Anemones and Relatives

Sea anemones and their relatives (sea jellies, sea pens, hydroids, and corals) are a group that have somewhat specialized organs for digesting or stinging, mainly to capture prey. Their bodies consist of a jelly-like substance, with two basic body forms: swimming medusae and sessile polyps.

Painted anemone

painted anemone

Urticina crassicornis

Description: Body is stocky with a hundred or more tentacles on top. Has many color variations from entirely tan, olive or bright red to striped with green and red. Under water it resembles a big flower. Out of the water resembles a deflated, elongated sac.

Food: Within each tentacle are stinging harpoon-like cells (nematocysts) that fire - paralyzing plankton, small animals and fish when they come into contact. Mussels and other small animals may be washed into the tentacle's reach.

Reproduction: Can have sexual reproduction with individuals being female or male and release egg or sperm, or divides to form clone of itself (asexual reproduction).

Fun Facts: Unable to sting through human skin. May live to 60 years.

Aggregating anemone

aggregating anemone

Anthopleura elegantissima

Description: Common on rocks and sandy areas. Olive green body, when tentacles extended they are pink-tipped. May divide by fission (cloning) to form large colonies of genetically identical individuals.

Food: Within each tentacle are stinging harpoon-like cells (nematocysts) that fire - paralyzing plankton, small animals and fish when they come into contact. Feeds on crustaceans and other small organisms.

Reproduction: Can have sexual reproduction with individuals being female or male and release egg or sperm, or divides to form clone of itself (asexual reproduction).

Fun Facts: Competing colonies attack each other, forming a "no-mans-land" between them.

Brooding anemone

brooding anemone

Epiactis prolifera

Description: Small. Color usually green, found growing on eelgrass or algae. About 100 short tapered tentacles. Usual local habitat is quiet sandy beaches in eelgrass beds.

Food: Within each tentacle are stinging harpoon-like cells (nematocysts) that fire - paralyzing plankton and other tiny creatures when they come into contact.

Reproduction: Can have sexual reproduction with individuals being female or male and release egg or sperm or divides to form clone of itself (asexual reproduction).

Fun Facts: Tiny anemones growing alongside adults settled there as larvae, and are protected by the parent's tentacles until they mature and move off on their own.

Moonglow anemone

moonglow anemone

Anthopleura artemisia

Description: Body color varies from gray, to brown, to olive green. Tentacles tapering, pink, orange, green, or blue in color banded by white. Body up to 2 in (5 cm) in diameter, though usually covered by sand and bits of shell. Found along protected rocky or cobble beaches in sand. Attaches to rock or shell buried in the sand.

Food: Within each tentacle are stinging harpoon-like cells (nematocysts) that fire - paralyzing plankton, small animals and fish when they come into contact. Mussels and other small animals may be washed into the tentacle's reach.

Reproduction: Can have sexual reproduction with individuals being female or male and release egg or sperm, or divides to form clone of itself (asexual reproduction).

Fun Facts: Its common name refers to the luminous quality exhibited by the tentacles. Also known as the "burrowing anemone".

Plumed anemone

plumed anemone

Metridium giganteum

Description: Tall, white to tan cylindrical body with numerous, fine tentacles. Large individuals may grow to 6 in (15 cm) length. Found subtidally on rocks and pilings. Most easily seen locally on the pilings of the Edmonds Fishing Pier.

Food: Within each tentacle are stinging harpoon-like cells (nematocysts) that fire - paralyzing plankton and small animals when they come into contact.

Reproduction: Can have sexual reproduction with individuals being female or male and release egg or sperm or divides to form clone of itself (asexual reproduction).

Fun Facts: Very long lived. Predated upon by the shaggy mouse nudibranch.

Lion's mane jellyfish

lion's mane jellyfish

Cyanea capillata

Description: Muscular bell is transparent with long, frilly tentacles (manubrium) beneath it. Eight groups of tentacles hang from the margin and can be up to 6 ft (1.8 m) long below the bell. Internal organs vary in color (red, purple or yellow).

Food: Within each tentacle are stinging harpoon-like cells (nematocysts) that fire - paralyzing plankton and small fish when they come into contact.

Reproduction: Alternates sexual and asexual reproduction. Male release sperm and fertilize eggs in female stomach. Once fertilized, eggs settle-out on substrate to form 6-7 mm (4/17 in)polyps. After a time, will develop into free-swimming medusae and grow to be large jellies.

Fun Facts: World's largest jelly! In the Arctic specimens reach 8 ft (2.4 m) in diameter, local ones may exceed 36 in (91 cm). Often seen washed up on the beach or in calm bays in late summer. Lion's Mane stinging cells (nematocysts) are very potent and will cause a severe skin reaction. A jelly can sting people even after it is dead. Jellies' stinging cells are sticky, they can stick to wood, buckets or shoes and deliver a nasty sting when touched.

Moon jellyfish

moon jellyfish

Aurelia aurita

Description: Common, large, clear to whitish jelly. Bell is firm and flattened. Can be 6 in (15 cm) or more across. Four semicircular gonads (pink, purple or yellow) form a cloverleaf pattern near the center of the transparent bell. Has numerous tiny tentacles that fringe along the bell margin.

Food: Feeds on plankton.

Reproduction: Alternates sexual and asexual reproduction. Male release sperm and fertilize eggs in female stomach. Once fertilized, eggs settle out on substrate to form 6-7 mm (4/17 in) polyps. In time polyps will develop into free swimming medusae and grow to be large jellies.

Fun Facts: Moon jelly has stinging cells (nematocysts) and mucus to catch food. This jelly has less potent stinging cells and not all people feel a sting. Typically lives about one year.

Fried egg jellyfish

fried egg jellyfish

Phacellophora camtschatica

Description: Common locally. Clear to whitish jelly with distinctive yellow spot in center. A large jelly with a bell up to 2 ft (60 cm) across and long, hanging tentacles that can reach up to 15 ft (5 m) long.

Food: Feeds on plankton and smaller jellies.

Reproduction: Alternates between a benthic stage that is attached to rocks and pilings that reproduces asexually and the planktonic stage that reproduces sexually in the water column.

Fun Facts: Many small crustaceans regularly ride on its bell and even steal food from its tentacles.

Sea pen

Sea pen

Ptilosarcus gurneyi

Description: Body when extended resembles a large orange feather with a swollen quill. Each individual is actually a colony of smaller animals. Found in shallow subtidal to 330 ft (101 m) in depth.

Food: Each plume is comprised of paired branches, each with numerous feeding polyps. The fleshy "quill" pumps water throughout the colony.

Reproduction: Reproduction either by sexual or asexual means. The animals free-spawn and produce planktonic larvae that develop in the water column.

Fun Facts: This species of sea pen is bio-luminescent in the dark when disturbed.