Tag Archive: cnidarians

Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Order: Actiniaria
Family: Stichodactylidae

Genus/species: Heteractis magnifica

GENERAL CHARACTERISTICS: H. magnifica is the second largest in size of all sea anemones. Disc to 1 m (3 ft) in diameter. Column which may be red, purple, or pink, grows to 20 cm (8 in). Tentacles (exceed 8 cm 3 in long) are of uniform thickness and do not taper at te tip; tentacles and oral disc are colored alike in shades of magenta-purple, blue, green , red, white or brown.


DISTRIBUTION/HABITAT: Found in the Indo-Pacific at 1–25 m (3-85 ft) often on prominent structures in strong currents or in strong surge locations.

DIET IN THE WILD: Most nutrition is from products of zooxanthellae. Also may eat fish and crustaceans using their stinging nematocysts.

REPRODUCTION: Asexual reproduction by longitudinal fission. The presence of the symbiotic clown fish Amphiprion chrysopterus can increase the amount of asexual reproduction and general growth.
Sexual reproduction, their fertilized eggs develop into a planula larvae which settles on the ocean floor and develops into a polyp.


PREDATION: Symbiotic clownfishes, chase away any nibbling predators, especially bristle worms.

LONGEVITY: in the wild. It is estimated that some of these anemones are hundreds of years old. In captivity, the longest lifespan is 80 years.


REMARKS: Host to at least 12 anemonefish species. When disturbed, H. magifica “balls up,”showing only the column with only a few tentacles protruding.
The magnificent anemone is motile when trying to re-position itself to obtain more sunlight. This species moves by creeping on its basal disc, or by letting the tide carry it.
Anemones can be semi-aggressive and sting other anemones that invade their space.


California Academy of Sciences Water is Life Animal Attractions 2017

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Animal Diversity Web animaldiversity.org/accounts/Heteractis_magnifica/

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Kingdom: Animalia
Phylum: Cnidaria
Class: Scyphozoa
Order: Rhizostomeae
Family: Mastigiidae

Genus/species: Mastigias papua 


GENERAL CHARACTERISTICS: The translucent bell of M. papua is usually hemispherical, with a diameter ranging from 30 to 80 mm (1 in to 3 inches). This species has 8 frilled oral arms, rather than tentacles. These arms end in a club-like filament that has a triangular cross-section, though this is absent in some species. Each oral arm has mouths on the club, as well as along the length towards the bell.
Color variation exists within Mastigias papua, though the bell is usually greenish blue to olive-green with yellow, white, and/or brown oval, granular spots across the rim (over the exumbrella). Coloring can be attributed to the zooxanthellae that reside symbiotically within the lagoon jellyfish (mostly in the mesoglea)

DISTRIBUTION/HABITAT: Tropical Pacific ocean usually bays, harbors and lagoons.

DIET IN THE WILD: Instead of a single mouth, they have many small mouth openings on their oral-arms, which capture small animal plankton. In addition, each jelly grows a crop of algae, which gives them a greenish-brown color. They harvest some of their food directly from the algae.

MORTALITY: Lifespan of approximately 4 months

PREDATION The only creature that has been confirmed to prey on Mastigias papua is a sea anemone, Entacmaea medusivora.


REMARKS: Some species of small, juvenile fishes are known to shelter within this jelly’s bell for protection from larger predators.
The famous jellyfish of Jellyfish Lake, a well-known dive site in the Pacific islands of Palau, are descended from M. papua However unlike its jellyfish lake cousin M. papua possess venomous stinging cells for feeding and protection.

Human contacts may  experience many adverse effects such as rashes, severe itching, nausea, and vomiting when contacting tentacles.


California Academy of Sciences Steinhart Aquarium Color on the Reef 2017 AQA17

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

ADW animaldiversity.org/accounts/Mastigias_papua/

EOL  eol.org/pages/203445/overview

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California Academy of Sciences Steinhart Aquarium Color on the Reef 2017 AQA17

Monterey Bay Aquarium


ADW animaldiversity.org/accounts/Mastigias_papua/

Eol eol.org/pages/203445/overview



Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Order: Scleractinia
Family: Trachyphylliidae (Solitary stony Coral)

Genus/species: Trachyphyllia geoffroyi

GENERAL CHARACTERISTICS: Name comes from Gr: trachys (rough) and phylon (leaf) as it looks like a leaf lying on the substrate. Trachyphyllia are secondarily free-living, usually beginning growth as a single polyp attached to a hard surface. Later it breaks off, and is found detached on sandy or muddy bottoms. Color may vary with depth or substrate: pink to red,
brownish, gray, green, or blue, even multistreaked and iridescent. Fleshy polyps extend well beyond the margin of the stony skeleton.

Open Brain Coral30683128974_b9d9e4ba50_k

DISTRIBUTION/HABITAT: Found in the Indian and Western Pacific oceans on sandy bottoms among seagrass in the outer feel margins.

DIET IN THE WILD: Nutrition from photosynthetic zooxanthellae; also microplankton and other small food bits. Tentacles extended in low light or at night to capture plankton.


REMARKS: Tangs and angelfishes like to nip and feed on them.
At night their soft tissues may swell to remove debris and sand that accumulates during the day.


California Academy of Sciences Steinhart Aquarium Color on the Reef AQA17

Aquarium Corals E H Borneman TFH Publications 2001 pages 301-3

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Australian Institute of Marine Science  coral.aims.gov.au/factsheet.jsp?speciesCode=0350

Arkive.org www.arkive.org/open-brain-coral/trachyphyllia-geoffroyi/

IUCN www.iucnredlist.org/details/133260/0

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Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Order: Actiniaria
Family: Actiniidae (the largest family of sea anemones)

Genus/species: Entacmaea quadricolor

GENERAL CHARACTERISTICS: The Bubbletip Sea Anemone has an adherent base which attaches to the shape of the substratum. At the top of the column is a flattened oral disc with an oval mouth in the middle. The oral disc and column are smooth and brown, green, or occasionally a fluorescent reddish-orange. Tentacles are up to 10 cm (4 inches) length, often but not always inflated and balloonlike at the tips. 

Length up to 40 cm (16 inches)

Bubble tip anemone5389669474_fb02a667dc_o

DISTRIBUTION/HABITAT: Found in the Indo-Pacific, usually in deep crevices with only the tentacles visible.

Bubble tip anemone16122486362_7ee3a9b81d_o

DIET IN THE WILD: E. quadricolor obtains the majority of its energy from solar radiation via its symbiotic zooxanthellae.
Thet are also opportunistic carnivores that capture prey using cnidocytes on their tentacles which contain many “stinging organs” known as nematocysts (or cnidae).

REPRODUCTION: Bubbletip Sea Anemones are broadcast spawners releasing gametes directly into water.

The most common means of asexual reproduction for these anemones is called longitudinal fission, which amounts to them splitting down the middle to make two anemones from one. When it reproduces it will begin to pinch in at two points opposite each other on their base. Then the indentions will draw closer until it splits in two.

CONSERVATION: IUCN Red List Not Evaluated

REMARKS: They are symbiotic with many species of anemonefishes, such as the common clownfish (Amphiprion ocellaris)

E. quadricolor has obligate photosynthetic zooxanthellae, brown algae, which live inside the anemone acting as a carbon and nitrogen source.

This anemone also exhibits biofluorescence.


California Academy of Sciences Steinhart Aquarium Color on the Reef 2017 AQA16

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The University of Queensland


SeaLifebase www.sealifebase.org/summary/Entacmaea-quadricolor.html



Kingdom: Animalia
Phylum: Cnidaria
Class: Scyphozoa
Order: Rhizostomeae
Family: Catostylidae

Genus/species; Catostylus mosaicus

GENERAL CHARACTERISTICS: The blue, white or brown colors are derived from pigment produced by the jellyfish itself (not symbiotic algae, as in some other jellyfish). There is no obvious mouth on the underside, but there are small openings on each of its eight arm, through which food is passed to the stomach. Diameter up to 30 cm (18 in)  


DISTRIBUTION/HABITAT: Found in coastal waters of Australia, Queensland, New South Wales and Victoria.

DIET IN THE WILD: The tentacles also have stinging cells that can capture tiny crustaceans and other plankton.


REMARKS: The Chinese believe eating jellies will reduce high blood pressure. Dried jellies are popular in many Asian countries, especially Japan, where they’re considered a culinary delicacy. The texture is reportedly crispy, yet elastic—hence the name “rubber band salad” for a dish sold in China.


California Academy of Sciences Steinhart Aquarium Color on the Reef  2017 AQA10

EOL eol.org/pages/203402/details

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

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Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Order: Actiniaria
Family: Metridiidae

Genus/species: Metridium farcimen  aka Metridium giganteum
Metridium farcimen4545409258_06cac3dd83_b

GENERAL CHARACTERISTICS: Erect smooth column. Usually 50 cm (20 in) or less in height The column is slender, smooth and studded with acontia. These are openings through which thread-like nematocysts from inside the body wall can protrude. The oral disc is lobed and deeply convoluted at the edge and bears well over 100 fine, short, tapering tentacles. Color variable from white through cream to tan, brown and orange. Carries short, feathery tentacles in white, brown or gray.

 Metridium farcimenIMG_9548

DISTRIBUTION/HABITAT: Eastern North Pacific: Alaska to Baja California. Found in sub tidal areas attached to rocky substrate. Individuals usually aggregate in groups on deeper rocky reefs.

 Metridium farcimen4673318353_928bfcd2f0_o

DIET IN THE WILD: Plankton—whatever drifts by or is carried in by the tide; predators include Pisaster spp. sea star and some species of nudibranchs.

REPRODUCTION: Eggs and sperm from the gonads embedded in the body wall which are ejected through the mouth. Fertilised eggs develop into planula larvae which settle and metamorphose into polyps.                   

PREDATORS: Pisaster spp. sea star and some species of nudibranchs.

REMARKS: When attacked, they contract suddenly, extruding specialized nematocysts through the mouth and body wall that, much larger than those found in the tentacles, can deter or even kill predators.

 Location: California Rocky Coast and Giant Pacific Octopus exhibits


 The University of Kansas kuscholarworks.ku.edu/dspace/handle/1808/6043

 eol eol.org/pages/704280/details#type_information


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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

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Encyclopedia of Life  eol.org/data_objects/27560182

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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…

Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Order: Actiniaria
Family: Metridiidae

Genus/species: Metridium senile

GENERAL CHARACTERISTICS: M. senile is colored white, cream, tan, orange or brown. Height to 5 cm (2 inches). Tentacular crown diameter to 25 cm (9.75 inches), Up to one hundred small, slender tentacles give a feathery (plumose) appearance.

 Metridium senile 3074666433_ab584596e9_o

DISTRIBUTION/HABITAT: Southern Alaska to Southern California and both Atlantic coasts. Found live in groups of up to 500 specimens per square meter at depths to 166 m (540 feet). M. senile lives on rocks, shells, wood pilings and stony breakwaters in bays and harbors in the low intertidal and subtidal zones. Plumose anemones crawl slowly along the substrate by muscular waves of the pedal disk.

DIET IN THE WILD: Mostly small zooplankton, though they may also eat small benthic polychaetes, fish, and squid.

REPRODUCTION: Protandric hermaphrodite starting life as one sex and changes to the other when it is older. Eggs or sperm develop in the gonads embedded in the mesentery that lines the coelom. They are ejected through the mouth, and when fertilised develop into planula larvae which settle and become juveniles.

They also reproduce asexually by binary fission, budding and fragmentation.

PREDATORS: Nudibranch Aeolidia papillosa (on small individuals), and the seastars Hippasteria spinosa and Dermasterias imbricata, which can eat even quite large individuals.  Attacked individuals may detach and drift to a new location.

Location: California Rocky Coast and tide pool


Walla Walla University: www.wallawalla.edu/academics/departments/biology/rosario/…

eol  eol.org/pages/421495/details 

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Kingdom: Animalia (animals)
Phylum: Cnidaria
Class: Anthozoa
Subclass: Ceriantipatharia,
Order: Ceriantharia
Family: Cerianthidae

Genus/species: Pachycerianthus fimbriatus

GENERAL CHARACTERISTICS: Solitary tube to 35 cm (14 inches) long when expanded. The tough, slippery, black, secreted tube projects above the mud substrate. Tentacular crown with two circles of translucent whitish to brown-gold tentacles. The inner
circle usually held over the mouth, the outer circle projecting up or out. Like most anemones, the tube-dwelling anemone contains stinging cells or nematocytes along its tentacles.

Tube Anemone  3236526239_4f6bd4f600_o

DISTRIBUTION/HABITAT: California (total distribution poorly known). Fairly common in soft mud bottoms of bays and harbors and protected sandy substrates of the outer coast. Low intertidal and subtidal in S. California; subtidal only in N. California to at least 54 m (177 feet).

Tube Anemone 3288842115_73a426d48d_b

DIET IN THE WILD: Small invertebrates, hydromedusae, small crustaceans and plankton

PREDATORS: Barber slugs clip off its tentacles, resulting in P. fimbriatus retreating quickly down the tube—sometimes pulling the slug in with it. The tentacles grow back after an attack.

REMARKS: Unlike sea anemones the anal pore is at the end of the body.


eol eol.org/pages/199417/details

 Walla Walla Universitywww.wallawalla.edu/academics/departments/biology/rosario/…

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

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Class: Scyphozoa
Order: Rhizostomae
Family: Cassiopeidae

Genus/species: Cassiopea andromeda


GENERAL CHARACTERISTICS: To 30 cm (12 in) diameter, disc-shaped bell has elaborately fringed oral arms. Coloration is gray, brown or green with triangular white blotches surrounding the bell. Zooxanthellae are the responsible for the color

DISTRIBUTION/HABITAT: Native to Indo-Pacific, but introduced in Caribbean, southern Florida, Hawaii. Upon shallow substrates, typically in calm sandy areas, often around mangroves. Intertidal to 10 m (33 ft).

DIET IN THE WILD: Consumes small marine animals after it paralyzes its prey with its mucous and nematocysts. Symbiotic algae in its tissues provide nutrition by photosynthesis, thus the upside down posture that allows algae, which live on the ventral surface, to receive maximum sunlight. The rhythmic pulsations create water flow that carries zooplankton over the tentacles to supplement the diet.

REPRODUCTION: Asexually (by budding) and sexually in the medusa form.


REMARKS: The sting is relatively mild, but may create an irritating, itchy rash; especially sensitive individuals can experience vomiting and skeletal pain.

Mildly venonomus.

Reef Partners Cluster PR35

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