Abstract
The individual habitats of 9 species of sea anemones
found in 3 areas of different exposure are described. Two
species, Cnidopus ritteri (Torrey, 1902), and Diadumine li
1955, not previously reported from Monterey Peninsula,
Hand,
California are noted, along with the more commonly occurring
species, Anthopleura elegantissima (Brandt,1835), Cactosoma
arenaria Carlgren, 1931, Corynactus californica Carlgren, 1936,
Epiactis prolifera Verrill, 1869, Telia coriacea (Cuvier, 1798),
Telia lofõtensis (Danielssen, 1890). The presence of Tetraclita
squamosa and coralline algae as wave-dissipators appears to
affect the distribution of some anemones in the intertidal.
A possible competitive interaction for space between Antho-
californica, a chiton, is
pleura elegantissima and Nuttallins
described.
Introduction
This paper examines the intertidal distribution of anem-
one species at three locations on the southern part of the
Monterey Peninsula. No previous study of this distribution
has been made in this area. Previous work by Hand (1954) fo-
cused primarily on identification and classification of anem-
ones found here and elsewhere in central California. This
study will focus on habitat discriptions for anemones found
at three locations.
Study Areas
Pescadero Point, Mission Point, and Stillwater Cove
vary widely with respect to exposure and substrate. Though
within a three mile radius, the conditions at the three sites
range from the most exposed area of the Peninsula (Pescadero
Point) to the most sheltered area (Stillwater Cove).
Pescadero Point (121°57'14"W, 36°33'16"N) is comprised of
large granite boulders directly exposed to wave and swell action.
With the 10-fathom line only 150m offshore and with no inter-
vening islands, little wave energy is dissipated before the
waves break upon the rocks. A significant feature of the
granite boulders is the abundance of weathered cracks 18-307cm
in width. Plant life consists of Egregia menziesii and
articulated corallines on the outer rock faces, with Iridaea
flaccida the dominant alga of the inner, more protected rocks.
Phyllospadix scouleri (Spermatophyta) is present in the surge
channels between the boulders. Mytilus californianus (Bivalvia)
and Pollicipes polymerus (Cirripedia) form beds on the exposed
rocks. Wave refraction, the conyerging of waves on an exposed
point, insures surf action at Pescadero Point on even calm
days.
Stillwater Cove, situated immediately south of Pescadero
Point, provides a sharp contrast to Pescadero Point. Offshore
islands, shallow water (10-fathom line approximately 600 m
offshore), and a Macrocystis bed several hundred meters thick
damp much of the wave action. The soft sandstone substrate
has suffered extensive erosion, leaving several sandstone
spits (75x20 m) in the area of study. Parts of the sandstone
spits are pock-marked with holes 1-3 cm deep by 3-4 cm diameter.
These holes are occupied by either the chiton Nuttallina
alifornica, or the anemone Anthopleura elegantissima.
A small Mytilus-Pollicipes-Tetraclita squamosa community
exists on the outermosttportions of these spits, but, in
general, waves do not sweep the sandstone even at higher
high water. Dominant algae of this community include Macrocystis
integrifolia, Ulva spp., and Porphyra perforata.
Mission Point, weat and south of Pescadero Point, combines
granite substratum With moderate exposure, thus forming a
study area intermédiate in physical characteristics between
Pescadero Point and Stillwater Cove, A dense offshore kelp
bed, moderately shallow water (10-fathom line 400 m offshore),
and the situation of the Point in the middle of a bay reduce
wave exposure. This area is additionally characterized by a
granite sand beach, sheltered tide pools, and jumbled granite
boulders forming a 40 m peninsüla. Boulders support Mytilus,
Pollicipes, and Balanus, with chitons, nudibranchs, and hermit
crabs inhabiting the tide pools. Algae include Ulva spp.,
Iridaea flaccida, Egregia menziesii, and Endocladia muricata.
Methods
Anemones were studied at each study site for distribution
with respect to tidal height, abundance, community organisms,
and physical microenvironment. Identification was made
using Hand's Key to Anthozoa in Lights Manual (1975), Hand's
monograph on anemones in central California (1954), and a
paper on Cnidopus ritteri (Torrey) by Hand and Dunn (1974).
Both field and laboratory observations were made for identi-
fication of anemones, though gross physical characteristics
easily seen in the field were sufficient for most species.
No special equipment was used in performing the field studies,
other than wooden frame quadrats and meter sticks.
Anemones described in paper:
Anthopleura elegantissima (Brandt, 1835)
Anthopleura xanthogrammica (Brandt, 1835)
Cactosoma arenaria Carlgren, 1931
Cnidopus ritteri (Torrey, 1902)
Corynactis californica Carlgren, 1936
Diadumine lighti Hand, 1955
Epiactis prolifera Verrill, 1869
Telia coriacea (Cuvier, 1798)
Telia lofotensis (Danielssen, 1890)
Anthopleura elegantissima (Brandt, 1835)
This ubiquitous anemone was found at all three study sites,
ranging from -2ft to +14 ft tidal level. The greatest vertical
range was found, as expected, at Pescadero Point where the
splash zone extends over +20 ft on days of moderate sea.
Only occasionally were these anemones found under algal
cover—their most frequent location at these three sites is
unshaded by plant life.
At Pescadero Point, anemones on rocks exposed to surf
or surge inhabit cracks in rocks. Density of population
ranges from 0-30 anemones per linear meter of crack for
the most exposed cracks, to 60-120 anemones per meter for the
less exposed cracks. Areas of heavy Iridaea flaccida cover
yielded no A. elegantissima. One area of heavy articulated
coralline alga cover does support a population of small
(+1 cm diameter) anemones. This horizontal granite shelf
extendsd from -2 to 0.0 ft tidellevel and is exposed to strong
wave action. On exposed rocks, the community consists of
Mytilus californianus, Pollicipes polymerus, generally above
A. elegantissima, Strongylocentrotus purpuratus, A. xanthogrammica,
Katharina tunicata among the anemones, and Haliotis cracheroddi
below A. elegantissima.
The A. elegantissima of Stillwater Cove inhabit the
holes in the sandstone and tide pools. The anemones extend
in a band 18-36 cm wide along the vertical face of a sandstone
spit, from O to 43 ft level. Other holes in the sandstone
are occupied by the chiton Nuttallina californica, and the
alga Corallina vancouveriensis. Aspects of this community
will be discussed later in this paper. Anemones were also
found at 0.0 ft level living among Ulva
Anemones at Mission Point range from rocks imbedded in
sand at shoreline to the higher portions (+3 to 4 ft) of rocks
farther out. Their distribution here parallels their distri-
bution at Hopkins Marine Station. At Mission Point, anemones
living on shaded rock surfaces show a spacing apart of in-
dividuals (1-4 cm). Anemones on the same rock living on an
unshaded side are clumped tbgether, individuals touching each
other.
Anthopleura xanthogrammica (Brandt, 1835)
This anemone was found at all three study sites. At
Pescadero Point and Mission Point, A.xanthogrammica lives
in the same habitat as A.elegantissima--cracks or other
areas offering some protection from wave shock, areas free of
overgrowing Iridaea flaccida-but lower in the intertidal than
A. elegantissima. At Stillwater Cove no A. xanthogrammica
were observed living in the pockmarks on vertical faces of the
sandstone spits; here A. xanthogrammica are confined to tide-
poolsgandtidal flats. None was observed in areas of Macrocystis.
Cactosoma arenaria Carlgren, 1931
This small (30-60 mm diam.) orange anemone was found only
at Stillwater Cove. A useful trait for field identification
is the very rapid retraction of tentacles, oral disc, and
upper third of column by the anemone upon disturbance. The
speed of retraction mimics that of the serpulid worm Spirobis.
At Stillwater Cove,tthese anemones were found in two
habitats: on crustose and articulated coralline algae covered
rocks, and among Phyllospalix roots. Population densities
measured for the tidal range of +.5 to -1 ft were 7/m among
Phyllöspadix and 17/me on coralline covered rocks. Both
habitats are located in regions of Macrocystis holdfasts.
Other members of the Cactosoma community include the anemones
Epiactis prolifera Verrill, 1869, and Diadumine lighti Hand,
1955.
Cactosoma requires sheltered water. Areas of similar
habitat but more wave exposure at Pescadero and Mission Points
do not support populations of Cactosoma.
Cnidopus ritteri (Torrey, 1902)
This anemone was first described from a specimen taken
in Alaskan waters. Later work has shown that its range ex-
tends into Oregon and California, as far south as Shell Beach,
Sonoma County, (Hand and Dunn, 1974). This anemone was also
found at Stillwater Cove, in the -2 ft tide level. Here,
it is located among Macrocystis, attached to rock in crevices
and depressions. This habitat also contains sand, which the
anemone attaches to its column.
Cnidopus does not appear to be abundant in the intertidal
at Stillwater Cove. Only two specimens were observed in a
30 mx 30 m area. A total of five specimens were found,
and ranged in size from 4 to 6 cm expanded diameter.
A kelp bed on the southern end of Monastery Beach, south-
west of the study areas, contains larger specimens (approx¬
imately 12 cm expanded diameter) and in greater abundance,
C
at approximately 25 ft depth, indicating that the anemone
may be primarily a subtidal species.
Corynactis californica Carlgren, 1936
This anemone was found at Pescadero Point and at Mission
Point. At both locations, the preferred habitat is shaded
cracks and crevides, areas protected from wave shock and
sunlight in the low intertidal. Specimens were found also
in higher tidepools. Members of the Corynactis community
include the alga Petrocelis franciscana and, at Pescadero,
the solitary coral Balanophyllia elegans Verrill, 1864.
Diadumine lighti Hand 1955
Previously reported only at Hopkins Marine Station by
Hand, (1955), this anemone was also found at Stillwater Cove,
There, Diadumine lighti occupies the same habitat as Cactosoma
arenaria: coralline algae covered rocks and Macrocystis holdfasts.
Superficially resembling Cactosoma in appearance, the small,
(30-60 mm diameter) orange-yellow anemone may be easily dis-
tinguished from Cactosoma in the field by its slower retraction.
Hand, (1955), reports population densities of 1087m
among Gigartina spp.,holdfasts at Hopkins Marine Station.
Measured population densities at Stillwater Cove range from
.5 to 1 per m’. Actual population density may be greater
than measured, due to the difficulty in spotting these small
anemones.
Epiactis prolifera Verrill, 1869
This anemone was found at all 3 study sites. Tidal
height ranged from -1 to +3 ft. Exposure to wave shock
ranged from slight to heavy (but see discussion—Microenviron-
ment), indicating that this anemone is less fragile than
Cactosoma or Diadumine, two members of its community at Still-
water Cove. FEpiactis was found on crustose coralline algae
covered rocks and among Macrocystis holdfasts at Stillwater
Cove. At Mission Point, the anemone grows on jumbled boulders
in the mid to low intertidal, living with Tonicella lineata,
a chiton, Iridaea flaccida, and Telia coriacea. At Pescadero
Point, Epiactis was unexpectedly found on an extremely exposed
rocky ledge covered with coralline algae. Measured density
at this exposed location was 15/m2.
Telia coriacea (Cuvier, 1798)
This anemone is common at Pescadero Point and Mission
Point. At Pescadero, the anemones live in cracks, predom-
inantly on the wave sheltered side of boulders. Maximum
population density observed was 57m of crack. At Mission
Point, populaion densitjes of both Anthopleura xanthogrammica
and T. coriacea equal 1 per 4 or 5 m2 in themid intertidal
(+1 ft). As at Pescadero, anemones were located in areas
sheltered from waves.
At both study areas T. coriacea was found in shaded locations.
The shade was provided either by the dense algal cover, or
by rock (deep cracks, overhanging ledges). Often anemones
were found half buried in the gravel which had collected in
those cracks, or depressions containing anemones. Contrary
to Hand (1955), T. coriacea was also found in gravel-free areas
at both Mission and Pesdadero Points. Vertical distribution
observed was -1 to +3 ft. tidal level.
The T. coriacea community is characterized by dense
algal cover. Among species observed in greatest abundance
are Iridaea flaccida, and Egregia menziesii. The algal cover
can be either denselj attached such as provided by Iridaea,
or sparsely attached but with abundant floating fronds (Egregia).
A single Egregia with long stipes can provide several meters
of shade to anemones in cracks. To a lesser extent, these
anemones were observed in Phyllospadix beds.
Tealia lofotensis (Danielssen, 1890)
T. lofotensis is primarily a subtidal anemone. However,
Stillwater Cove and Mission Pont each yielded one specimen
in the intertidal. Both anemones were found at the +3 ft
tide level. At Stillwater Cove, the anemone was located on
a horizontal sandstone shelf. well shaded from the sunlight.
The Mission Point anemone was also well shaded, due to its
location in a deep ++ meter) crack.
The communities for these anemones consisted of the
Anthopleura elegantissima community at Stillwater Cove and the
Mission Point Corynactis californica community. However,
due to the rare occurance of T. lufotensis in these communities,
in my study regions, I do not believe that these two communities
are truly representative of the anemone. As one observer
of the intertidal has noted, "If you look long enough, you
can find almost anything, anywhere."
Discussion
Microenvironment
One main advantage of a field study is the opportunity
it offers to obseive interactions between members of a comm¬
unity. Living space is a prime factor governing population
size and distribution in the intertidal. Not all space in
thejintertidal is suitable for anemones. At Pescadero Point
the amant of exposure to wave shock governs, in many instances,
the amount of space suitable for Anthopleura elegantissima
colonization. However, the microenvironment the anemone actuall;
faces is not necessarily the environment one sees.
At Pescadero Point, A. elegantissima concentrates its
population in cracks and crevices. Rarely are any concentrations
of anemones found on flat, exposed rock surfaces. In two
instances, though, other members of the community have modified
the exposedd environment to a sheltered microenvironment that
supports anemones. Tetraclita squamosa, an acorn barnacle,
has colonized some exposed parts of Pescadero Point. Where
populations of crack-dwelling anemones abut populations of
this barnacle, limited anemone colonization of the "exposed"
areas has occurred: the anemones are interspersed with the
barnacles. By diminishing the shearing force of surge,
Tetraclite has modified the microenvironment of the anemones
settling on exposed rock faces. Here the presence of a living-
space competitor favorably modifies the environment, providing
additional room for anemone colonization.
In a similar manner, coralline algae have allowed anemones
to colonize an exposed granite slope at Pescadero. A thick
cover of articulated algae shelters A. elegantissima and
Epiactis prolifera at the -2 ft to 0.0 ft level. Though
appearing to be an area of strong wave action, actual water
shear force on the base rock had been greatly reduced by the
bed of algae. The microenvironment modification opens the
area to anemone colonization.
Nuttallina californica and Anthopleura elegantissima
At Stillwater Cove a competition for the holes in the
sandstone may exist between A. elegantissima and the chiton
Nuttallina. In areas with no anemones, the chitons occupy
holes from O.O to +4 ft. In areas with no chitons, the anemones
occupy holes from 0.O to 44 ft. In areas with both, however,
the anemones exist in a band 18-36 cm wide starting at about the
+2 ft level and extending upwards. The chitons exist in an
essentially non-overlapping band directly adjacent to and
below the band of anemones.
The presence of a straight horizontal boundaryssuggests
a border maintenance factor of some sort. Because both pop-
ulations are able to extend higher and lower when separated,
tidal height per se, appears not to be the controlling factor.
No short-term (1-3 day) aggression, or other interactions
between the two organisms were observed in the labaratory.
No interactions were observed in the field at low tide. This
border problem requires further research.
Summar
Nine anemone species were found, including two (Cnidopus
c
ritteri (Torrey, 1902),and Diadumine li
ghti Hand, 1955,pre-
viously not reported for this area. Hand, (1954), report:
finding three additional species in this area:
lcampa decemtentaculata Hand,1954. "Garmel".
Metridium exilis Hand,1955. "Carmel Cove"
Telia crassicornis (Mueller, 1776)."As far south
as Carmel".
I was unable to find these species at my study sites.
The effects of other animal species on anemone distribution
in the intertidal are not well understood. The Nuttallina
lifornica/Anthopleura elegantissima interaction provides
a relationship future investigators may wish to utilize in the
study of biological interaction.
Acknowledgement
I would like to thank Dr. Isabella Abbott for her help-
ful comments and criticism of this study. Also I would like
to express my appreciation to the Del Monte Foundation for
allowing me access to Pescadero Point and Stillwater Cove.
Literature Cited
Hand, C.
1954. The sea anemones of central California. Part I,
The corallimorpharian and athenarian anemones.
Wasmann J. Biol. 12:345-375
1955. Part II. The endomyarian and mesomyarianaanemones.
Wasmann J. Biol. 13:37-99
1955. Part III. The acontiarian anemones.
Wasmann J. Biol. 13:189-251.
1975. Key to the Anthozoa in: Light's Manual:
Intertidal Invertebrates of the Central
California Coast. Smith, R.I., and J.J. Carlton
(eds.). U. of California Press, Berkeley. 716p.
Hand,
C. and D. Dunn
1974. Redescription and Range Extension of the Sea Anemone
nidopus ritteri (Torrey)
(Coelenterata: Actiniaria).
Wasmann J. Biol. 32 (2):183-194.
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