"Coastal view, Cabrillo National Monument, 2015." by U.S. National Park Service , public domain
![]() | Field GuidesIntertidal Guide |
Intertidal Field Guide for Cabrillo National Monument (NM) in California. Published by the National Park Service (NPS).
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Intertidal
Field Guide
C ABRILLO N ATION AL MONUMENT
C ABRILLO N ATION AL MONUMENT
Intertidal
Field Guide
About the
Ecosystem
Field
Guide
Our
Role
Cabrillo
Guide
1
C ABRILLO N ATION AL MONUMENT
About the Ecosystem
Welcome to one of the world’s rarest
ecosystems. This vast expanse, where land
meets sea, supports a thriving body of
marine organisms and plants all adapted to
live under the harsh environmental
pressures characteristic of this area.
Dictated by the gravitational pull of the
moon and sun, the tides predictably flow in
and out cyclically creating a low, high, and
middle tidal zone. Each of these zones
supports a distinctive community waiting
for you to explore. Use this guide to help
you in your adventure and discover the
organisms that call the intertidal home.
Intertidal Safety Tips
• Remember this area is federally protected;
taking of any kind is against the law.
• Only explore in designated areas.
• Be respectful of the critters that live here;
avoid disturbing their homes, and only
touch gently with two fingers.
• Waves and algae can make the area
extremely slippery. Wear sturdy shoes and
step with caution.
• Be aware of the incoming tide. Do not
turn your back to the waves and make
sure you can always reach dry land.
R E T U R N T O 2H O M E P A G E
C ABRILLO N ATION AL MONUMENT
Field Guide
WHAT ARE YOU LOOKING AT?
Invertebrates
Marine Plants
• Lack a spinal column
• May have exoskeleton
• Gain nutrients from the sun
• Provide food for ecosystem
Fish
Marine Mammals
• Aquatic vertebrates
• Use gills to breathe
• Breathe air and have hair
• Give birth to live young
3
FIELD GUIDE
Invertebrates
Invertebrates
without Exoskeleton
Invertebrates with
Exoskeleton
R E T U R N T O 4F I E L D G U I D E
F I EFL IDE LGDU G
I DUEI D E
F I E LF D
I DUEI D E
I E LGDU G
FIELD GUIDE
Invertebrates
without
Invertebrates
without
Black
Sea Hare E
Invertebrates
without
Invertebrates
without
Invertebrates
without
Exoskeleto
Invertebrates
without
Exoskeleton
Dorid
Hermissenda
Invertebrates without Exoskeleton
FIELD GUIDE
Aggregating Anemone
Exoskeleton
ates
without
Exoskeleton
Black
Sea
Hare
Sea Hare
Dorid
Black
Sea
Hare
atesNavanax
withoutBrown
Exoskeleton
Black
Sea
Hare
Black
Sea
Hare
Anemone
Solitary
Anemone
Brooding
Anemone
Black
Sea
Hare
Black
Sea
Hare Brooding
Aggregating Anemone
Aggregating
Anemone
Aggregating
Anemone
Aggregating
Anemone
Aggregating
Anemone
Aggregating
Anemone
Brown
Sea
Hare
Brooding
Anemone
Brooding
Anemone
Hopkins
Rose
Brown
Sea
Black
Sea
Hare
Brooding
Anemone
Brown
Sea
Hare
Brown
Sea Hare
BlackSea
Sea
Hare
Brown
Hare
Dorid
Spanish
Shawl
Brown Sea Hare
UIDE
5
Dorid
Dorid
Hermissenda
Navanax
Dorid
Dorid
Nudibranch
Dorid
Dorid
Hermissenda
RETURN TO INVERTEBRATES
Hermissenda
Nudibranch
Dorid
Hermissenda
Dorid
Hopkins
Rose
Hopkins
Rose
Hopkins
Rose
Nudibranch
Hopkins
Rose
Hermissenda
Hopkins
Two-Spot
Octopus
Hermissenda
Hopkins
Rose
Navanax
Hopkins
Rose
Navanax
Solitary Anemone
RETURN TO FIELD GUIDE
Two-Spot
Octopus
Solitary
Anemone
Navanax
Two-Spot
Octopus
Two-Spot
Solitary
Anemone
Navanax
Solitary
Anemone Two-Spot
Two-Spot
Octopus
SpanishOctopus
Shawl
Two-Spot Octopus
Spanish Shawl
RETURN TO FIELD GUIDE
Spanish Navanax
Shawl
Nudibranch
Navanax
Spanish
Shawl
Navanax
Solitary
Anemone
Navanax
RETURN
5
RETURN T
Spanish
Shawl
Spanish
Shawl
Spanish
Shawl
Spanish
Shawl
TO INVERTEBRATES
R E T U5R N T O F I E L D G U I D E
RETURN
5
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T
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N
T
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5
5
RETURN TO FIELD GUIDE
R E T U R N T O I N V E R T E B R A T E S RE ET TUUR R
5
RETURN TO FIELD GUIDE
RETURN T
INVERTEBRATES
Aggregating Anemone
Anthopleura elegantissima
Tidal Zone: High to Middle
Description: 5-7cm in diameter when open. Closes
during low tide and is covered with shells and sand.
Distribution: Alaska to Baja California
Interesting Facts: To reproduce, individual anemones
divide and separate into two new anemones of the same sex.
RETURN TO FIELD GUIDE
R E T U R N T O6 I N V E R T E B R A T E S W I T H O U T E X O S K E L E T O N
INVERTEBRATES
Solitary Anemone
Anthopleura sola
Tidal Zone: Low to Subtidal
Description: A 7-10 cm disc rimmed with tentacles;
usually light green with stripes extending from the center.
Distribution: Alaska to Panama
Interesting Facts: The stinging cells, or nematocysts, in
their tentacles are used to capture food.
RETURN TO FIELD GUIDE
R E T U R N T O 7I N V E R T E B R A T E S W I T H O U T E X O S K E L E T O N
INVERTEBRATES
Brooding Anemone
Eplactis Prolifera
Tidal Zone: Low
Description: Orange, red, or brown 2 cm disc.
Distribution: Alaska to Southern California
Interesting Facts: Eggs are fertilized within the body of
the adult, then released out of its mouth.
RETURN TO FIELD GUIDE
R E T U R N T O 8I N V E R T E B R A T E S W I T H O U T E X O S K E L E T O N
INVERTEBRATES
Black Sea Hare
Aplysia vaccaria
Tidal Zone: Low to Subtidal
Description: Dark purple to black sea slug that grows up
to 76 cm long.
Distribution: Southern California to Baja California
Interesting Facts: Unlike the California Sea Hare, this
species does not ink. Instead, its primary defense is
camouflage. This is the largest of all sea slugs.
RETURN TO FIELD GUIDE
R E T U R N T O 9I N V E R T E B R A T E S W I T H O U T E X O S K E L E T O N
INVERTEBRATES
Brown Sea Hare
Aplysia californica
Tidal Zone: Low
Description: Rusty brown to red sea slug with dark
streaks or spots. 12 cm - 15 cm long.
Distribution: Northern California to Baja California
Interesting Facts: Gets its coloration from the red algae
it eats. This species will ink like an octopus when disturbed.
RETURN TO FIELD GUIDE
R E T U R N T O 10I N V E R T E B R A T E S W I T H O U T E X O S K E L E T O N
INVERTEBRATES
Dorid Nudibranch
Diaulula sandiegensis
Tidal Zone: Middle to Low
Description: Small, tan-bodied sea slug with dark brown
or black rings on its back. Up to 7.6 cm long and 5 cm wide.
Distribution: Pacific Coast from Northern Japan to Baja
California
Interesting Facts: Feeds on sponges found on the
undersides of rocks.
RETURN TO FIELD GUIDE
R E T U R N T O 11I N V E R T E B R A T E S W I T H O U T E X O S K E L E T O N
INVERTEBRATES
Hermissenda Nudibranch
Hermissenda crassicornis
Tidal Zone: Low
Description: Small, 5 cm long sea slug with transparent
gray, white, or blue body. The tentacle-like cerata on its back
can be red, orange, green, brown, or black.
Distribution: Alaska to Baja California
Interesting Facts: The tips of the cerata contain
stinging cells, or nematocysts.
RETURN TO FIELD GUIDE
R E T U R N T O 12I N V E R T E B R A T E S W I T H O U T E X O S K E L E T O N
INVERTEBRATES
Hopkins Rose Nudibranch
Hopkinsia rosacea
Tidal Zone: Low
Description: Small sea slug, 2.5 cm in length, with a red
body and pink fleshy appendagescovering the body.
Distribution: Oregon to Baja California
Interesting Facts: This sea slug derives its color from
the rose-colored bryozoan, or small encrusting invertebrate,
it feeds on.
RETURN TO FIELD GUIDE
R E T U R N T O 13I N V E R T E B R A T E S W I T H O U T E X O S K E L E T O N
INVERTEBRATES
Spanish Shawl Nudibranch
Flabellina Iodinea
Tidal Zone: Low to Subtidal
Description: A small sea slug about 8 cm long with a
bright purple body and orange tentacle-like cerata on its
back. The ear-like rhinophores are a deep red color.
Distribution: British Columbia to Baja California
Interesting Facts: This nudibranch can flatten its body
and swim by bending back and forth to propel itself through
the water
RETURN TO FIELD GUIDE
R E T U R N T O 14I N V E R T E B R A T E S W I T H O U T E X O S K E L E T O N
INVERTEBRATES
Navanax
Navanax inermis
Tidal Zone: Low to Subtidal
Description: A 7-10 cm long sea slug that is black with a
series of orange, yellow, and blue dashes, spots, and stripes.
Distribution: Northern California to Baja California
Interesting Facts: This species of sea slug is carnivorous
and feeds on soft-bodied snails. Will also expel a yellow ink
when threatened.
RETURN TO FIELD GUIDE
R E T U R N T O 15I N V E R T E B R A T E S W I T H O U T E X O S K E L E T O N
INVERTEBRATES
Two-Spot Octopus
Octopus bimaculoides
Tidal Zone: Low to Subtidal
Description: The body can be from 5-20 cm in length
with arms three-times the length of the body. Has two dark
spots ringed with blue below the eyes, hence its name.
Distribution: Central California to Baja California
Interesting Facts: Masters of camouflage, octopuses
can change the color and texture of their skin. They will also
release a dark black ink when threatened.
RETURN TO FIELD GUIDE
R E T U R N T O 16I N V E R T E B R A T E S W I T H O U T E X O S K E L E T O N
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Invertebrates
Invertebrates with
with Exoskeleton
Exoskeleton
Sea
Sea Stars
Stars
Crustaceans
Crustaceans
Shelled
Shelled Invertebrates
Invertebrates
Other
Other
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Sea
Stars
Sea Stars
Banded
Brittle
Banded Brittle
Bat
Star
Bat Star
Knobby Sea Star
Ochre
Sea
Star
Knobby Sea
Sea Star
Star
Ochre Sea Star Knobby
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RETURN TO FIELD GUIDE
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INVERTEBRATES
Banded Brittle Star
Ophionereis annulata
Tidal Zone: Middle
Description: Small, round, brown body with five 10-12
cm long gray legs marked with brown bands.
Distribution: Southern California to Panama
Interesting Facts: Arms will easily break off when
disturbed, but will regrow.
RETURN TO FIELD GUIDE
19
RETURN TO SEA S TARS
INVERTEBRATES
Bat Star
Patiria miniata
Tidal Zone: Low to Subtidal
Description: Averaging 7.5 cm in diameter with five
triangular shaped legs. Usually orange in color.
Distribution: Alaska to Baja California
Interesting Facts: This species is omnivorous (eats both
plants and animals).
RETURN TO FIELD GUIDE
20
RETURN TO SEA S TARS
INVERTEBRATES
Ochre Sea Star
Pisaster ochraceus
Tidal Zone: Low to Subtidal
Description: Diameter of 45 cm - 50 cm. They range in
color from yellow, orange, brown, red, or purple.
Distribution: Alaska to Baja California
Interesting Facts: Once one of the most prolific sea
stars on the West Coast, this species was recently decimated
by Sea Star Wasting Disease.
RETURN TO FIELD GUIDE
21
RETURN TO SEA S TARS
INVERTEBRATES
Knobby Sea Star
Pisaster giganteus
Tidal Zone: Low to Subtidal
Description: A tan or brown base with blunt blue spines
tipped with purple, pink, or white. Usually about 36 cm - 48
cm in diameter.
Distribution: British Columbia to Baja California
Interesting Facts: Sea Stars eat their prey by expelling
their stomach and digesting prey externally.
RETURN TO FIELD GUIDE
22
RETURN TO SEA S TARS
rtebrates
Crustaceans
FIELD GUIDE
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Crustaceans
FIELD GUIDE
Blue-Legged
ns
Crustaceans
Snail
Hermit Crab
Globose
Kelp Crab
Chiton
Globose
pnacles
Crab Gray
Kelp
Crab
StripedWhelk
Shore Crab
Rock
CrabRock Kellet’s
Crab
Periwinkle
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etriped
Crab Shore
Crab
Spiny
Lobster
Spiny
s
Owl Limpet
RETURN TO FIELD GUIDE
Rock
Roc
Spiny
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23
Lobster
Thatched Barnacle
RETURN TO INVERTEBRATES WITH EXOSKELETON
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INVERTEBRATES
Blue-Legged Hermit Crab
Pagurus samuelis
Tidal Zone: High to Middle
Description: Shells about 2.5 cm in height with bright
blue color bands on their legs.
Distribution: British Columbia to Baja California
Interesting Facts: They favor empty Black Turban
Snail shells and feed on the remains of animals and plant
material.
RETURN TO FIELD GUIDE
24
RETURN TO SHELLED INVERTEBRATES
INVERTEBRATES
Globose Kelp Crab
Taliepus nuttalli
Tidal Zone: Low to Subtidal
Description: Purple to reddish brown, 10 cm body with
an overall diameter of 30 cm including the legs.
Distribution: Central California to Baja California
Interesting Facts: Feed on large kelp species, such as
Giant Kelp and Feather Boa Kelp.
RETURN TO FIELD GUIDE
25
RETURN TO CRUS TACEANS
IN
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Rock
Rock Crab
Crab
Cancer
Cancerproductus
productus
TidalZone:
Zone: Low to Subtidal
Tidal
Description: Red to brown oval crab 12 cm wide with
Description:
large
mouth
pieces
that
point
forward.
Adults
have
a
fringe
Distribution:
Distribution:
of hair on lower body surface and legs.
InterestingFacts:
Facts:
Interesting
Distribution: Oregon to Baja California
Interesting Facts: This species is known to feed on
hermit crabs.
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INVERTEBRATES
Striped Shore Crab
Pachygrapsus crassipes
Tidal Zone: High to Middle
Description: This crab can grow up to 5 cm wide and
has a square-shaped body in shades of red, purple, or green
with lateral stripes.
Distribution: Oregon to Baja California
Interesting Facts: They are scavengers, but can also
prey upon snails, limpets, and hermit crabs.
RETURN TO FIELD GUIDE
27
RETURN TO CRUS TACEANS
INVERTEBRATES
Spiny Lobster
Panulirus interruptus
Tidal Zone: Low to Subtidal
Description: Those found in the tidepools are usually
juveniles averaging about 30 cm in length. Brick red in color
with orange stripe down the legs.
Distribution: Southern California to Mexico
Interesting Facts: Lacking claws, like their east coast
relatives, these lobsters have spines on their bodies and sharp
tail segments for protection.
RETURN TO FIELD GUIDE
28
RETURN TO CRUS TACEANS
FFIIEELLDD G
GUUIIDDEE
FIELD GUIDE
FIELD GUIDE
FIELD GUIDE
Blue-Legged
Shelled Invertebrates
Invertebrates
Shelled
Shelled Invertebrates
Shelled
Shelled Inverteb
Chiton
Hermit
Crab
Blue-Legged
Gray
Periwinkle Black
Kellet’s
Whelk
Turban Snail
Barnacles
Turban
Snail Black
Barnacles
Hermit Crab
Blue-Legged
dChestnut
Invertebrates
brates
Thatched
Barnacle
Turban
Snail
Gray
Periwinkle
Chiton
Barnacles
Owl
Limpet
Chestnut
Cowry
Chiton
Black
Turban
Snail Black
Barnacles
Turban
Snail Black
Gray
Periwinkle
Turban
Snail
Cowry Black
Barnacles
Kellet’s
Whelk
Barnacles
Barnacles
Hermit
Crab
Blue-Legged
Blue-Legged
Barnacles
Gooseneck Barnacles Gooseneck
Hermit
HermitCrab
Crab
Blue-Legged
Blue-Legged
Barnacles
Gray
Periwinkle
Chestnut
Cowry
Gooseneck
Barnacles
Kellet’s
Whelk
Keyhole
Limpet
Kellet’s
Whelk
Gray
Periwinkle
Mussels
Owl
Limpet
Thatched
Barnacle
Chestnut
Cowry
Gooseneck
Barnacles
Gooseneck
Barnacles
Black
Turban
Snail Gooseneck
Chestnut
Cowry
Gray
Periwinkle
Chiton
Chestnut
Cowry
Keyhole
Limpet
Chiton
Chestnut
Cowry
Mussels
Owl
Limpet
Chiton
Hermit Crab
Hermit Crab
28T O
INVERTEBRATES WITH EXOSKELETON
Barnacle
Keyhole
Limpet
Mussels
Owl
Limpet
Worm
Snail Keyhole
Wavy
Turban
Snail Thatched
Thatched
Barnacle
Gooseneck
Barnacles
Keyhole
Limpet
Gray
Periwinkle
Keyhole
Limpet
Mussels
Owl
Limpet
Scaled
Worm
Snail Scaled
Wavy
Turban
Snail
Kellet’s
Whelk
Kellet’s
Whelk
Gray
Periwinkle
Keyhole
Limpet
Limpet
Mussels
Owl
Mussels
Limpet
Kellet’s
Whelk
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Scaled
Worm
Snail
Scaled
Worm
Snail
Thatched
Barnacle
Mussels
Owl
Limpet
Wavy
Turban
Snail
Wavy
Turban
Snail
Worm Snail
Barnacle
Scaled
Worm
Snail Thatched
Scaled
Wavy Turban
Worm
Snail
Snail Scaled
Wavy Turban
Thatched
Barnacle
Owl Limpet
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INVERTEBRATES
Barnacles
Balanus spp.
Tidal Zone: High to Low
Description: Averaging 1 cm - 15 cm depending on
species. Cream, brown, or pink in color.
Distribution: Canada to Baja California
Interesting Facts: Attach to rocks with their antennae
and feed with their feathery legs at high tide.
RETURN TO FIELD GUIDE
30
RETURN TO SHELLED INVERTEBRATES
INVERTEBRATES
Thatched Barnacle
Tetraclita rubescens
Tidal Zone: Middle to Low
Description: 2-4 cm diameter pink to red shells that
grow into the shape of a volcano.
Distribution: Northern California to Baja California
Interesting Facts: Juveniles are white, turning red once
mature.
RETURN TO FIELD GUIDE
31
RETURN TO SHELLED INVERTEBRATES
INVERTEBRATES
Gooseneck Barnacles
Pollicipies polymerus
Tidal Zone: High to Middle
Description: Grey to white clusters of individuals from
10-15cm in length grouped on surface of rocks.
Distribution: British Columbia to Baja California
Interesting Facts: The body is covered with plates and
scales for protection.
RETURN TO FIELD GUIDE
32
RETURN TO SHELLED INVERTEBRATES
INVERTEBRATES
Chiton
Nuttalina fluxa
Tidal Zone: High to Middle
Description: Narrow, eight-plated oval 2.5 cm - 3.5 cm
in length. Dark brown to brownish-yellow.
Distribution: Central California to Baja California
Interesting Facts: Can live up to 20 - 25 years. Create
pits in the rock to trap algae for food and to hold water
during low tide.
RETURN TO FIELD GUIDE
33
RETURN TO SHELLED INVERTEBRATES
INVERTEBRATES
Black Turban Snail
Tegula funebralis
Tidal Zone: High to Middle
Description: Smooth, dark, purple-black with white tip
of shell. 2 cm - 4 cm in height.
Distribution: British Columbia to Baja California
Interesting Facts: Empty Black Turban Snail shells are
a favorite of Hermit Crabs.
RETURN TO FIELD GUIDE
34
RETURN TO SHELLED INVERTEBRATES
INVERTEBRATES
Blue-Legged Hermit Crab
Pagurus samuelis
Tidal Zone: High to Middle
Description: Shells about 2.5 cm in height with bright
blue color bands on their legs.
Distribution: British Columbia to Baja California
Interesting Facts: They favor empty Black Turban
Snail shells and feed on the remains of animals and plant
material.
RETURN TO FIELD GUIDE
35
RETURN TO SHELLED INVERTEBRATES
INVERTEBRATES
Gray Periwinkle
Littorina planaxis
Tidal Zone: High
Description: Small, grayish-brown snail roughly 1.5 cm
tall.
Distribution: Washington to Baja California
Interesting Facts: Unlike most other marine animals,
this snail can survive in fresh water.
RETURN TO FIELD GUIDE
36
RETURN TO SHELLED INVERTEBRATES
INVERTEBRATES
Chesnut Cowry
Neobernaya spadicea
Tidal Zone: Low to Subtidal
Description: Snail with a 3.8 cm - 6.3 cm long shell.
Shell is a light Chestnut brown with a dark brown band that
separates a white base.
Distribution: Central California to Baja California
Interesting Facts: In the summer, females deposit 100
or more egg capsules, each capsule containing hundreds of
eggs.
RETURN TO FIELD GUIDE
37
RETURN TO SHELLED INVERTEBRATES
INVERTEBRATES
Kellet’s Whelk
Kelletia kelletii
Tidal Zone: Middle to Low
Description: A sea snail with a spiraled, spindle-shaped
shell up to 17.5 cm in length.
Distribution: Northern California to Baja California
Interesting Facts: Predatory sea snail that is also a
scavenger. Feeds using a long proboscis that helps the snail
sense its environment.
RETURN TO FIELD GUIDE
38
RETURN TO SHELLED INVERTEBRATES
INVERTEBRATES
Wavy Turban Snail
Megastraea undosa
Tidal Zone: Low to Subtidal
Description: A large snail with a spiraling conical
shaped shell 5 - 10 cm in height.
Distribution: Central California to Baja California
Interesting Facts: An active snail that moves around the
rocks in search of algae to eat.
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INVERTEBRATES
Keyhole Limpet
Megathura crenulata
Tidal Zone: Low
Description: An oval shaped snail growing up to 10 cm
in length. The shell is covered with a fleshy mantle, or
covering, that can be solid black, brown, mottled, or striped.
Distribution: Central California to Baja California
Interesting Facts: The "keyhole" at the top of the shell
is used to expel solid and liquid waste.
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INVERTEBRATES
Mussels
Mytilus californianus
Tidal Zone: High to Middle
Description: A dark purple to black, teardrop-shaped
bivalved mollusk, grouped in masses called "beds" on rocks.
Distribution: Alaska to Baja California
Interesting Facts: Mussels attach themselves to rocks
with strong hair-like strands called byssal threads.
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INVERTEBRATES
Owl Limpet
Lottia gigantea
Tidal Zone: High
Description: 2-6 cm mollusk with a flattened cap-like
shell. They feed on algae and use their strong "foot" to stay
attached to the rocks.
Distribution: Washington to Baja California
Interesting Facts: Members of this species are born
male and turn into females when they reach a certain size
(about 4 cm).
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INVERTEBRATES
Scaled Worm Snail
Thylacodes squamigerus
Tidal Zone: Middle to Low
Description: This snail lives in curvy tubes 12-15 cm
long and about 1.3 cm in diameter. These snails group in
masses under rocks and in crevices.
Distribution: Northern California to Baja California
Interesting Facts: These snails feed by secreting a
triangle-shaped mucus fan. They wave this fan into the
current to collect organisms and detritus floating by.
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INVERTEBRATES
Sand-Castle Worms
Phragmatopoma californica
Tidal Zone: Middle
Description: A 5 cm long worm that builds large
colonies under and between rocks. They cement sand grains
to form the tubes they live in, building large honeycombshaped colonies.
Distribution: Northern California to Baja California
Interesting Facts: The worms are hidden in their tubes
at low tide, but reach out tentacles to feed during high tide.
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RETURN
44 T O I N V E R T E B R A T E S W I T H E X O S K E L E T O N
FIELD GUIDE
Marine Plants
Coralline Algae
Dead Man’s Fingers Feather Boa Kelp
Plocamium
Rockweed
Seagrass
Sea Bubble
Sea Lettuce
Wire Weed
R E T U R N T O 45
FIELD GUIDE
MARINE PLANTS
Coralline Algae
Corallina spp.
Tidal Zone: Low to Subtidal
Description: A red algae with calcium carbonate
segments, giving it a pink or white color.
Distribution: Globally
Interesting Facts: This algae is stiff and crunchy to the
touch due to the calcium carbonate segments.
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MARINE PLANTS
Dead Man’s Fingers
Codium fragile
Tidal Zone: Low to Subtidal
Description: A dark green algae that forms finger-like
branches up to 30 cm long and 1 cm in diameter. It attaches
to rocks at a base point and hangs off the rock at low tide.
Distribution: Temperate waters worldwide
Interesting Facts: A single Dead Man's Fingers plant is
said to be only one large cell because there are no cell walls
separating one nucleus from another.
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MARINE PLANTS
Feather Boa Kelp
Egregia menziesii
Tidal Zone: Middle to Low
Description: A dark brown algae that grows from a
holdfast, or base, up to 5 m long. Blades about 5 cm long
grow from a flattened center 'stipe' that give it a feather boa
look.
Distribution: Alaska to Baja California
Interesting Facts: The seaweed limpet (Notoacmea insessa)
exclusively feeds and lives on this kelp.
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MARINE PLANTS
Plocamium
Plocamium pacificum
Tidal Zone: Middle to Low
Description: Red algae with a height of about 50 cm;
bright red fanning branches give it a lace-like appearance.
Distribution: Temperate waters worldwide
Interesting Facts: Some species fronds are annual,
growing back each year from the base.
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MARINE PLANTS
Rockweed
Silvetia compressa
Tidal Zone: Middle to Low
Description: An olive brown to yellowish brown algae
that grows about 30 - 90 cm in length. Thick, narrow fronds
cover rocks to form beds.
Distribution: British Columbia to Baja California
Interesting Facts: Supports many other animals within
its beds by creating a damp microhabitat.
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MARINE PLANTS
Seagrass
Phyllospadix scouleri
Tidal Zone: Middle to Low
Description: Green blades about 2 mm wide and up to
90 cm long. Grows from base clumps and spreads using a
root-like system of rhizomes.
Distribution: Alaska to Baja California
Interesting Facts: This is a flowering plant with male
and female flowers on different plants.
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MARINE PLANTS
Sea Bubble
Colpomenia spp.
Tidal Zone: Middle to Low
Description: A brown algae forming thin hollow bubbles
ranging in size, up to 30 cm in diameter and 10 cm high.
Distribution: Globally
Interesting Facts: This algae has been known to grow
on oysters and carry them away when the bubble gets large
enough.
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MARINE PLANTS
Sea Lettuce
Ulva californica
Tidal Zone: Middle to Low
Description: An emerald green algae that grows like
turf on top of rocks.
Distribution: Alaska to Baja California
Interesting Facts: This algae is only two cells thick.
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MARINE PLANTS
Wire Weed
Sargassum muticum
Tidal Zone: Middle to Low
Description: A brown algae growing from a holdfast up
to 10 m in length with small air sacks.
Distribution: Native to the East Coast of Japan; now
found globally
Interesting Facts: This invasive species was introduced
to the California Coast in the 1940s and, while now
abundant, can be toxic to native species that try to eat it.
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FIELD GUIDE
Fish
Garibaldi
Opaleye
Leopard Shark
Moray Eel
Wooly Sculpin
R E T U R N T O 55
FIELD GUIDE
FISH
Garibaldi
Hypsypops rubicundus
Tidal Zone: Low to Subtidal
Description: The largest of the Damselfish family, these
bright orange fish average about 30 cm in length. The
juveniles have bright blue spots until they mature.
Distribution: Northern California to Baja California
Interesting Facts: This territorial fish is the state marine
fish of California.
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FISH
Opaleye (Rudderfish)
Girella nigricans
Tidal Zone: Low to Subtidal
Description: Juveniles in the tidepools average 5 - 10 cm
and adults are 45 - 60 cm in length. They are a dark olive
green with two light spots on either side of the dorsal fin.
Distribution: Northern California to Baja California
Interesting Facts: The juveniles can breathe air when
exposed at low tide.
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FISH
Leopard Shark
Triakis semifasciata
Tidal Zone: Subtidal
Description: A silvery-gray shark up to 2 m long with
dark oval spots across its back and spots on its sides.
Distribution: Oregon to Central Mexico
Interesting Facts: Females keep fertilized eggs inside
them and can give birth to as many as 33 live pups after a 10
- 12 month gestation period.
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FISH
Moray Eel
Gymnothorax mordax
Tidal Zone: Low to Subtidal
Description: With a light brown or green snakelike body that is up to 1.5 m in length, these fish hide in rock
crevices and wait to ambush their prey.
Distribution: Central California to Baja California
Interesting Facts: This eel has to open and close its
mouth to breathe, which can be misinterpreted as aggressive
behavior.
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FISH
Wooly Sculpin
Clinocottus analis
Tidal Zone: Low to Subtidal
Description: This fish comes in many colors (brown,
green, and reddish colorations) and is about 18 cm in length
when fully grown.
Distribution: Northern California to Baja California
Interesting Facts: This intertidal fish can breathe air for
up to 24 hours if exposed at low tide.
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FIELD GUIDE
Marine Mammals
Gray Whale
Harbor Seal
Bottlenose Dolphin California Sea Lion
R E T U R N T O 61
FIELD GUIDE
MAMMALS
Gray Whale
Eschrichtius robustus
Tidal Zone: Coastal Waters
Description: Roughly 15 m in length and weighs up to
35,000 kg with characteristic dorsal "hump".
Distribution: Pacific Ocean
Interesting Facts: These whales feed on the ocean floor
by swimming on their sides and scooping up sand. They use
their baleen to filter out amphipods (small crustaceans).
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MAMMALS
Common Harbor Seal
Phoca vitulina
Tidal Zone: Coastal Waters
Description: A dark tan, gray, or silver-white speckled
seal about 2 m long that weighs about 120 kg. This seal will
haul-out on rocks and beaches to rest when not feeding.
Distribution: British Columbia to Baja California
Interesting Facts: They have distinct V-Shaped nostrils
and no ear flap because they are a true seal.
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MAMMALS
Common Bottlenose Dolphin
Tursiops truncatus
Tidal Zone: Coastal Waters
Description: A gray dolphin averaging 3 - 4 m in length
and weighing about 498 kg. They have a short, thick snout
with a curved mouth.
Distribution: Oceans in Tropical and Temperate zones
Interesting Facts: Bottlenose dolphins use echolocation,
or the echo from loud, rapid clicks, to hunt for prey.
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MAMMALS
California Sea Lion
Zalophus californianus
Tidal Zone: Coastal Waters
Description: Dark to golden brown. Males about 3 m in
length and a prominent forehead called a sagittal crest.
Females are smaller in stature and lack the sagittal crest.
Distribution: Alaska to Baja California
Interesting Facts: Distinguished from seals by their ear
flaps, loud bark, and the ability to “walk” on land using their
flippers.
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C ABRILLO N ATION AL MONUMENT
Our Role
The core mission of the National Park
Service is to protect and preserve natural
resources, processes, systems, and values
of America’s parks. Our philosophy is to
protect, and restore when necessary,
native ecosystems and let natural processes
play out. Park Rangers and Volunteers
document their observations of flora and
fauna. Scientists conduct research to try to
understand the status and trends of the
species and systems they protect. This
information is vital to advising park
management and philosophy.
Connect With Us
To learn more about how
you can help, visit:
• NPS Website
• Field Notes
R E T U R N T O 66H O M E P A G E
C ABRILLO N ATION AL MONUMENT
Cabrillo Guide
Rules for Exploration:
Activity:
• No running nor swimming
1. How do these marine animals
survive when it’s a low tide?
• Stay on the marked trails/sidewalks
• No picking or taking of any kind
• Pack it in, pack it out - No littering
2. How many different species of flora
and fauna you can count on one rock?
R E T U R N T O 67H O M E P A G E
C ABRILLO N ATION AL MONUMENT
All Rights Reserved © 2017
Editor: Nicole Ornelas
Photos: N. Ornelas, P. Simpson,
J. & W. Tam, S. Root
Sources: A. Rosales
Life Between the Tides - Brandon & Rokop
Cabrillo National Monument
1800 Cabrillo Memorial Drive
San Diego, Ca. 92106
WWW.NPS.GOV/CABR
R E T U R N T O 68H O M E P A G E