Some Red Seaweeds

Last weekend I took a little stroll on my local beach in Flushing and had a quick look at the variety of red seaweeds washed ashore. I saw some that I did not know, some that I knew, and some that I thought I knew….
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I have recently joined the facebook group ‘Seaweeds of the NE Atlantic‘ and so immediately asked the experts for some help in identification. It turned out that the only one I correctly identified was the one on the bottom right: Solier’s red string weed Soliera chordalis. This (invasive) species did well in the aquarium and so did the one on the top right, which I always thought was Dudresnay’s whorled weed Dudresnaya verticillata but it isn’t! It is actually Chrysymenia wrightii, which is also an invasive species. Moreover, my ID of the bottom left species was also wrong: not Fine-veined crinkle weed Cryptopleura ramosa but Beautiful fan weed Callophyllis laciniata (I should have known this as I have found crinkle weed in France this year…). The small flat seaweed on top is Cock’s comb Plocamium cartilagineum. The dark mop top left could not be identified based on this picture so I have to go back to take a better one. So dear reader be warned and take my identification of seaweeds in previous posts with a grain of (sea)salt!

seaweeds in the aquarium Part I

After some musing on animals that I had good- (here and here) or bad (here) experiences with during the past year-and-a-bit that I have my aquarium, I thought it would also be good to take stock of my experiences with seaweeds. Not many people have temperate marine aquariums, and only few of those who do seem to focus on seaweeds. That is understandable, because it is hard keeping seaweeds! I currently have almost no seaweeds in my tank, as I wanted a break from the problems I had with die backs and resulting detritus. Below a picture of my 130 liter aquarium at its prettiest (see this post); unfortunately it did not look that way for long (see this post):IMG_1981Although keeping seaweeds in the aquarium is difficult, they are so beautiful, diverse and abundant that it is definitely worthwhile to try. The range of shapes and colors is much greater than that of the vascular plants in freshwater tanks. Also, the fact that so few people seriously try to grow different seaweeds in their tank makes it an extra interesting challenge. My fellow aquarists reading this will agree that it is great to look at a ‘finished’ tank, but building it up and experimenting to ‘get it right’ is an integral part of the fun. Keeping a native tank means that you can collect yourself which is a great activity in itself (and free). being able to observe organisms in their own habitat also gives you some clues on how to best keep them in the aquarium. Anyway, below my personal- and somewhat disjointed thoughts on the topic of keeping seaweeds in the aquarium (with some links to previous posts). Quite a lot to write about so I’ll save some pondering for a part II.IMG_0304

1. Many Seaweeds are seasonal

Coming back to the same rock pools over the course of the year, it is very striking to see the composition of seaweed species change. Some species are annuals and always there (although sometimes somewhat overgrown and smaller), but many species are only abundant for a season or even less than that. For example, Dumont’s tubular weed Dumontia contorta was abundant only in early spring this year, whereas Codium tomentosum has just appeared now and will disappear come spring. This must be due to adaptation to annual variations in temperature and daylight (and competition with other species that are present in different months). Although light and temperature conditions can be kept constant in the aquarium, seaweeds are likely ‘programmed’ to thrive at specific times of the year. So in contrast to fresh water planted aquariums where plants just grow and need occasional trimming but otherwise stay the same, marine planted tanks never stay the same. A good example of how a tank can change over time is the series of monthly pictures taken by Jon Olav of his Norwegian native aquarium. I guess for some people, the unpredictability of seaweeds is a downside, not an upside.

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2. ‘Planting’ Seaweeds is difficult

The above picture is of Grape pip weed Mastocarpus stellatus. Like many seaweeds, it is very firmly attached to the rocks. Ripping it off results in a handful of separate fronds which will just float around when transferred to the aquarium. Such species (see here for another example) can only be brought over to the aquarium attached to a rock. Some species readily grow on smaller rocks (Solier’s red string weed often is washed up attached to shells) but others don’t. It is possible with suitably shapedseaweeds to weigh them down using a piece of string and a pebble. (I am not sure about the lead weights used to weigh down plants in freshwater aquariums; on one hand lead is toxic, but on the other hand a layer of lead oxide will form around the weight which prevents leaching. Leaching should be less of a problem in salt water which is slightly alkaline anyway. I’ll stick with pebbles in any case!) Some seaweeds on Castle beach in Falmouth when pulled from the substrate take with it a shard of rock, which makes it easy to anchor them in the aquarium (check):IMG_1746

3. Seaweeds can get eaten

Herbivores, such as snails or prawns can start munching on some seaweeds, especially flat greens and reds seemed vulnerable. Perhaps if you provide enough food, they will leave the seaweeds alone (but you risk overfeeding and the disasters that come with that of course). If you are really into your seaweeds, you could also choose to ditch such critters.IMG_1319

more seaweeds

I had to remove the False eyelash weed from the aquarium; some bits were looking fine but in general a substantial amount of the branches had died off. Perhaps this is what normally happens in nature, only in rock pools any dead material is quickly washed away and so it goes unnoticed. I had to make some water changes to get rid of the debris which required some healthy exercise bringing buckets of waters down from the quay. Although it was windy and cold, I could not resist the urge to have a look at my local beach in Flushing last Saturday, hunting for some more seaweeds. It was noticeable that one particular seaweed had started to grow everywhere: Dumont’s tubular weed Dumontia contorta:

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Slightly slimy and impossible to remove from the rock without ending up with a hand of loose strands. I therefore have placed a large pebble with one small plant in the aquarium just to see how it goes. I found small plants of Solier’s red string weed Soliera chordalis again that did well in the aquarium last year, as well as a whole bunch of other red seaweeds that I have trouble to identify (not the first one, that is Bunny ears Lomentaria articulata):

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To test whether they are able to grow in the aquarium, I have placed them in an old floating fish fry box I had lying around:

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first attempts at aquascaping

I am not sure if I like the term aquascaping much because of it’s connotations with gardening and I like a more natural look. However, aquascaping is the general term for arranging plants in an aquarium nowadays and that is what I attempt to do as well with seaweeds. (Also, I cannot pretend that my tank looks particularly like a real rock pool…). Anyway, I will post some more thoughts on the topic of aquascaping, marine or fresh water, later but for now just wanted to show some of the first attempts at planting my aquarium, It is challenging to make any tank look ‘right’, but I found it particularly hard to recreate a rock pool feel. I soon found out that I did not have enough rock in the tank and so hauled some *heavy* ones from a nearby beach. The bare tank:IMG_0551

Some wrack added (I cannot remember what species and cannot tell from the picture, it did well though). A strawberry anemone Actinia fragacea on the right.IMG_0593

Another version with Serrated wrack Fucus serratus (left), a small mop of Dudresnay’s whorled weed Dudresnaya vertillicata (far left) and some Solier’s red string weed Soliera chordalis (middle and right). A bit messy:IMG_0362

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A worm pipefish, dog whelk and hermit crab in front of the serrated wrack. There is a lot of algal growth and detritus on the wrack. (I have since bought a circulation pump to keep detritus in suspension so it can go into the filter, more about that later).IMG_1285Another go. The nice thing about having an aquarium with native species is that you can collect them yourself, which is half the fun (and free), and when something does not work out you just chuck it back and try something else.  The green seaweed is velvet horn Codium tomentosum, the long brown seaweed is wireweed Sargassum muticum. Both did well, the wireweed grew quite fast, perhaps not a surprise as it is an invasive species in the UK. The red seaweed on the left is dulse Palmaria palmata, on the right harpoonweed Asparagopsis armata. The harpoonweed was not exactly thriving and the dulse was quickly eaten by the prawns:IMG_1319IMG_1701Recently, I noticed the Dudresnay’s whorled weed (love that name) sprouting from the rocks everywhere. This happened some months after removing a pluck of this weed from the aquarium. Up till then I had just planted seaweeds, but having them establish spontaneously I had not seen before. Most of the newly established weeds are only a couple of centimeters and do not seem to grow very fast, but the two weeds pictured above grew to 10 centimeters in a couple of weeks. Perhaps very local conditions in the aquarium matter.

introduction

Hello! For the last half year or so, I have been messing with a marine aquarium housing sea weeds and critters collected from local rock pools here in Cornwall. I thought it would be fun to blog about my aquarium project, especially after I discovered that it is quite easy to take nice aquarium pictures using an iPhone (which I found nearly impossible using a standard digital camera). After doing some internet research, I settled on a Red Sea Max 130D ‘plug-and-play’ aquarium (I will post about the actual tank later). I could not find much information on the web on temperate marine tanks, especially ones without a chiller or a sump. and few of those seem to focus on seaweeds. So who knows I may have found a niche. Below I have posted some pictures from when I was setting it up last year:

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Half a bucket of gravel collected from a nearby beach, RO water taken home from the lab where I work (carried back 2×10 L at the time, the tank is 130 L) mixed with a free bucket of sea salt that came with the tank. Few sea weeds and not too many rocks. I have since replaced the rocks with bigger ones; most critters are benthic and you do not want to have too much ‘open water’ around with nothing in it. Although too bare, I do like the purple look of this set-up, which has since disappeared because of inevitable algae taking over from the purple crustose seaweeds.

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A shanny Lipophrys pholis, this is a very common fish around here that can easily be picked up when turning stones at low tide. The branched seaweed on the left is Solier’s red string weed Solieria chordalis; in the back on the right there is a little pluck of Berry wart cress Sphaerococcus coronopifolius.

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A snakelocks anemone Anemonia viridis. Behind it some Slender-beaded coral weed Jania rubens. This weed died off quite quickly; first it turned a bright orange, then white.

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The Star ascidian Botryllus schlosseri, a colony-forming tunicate. It did not survive for too long, but that might just have been because the particular broad-leaved red seaweed they grew on are very popular with prawns and hermit crabs. What animals and sea weeds do well has been trial and error. I might compile a list of ‘easy’ species and ones to avoid at some point.