Coldwater marine aquarium Blog 2008 June
June 22 2008
Pholis gunnellus

Rock eel (Pholis gunnellus)

I haven't done very much with the tank the last month, mostly it has been left to go and grow by itself. I've made some modifications like removing all the remaining large kelp specimens. The are new ones popping up though so I still have some. I have some of that "been there done that" feeling regarding kelp right now. They are very dominating organisms in such a small tank so will focus on other algae for awhile. The general developments are that my wracks, the Fucus vesiculosus and Fucus serratus, are growing surely and steadily, and do not have major problems with epiphytes. I am so amazed to see that these species, that I thought were impossible, are now the ones that seem best adapted to long term tank growth. Even if they get some epiphytes now in the summer, those will disappear later in fall when the light levels are sinking. The "Pig wrack" Ascophyllum nodosum is showing some signs of growth. The coralline algae, most likely Lithothamnion sp. or Phymatolithon sp. is now spreading more rapidly than before. Hundreds of tiny patches have popped up. With careful examination of the rocks I can now see hundreds of other tiny alge popping up here and there too. Many of these are of the slow growing reds and browns that one finds in very large quantities i nature. My careful collection of live rocks is starting to pay off. I feel that a more permanent forest of algae is growing now.

Lupagus's sea snail (Liparis montagui) hiding in thick bush of hairy brown algae.

The two summer species of algae seem to be over the top. One first showed signs of dying by being overgrown with epiphytes, then let go of the ground and disappeared. This was the one formed as long spaghettis, brown algae. The other one (in the picture) is still hanging in there but is covered with epiphytes. I guess that is its natural lifespan. It will be exciting to see if it pops up next year too.

Monterey Bay

I was on early summer vacation in the USA this year. Drove around in California, Arizona, Utha and Nevada with two friends. Our main objective was to see nature. We visited a whole bunch of national parks, forests and reserves in just one week. A hectic schedule in other words. One of the highlights was the visit to The Monterey Bay aquarium. What a great aquarium! I haven't been to many public aquaria before, four actually including Monterey Bay, so I can't say how it compares to the great ones. But it was in a class by itself when compared to the usual local public aquariums. It was bigger, though not really massive. The difference was mostly in the professional way it was run. It was clearly planned and maintained in a modern way, by competent people. It also seemed like a quite expensive aquarium, with lots of employees. It had lots of small tanks with fish and invertebrates from the bay. These were well kept and planned. They also had a nice area with birds, not to mention all the otters. Many people liked the jellyfish tanks. I did too, but they were a bit to arty. The greatest impression for me was the large ocean tank where we could see huge tuna pass at cruise speed close to our faces. That was immense. Second was the huge tank were they actually grew giant kelp. Afterwards we drove down Highway One and got to see lots of giant kelp, sea otters, seals and pelicans.

Pacific shore snail

This seemed to be the pacific version of our periwinkle, the common shore snail. Not all that different really.

Kelp, otters, birds

There was giant kelp and sea otters everywhere. Kind of hard to see the otters here, but they were out there.

Local crabs

Here are some pictures of three of the crab species found locally in my region. The first one is the common shore crab (Carcinus maenas). It one of the best known crabs by people here since specimens are found practically under every rock in the tidal zone. It an active and lively animal. Very popular with children. All is not well though since it is listed as one of the 100 worst invasive species on the planet. It is introduced on several continents and a great threat to bio diversity. But here in Europe it is native. The second is the edible crab (Cancer pagurus). This is one of the few crabs that norwegians eat. It can be large, 25 cm across the carapace. The claws are very strong and popular as human food. The third one , the furrowed crab (Xantho pilipes), is less seen. I have only found it under rocks in wave exposed areas. It is also a comparatively small crab.

Carcinus maenas

Common shore crab (Carcinus maenas)

Carcinus maenas

When stressed it folds out its limbs. The claws for defense and the legs for running away. That, combined with quick reactions and high speed makes it look aggressive and intelligent.

Cancer pagurus

Edible crab (Cancer pagurus)

Cancer pagurus

When stressed this crab folds up it legs and claws to become bulky, spiky and hard to eat.

Xantho pilipes

Furrowed crab (Xantho pilipes)

Xantho pilipes

I hadn't seen a furrowed crab until last year when I started looking under rock in outer, wave exposed areas. But I find them almost every time I search in such locations.



This one has plenty of flow, but the position is kind of awkward.

The few barnacles that manged to settle in good places are doing well. Most of them are growing rapidly. Often more so than their wild counterparts. There must be plenty of food for them. They sure like flow. The ones that are growing fastest are the 10 or so inside the skimmer. Sigh.

Yellow water

One of the issues I've had for a long time is that the water is getting yellow. It starts out pretty clear after a waterchange, but already after a few days I can see a brownish yellow coloration gradually increasing. I have read that algae may release phenols and indols to the water, creating the color. I've worried that these may be toxic to both algae and animals. I haven't seen indications that they bother any organisms. But such indications can be difficult to observe. It is also possible that the color comes from something else, like humic acid. I feel pretty sure that whatever causes it is something that comes from the great biochemical activity in the tank. There is so much food going in and that food is being broken down and built up again in rapid tempo, up to several times before it is removed from the system through waterchanges, gas exchange or skimming. Some of the substances are more difficult for bacteria to break down than others. So they accumulate in the system. I've been thinking about this for a long time. The color is quite annoying and reduces the esthetics of the tank, but the fact that there can be quite a large amount of toxic remains in the tank that organisms have to deal with, is even more problematic. There may be a remedy against this though, namely activated carbon. I haven't really considered that option before. In my freshwater days I did some research, but came to the conclusion that this was something used only for removal of medicines and heavy metals. I actually though carbon would color the water by itself since it would leak out carbon powder. Since I had access to top quality drinking water in unlimited quantities I just forgot about the whole thing. When I started to look at the issue again I found a different picture. Activated carbon is now widely used in the marine hobby. People use it continously to prevent buildup of the aforementioned chemicals. There are some really fine discussions on the topic at reefcentral. People with high integrity agree that it is safe to use and useful. Activated carbon is definitely something I am going to look better into. The same goes for Ozone, I haven't given that a good look before either. But it looks very interesting.

Camouflaged crab

I haven't managed to identify my camouflaged crabs yet. (They're too well camouflaged).

Aeolidia papillosa

Another one of these sea mice nudibranchs (Aeolidia papillosa) popped up from nowhere recently. They are nice animals, but since they are specialized anemone eaters, and I try to keep my anemoes, I let it back in the ocean.

Calliostoma zizyphinum

I've been lucky enough to find some more painted topshells (Calliostoma zizyphinum). They have been said to be Norway's most beautiful snails.

Calliostoma zizyphinum

Here is an another example of the painted topshell using its foot to cover the shell with mucus. Plankton that sticks to the mucus is consumed by the snail when it later removes it at lays a new layer of mucus.

Actinia equina

Beadlet anemone (Actinia equina).

Palaemon sp.

Palaemon sp.

sea hares

Sea hares with their ususal activity of eating, having sex and pooping all at the same time.

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