1a |
With 5 or 6 rays (except
in specimens that have lost a ray,
or that have regenerated extra rays
after being injured) |
2 |
1b |
With 8 to 20 or more rays |
24 |
2a |
With 6 rays; diameter
rarely greater than 11 cm (Note: Some individuals may have 4, 5,
or 7 rays. This may
be a species complex. See
this note from the 1996 edition for more information.) Also check
here for Leptasterias aequalis. |
Leptasterias hexactis |
2b |
With 5 rays; diameter
frequently greater than 11 cm |
3 |
3a |
Rays bordered by conspicuous
marginal
plates that are much larger than any other ossicles
visible at the surface (picture)
(in Hippasteria spinosa, each plate bears a single stout spine,
and in Luidia foliolata each plate bears several spines) |
4 |
3b |
Rays not bordered by
conspicuous marginal
plates (small marginal
plates may be present, but these are not likely to be noted without
magnification) |
11 |
4a |
Marginal plates
not visible when the animal is viewed from above, and the plates either
without spines or with only 1 or 2 stout spines |
Luidia foliolata |
4b |
Marginal plates
visible when the animal is viewed from above, and the plates either without
spines or with only 1 or 2 stout spines |
5 |
5a |
Each marginal
plate with 1 or 2 spines |
6 |
5b |
Marginal plates
without spines |
7 |
6a |
Color of aboral surface
orange to vermilion; aboral
surface with some conspicuous bivalved, unstalked
pedicellariae;
most marginal plates
with 2 spines (Hippasteria spinosa in key) |
Hippasteria phrygiana |
6b |
Color of aboral surface
gray or yellowish; aboral
surface without pedicellariae;
each marginal plate
with a single spine |
Ctenodiscus crispatus |
7a |
Tube feet pointed;
diameter up to about 9 cm |
Leptychaster pacificus |
7b |
Tube feet tipped
with suckers; diameter generally greater than 9 cm |
8 |
8a |
Rays so short that the
body appears almost pentagonal (diameter of the disk
at least three-fourths the total diameter) |
9 |
8b |
Rays not so short that
the body appears almost pentagonal |
10 |
9a |
Flat-topped plates of aboral
surface with 4 to 12 marginal units surrounding 1 to 3 central units |
Ceramaster arcticus |
9b |
Flat-topped plates of aboral
surface with 12 to 15 marginal units surrounding 4 to 12 central units |
Ceramaster patagonicus |
10a |
Aboral surface with
circular paxillae that
consist of numerous granulelike spines, all of which are similar |
Gephyreaster swifti |
10b |
Aboral surface with
circular to oval or hexagonal, flat-topped plates, each consisting of about
25 marginal granules and a central mass of slightly different and less
markedly flattened granules (picture)
(with an odor like that of exploded gunpowder) |
Mediaster aequalis |
11a |
Aboral surface smooth
and slippery, with few if any exposed spines |
12 |
11b |
Aboral surface rough
or gritty due to exposed spines or plates |
13 |
12a |
Thickness equal to about one-third the diameter; aboral
surface with a conspicuous and slightly elevated central opening (this
leads to a spongy cavity that lies between the body wall proper and a superficial
membrane);
madreporite
not visible; color of aboral
surface usually pale orange or brownish yellow; without an odor like that
of exploded gunpowder, but generally secreting a large amount of nearly
gelatinous mucus, especially when first collected; subtidal |
Pteraster tesselatus |
12b |
Thickness less than one-third diameter; aboral
surface without a conspicuous and elevated central opening (there is no
spongy cavity covered by a membrane distinct from the rest of the body
wall); madroporite evident, though sunken; aboral
surface usually reddish brown, with some patches of gray or purple; with
an odor like that of exploded gunpowder, but not secreting a large amount
of nearly gelatinous mucus; intertidal and subtidal |
Dermaterias imbricata |
13a |
Diameter of disk
about one-third to one-half the total diameter (found on the west coast
of Vancouver Island and in California, but rarely if ever encountered in
Washington or Oregon)
(Named Asterina miniata in key) |
Patiria miniata |
13b |
Diameter of disk
much less than one-third total diameter |
14 |
14a |
Pedicellariae
absent; aboral surface
often with the texture of fine sandpaper when rubbed with a finger, but
not noticably spiny when viewed without magnification |
15 |
14b |
Pedicellarie
present; aboral surface
noticeably spiny |
20 |
15 |
Our representatives of the genus Henricia, couplets 15 to 19,
need study. Although all intertidal and nearly all shallow subtidal
specimens will key to H. leviuscula, this species, as presently
understood, is extremely variable. Several subspecies were proposed
by Fisher (1911, 1930) and by Verrill (1914), but they intergrade and no
attempt will be made here to separate them. 2010: The dwarf
mottled Henricia pumila is one
species of this complex that has just been described. See its description
here. |
|
15a |
Plates forming the ridges on the aboral
surface with a single row of conical spines (1-4 spines per plate), these
largely covered with tissue so that they may not at first be distinct (rare
subtidal species; only a few specimens known) |
Henricia asthenactis |
15b |
Plates forming the ridges on the aboral
surface bearing minute, scattered spines or clusters of prominent spines,
or modified as spiny paxillae,
all of these elements exposed and readily apparent with magnification |
16 |
16a |
Diameter of meshlike areas on the aboral
surface appreciably greater than the width of the ridges that separate
them (the ridges bear minute, scattered spines or clusters of spines whose
length is commonly 1 to 1.5 mm) |
17 |
16b |
Diameter of meshlike areas on the aboral
surface no greater than, and generally less than, the diameter of the spiny
paxillae
that separate them |
18 |
17a |
Ridges separating the meshlike areas of the aboral
surface with scattered, minute spines (aboral
surface yellow to brick red; rare subtidal species) |
Henricia aspera |
17b |
Ridges separating the meshlike areas of the aboral
surface with radiating clusters of sharp spines (these commonly 1 to 1.5
mm long, and 2-9 in a cluster) (aboral
surface mostly white; rare subtidal species) |
Henricia longispina |
18a |
Marginal plates
prominent and arranged in 3 distinct rows; rays
not thickened so much at the base that they are separated from one another
by a crease that extends into the disk
(aboral surface usually
orange, brick-red, or brown, but sometimes cream or some other color; color
not always uniform, and there may be mottling, gray patches, etc.) |
19 |
18b |
Marginal plates
not prominent and not forming distinct rows; rays
usually noticeably thickened at the base and separated from one another
by a crease that extends into the disk
(color off-white to orange; subtidal) |
Henricia sanguinolenta |
19a |
Genital pores (located between the rays)
slightly aboral with
respect to the margin of the disk;
diameter frequently exceeding 8 cm; color uniformly orange or orange-red,
or with a disk
of a different color than the rays
(the disk is
sometimes mottled, but the rays
are not mottled); females not known to brood young (common intertidal and
subtidal species) (Note from 1996 key: Specimens keying to Henricia
leviuscula belong to this species and to what may be an undescribed
species or hybrid.
H. leviuscula reaches a diameter of about 10
cm and its aboral surface
is uniformly orange. Specimens of about the same size, but orange-red
or pinkish in color, are perhaps distinct. Another color morph reaches
a diameter of about 15 cm; it is mostly orange or reddish and has gray
or lavender patches where the rays
join the disk.) |
Henricia leviuscula |
19b |
Genital pores slightly oral
with respect to the margin of the disk;
diameter rarely greater than 5 cm; disk
and rays irregularly mottled;
females brooding young under oral
surface in winter or early spring (intertidal and subtidal)
An apparently undescribed species, believed to be conspecific with
the "brooding variety" of H. leviuscula reported by Fisher (1911)
(Henricia sp. in original key) |
Henricia pumila. |
20a |
Spines on upper parts of aboral
surface generally not higher than 2 mm, typically in irregular clusters
or arranged in networklike pattern, though some may be single and some
may be in short rows; most pedicellariae
in raised, hemispherical cushions that have a central spine |
21 |
20b |
Spines on upper parts of aboral
surface
mostly 3-5 mm, typically well seperated and more inclined to form poorly
defined rows than clusters or networks; most pedicellariae
concentrated in raised, hemispherical cushions that have a central spine |
23 |
21a |
Diameter of disk
not more than one-sixth the total diameter; rays
typically broadest a short distance way from the disk;
jaws of the straight pedicellariae
not forked at their tips into a pair of blades; color extremely variable,
may be gray, greenish, brown, orange, or red, but not likely to be purple
or pink |
Evasterias troschelii |
21b |
Diameter of disk
usually greater than one-fifth the total diameter; rays
typically broadest where they join the disk;
jaws of the straight pedicellariae
forked at their tips into a pair of unequal blades; color generally orange,
orange-ochre, brown, purple, or some shade of pink |
22 |
22a |
Spines on upper parts of aboral
surface usually arranged in a networklike pattern; color orange, orange-ochre,
brown, or purple; diameter not often exceeding 25 cm; intertidal and subtidal  |
Pisaster ochraceus |
22b |
Spines on upper parts of aboral
surface usually single or clustered, but sometimes arranged in a networklike
pattern; color some shade of pink; diameter commonly exceeding 25 cm, and
sometimes exceeding 40 cm; almost strictly subtidal |
Pisaster brevispinus |
23a |
Prevailing coloration of aboral
surface
some shade of red, often concentrated in blotches or bands that contrast
with a light background; teeth on jaws of crossed pedicellariae
essentially a series of small serrations, none of them fanglike; intertidal
and subtidal |
Orthasterias koehleri |
23b |
Prevailing coloration of aboral
surface dark brown, olive, or gray, without any obvious reddish tones;
teeth on jaws of crossed pedicellariae
long, the pair at the tip of each jaw fanglike; subtidal |
Stylasterias forreri |
24a |
With 8-16 rays (except
in very small individuals); without pedicellariae;
body not flabby; diameter not exceeding 50 cm |
25 |
24b |
With 20-24 rays (except
in very small individuals); with pedicellariae;
body flabby when separated from the substratum; diameter up to 80 cm |
Pycnopodia helianthoides |
25a |
Paxillae of aboral
surface rather widely separated and giving rise to long, slender spines
of uneven length (thus the aboral
surface appears prickly) |
Crossaster papposus |
25b |
Paxillae of aboral
surface crowded, giving rise only to short, blunt projections (thus the
aboral
surface is rather smooth) |
26 |
26a |
Diameter of disk
usually about 1/4 the total diameter; aboral
surface usually some shade of orange or pink, with a grayish blue streak
radiating from the center of the disk
to the tip of each ray;
intertidal and subtidal |
Solaster stimpsoni |
26b |
Diameter of disk
usually about 1/3 the total diameter; aboral
surface usually orange, brown, or gray, without conspicuous darker streaks
radiating from the center of the disk |
27 |
27a |
Rays (of which tere
are 8-10) typically narrowing rapidly just after leaving the base, thus
becoming slender rather quickly; aboral
surface usually orange; subtidal and extremely rare |
Solaster paxillatus |
27b |
Rays typically tapering
rather evenly from the base; aboral
surface usually orange, brown, or gray; common subtidal species |
28 |
28a |
With 7-13 rays (usually
8-11); paxillae of aboral
surface almost contiguous; aboral
surface usually pale orange, sometimes orange-red |
Solaster endeca |
28b |
With 8-16 rays (usually
11 or 12); paxillae
of aboral surface separated
from one another for a distance about equal to their diameter; aboral
surface usually gray or brown, but sometimes orange, and occasionally showing
a mottled pattern in which there are 2 shades of brown |
Solaster dawsoni |