Friends of Netarts Bay Watershed, Estuary, Beach, and Sea

Hydractinia sp.
Fur Hydroid
Alaska to Mexico
Family Hydractiniidae
Native

Hydractinia forms furry colonies on the shells of snails, barnacles, crabs, and even on rocks. This one was collected from a lower intertidal basalt rock along Tunnel Beach. It is a small athecate hydroid with no medusa stage. Colonies are either male or female. The males shed sperm into the water which then fertilize eggs brooded by the female colony. The fertilized egg develops into a crawling planula larva. When the planula finds a suitable shell or other surface, it metamorphoses into a single polyp, and a colony develops from asexual budding that originated from that single individual. The polyps of the colony specialize into feeding, reproductive, and defensive polyps, all linked together by stolon-like extensions of their guts. Adjacent colonies may attack each other using nematocysts to kill the other's polyps, or they may fuse into a single colony.

The feeding polyps will consume small invertebrate larvae, nematodes, and even some benthic organisms. They may be preyed upon by nudibranchs.

Feeding and defensive polyps.

Reproductive polyp, a gonozooid.

Stylantheca sp.
Encrusting Pink Hydrocoral
Alaska to California
Family Stylasteridae
Native

If the tide is low enough or you are willing to risk some pounding waves, there is a shallow cave and arch on the outside of some of the rocks on Tunnel Beach where you can find the vibrant deep pink encrusting hydrocoral Stylantheca, probably S. potphyta, formerly called Allopora potphyta. This hot-pink colonial cnidarian coats the walls of this cave with a hard calcium carbonate exoskeleton that shapes itself in sheets over the rough rock surface. Generally found in the low-intertidal to sub-tidal zones, it inhabits the most exposed outer shore where breakers are strong. Magnified, you can see individual polyps within the surrounding exoskeleton, and you can sometime see individual zooids tucked into their protective cups. The species may range in color from orange to purple. It is in the Class Hydrozoa, even though it looks like a true coral. It is said to be eaten by the ochre star Pisaster ochraceus.

Chrysaora fuscescens
Pacific Sea Nettle
Alaska to California
Family Pelagiidae
Native

Chrysaora fuscescens is in the class Scyphozoa, large jellies (formerly jellyfish) with long, frilly but fragile oral arms that extend from the mouth and drape below the bell. Scyphozoans have no vellum, a membrane that encircles the inside of the margin of the bell of other jellyfish in the class Hydrozoa. What you see on beach is mainly the gelatinous, dome-shaped bell, flattened because it has washed ashore and is no longer buoyed by water, and you may see some tentacles extending from the bell's edge. In the water these are handsome creatures, their oral arms and tentacles trailing many feet behind the bell that slowly pulsates with rhythmic contractions. Jellies are considered part of the plankton because their ability to swim is limited and they mainly drift with the current.

Chrysaora has a lovely golden-brown bell and 24 dark brown tentacles equipped with potent stinging cells (nematocysts) that rim the edge. Its white oral arms and many of the tentacles are almost always lost from individuals that have been pummeled in the surf then stranded on shore. It is reputed to have a vicious sting and should be avoided. They, as other jellys, are carnivorous and use these stinging cells to capture prey, including small fish, other jelly fish, ctenophores, marine eggs and larvae, any animal of appropriate size. Chrysaora may form dense offshore swarms that wash onto the beach. A related species, C. melanogaster, which has 16 radiating dark streaks on the bell, may occasionally wash ashore.

Aurelia labiata
Moon Jelly
Alaska to California
Family Ulmanidae
Native

The moon jelly, Aurelia labiata, can be dinner plate size. It is easily identified by its frosty, semi-transparent bell with four purple, horseshoe-shaped gonads easily seen through the upper surface. Most jellys are dioecious, that is there are males and females, but Aurelia is hermaphroditic, possessing both male and female reproductive organs. Aurelia is the jelly whose life cycle is typically shown in biology text books. It has both asexual and sexual phases. The asexual phase starts with a small polyp called a scyphistoma that, at the proper time of the year, begins budding off small eight-armed, free-swimming medusas, the ephyrae. The scyphistoma buds by strobilization, where the ephyrae, which are stacked like cupcake cups on the oral end of the scyphistoma, separate themselves and swim away as new ones are produced. The scyphistoma at this stage is termed a strobila. The ephyrae swim around for about three months before they mature into the jellyfish we are familiar with. These jellies produce eggs that, when fertilized, grow into larvae, the planulae, which settle on a hard substrate, such as the underside of a rock, and become scyphistomae.

Photo by Keri Fadler

Aequorea sp.
Crystal Jelly, Water Jelly
Alaska to Mexico
Family Aequoreidae
Native

This transparent hydrozoan jelly could be one of at least four different species along our coast, all difficult to identify. The medusa may have up to a hundred radial canals extending out from a central disk to the bell's margin, giving it the appearance of a wheel with many spokes. Its tentacles are short and loaded with nematocysts for capturing prey, but these stinging cells are not felt by humans in the water, though they may later result in a mild rash. It feeds on small zooplankton, other hydrozoans, ctenophores, and even other Aeoquorea. It reproduces both sexually and asexually almost any time of the year, depending on water temperature and food.

The medusa of Aeoquorea victoria, one of the possible species, is bioluminescent, that is it glows in the dark, because more than one hundred light-producing organs surround the edge of the bell. Two proteins, aequoin and green fluorescent protein (GDP), discovered by Osamu Shimomura and his colleagues at Princeton University, are involved in producing the bioluminescence. The research led to the discovery that GDP can be used as a marker for following gene expression and can be visualized by fluorescence microscopy. For this work he was awarded the 2008 Nobel Prize.

Swedish scientists found another use for GDP: the creation of solar cells. When GDP is dripped onto silicon dioxide between two electrodes and exposed to ultraviolet light, it emits electrons (an electrical current).

Polyorchis penicillatus
Red-eye Medusa
Alaska to Mexico
Family Corynidae
Native

This small jelly is a hydromedusa, a small medusa from the Class Hydrozoa with a velum but no lappets along the bell margin, that is common along the Pacific Coast and occasionally washes up on our beaches or can be found in Netarts Bay. It has red eyespots around the bell margin at the base of each tentacle (second image), hence the common name. When washed ashore, it flattens to a clear round blob about two inches (5 cm) in diameter. It has four radial canals each with short diverticula extending out at right angles. Finger-like gonads hang from the radial canals in the upper part of the bell. Its generic name Polyorchis is from Greek and means many testicles.

Its typical habitat is near shore and bays, often in eelgrass where it feeds on small crustaceans, including caprellid amphipods, small worms and other plankton. Sexes are separate, but it also reproduces asexually

Red eyespots

Anthopleura elegantissima
Pink-tipped Anemone
Alaska to Mexico
Family Actiniidae
Native

Also called the aggregating anemone, dense clonal aggregations of this sea anemone cover large expanses of rocks in the mid-intertidal zone of Tunnel Beach. To form these carpeting aggregations, individuals split by longitudinal fission, making genetically identical copies of themselves. These animals also reproduce sexually by broadcast spawning eggs and sperm to expand their genetic diversity. When one cloanal carpet closely neighbors a different cloanal carpet, they war with each other. Individuals on the edges of each assemblage, the warrior anemones, will attack its neighbor from the other assemblage when they come in physical contact by exchanging poison darts from their nematocysts, injuring and sometimes killing each other. This may leave a blank so called "demilitarized zone" between the different aggregations.

When out of the water, the pink-tipped tentacles are usually retracted, and what we see are olive green individuals often coated with pieces of shells and rock that adhere to sticky tubercles on their surfaces and serve as camouflage and reduce drying. Assemblages are frequently covered by sand that is washed ashore. The anemones can live up to three months completely buried. Most of the green color is from a unicellular green alga that lives symbiotically in the tissues of the anemone that provide some nutrition to the animal. It is also a carnivore, feeding on almost anything, including crustaceans and fish, that comes within range of the nematocyst of its tentacles.

Anthopleura xanthogramica
The Green Surf Anemone
Alaska to Mexico and Central America
Family Actiniidae
Native

This showy anemone with bright green tentacles lives in tide pools and surge channels along the outer coast. It is also called the Giant Green Anemone because its column can reach a foot in diameter, making it one of the world's largest anemones. You can find it among the rocks along Tunnel Beach, below the bands of California Mussels and often below Ocher Stars if they are present. It is considered solitary, not aggregative as is A. elegantissima. It does not divide by fission. They reproduce in spring and summer by broadcast spawning. Their green color is derived from symbiotic one-celled green algae (zoochlorellae) or dinoflagellates (zooxanthellae) living in their tissues. If, during the lowest of tides, you can walk past Tunnel Beach to Lost Boy Beach and into Lost Boy Cave where it is dark, you will see that all the anemones are devoid of symbiotic algae. The Green Surf Anemones feed on mussels, crustaceans, sea urchins, fish or any other appropriate animal that gets caught in its tentacles.

Urticina sp.
White-Spotted Rose Anemone
Alaska to California
Family Actinidae
Native

This beautiful anemone with its red tentacles and column, the latter decorated with vertical rows of white spots (verrucae), is often located subtidally in rocky outer shore surge channels where there is lots of current. This one was in Netarts Bay in the cobble area just off the Netarts beach, also subject to strong daily currents, in two feet of water at low tide. The anemone is dioecious, that is sexes are separate, so reproduction is by spawning. They probably also reproduce by fission. It has a curious relationship with the painted greenling, a native fish. Juveniles, like Disney's Nemo, will hang out among the tentacles of the anemone for protection, and adults may sleep near its base. The venomous nematocysts in the tentacles are poisonous to other animals but not the greenling.

Over the past few years there has been confusion over, and changes to, the genus and species of this anthozoan, based on its relation to similar anemones in other parts of the world. I learned it in my student days as Tealia lofotensis. It was changed to Urticina lofotensis also to Madoniactis lofotensis, both now obsolete names, and was renamed Urticina equis which turns out to be a European species different from our anemone in the Pacific Northwest. In 2006 the name was changed to Cribrinopsis albopunctata. But this is a Russian anemone that does not occur here. So, in their recent book "Beneath Pacific Tides: Subtidal invertebrates of the Pacific Coast", Gregory C. Jensen, D. Gotshall, and R.F. Miller labeled it Urticina sp. It may be an undescribed species.

Metridium senile
Short Plumose Anemone
Alaska to California
Family Metridiidae
Native

Often in colonies in the protected waters of bays and harbors, you can find this anemone at low tide among the rocks at the boat ramp in Netarts Bay. It prefers shaded habitats, out of direct sunlight at depths from mid intertidal to subtidal. It is usually white, especially when young, but may range in color from grey to orange and brown as it ages. It is small, no more than five inches long and usually about two. Its column is usually a pale translucent white, topped by many fine short tentacles. It reproduces both sexually and asexually. Males and females broadcast their eggs and sperm from their mouths into the water, usually males first which triggers females to release eggs. The fertilized egg (the zygote) develops into a planula larva which settles to become a juvenile. Asexually, it reproduces by either by longitudinal splitting or by fragmentation of the column base. This type of reproduction contributes to colony formation. Young and adults attach to hard substrates but can detach and move if conditions warrant. It feeds on small copepods and other tiny invertebrates.

Velella velella
By-the-wind Sailors
British Coloumbia to California
Family Porpitidae
Native

Sometimes during the spring and summer, after persistent winds from the west, rows of blue-bodied jellyfish-like animals litter the sand where they wash ashore like shipwrecked sailboats with Prussian blue hulls and clear sails, deposited by waves that recede with the outgoing tide. These are Velella velella, poetically but very appropriately named "by-the-wind-sailors." The appropriateness will be discussed in a moment. Though they resemble jellyfish, they are somewhat a conundrum. Velella have been considered, not individual organisms, but complex floating colonies of polyps that resemble the siphonophore, Physalia, the Portuguese man-of-war, though this may be a case of convergent evolution. Velella is a member of the Cnidaria, the phylum that includes jellies (jellyfish), sea anemonies, corals and other hydroids, many of which exhibit polymorphism - different forms of a species that occur together. However, a few decades ago Velella was placed in another order, the Chondrophora, which also have polymorphic members, and today many authors still consider it a chondrophor, some saying it is a colony, others claiming it to be a single animal. Sorting out these different schemes of classification gets very confusing and the question of whether Velella is a colony or a single organism is still not fully addressed.

Though it may well be a single animal (a highly modified upside-down hydroid polyp), here we will call it a colony, mainly because that is the way it is still described in recent (but not all) text books. By-the-wind-sailors Velella is composed of highly specialized and modified zooids, which are individual polyps and medusae that suspend downward and form the "organs" of this super-animal. There is a gastrozooid that ingests food, dactylozooids that capture food and protect the colony, and gonozooids that are involved in reproduction. There is an upper, many-chambered, chitinous float that bears a clear sail set at an angle of about 30 degrees. Around the float is a beautiful Prussian blue mantle, called a raft, with fore and aft lobes that are about 15 degrees oblique to the float, so that the sail is 45 degrees to the long axis of the colony or organism. The direction of the sail's angle is different depending on which part of the world Velella occurs. On our Pacific Coast, the sail angle is such to take advantage of winds prevailing from the north, and that serves to keep them offshore. Velella's sail is fixed, it cannot shift its sail like a sailboat to change direction. It is, in sailing parlance, "running before the wind" or "by the wind", hence its poetic name. When the winds shift, Velella may be driven ashore to litter the beaches with their blue bodies which decompose in a few days, leaving just the cellophane sail and floats. In other parts of the world, the direction of the sail is actively selected to take advantage of prevailing winds there. In yet other locations, sails may be in either direction. Some authors say that all Velella populations are born with sails angled in both directions, so that unfavorable winds will blow only half of them to the beach, allowing the other half to live.

It is interesting to speculate on the growth rate of Velella based on the sizes of those washed on to the beaches during different parts of the year. I've seen windrows of tiny Velella, most less than a millimeter, washed ashore during winter and early spring. In early May there were both small and larger ones, and by late June most were large, six, seven, even ten centimeters long. If all the Velella were from the same population, then the differences in length during the different months may indicate growth from young to older Velella. But these sizes may well have been from different younger and older populations that mixed during May and do not necessarily represent growth in a single group of animals. It is hard to say which is true.

Velella is a carnivore, feeding on fish and invertebrate eggs and small zooplankton that live near the surface because its tentacles (dactylozooids), which contain nematocysts (cells that sting on contact), are short and do not reach far into the water. Some of the zooids contain photosynthetic, symbiotic algae (zooanthellae) in their tissues. It spends most of its life floating on the ocean, only the reproductive medusae descending into deep waters to produce eggs and sperm and the resulting young embryos that then rise back to the surface.

Pleurobrachia bachei
Sea Gooseberry
Alaska to Mexico
Family Pleurobrachiidae
Native

Though it resembles a jelly (jellyfish), it is not. It is a Ctenophore, one of the Comb Jellies. Ctenophores belong to their own phylum, the Ctenophora. The name is from Greek: "cten" means comb and "phero" is to bear. Comb Jellies come in different shapes and sizes, some round and globular like our familiar Sea Gooseberry, some long and slender and ribbon-like. They are mostly planktonic and strictly marine. They differ from Cnidarians in that they are monomorphic (they don't have anything akin to the different polyp forms of Cnidarians), they are never colonial, and they have no sessile stage. Their larva is a cydippid, not a planula. And they are characterized by their ctenes, ciliary plates, also called combs, arranged in eight rows that are used for propulsion.

Pleurobranchia bachei has an elliptically globular shape with the eight rows of ctenes running the length of its body, and two long branched tentacles arising from a pair of tentacular canals on the aboral hemisphere of the body which are used to capture prey. The tentacle branches, called tentilla, extend from only one side of the tentacle. They are adhesive and act as a net to capture small crustaceans and other prey which they then pull into the mouth. Food passes from the mouth through a pharyngeal canal into a muscular pharynx that grinds it into small particles for digestion in the stomach.

The ctens are composed of closely adhered groups of thousands of cilia that form little paddles that beat in a rhythmic and coordinated pattern, propelling the animal with its mouth forward. Light is diffracted through the ctens resulting in iridescence, delivering a spectral display of colors along the comb rows.

You will see P. bachei along all of our beaches as little round globes of jelly, washed ashore by the receding waves.

Ctens or combs of Pleurobrachia

Sponsored by the Friends of Netarts Bay Watershed, Estuary, Beach and Sea (WEBS)

Sponsored by the Friends of Netarts Bay Watershed, Estuary, Beach and Sea (WEBS)