Disclaimer

I am not a scientist, I'm just a hobbiest that has enjoyed keeping my own tidepool for a while. Everything on this page is information I found through research on the internet, in conversations with divers, or from my own experience. (I'm actually an electrical engineer.)

Introduction

I got into this hobby, in the spring of 1999, when my wife and I brought a bunch of these creatures back from the beach to her preschool classroom in eastern Washington. Many of the kids had never been to the ocean, and some of the rowdiest children were mesmerized by the creatures in the small 10 gallon tank. From that time on I've had the anemones and some of the other creatures living in my saltwater tank.

This page gives you a glimpse of most of the tidepool creatures I've had, or have. It also gives some information about each, either from research or my own experience. I hope you find this page interesting and helpful.

I have linked the scientific names of each of the animals (those I've figured out) to a site maintained and updated by Corrina Chase, an MIT student, The Tide Pool Page. I've also linked parts of the Nudibranch section to the Sea Slug Forum. Another site with lots of information about the Pacific coast of North America is the Lane Community College Marine Biology page. There are a few other links to miscellaneous pages that have useful information.

Here is a new link to the WSU/Beach Watchers EZ ID WEB page. This page has added a lot of new species since I first built my page.

Interesting Temperate Zone Animals

All of these animals are found in the Pacific Northwest (northwest coast of the United States). They live in the intertidal zone, on rocks or in tide pools. Some of them can live much deeper. These creatures prefer cool temperatures of 50 to 60 degrees Fahrenheit. This means if you want to keep them in an aquarium, you should probably have a chiller.

Anemones

Unfortunately, I've discovered that these anemones can survive just about anything. Drastic changes in salinity and temperatures up into the lower 80's hardly phase them. Other creatures, such as sculpins, are not so hardy. These anemones need lots of light and some feeding. In the ocean they live off of crustaceans, small fish, and floating debris. The anemone to the right is an "Agregating Anemone" (anthopleura elegantissima). It gets its name from a peculiar behavior. When it reproduces, often by splitting down the middle into two anemones, it forms colonies of relatives. These colonies can cover large expanses of rocks in the intertidal zone. When two colonies meet they will form a distinct line between them, and attack each other with their stinging tentacles. In my first 10 gallon tank I started out with four of these anemones, and over the course of a year and a half, ended up with 10 of them.

The anemone to the left is called a "Giant Green Anemone" (anthopleura xanthogrammica). The two in the picture aren't very big (the large one is about 1.5 inches in diameter), but I've seen some over 8 inches tall and 6 inches in diameter. I believe they can get even bigger than that. To feed the anemonies I freeze oysters packed in saltwater that I buy in the meat department. Once or twice a week I use a knife to cut/scrape out small pieces of oyster, which I place on their tentacles. If you have a good current in the tank (I take the filter bags out of my filter while feeding), you can let them catch their own food. They would probably prefer plankton, but that's too hard to come by. They need lot's of light to stay healthy, because they have symbiotic algae which produces some of their food.

Sea Stars

Another fascinating creature is the sea star (starfish). The one climbing over the snail shell to the right is an "Ochre Star" ( pisaster ochraceus ). I don't have much experience with these animals because the only one I had died within the first month. The mussel that the anemones and starfish are on is about four and a half inches long. The clam in the picture I bought in the Fred Meyer meat department. Just below the clam is a limpet. Limpets are related to snails, but they have round cone shaped shells. They eat algae off rocks, or glass. They have this bad habit of climbing up to the top of the tank and waiting for the tide to come in...it never does.

We saw these two beautiful sea stars on the Oregon coast. They look like they're hugging. Above the orange one is a small group of yellow pods. Thanks to an email from Jim Anderson at scottish nudibranchs, I've tentatively identified these as Rock Whelk (nucella emorginata) egg capsules. To the right is a closeup of some others we found. If you have any other ideas, please email me.

Crabs

Here's one of the common hermit crabs that are in every tidepool I've ever looked into. I believe this one is called a blue band hermit crab ( pagurus samuelis ). They have brownish legs with white stripes around them, and blue spots or stripes near the joints. I added several shells I found for them to grow into. This crab is wearing a very eroded shell that I added. These crabs will fight each other for the shells. One of them grabbed another by the antenna and pulled it right out of the shell. Turns out the shell was too small, so the homeless hermit got his shell back. They look so funny running around with their soft curled bottoms bare. Their backsides curl to fit in the spiral shell.

I believe this burly fellow is a "Red Rock Crab" ( cancer antennarius ). He was a rather shy fellow whenever there were larger animals around. He would burrow into the sand and just leave his eyes sticking out most of the day. However, when he didn't feel threatened, he would come out and use his big pinchers to crack open the small mussels (1/2 inch or less) I had in my tank, and eat them. He destroyed anything small enough for him to get his pinchers around. He didn't care much for the frozen oyster that I fed the other animals. I would not recommend this animal for an aquarium creature.

Of the three crabs I kept for a while, this was definately the best. This is a "Purple Shore Crab" ( hemigrapsus nudus ). This crab had a smooth, purplish red body, with darker spots spattered all over. His belly and pinchers were white. This one was a scavenger and didn't bother anything that was alive. The instant something died, he was there to clean up. He shed his exoskeleton two or three times in the six months that I had him, and became quite large. He even climbed out of the tank once. In the middle of the night our dog woke us up pawing at something in the corner. He sure looked like one big spider to groggy eyes!

The body of this blue crab is about the size of a dime. It lost a few of its appendages to a larger creature. This little guy was really beautiful with its blue body and red highlights. I haven't been able to identify it yet. It did not survive very long.

Barnacles

These creatures are hard to identify. They are either "Acorn Barnacles" ( balanus glandula) or buckshot barnacles (?). These barnacles are growing on the base of a piece of seaweed. The crabs loved to eat this seaweed. I'm quite certain that the grayish barnacles in the other pictures are "Thatched Barnacles" ( semibalanus cariosus). They have the gray thatched look, have a wavy line where the top plates join, and some of them are about an inch and a half across. Barnacles are kind of like filter feeders. They open their top plates and use their feathery "foot" to capture plankton and small crustaceans. Since plankton is hard to come by, I don't recommend these for the aquarium either. Some of mine lasted a couple of months, and one even lasted for over six months. If you do want to keep these animals, you must supply very fine food in the water column, and keep the environmental parameters fairly steady.

Nudibranchs

This beutiful creature is a "Sea Lemon Nudibranch" ( archidoris montereyensis ). Originally I thought it was anisodoris nobilis because this is what most people around here think of when they hear Sea Lemon. However, A. nobilis has a white "crown" for its gill plume and any dark pigment is not on its tubercles (the little spiky bumps all over its mantle). In A. montereyensis the gills are the same yellow color as the mantle, and dark pigment is often present on some of the tubercles, like on this specimen. At about two inches long, this one is about average size.

Nudibranchs are mollusks, along with snails, limpits, mussels, and other shell bearing creatures. They are unique because they don't have a shell. They have a terrible taste, and thus have very few predators, if any. All true nudibranchs are carnivorous. Most eat sponges or sea squirts (tunicates). Some eat other nudibranchs, or different types of coral. Most nudibranchs are highly specialized feeders, only eating one, sometimes a few, species of their preferred prey. The two "horns" on the front are sensory structures called rhinophores. They work like your nose: nudibranchs use them to smell their food. The feathery structure on the back are its gills. Here's a link to a page about the digestive system of the dorid family of nudibranch. It also talks a little about the placement of the gills.

	I think the orange shell in the picture to the left may be from a juvenial Rock Whelk. I placed the shell in the tank hoping the hermit crabs would use it. If you'd like to learn more about nudibrachs, check out this link or the Sea Slug Forum. It was quite difficult to find the full taxonomy of these nudibranchs on the internet. I decided to add it here for those of us who don't have a biology degree, and can't remember much from our high school classes.
	TAXONOMY OF A. MONTEREYENSIS
	Kingdom: Phylum: Class: Sub-Class: Order: Sub-Order: Family: Genus: Species:	Anamalia Mollusca Gastropoda Opistobranchia Nudibranchia Doridina Dorididae Archidoris Montereyensis

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This page was last updated on: August 8, 2003