Tag Archive: tidepool

Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Clade: Vetigastropoda
Superfamily: Trochoidea
Family: Turbinidae

Genus/specie: Megastraea undosa

GENERAL CHARACTERISTICS: The Wavy Turbin Snail has a heavy, sculptured shell with undulating ridges in a turbinate-conical shape with a thick, pearly lining.
The light brown or tan shell color is caused by the fibrous periostracum covered with coralline algae and other epiphytes.

Size: up to 6 inches

DISTRIBUTION/HABITAT: Found from Point Conception and the coastal Channel Islands to northern Baja California, Mexico. They range from the intertidal zone down to depths of over 250 feet.

DIET IN THE WILD: M. undosa are herbivores feeding on various types of algae.

REPRODUCTION; Year around with peaks in spring and fall.

CONSERVATION: Because wavy turban snails are hand-picked by divers, the fishery is at low risk for bycatch .
Wavy turban snails are abundantly available and have a high productivity rate, so over- harvesting is less likely.

REMARKS: The shells of wavy turban snails are used to make buttons!

The meat has an abalone-like texture and taste; foot of the snail is processed and sold to restaurants as an abalone-like product, “wav alone”.  They can be prepared many ways: grilled, sautéed, battered and fried, in pastas, in chowders and soups, and in stir fries.


California Academy of Sciences Steinhart Aquarium Tidepool 2017

Ron’s flickr https://www.flickr.com/photos/cas_docents/34539982943/in/dateposted-public/

Spearboard.com www.spearboard.com/showthread.php?t=99314

U of CA San Diego caseagrant.ucsd.edu/sites/default/files/fact-sheet-wavy-t…

Gastropods.com www.gastropods.com/2/Shell_292.shtml

Ron’s WordPress Shortlink  http://wp.me/p1DZ4b-1Qf

Kingdom: Animalia
Phylum: Echinodermata
Class: Asteroidea
Order: Forcipulatida
Family: Asteriidae

Genus/species: Pisaster ochraceus

GENERAL CHARACTERISTICS: Color varies from orange, violet, dark brown or mottled, but very rarely ochre. One study showed that less than two percent of the individuals in three local Northern California populations were “ochre” in color. When dead and dry they become ochre in color.

The aboral surface contains many small spines (ossicles) that are arranged in a netlike or pentagonal pattern. Papulae or coelomic pouches give the seastar’s surface a soft, fuzzy appearance. They are used for respiration and waste excretion. P. ochraceus may have an arm radius of up to 28 cm (11 in), but the more common radius is half that figure. They typically have five arms or rays, but the number can range from four to seven. Like all sea stars, an adult P. ochraceus has tube feet which they use for locomotion and for handling prey.

DISTRIBUTION/HABITAT: Ochre stars range from Alaska to Santa Barbara County, California. They prefer the low-to-mid intertidal zones on rocky shores, especially on mussel beds, and are also found in the subtidal zone to a depth of 88 m (288 ft). Juveniles are found in crevices and under rocks.

DIET IN THE WILD: California mussels are the favored and locally abundant prey. They also consume acorn barnacles, emarginated dogwinkles, gooseneck barnacles, owl limpets, etc. They can insert their stomach into slits as narrow as 0.1 mm between the valves of bivalves and begin digestion.

ACADEMY DIET: Manila clams, chopped fish, large krill, chopped squid; it also eats other exhibit inhabitants.

REPRODUCTION: They are mainly dioecious (separate sexes). Male gametes are produced, but at a later date only females gametes are produced. During a transitional period, both eggs and sperm are produced. The gonopores of the individual gonads open at the bases of the arms. Fertilization is external. Larvae are free-swimming and plankton-feeding.

LIFESPAN: Up to 20 years

PREDATORS: Adults are eaten by sea otters and seagulls. According to Dr. Thomas Niesen, the sea otter can crunch them up but is also known to bite off the tips of the arms and suck out the gonads.

REMARKS:  One study showed that less than 2% of the individuals in three local Northern California populations were “ochre” in color. When dead and dry they become ochre in color.

P. ochraceus tolerate strong surges, large temperature changes, dilution by rainfall. It is resistant to desiccation and it can tolerate a loss of thirty-percent of its body weight in body fluids.

Sea stars can regenerate lost arms with a portion of the central disc intact and in some species from a single arm.

NOTE:   SEA STAR WASTING SYNDROME has become a major issue in both the Pacific and Atlantic Oceans since 2013. For an excellent summary check this link to the University of Santa Cruz 9-9-14.  http://www.eeb.ucsc.edu/pacificrockyintertidal/data-products/sea-star-wasting/updates.htm

Fitzgerald Marine Reserve. www.fitzgeraldreserve.org/newffmrsite/wp-content/uploads/...

11-17-14 Recent research identifies a virus (Parvoviridae) to be responsible for the wasting disease. Introduced virus was able to infect healthy sea stars with the virus, which then leads to the wasting symptoms. Published in the Proceedings of the National Academy of Science. http://theconversation.com/mystery-virus-that-turned-millions-of-starfish-into-goo-is-finally-identified-34336


Additional References

California Academy of Sciences Docent Tidepool Guide 2015

Woods Hole www.whoi.edu/science/B/people/kamaral/SeaStar.html

Bishop Museum hbs.bishopmuseum.org/pubs-online/pdf/op11-8.pdf

Encyclopedia of Life  eol.org/pages/598469/details

Animal Diversity Web, U of Michigan  animaldiversity.ummz.umich.edu/accounts/Pisaster_ochraceus/

Ron’s WordPress Shortlink  http://wp.me/p1DZ4b-sC

Ron’s flickr  https://www.flickr.com/photos/cas_docents/3407968572/in/set-72157608501343477/


Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Subclass: Hexacorallia (includes stony corals, all sea anemones, tube anemones, and zoanthids)
Order: Actiniaria (sea anemones)
Family: Actiniidae (largest family of sea anemones)

Genus/species: Anthopleura elegantissima

GENERAL CHARACTERISTICS: Most are olive to bright green (depending on the species of algal symbionts present) with tentacles tipped in pink. The oral disk has approximately 100 tentacles in three or four rows around its margins. Those that are deficient in photosynthetically active radiation, such as under docks or in caves, lack symbionts and are pale yellow to white in color.
Disc 2-3 cm (0.78-1.2 in) across, under water.

Aggregating Anemones23710001752_0cf3a8e808_k

DISTRIBUTION/HABITAT: Common in tide pools. The body of the anemone is firmly attached to rock substrate and detritus and sand adheres to the column almost covering them.

DIET IN THE WILD: Capture tiny crustaceans and other animals past their tentacles using their stinging nematocysts (also called cnidocytes) on the surface of their tentacles.

REPRODUCTION: To clone themselves, anemones split in half tearing themselves apart (asexual reproduction). Aggregating anemones also reproduce sexually by broadcasting eggs and sperm.

PREDATORS: Their are few known predators but include the nudibranch Aeolidia papillosa, leather star Dermasterias imbricata and mosshead sculpin Clinocottus globiceps.

REMARKS: When one colony of genetically identical polyps encounters a different genetic colony, the two will wage territorial battles. A. elegantissima has specialized tentacles called acrorhagi to deter non identical colonies from encroaching on their space. It extends the acrorhagi to attack the competing anemone with nematocytes leaving behind a ‘peel’ of the ectoderm and nematocysts that causes tissue necrosis in the receiving animal.


California Academy of Sciences Tidepool

Ron’s flickr  https://www.flickr.com/photos/cas_docents/23710001752/in/album-72157625127345346/

Encyclopedia of Life  eol.org/data_objects/27560182

Ron’s WordPress shortlink  http://wp.me/p1DZ4b-1D1

Monterey Bay Aquarium www.montereybayaquarium.org/animal-guide/invertebrates/ag…

Slatter Museum of the U. of Puget Sound www.pugetsound.edu/academics/academic-resources/slater-mu…

Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Gobiesocidae

Genus/species: Gobiesox maeandricus

GENERAL CHARACTERISTICS: Like all clingfish, the northern clingfish possesses an adhesive disc, partially developed from the pelvic fins, that allows it to cling tightly to rocks or blades of kelp even in strong currents or crashing waves. The tapering, tadpole-shaped body, about 17 cm (6.5 in) long, has a single, posteriorly located dorsal fin, a fanlike caudal fin, no spines, and a flattened head. The skin is smooth and scaleless, with a thick layer of protective mucus. Its cryptic coloration makes the animal difficult to see among rocks or kelp.

DISTRIBUTION/ HABITAT: The family totals about 150 species worldwide; only 2 – the northern kelpfish (Gobiesox maeandricus) and the kelp clingfish (Rimicola muscarum) are found in northern California. They are bottom-dwelling fishes, typically found on or under rocks or high up in the kelp.

DIET IN THE WILD: Worms, molluscs, small crabs and other crustaceans.

PREDATORS: The clingfish is preyed upon by various aquatic animals that hunt among the rocks at high tide, and terrestrial predators such as snakes and raccoons that hunt at low tide.

REPRODUCTION: The male nudges the female’s belly. If she accepts him, the male moves parallel to her and quivers, stimulating egg laying. Fertilized eggs are deposited on stones, algae, or other bottom material, and are usually guarded by the male. Larvae are planktonic. Life span is about two years.

CONSERVATION: IUCN Red List Status Not Evaluated 

REMARKS: Like a number of other bottom-dwelling fishes, clingfish lack swim bladders, an internal sac used by the majority of fish species to control their position in the water. Clingfish can adhere so tightly to a surface that a rock might be moved some distance by strong currents with the fish still attached! Its suction cup also holds water from which the fish can extract oxygen even when exposed by a low tide.


California Academy of Sciences Tidepool Docent Guide 2015

fishbase  www.fishbase.org/summary/3075

Eschmeyer, W.N., E.S. Herald and H. Hammann, 1983. A field guide to Pacific coast fishes of North America. Houghton Mifflin Company, Boston, U.S.A. 336 p.

Encyclopedia of Life eol.org/pages/203811/details

Ron’s flickr  http://www.flickr.com/photos/cas_docents/sets/72157626486149324/

Ron’s WordPress shortlink  http://wp.me/p1DZ4b-vx

Phylum Cnidaria
Class Anthozoa
Subclass Zoantharia
Order Actiniaria (anemones)
Family Actiniidae

Genus/species: Anthopleura xanthogrammica

GENERAL CHARACTERISTICS: A  solitary species and one of the largest species of anemone in the world. Column to 30 cm (12 in) tall and 30 cm (12 in) tentacular crown with 25 cm (10 in ) diameter mid base. The base bottom is only slightly larger than column diameter and adheres to rocks.  Tentacles are green, blue, or white without pink on the tips.  No marks or bands.  The oral disk is flat and usually green, but can be grayish-blue to greenish-blue.  Contracted animals form a green to dark greenish-brown, occasionally white hemispherical mound.

DISTRIBUTION/HABITAT: Alaska to Panama in prefers rocky areas and deeper tide pools of the low to middle intertidal zones to 9 m (30 ft), and wharf pilings. Usually solitary; in favorable locations can occur in numbers to 14 per square m.

DIET IN THE WILD: Detached mussels and sea urchins, also take crabs and small fishes. Zoochlorellae endosymbionts supplement host’s diet.

PREDATORS: Nudibranchs, snails, sea spiders and some sea stars, especially leather stars.

REPRODUCTION: A. xanthogrammica have separate sexes releasing sperm and eggs in late spring to summer. The larvae swim or float freely. They do not use asexual reproduction.


REMARKS: Some fishes and the hermit crab Pagurus samuelis develop protection from the anemone’s toxins by covering themselves with mucus that prevents them from being stung.

The bright green can be attributed to green pigment in the anemone epidermis and to symbiotic algae that live in the tissues that line the gut. Inside there may be zoochorellae (green algae) or zooxanthellae, which are dinoflagellates. The symbiotic algae are reduced in numbers or even absent (aposymbiotic) when in shady areas.

LOCATION: Tidepool and California coast.


Walla Walla University


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Phylum: Mollusca
Class: Bivalvia
Order: Filibranchia
Family: Mytilidae

Genus/species: Mytilus californianus

GENERAL CHARACTERISTICS: California mussels are relatively large mussels, with a blue-black shell with strong radial ribs and irregular growth lines. Maximum size is about 13 cm (5 in). The shell surface is often worn and eroded.


DISTRIBUTION/HABITAT:  California mussels form extensive beds, commonly mixed with gooseneck barnacles (Pollicipes polymerus). Attached firmly to the substrate by tough proteinaceous byssal threads, mussels are able to thrive in the most surf-swept areas. Mussel beds break the force of waves and collect organic debris, and so provide shelter and food for other organisms. Worms, chitons, snails, clams, isopods, crabs, and sea cucumbers are among the invertebrates found in mussel beds.

The upper limit of the mussel beds is set primarily by physical factors, particularly time out of water. The lower limit is set in part by the predation of the ochre star (Pisaster ochraceus), which practices vertical foraging, moving up and down with the tides. Mussels range from low intertidal to 40 m (131 ft) deep and are common in surf-swept, rocky areas, and are found from Alaska to southern Baja California.


DIET IN THE WILD: Mussels filter fine organic detritus and living plankton from sea water. A mussel filters 1.8 l to 2.8 l (2 to 3 qts) of water an hour.


PREDATORS: California mussels are favored food items of seas stars (especially ochre stars), crabs, predatory snails, shorebirds, sea otters, and humans. Sea otters have devastated formerly extensive mussel beds in Monterey Bay.


REPRODUCTION: Mussels are either male or female. During breeding they broadcast sperm or eggs into the sea where fertilization occurs. They spawn November to May. Mussel larvae are free-swimming for about four weeks. After settling and attachment they grow to full size in about three years.



  • The California mussel attaches to rocks by fibers called byssal threads. These threads are produced as a liquid by the byssal gland. The liquid runs down a groove formed by the foot. When the foot pulls back, exposing the liquid to sea water, the liquid solidifies into a thread.
  • A large mussel moves by breaking old threads, then attaching new ones to another spot; a small mussel creeps around on its foot.
  • By filtering algae spores from the water, mussels may limit algae growing around mussel beds.
  • Coastal areas are at risk from development and pollution. Mussels are also at risk because many of their homes are in danger of being ‘loved too much’ by too many tide pool visitors.


California Academy of Sciences Docent Guide 2015

flickr http://www.flickr.com/photos/cas_docents/5118861762/in/set-72157608597736188/

WordPress shortlink:  http://wp.me/p1DZ4b-wF

Encyclopedia of Life eol.org/pages/449960/details

Monterey Bay Aquarium www.montereybayaquarium.org/animal-guide/invertebrates/ca…

Phylum: Echinodermata
Class: Echinoidea
Order: Echinoida
Family: Strongylocentrotidae

Genus/species: Strongylocentrotus purpuratus

GENERAL CHARACTERISTIC: Round body with radially symmetrical test, (shell), covered with large spines 0.5 cm (2 in) in diameter, rarely to 10 cm (4 in). Test and spines are pale green (young) to purple (adults). Also covering the test or shell, are tube feet and pedicellariae (pincers). The long
suckered tube feet visible above the spines are used for locomotion and capture of food, which is then passed along to the mouth. The oral side of the urchin, on which the mouth is located, faces the substrate (down). Sexes are not physically distinguishable from one another (monomorphic).

DISTRIBUTION/HABITAT: British Columbia to Baja California in the lower intertidal to 160 m (525 ft) depth. Rounded burrows in rock that have been scoured out by the present or previous urchin using its teeth (Aristotle’s lantern) and spines, a strategy that protects from predators and surge.  Subtidal purple urchins live, often in large numbers, on the substrate among kelp holdfasts.


DIET IN THE WILD: Herbivore/Detritivore. Uses calcite (CaCO3) teeth (Aristotle’s lantern) to feed on kelp, other algae, diatoms and scavenge on dead animals. These urchins prefer the giant brown kelp Macrocystis and can destroy entire forests of kelp which are commercially important for fisheries. Algin a product from kelp is also used in the manufacturing of plastics, paints and as a thickening agent in foods such as gravy and pudding.

REPRODUCTION: Sexually mature during their second year. Sexes are separate, although hermaphrodites occur. Broadcast spawning deposits sperm or eggs into the sea where random fertilization occurs. Pluteus larvae hatch, drift and settle. Growth after metamorphosis is slow.

PREDATORS: Preyed upon by seastars such as the sunflower star and cancer crab species as well as fish such as the California sheepshead, shorebirds and sea otters. Sheephead blow over sea urchins and nibble at the oral side where the spines are shortest. When approached by most sea stars, the urchin allows the potential predator to get close, then uses its pincers to attack the sea star’s tube feet. Most sea star species will beat a hasty retreat; however, the sunflower star is too big and fast; the urchin cannot escape and is swallowed whole! Average lifespan 20 years but can live to more than 30 years.

CONSERVATION: CITES; no special status

REMARKS: Purple pigments from this urchin lodge in the bones and teeth of sea otters, turning the otter’s skeleton and teeth purple.

In the wild, they protect themselves from predation, drying out, and damage from the sun’s UV light by covering themselves with seaweed or shells.

Sea urchin is commonly used in sushi and is considered a delicacy Japan. The primary urchin harvesting company in California sends 75% of the harvest to Japan.


RockyReefcluster, Abalone and urchins, Rocky Coast Main Exhibit, Tidepool


California Academy of Sciences Docent Water is Life Guide 2015

eol  http://eol.org/pages/598175/details

Ron’s flickr http://www.flickr.com/photos/cas_docents/sets/72157608501343477/

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Kingdom: Animalia
Phylum: Echinodermata
Class: Asteroidea (Starfish or sea stars)
Order: Forcipulatida
Family: Asteriidae

Genus/species: Asterina miniata

GENERAL CHARACTERISTICS: Colors may be colored red, orange, brown, purple or mottled. They have webbing between their short, triangular arms, which gives them a batlike look. Size is up to 20 cm (eight inches) across. Radially symmetrical they normally have five arms, but they occasionally have as many as nine arms. They have tube-feet that allow locomotion.

DISTRIBUTION/HABITAT: Sitka, Alaska to Baja California, Mexico. Found in low intertidal areas on rocks overgrown with surfgrass, large algae and sponges. Depth intertidal to 290 m (950 ft) on rocky or sandy substrates.

DIET IN THE WILD: Sensors at the end of each arm that sense light and detect prey. Typically an omnivore or scavenger: surfgrass, algae, colonial tunicates, organic films on hard surfaces, as well as other seastars.  Like most seastars, feeds by everting its stomach over prey.

See everted Bat Star stomach below.

REPRODUCTION: Usually spawns May to June. The male broadcasts sperm and the female broadcasts eggs from pores near the bases of their arms. Embryos and larvae are transparent.

PREDATORS Other sea stars, molluscs, and crustaceans. Like some other sea stars, bat stars can sometimes avoid predation by secreting chemicals that evoke flight responses in other animals.

CONSERVATION: IUCN No special status. Collecting by tidepool visitors has diminished some populations, for example around the Monterey Peninsula.

REMARKS: When two bat stars bump into each other, a gentle brawl begins. They seem to be “arm wrestling” in a slow motion skirmish where no winner is usually obvious.

Bat stars lack the pedicillariae, or pincers, common to most other sea stars and used to clear the animal of unwanted parasites and other debris. Even so, bat stars are free of debris, perhaps because small, constantly moving hairs (cilia) discourage settling

Sea stars have endoskeletons made up of plates (calcified ossicles) joined by connective tissue to protect the bat star’s vital organs.  The bat star’s ossicles are so large and defined that they look like rough shingles. 


REMARKS:  SEA STAR WASTING SYNDROME has become a major issue in both the Pacific and Atlantic Oceans. For an excellent summary check this link to the University of Santa Cruz 9-9-14.  http://www.eeb.ucsc.edu/pacificrockyintertidal/data-products/sea-star-wasting/updates.htm

Fitzgerald Marine Reserve.  http://www.fitzgeraldreserve.org/newffmrsite/wp-content/uploads/2014/09/BetweenTides_9-14_web.pdf



Monterey Bay Aquarium  http://www.montereybayaquarium.org/animal-guide/invertebrates/bat-star

U. of Michigan Animal Diversity Web http://animaldiversity.ummz.umich.edu/accounts/Patiria_miniata/

Ron’s flickr    http://www.flickr.com/photos/cas_docents/sets/72157608501343477/

Ron’s WordPress shortlink   http://wp.me/p1DZ4b-to

Kingdom: Animalia
Phylum: Echinodermata
Class Asteroidea
Order: Forcipulatida
Family: Asteriidae

Genus/species: Pisaster brevispinus

GENERAL CHARACTERISTICS The pink sea star reaches a maximum diameter of nearly 65 cm (2 ft); however, individuals are usually smaller. Its central disc has a raised, humplike appearance. They are robust, pink in color and have aboral spines much shorter than those of other Pisaster species, thus its scientific name, which translates as “short-spined sea star.”


DISTRIBUTION/HABITAT They range from Sitka, Alaska to San Diego County, California. They can occasional be seen in the low intertidal zone, but are more commonly found in deeper water to 90 m (300 ft ) on sand and mud substrates, but sometimes on rocks and pier pilings in calm waters. They cannot tolerate prolonged exposure to air.

DIET IN THE WILD: Pink sea stars prey on live clams, snails, sand dollars, barnacles, mussels, – annelid worms, and scavenge on dead fish and squid. On soft surfaces, P. brevispinus digs into sand or mud with its arms. It also can extend its tube feet (the ones around its disk) to a length of 20 cm (8 in). When the tube feet reach a clam buried in the mud, they attach and the sea star hauls it up. On shale, it can lower its stomach into the burrow of a clam and digest the animal in place. Their large size may well be due to their access to a plentiful food supply of large organisms unavailable to potential competitors.

PREDATORS Large adults have few predators, but they may be taken by the sunflower sea star Pycnopodia helianthoides. Sea otters have been known to detach rays to consume gonads, and sea gulls occasionally feed on individuals exposed during very low tides.

REPRODUCTION They spawn in the spring. Sexes are separate and fertilization takes place externally. Larvae disperse in the water column.

Pink stars can live up to 20 years.

REMARKS: Can chemosense clams through sand. May dig down to the clam for 2 –3 days or extend tube feet to the clam a distance equal to the arm radius to 20 cm (7.8 in). Once contacted,
the clam is lifted from the substrate or the stomach may be everted to 8 cm (3.15 in) to digest the prey in place. Some sand-bottom invertebrates including the sand dollar Dendraster excentricus and the snail Olivella biplicata chemosense the presence of a pink star and attempt to avoid contact by burrowing.


California Academy of Sciences Tidepool exhibit 2015

Walla Walla Univ. www.wallawalla.edu/academics/departments/biology/rosario/…

EOL eol.org/pages/598470/details

Ron’s WORDPRESS SHORTLINK  http://wp.me/p1DZ4b-tA

Ron’s flickr http://www.flickr.com/photos/cas_docents/sets/72157608501343477/

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