyright 1987, 1996, University of Washington Press.  Used in this web page by permission of University of Washington Press)
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1a Carapace smooth, and only a portion of it (shield) calcified (picture); basal portions of eyescales not covered by the carapace, visible from above (picture); leg 4 subchelate (picture); male with pleopods, but these are unpaired  2
1b Carapace with dorsal spines, and almost all of it calicified; basal portions of eyescales covered by the carapace, not visible from above; male without pleopods Labidochirus splendescens
2a Abdomen not coiled; uropods symmetrical; in tubes of sabellariid or serpulid polychaetes, or in shells of scaphopod molluscs (rarely shells of gastropod molluscs) 3
2b Abdomen coiled; uropods asymmetrical (picture); in shells of gastropods or in sponge masses 4
3a Palm (propodus) of right chela wider at the level where the dactyl and fixed claw originate than at its proximal end; right and left halves of telson partly separated by a groove; in shells of scaphopod molluscs; subtidal off the open coast  Orthopagurus minimus
3b Palm of right chela little if any wider at the level where the dactyl and fixed claw originate than at its proximal end; right and left halves of telson not separated by a groove; almost always in tubes of sabellariid and serpulid polychaetes (rarely in shells of gastropods); subtidal, but occurring in inland waters as well as off the open coast Discorsopagurus schmitti
4a Carpus of right cheliped at least slightly longer than wide (picture); neither the carpus nor the propodus of the right cheliped much flattened or with 1 or both margins thinned further; eyescales without a deep median furrow (picture) 5
4b Carpus of right cheliped as wide or wider than long; either the carpus or propodus, or both, much flattened and with 1 or both margins thinned further; eyescales with a deep median furrow 22
5a Dactyl of legs 2 and 3 obviously twisted in relation to the propodus, and with 2 reddish brown stripes (photo) 6
5b Dactyl of legs 2 and 3 not twisted in relation to the propodus, and without stripes (picture) 8
6a Dactyl and propodus of chelipeds spiny dorsally and marginally, but with relatively few spines on the ventral side Pagurus armatus
6b Dactyl and propodus of chelipeds  with about as many tubercles or small spines on the ventral surface as on the dorsal surface 7
7a Dorsal surface of dactyl of legs 2 and 3 with a single distinct longitudinal groove; merus and carpus of chelipeds without an opalescent sheen Pagurus aleuticus
7b Dorsal surface of dactyl of legs 2 and 3 with longitudinal rows of small spines or tubercles, these rows separated by 2 shallow, indistinct grooves; merus and carpus of chelipeds with an opalescent sheen Pagurus ochotensis
8a Dorsal surface of palm (propodus) of left chela with a prominent ridge or crest near the midline, and with a distinct concavity lateral to this; subtidal, and found only in deep water off the open coast 9
8b Dorsal surface of palm of left chela without a prominent ridge or crest near the midline (but there may be a slight eminence) (picture), and without a concavity; includes intertidal and subtidal species, some of which occur in inland waters 11
9a
9b
10a
10b
11a Ventral surface of merus of right cheliped with 1 or 2 prominent tubercles (these are about twice as large as the other tubercles) (picture); includes intertidal and subtidal species 12
11b Ventral surface of merus of right cheliped without prominent tubercles (photo) strictly subtidal species 17
12a Ventral surface of merus of right cheliped with 2 prominent tubercles (picture) 13
12b Ventral surface of merus of right cheliped with only 1 prominent tubercle (and in Pagurus hirsutiusculus, a common intertidal species, this is often obscure) 15
13a Ventrolateral surface of dactyl and propodus of left leg 3 without spines or tubercles, or the propodus with only 1 or 2 spines on its distal portion; legs, including the chelipeds, olive-green, with small blue dots Pagurus granosimanus
13b Ventrolateral surface of dactyl and propodus of left leg 3 with 1 or more irregular rows of small spines or tubercles (picture); color of legs not olive-green with small blue dots 14
14a Shield of carapace about as wide as long (picture); chelae with small spines rather than tubercles or granules (picture); dorsal surface of carpus of left cheliped with a single row of stout spines; rostrum generally rounded (picture); legs 2 and 3 with a red band at the articulation of the dactyl and propodus (picture); not restricted to the open coast, but found only subtidally and in the lowest part of the intertidal region Pagurus beringanus
14b Shield of carapace decidedly longer than wide; chelae with tubercles or granules; dorsal surface of carpus of left cheliped with 2 rows of rather short spines; rostrumacute; dactyl of legs 2 and 3 bright blue [often a band, or a white band in juveniles]; restricted to the open coast, where it occurs intertidally Pagurus samuelis
15a Chelae with irregular rows of rather stout spines, these partly obscured by tufts of long setae; antennae 2 reddish brown and without white spots or bands; with a white band at the articulation of the propodus and dactyl of legs 2 and 3 Pagurus caurinus
15b Chelae with closely spaced tubercles or granules, these often inconspicuous (scattered tufts of setae may also be present); with or without white spots or bands on antennae 2; with or without a light band at the articulation of the propodus and dactyl of legs 2 and 3 16
16a Ventral side of carpus of right cheliped greatly swollen; shield of carapace decidedly longer than wide; antennae 2 orange-red and without white spots or bands; legs, on the whole, dark red with minute yellow spots, but without a light band at the articulation of the propodus and dactyl; on the open coast, where it is restricted to the lowest part of the intertidal region and the shallow subtidal region Pagurus hemphilli
16b Ventral side of carpus of right cheliped not greatly swollen; shield of carapace about about as wide as long, or wider than long; antennae 2 largely green with white spots or bands; legs greenish brown, legs 2 and 3 with white or bluish bands at the articulation of the propodus and dactyl; on the open coast and in inland waters, mostly in the mid-intertidal region Pagurus hirsutiusculus
17a Dactyl of left chela bowed to the extent that when it is closed against the fixed claw, there is a prominent gap between them; eyescale usually tipped with 2 to 5 spines Pagurus quaylei
17b Dactyl of left chela not bowed to the extent that there is a prominent gap between it and the fixed claw; eyescales terminating in a single spine or merely acute 18
18a Carpus of left cheliped about 3 times as long as wide, and usually appreciably longer than the merus 19
18b Carpus of left cheliped about 2 times as long as wide, and about the same length as the merus 20
19a Carpus of right cheliped about twice as long as wide; left chela more nearly triangular than elongate-ellipsoidal, and with a double row of divergent spines on the eminence ner the midline of the dorsal surface of the palm (propodus); rostrum not pronounced, with a blunt tip; distal part of the merus of chelipeds without a white band Pagurus stevensae
19b Carpus of right cheliped about 1.5 times as long as wide; left chela more nearly elongate-ellipsoidal than triangular, and with a single row of large spines on the eminence near the midline of the dorsal surface of the palm; rostrum pronounced, triangular and sharp-tipped; distal part of the merus of the chelipeds with a distinct white band Pagurus dalli
20a Dorsal side of the base of the cornea with a tuft of setae; eyestalks (including the cornea) about 5 times as long as wide; distal portion of the merus of chelipeds with a white band; antenna 2 with light and dark bands Pagurus kennerlyi
20b Dorsal side of the base of the cornea without a tuft of setae; eyestalks (including the cornea) generally not more than 4 times as long as wide; distal portion of the merus of chelipeds without a white band; antenna 2 not banded 21
21a
21b
22a Propodus of right cheliped, in dorsal view, slightly wider than the carpus; dorsal surface of propodus of right cheliped roughened by tubercles and spines; margins of merus of legs (especially chelipeds) bright grayish blue (elsewhere on the legs the color ranges from cream to red) Elassochirus tenuimanus
22b Propodus of right cheliped, in dorsal view, narrower than the carpus; dorsal surface of propodus of right cheliped nearly smooth; prevailing coloration of legs orange to red, without grayish blue on the margins of the merus 23
23a Dorsal surface of carpus of right cheliped with 1 or more irregular rows of small spines; merus and carpus of chelipeds with a lavender-purple area Elassochirus cavimanus
23b Dorsal surface of carpus of right cheliped without small spines; chelipeds rather uniformly orange to red Elassochirus gilli



Taxonomic Levels Represented in this Key:

  Discorsopagurus schmitti
  Elassochirus tenuimanus
  Labidochirus splendescens
  Pagurus armatus
  Pagurus beringanus
  Pagurus caurinus
  Pagurus dalli
  Pagurus granosimanus
  Pagurus hirsutiusculus
  Pagurus kennerlyi
  Pagurus quaylei
  Pagurus samuelis
  Pagurus stevensae


Page created by Janisse Maxwell, 7-2002
Edited by: Hans Helmstetler 10-2002, Dave Cowles 2005, 2007