Tide Pool Animal Scientific Names

Scientific classifications for tide pool plants and animals      Phylum > Class > Order > Family* > Genus > Species

(Only the major Classes are shown in list below, * general subgroup of animals sometimes associated with Family but not alwasy, used for organizational purposes only.)

Dodecaceria creates large colonies of animals.

The shells of the animals will fuse together creating a single, large structure
Dodecaceria fewkesi - These animals form large colonies that look like rocks with small holes. The shells or casings of the worms will fuse together forming a large coherent structure. They are filter feeders and use specialized appendages to capture plankton from the water flowing by.
Typical sand castle worm colony in protected high water flow area

Single Sand Castle worms attached to rocks. They usually settle next to other individuals but not always
Large Sand Castle worm colony
More examples of Sand Castle colony
Sand Castle worms need plenty of sand and moving water
Sand Castle worms compete with many other life forms for space

Phragmatopoma californica - ( Sand Castle Worms ) These animals are worms similar to the common garden worms. They build tubes made of sand that are glued together by special proteins. This glue is unique in that it hardens in water. These proteins are being studied for possible commercial use. These worms form large colonies and only live near areas where there is lots of sand and fast moving water.
Crabs and Lobsters
Molt of a striped shore crab

Striped shore crab semi burried in a sea anemone
Striped shore crab
Striped shore crab
Striped shore crab hiding in rock
Juvenile striped shore crab
A few shore crabs hiding in pool of water

Pachygrapsus crassipes - ( Stripped Shore Crab ) These are the most commonly seen crabs in tidepools. They have a dark red and greenish colored shell with legs that have white patches. Shore crabs are very good at detecting predators and are usually seen scurrying away at the first sign of movement. They will hide in small cracks and under rocks. Shore crabs are typically one to two inches wide with larger specimens seen on occasion.
Larger hermit crab attacking smaller hermit crab

Hermit crabs feeding on algae
Hermit crab feeding on algae
Hermit crab
juvenile hermit crabs have white stripes

Pagarus sp. - ( Hermit Crabs ) Hermit crabs are unusual in that they use shells of other animals ( mainly snails ) as their homes. They seem to be always looking out for a “better” home and can frequently be seen battling other hermit crabs for the good shells. Hermit crabs are almost never seen without a shell. Hermit crabs can be identified by looking for small greenish and reddish legs protruding from a snail shell. Some have a blue stripe on the tips of their legs while others have white stripes. Adult Hermit crabs are generally about an inch long but very large specimens have been observed.
DSC00426 Several Species - ( Rock Crabs) This crab is can be identified by an overall reddish brown color. They can grow to several inches in length and are one of the larger crabs found in the intertidal regions. These crabs are well known by seafood lovers as they are sold in restaurants and seafood stores. These crabs are found in sandy areas near the base of rocks.



Panulirus interruptus - ( Spiny Lobster ) >Most visitors to the tidepools or simply beach combing will encounter a lobster, or rather the molt (shell ) of a lobster. Lobsters live in deeper water and seldom are seen in the intertidal zone. Lobsters like other crabs will shed their hard outer shell periodically. This discarded shell is called a molt and this is what most people see washed up on the beach or tidepool.
Group of Gooseneck barnacles

Close up of Gooseneck barnacles
Group of Gooseneck barnacles, smaller Acorn barnacles to left and Buckshot barnacles in lower sections
Gooseneck barnacles clumping on side of rock
Gooseneck barnacles in field of mussels with other smaller barnacles and limpets
Gooseneck barnacles on exposed side of rocks
Clump of Gooseneck barnacles on exposed rock
Gooseneck barnacles along with Red Thatched barnacles
Close up of feeding structure ( Cirri ) in Gooseneck barnacle

Pollicipes polymerus - ( Gooseneck Barnacle ) Gooseneck Barnacles are a common sight in the exposed areas of the middle intertidal zone. They can be identified by several light colored plates that form the top of a cone that sit on top of a dark stalk. These barnacles are typically found in large clumps and often in the midst of mussels. Gooseneck barnacles can grow several inches long depending on the conditions.
Red Thatched Barnacle

Group of Red Thatched Barnacles on rocks
Red Thatched Barnacles in group of mussels and smaller buckshot barnacles
Single Red Thatched Barnacle. Notice closed mouth parts on top.
Two Red Thatched Barnacle next to Acorn Barnacles
Red Thatched Barnacles next to Acorn Barnacles and smaller buckshot barnacles attached to Red Thatched.
Single Red Thatched barnacle in field of buckshot barnacles and limpets

Tetraclita rubescens - ( These barnacles appear reddish in color and have a rough or corrugated outer shell. Adults of this species are typically between ½ and 1 inch in diameter. They live in similar places as other barnacles on exposed rock surfaces. A similar species is the Red Stripped barnacle that is more stripped that a solid reddish color. )
Close up of Acorn barnacle

Acorn and smaller buckshot barnacles
Single large acorn barnacle with smaller buckshot barnacles and periwinkle snails
Acorn and smaller buckshot barnacles
Acorn and smaller buckshot barnacles

Balanus spp. - ( Acorn Barnacles ) These barnacles are small animals that typically live in the mid to upper tidal zone. The color ranges from white to light brown in color. The average adult size is about 1/4 to 1/2 inch wide. They look like a tiny mountain that is a bit larger at the base and tapers near the top. There is an opening at the top where the feeding tentacles emerge. A similar species is the Buckshot Acorn barnacle but the adult size is much smaller.
Close up of buckshot barnacle

Buckshot barnacle on mussel along with larer Red Thatched barnacle
BBarnacles will live almost anywhere, even on an Owl Limpet
Buckshot barnacles
Close up of buckshot barnacles and a few periwinle. Most are 1/4 inch
Buckshot barnacles on side of rock

Chthalamus spp - ( Buckshot Barnacle ) This barnacle closely resembles the Acorn barnacle except that it is much smaller. They can live one most any surface where they can attach to. These barnacles range from 1/8 to 1/4 inch wide for adults. This includes many other animals like limpets, snails, mussels and even other barnacles. Chthalamus has an oval shaped opening whereas the Balanus is diamond shaped. They can settle in very high densities that will cover entire areas of rock. ( other names: grapeshot barnacle, Acorn )
Megabalauns barnacle

Megabalauns barnacle
Megabalauns barnacle

Megabalanus californicus - ( Megabalanus ) This is the most colorful barnacle in the intertidal zone. This particular barnacle lives primarily in the subtidal region and seldom seen in a natural state. The shells of this barnacle however are commonly found attached to mussels that have washed ashore. The shell is red and white stripped and typically found in small groups
Small group of aggregating anemones open in pool of water

Group of open aggregating anemones in water
Large mass of closed aggregating anemones on exposed rock
Group of open and closed aggregating anemones
Group of open and closed aggregating anemones with solataire anemones on right
Large colony of aggregating anemones along with large mussel bed
Open aggregating anemones
Close up of aggregating anemones with bits of shell covering body
Closed aggregating anemones covering upper part of exposed rock

Anthopleura elegantissima - ( Aggregating Anemone ) Aggregating anemones are typically small in size in the adult form. They range from less than an inch in diameter to a little over an inch. They appear pale green when open but most often found closed up and covered with bits of shell and other objects. These anemones also form large colonies composed of hundreds of animals tightly packed together.
Solitary anemone with sand covering oral disk

Anemone in closed state during low tide
Anemone in closed state during low tide
Close up of body area of anemone
Solitary anemones in closed state on exposed rock
Open anemone
Image of solitary anemone just under water
Close up of anemone

Anthopleura sola - ( Solitary Anemone ) Solitary Anemones are the most common non-aggregating anemones. The colors range from bright green, to pale green and even grayish and yellow. When under water, the tentacles are exposed and visible. When the anemone is exposed to air or disturbed, they will close up and sometimes have lots of small bits of shell and other objects attached to the body. ( other names: Sunburst Anemone, Starburst Anemone )
Loan Ochre sea star on rock

Ochre sea stars feeding on mussels
Ochre sea stars feeding on mussels
Ochre sea stars feeding on mussels
Ochre sea stars have different color variations
Single Ochre sea star feeding on mussel
Purple Ochre sea star near similar colored algae
Ochre sea stars exposed at low tide

Pisaster ochraceous - ( Ochre Sea Star ) >This is the most common sea star in the tide pool environment. These sea stars appear in a variety of colors including orange, browns and purple. They live in the lower inter tidal zone and almost always found near mussel and barnacle beds. They may appear higher in the tidal zone wedged inside cracks and nooks where they can preserve moisture and stay cool. When the tide is high they will start moving around looking for food. It has been estimated that an adult Ochre sea star will eat about 80 mussels in a year. Adults are usually between 8-12 inches but larger specimens can be found.
Multicolored bat star in aquarium

Pink colored bat star
Bat star exposed at low tide

Patiria miniata - ( Bat Star ) The Bat star is easily recognizable in that the arms are connected by a web. They also come in a variety of colors ranging from orange, red, purple and others. They are frequently molted and may have more than one color. Bat stars are omnivorous in that they will eat both plant and animals. They are fairly common in the lower inter tidal zone.
Amphiodia occidentalis - ( Brittle Star ) Brittle stars have five arms as other sea stars but the arms are much thinner and longer. They also can use these arms for movement whereas other sea stars rely on their tube feet for moving. This species of brittle star is usually a brownish to darker brown color and found under rocks in the lower tide zone.
Giant sea star in aquarium

Giant sea star
Close up of Giant sea star arm
Close up of Giant sea star eye spot ( red area on tip of arm )

Pisaster giganteus - ( Giant Sea Sta ) The giant sea star ( aka Knobby Sea Star ) is typically brownish to darker brown with lots of short spines that are white with blue rings at the base. This sea star gets its name in that the spines are larger than most other sea stars. Knobby sea stars can grow up to two feet in diameter. They are rarely seen in the tide pools as they typically live much deeper and like to live near kelp forests. They feed on a variety of mollusks.
Pink sea star in aquarium

Pink sea star in aquarium

Pisaster brevispinus - ( Pink Sea Star ) The pink sea star ( aka short spine sea star ) is another larger sea star rarely seen in the tide pools. Larger specimens can reach 2 feet in diameter. They typically live in much deeper water and feed on clams and mollusks.
Lone Purple sea star

Purple sea stars in bottom of pool
Sea stars have a hard test or shell. This is what many visitors find in tidepools
Lots of sea urchins living in pool
Sea urchins lying along cracks in bottom of pool
Sea urchins will stay in the same pool for long periods of time and sometimes their whole life
Lots of sea urchins living in pool

Strongylocentrotus purpuratus - ( Purple Sea Urchin ) The purple sea urchin is the most common sea urchin visitors will see in the tidepool. They have an unmistakable purple color. They are covered by hundreds of spines and tube feet. They are typically a few inches in width an found in pools of water. They prefer to be submerged all the time but on occasion will be caught above water as the tide reseeds.
Red urchin with smaller purple urchins

Deep red colored urchin with smaller purple urchins

Strongylocentrotus franciscanus - ( Red Sea Urchin ) >Red sea urchins range in color from a strong red to a very dark red almost black color. They are a little larger than the purple sea urchins and found in the deeper parts of pools. They are not very common so find one can be tricky. They feed on algae similar to the purple sea urchins.
Lytechinus anamesus - ( White Sea Urchin ) White sea urchins prefer deeper and cooler waters. Adults appear light brown with white and brownish spines. They are not as common as the purple sea urchins and not quite as large. They feed on algae and diatoms.
Adult mussels

Mussel bed. Notice upper limit and lower limit where mussels live
Mussels live in a similar niche as Gooseneck Barnacles
Mussels covered with buckshot barnacles
Mussels attached to rocks. Notice upper and lower boundary
Adult and juvenile mussels
Vast mussels beds
Ochre sea stars feeding on mussels. They are the reason for the lower limit

Mytilus californianus - ( California Mussel ) >This mussel is the most common mussel found in the intertidal zone. They are typically a few inches in length. The deeper and more exposed the location, the larger the mussels can grow. These mussels usually are dark blue and frequently have other animals attached to their shells. The smaller acorn barnacles are commonly found attached to these mussels. This mussel also lives in groups as the larvae when settling will favor locations where mussels currently exist.
Mytilus galloprovincialis - ( Bay Mussel ) >Bay mussels are similar to California mussels in that they appear darker in color. They are usually smaller in size and live lower in the intertidal areas. Bay mussels prefer areas with less wave action than the larger California mussels. Bay mussels also tend to move around a bit more after settling.
Jewel box clam with closed shell. The top part is usually covered with algae and hard to see

Jewel box clam shell. No longer living
Shell of Jewel Box Clam
Shell of Jewel Box Clam
Shell of Jewel Box Clam

Pseudochama exogyra - ( Jewel Box Clam ) This clam is also called the Reversed Chama in some publications. This species prefers to live in the lower intertidal zone with lots of expose to moving water. The shells are frequently covered by algae and other animals. This covering makes for a very good camouflage and difficult for the tidepool visitor to find. Most people see this animal after it has died and the shell is open.
Group of three Black Turban snails

Two larger Black Turban snails with smaller periwinkles
Numerous Black Turban snails that appear lighter in color due to bleached algae on shell
Single Black Turban snail in sand
Black Turban snails will frequently aggregate in shallow cracks and depressions at low tide
Black Turban snails will frequently aggregate in shallow cracks and depressions at low tide

Chlorostoma funebralis - ( Black Turban Snail ) >Probably the most common larger snail found in tide pools. The shells are typically about ½ - 1 inch in diameter. The lower part of the shell is black and the top part of the shell is a light brown or white color. They feed primarily on algae and found in the mid inter tidal zone.
Smaller periwinkles in group of barnacles

Periwinkles can be very small
Periwinkle like other snails will aggregate in small cracks and depressions at low tide
Periwinkle like other snails will aggregate in small cracks and depressions at low tide - close up view
Periwinkle snails feeding on algae in small pool
Periwinkle snails aggregating in cracks of rocks to prevent drying out

Littorina spp. - ( Periwinkle ) This is a very common snail found in the upper intertidal zone. They are small, less than ¼ inch and feed on micro algae that grows on exposed rocks. They can sometimes be hard to see as they are so small. There are three types of Periwinkles found in our tide pools but difficult to distinguish. They are Littorina keenaeLittorina keenae, Littorina scutulata and Littorina plena .
Wavy Top Turban snail

Wavy Top Turban snail

Astraea undosa - ( Wavy Turban Snail ) This is the largest snail found in the inter tidal zone. They are frequently found on sand in shallow areas as well as on rocks. They are herbivores and feed on various types of algae. Not as common as other snails and most visitors find the shell and not the living animal.
Small welk on rock

Two hermit crabs using welk shells
Predatory snail
Predatory snail

Several Genus, Specis - ( Predatory Snails ) There are several different types of predatory snails ranging from welks, murex, horn snails and dog emarginant dog winkles. These snails are characterized by having the spiral of the shell more horizontal oriented than vertically oriented. These snails will slowly move around the tidepool areas looking for mussels, barnacles and other shelled animals to feed on. Animals include Nucella emarginata, Acanthinucella punctulata, Acanthinucella spirata, Ocinebrina circumtexta
Kelp snail on mussel

Kelp snail
Kelp snail feeding on brown algae
Kelp snail with several barnacles growing on shell

Norrisia norrisi - ( Kelp Snail ) A very colorful snail typically with an orange colored shell. They usually live in deeper water and feed on various brown algae. They can be seen at very low tides in the larger brown algae communities. They have a bright orange/red foot and green under part of the shell.
Volcano Limpet on rock

Shell of a Volcano Limpet
Shell of a Volcano Limpet

Fissurella volcano - ( Volcano Limpet ) Volcano Limpets are easily identified by a small hole in the top of the shell. They are typically an inch or less in size and found in the mid intertidal zones. The color of the shell ranges from light brown to red with and have small ridges on the shell. This Limpet can be confused with juvenile giant key whole limpets as they also have a small hole on the top of the shell.
Owl Limpet on rock

Limpet on exposed rock. Notice the open area where the limpet will graze.
Single Owl Limpet in its home range. Owl limpets will graze a certain area
Owl Limpet covered with algae
Owl Limpet covered with buckshot barnacles
Owl Limpet

Lottia gigantea - ( Owl Limpet ) These limpets are one of the more common types of Limpets a visitor will see. They frequent the mid and upper tidal zones. They are commonly seen in large bare patches of rock where they will graze on algae. The shell color is light to medium brown and the shell is generally smooth. Larger Owl limpets frequently have other Limpets and barnacles attached to their shells.
Owl Limpet on rock

Limpet on exposed rock. Notice the open area where the limpet will graze.
Single Owl Limpet in its home range. Owl limpets will graze a certain area

Macklintockia scabra - ( Rough Limpet ) Rough Limpets are small limpets that are generally less than an inch in diameter. They are characterized by having ridges that radiate from the top of the cone out to the edges. The ridges are deep and obvious. Other limpets have ridges but not as deep as the Rough limpets. Rough Limpets range from light brown to darker brown and several other colors ranging on location.
Giant Keyhole Limpet exposed at low tide

Shell of a Giant Keyhole Limpet
Giant Keyhole Limpet with mantle covering entire shell

Megathura crenulata - ( Giant Keyhole Limpet ) The adult giant keyhole limpet is easily identified by its large shell with a single hole on the top of the shell. The shell is typically between 3-5 inches for an adult. These limpets are usually seen with a fleshy mantle that covers the upper part of the shell unlike any other limpet. This fleshy mantle is generally very dark in color.
Various limpets on rocks

Various limpets and buckshot barnacles
Various limpets on rocks
Various limpets on rocks
Limpets will live in depressions in rocks
Various limpets on rocks
Note white limpet on the gooseneck barancle
Various limpets on rocks

Lottia spp. - ( Finger/File/Checkered Limpets ) Limpets in this group are on the smaller side usually about an inch or less in diameter. The color of the shell ranges from brown, green, grey and reddish brown. These limpets are harder to identify as they are quite similar in both appearance and ecology.
Sea Slugs and Nudibranchs
Sea Hare feeding on algae

Sea Hares are very well camouflaged
California Sea Hare
California Sea Hare
California Sea Hare

Aplysia californica - ( California Sea Hare ) This is the most common sea slug found in the inter-tidal region. They prefer to graze on specific kinds of red algae. The pigments in the red algae contribute to the overall coloration of the sea hare. These sea hares are particularly difficult to see as they blend into the environment very well.
Sea Hare feeding on algae

Navanax inermis - ( Stripped Sea Slug ) This sea slug is predatory in that it feeds on other sea slugs, nudibranchs and some snails. The body is generally dark in color with thins blue and orange lines. The body has small white spots. Navanax is typically only a few inches long and found in the water in the lower parts of tide pools, kelp beds and areas with sea grass.
Navanax will track its prey using its keen sense of smell ( chemoreseptors ). The animals will encounter a chemical trail left by a sea slug or other prey item and follow it until it loosed the sent trail ore catches the animal.
Two Hopkins Rose Nudibranchs with a Spanish Shawl

Hopkins Rose on algae looking for bryozoans
Hopkins Rose

Okenia rosacea - ( Hopkins Rose ) The Hopkins Rose Nudibranch is very easily identified as the whole animal is pink in color. This Nudibranch is usually about an inch long. The body is covered by drooping spines that resembles a shaggy dog. This nudibranchs feeds almost exclusively on another very small marine organism called Bryozoans. These are really small animals that form colonies similar to coral.
Two Hopkins Rose Nudibranchs with a Spanish Shawl Flabellina iodine - ( Spanish Shawl ) This nudibranch is also easily identified as it has a bright blue/purple body with orange to yellow appendages ( cerata ). This animal is usually about 1-2 inches in length and found in pools of water closer to the ocean. This animal feeds exclusively on a single species of hydroid a very small marine animal. Spanish Shawls have an interesting defense mechanism. They will swim or flutter away if they are threatened. This swimming however is slow but can be effective against even slower moving predators like the predatory sea slug navinax.
Conspicuous Chiton

Conspicuous Chiton

Stenoplax conspicua - ( Conspicuous Chiton ) These chitons have shell plates that are more regular and straight. The plates appear as light grey with hints of blue color. They can grow quite large. Adults can grow to 3-4 inches in the right conditions. They are typically found under rocks or at the bottom of shallow pits and holes in rocks.
Spiny Chiton

Spiny Chiton
Spiny Chiton
Spiny Chiton
Spiny Chiton are often found at the bottome of small holes in rocks
Spiny Chiton
Spiny Chiton

Nuttallina fluxa - ( Spiny Chiton ) The spiny chiton is the most common chiton in Southern California tide pools. They girdle or fleshy part on the rim of the animal is frequently covered by algae and sometimes will cover the entire animal. Spiny chitons are found in the mid to lower tidal areas that are less exposed to wave action.

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