Key To Cambarus

Up
AVITICAMBARUS
CAMBARUS
DEPRESSICAMBARUS
EREBICAMBARUS
HIATICAMBARUS
JUGICAMBARUS
LACUNICAMBARUS
PUNCTICAMBARUS
VETICAMBARUS
 

 

 

KEY TO THE SUBGENERA OF THE GENUS CAMBARUS

(Based on First-Form Males)


1.   Antennae conspicuously fringed on mesial border (Fig. 86a);  lateral margin of fixed finger of chela
       serrate (Fig. 89a, f):........................................................................................ BARBICAMBARUS  Hobbs, 1969.

      (Monotypic:  Cambarus (B.) cornutus Faxon, 1884.  Streams in the Green River system in Kentucky.
        Literature:  Faxon, 1885;  Hobbs, 1969b).

      EDITOR's NOTE:  This species has been elevated to the generic level (i.e., Genus Barbicambarus).

  • Antennae not conspicuously fringed on mesial border (Fig. 86b);  lateral margin of fixed finger
    never serrate (Fig. 89b-e, g-o):........................................................................................................................  2
Fig. 86.  Dorsal view of cephalic region.  a, Cambarus cornutus;  b, C. b. bartoni.

2(1).   Albinistic, eyes without facets and pigment reduced or absent..................................................................  3

  • Pigmented, eyes with facets and always pigmented...................................................................................   5
Fig. 87.  Dorsal view of antennal scales.  a, Cambarus hamulatus;  b, C. setosus.

3(2).   Eyes with pigment spot:..............................................................  EREBICAMBARUS  Hobbs, 1969 (part)

  • Eyes without pigment......................................................................................................................................  4

 4(3).   Antennal scale more than twice as long as broad (Fig. 87a):...................................................................
            .................................................................................................................  AVITICAMBARUS  Hobbs, 1969.

  • Antennal scale less than twice as long as broad (Fig. 87b):.....................................................................
    ...........................................................................................................  JUGICAMBARUS  Hobbs, 1969 (part).
Fig. 88.  Lateral view of left first pleopods.  a, Cambarus pristinus;  b, C. obeyensis;  c, C. bouchardi;  d, C. b. bartonii;  e, C. reduncus;  f, C. friaufi.

5(2).   Central projection of first pleopod directed caudodistally at angle distinctly less than 90 degrees
            to principal shaft of appendage (Fig. 88a-c):....................................  VETICAMBARUS  Hobbs, 1969.

  • Central projection of first pleopod bent caudally at angle of at least 90 degrees to principal shaft of
    appendage (Fig. 88d-f):...............................................................................................................................  6

6(5).   Fingers of chela with poorly defined dorsal longitudinal ridges, sometimes moderately well
           developed in C. girardianus;  fingers widely gaping and usually with prominent cluster of
           plumose setae at base of fixed finger (Fig. 89b, c, k):......................  HIATICAMBARUS  Hobbs, 1969.

  • Fingers of chela with moderate to strong dorsal longitudinal ridges;  fingers seldom widely
    gaping and always lacking prominent cluster of plumose setae at base of fixed finger
    (Figs. 89d, e, g, i, 90):.................................................................................................................................  7

7(6).   Palm of chela with tubercles confined to 1 somewhat reguar row along mesial margin,
           sometimes with poorly developed row of few scattered ones adjacent to row;  dactyl never
           twice as long as mesial margin of palm (Figs.  89d, e, g, i, 90a):.........................................................  8

  •  Palm of chela with 2 or more rows of tubercles along mesial margin (except in C. nerterius in
    which dactyl of chela is twice as long as length of mesial margin of palm (Fig. 90c) and in
    C. veteranus which has acuminate rostrum), often with additional tubercles dorsolateral to
    2 rows (Figs. 89m-o, 90b, d, e):...............................................................................................................  10
Fig. 90.  Dorsal view of chelae.  a, Cambarus b. bartonii;  b, C. extraneus;  c, C. nerterius;  d, C. d. diogenes;  e, C. latimanus.

8(7).   Mesial margin of palm of chela with row of at least 8 tubercles; fingers never with conspicuous
            hairlike setae (Fig. 89d, g):..........................................................................  EREBICAMBARUS  (part).

  • Mesial margin of palm of chela with row of fewer than 8 tubercles, or fingers with conspicuous
    hairlike setae (Figs. 89e, i, 90a):.............................................................................................................  9

9(8).   Color blue and/or palm of chela subquadrate  (Fig. 89e);  central projection of first pleopod
           without subapical notch (Fig. 109) or, if notch present, central projection either recurved at
           angle distinctly greater than 90 degrees (Fig. 106b, c) or very short (Fig. 106a):...........................
           ..............................................................................................................  JUGICAMBARUS  Hobbs, 1969 (part).

  • Color olive to reddish brown; palm of chela not subquadrate (Fig. 90a);  central projection
    of first pleopod with subapical notch, recurved at angle of approximately 90 degrees, and never
    conspicuously short (Fig. 88d):......................................................................  CAMBARUS  Erichsonm 1846.

10(8).   Mesial margin of palm of chela usually with row of 8 or more tubercles (Figs. 89d, g, 90b, c),
             if only 7 then row with obvious gap:.......................................................................................................  11

  • Mesial margin of palm of chela with row of fewer than 8 tubercles (Fig. 90d, e):...............................  12
Fig. 91.  Dorsal view of carapaces.  a, Cambarus reburrus;  b, C. hubbsi. (cs, cervical spine).

11(10).   Strong cervical spines present (Fig. 91a, cs);  fixed finger of chela often with conspicuous
                deep dorsal and ventral impressions at base (Fig. 90b, c):............................................................
                ............................................................................................................   PUNCTICAMBARUS  Hobbs, 1969.

  • Cervical spines present or absent (Fig. 91b);  fixed finger of chela never with conspicuous
    dorsal and ventral impressions at base (Fig. 89d, g):................................  EREBICAMBARUS  (part).
Fig. 92.  Lateral view of left first pleopods.  a, Cambarus d. diogenes;  b, C. latimanus;  c, C. reduncus;  d, C. halli;  e, C. sphenoides;  f, C. unestami.  (n, subapical notch).

12(10).   Dactyl of chela with broad concavity on basal 1/2 of opposable margin (Fig. 90d);  first
                pleopod with central projection subequal in length to, or shorter than, cephalocaudal
                diameter of shaft at base of projection (Fig. 92a):...................  LACUNICAMBARUS  Hobbs, 1969.

  • Dactyl of chela lacking broad concavity on basal 1/2 of opposable margin (Fig. 90e);
    first pleopod with central projection distinctly longer than cephalocaudal diameter of shaft
    at base of projection (Fig. 92b-d):..................................................  DEPRESSICAMBARUS  Hobbs, 1969.

END OF CAMBARUS SUBGENERA

Last Updated:  10 September 2004