The last day of January I took an hour to explore a pool at the upper part of Castle Beach. The resulting shots turned out a lot better than they did the last time. As most of the pools are bare rock, there are no problems with sand/silt, but they are very shallow and on the receiving end of drainage pipes resulting in rain water mixing with the salt water, affecting visibility (this is not necessarily bad as it can make a photo more interesting). It was overcast and I did not experience problems with overexposure; I actually found that tweaking in Photoshop made the photos look worse. Below a Beadlet anemone Actinia equina, the most common anemone on rocky shores. They can be bright red or a drab brown (the green version is rare here) but have bright blue beadlets, or more technically acroraghi. These contain stinging nematocsysts used in territorial fights. After that a small Daisy anemone Cereus pedunculatus, which are usually more mottled in appearance (and not common here, or perhaps I do not know how to look for them…).Next up, a red growth which I should have investigated further, I am not even sure if it is a sponge or something else. After that, a worn Thick top shell Osilinus lineatus, a young Dumont’s tubular weed Dumontia contorta, a red Banded pincer weed Ceramium sp. happily producing oxygen and finally Patella limpets covered in Brown limpet paint Ralfsia verrucosa.
I have not posted as much on the blog as I would have liked this year (in fact, I keep posting less and less: 24 times this year, compared with 33, 46 and 64 posts the previous years). My new year’s resolutions will be to dive more, to go rock pooling more and to blog more. For now, I will post some miscellaneous photos from this year that I did not bother to put on the blog at the time (as I did last year). Below a Beadlet anemone Actinia equina on the beach in St. Ives as well as a young cormorant looking for food taken with my new Canon G16:I caught a number of different fish this year, the first photo shows a small Montagu’s blenny Coryphoblennius galerita in an aquarium net which were fun to watch in a little aquarium. Next a Longspined scorpionfish Taurulus bubalis caught with my big net off the quay and a Sand smelt Atherina presbyter (see here for a movie). The latter species did not last long in my tank unfortunately. I mentioned in the last aquarium update that a Topknot I caught seemed to have died in the tank too, but I found out it is still there, it just likes to hide behind the rocks.I visited the quirky Victorian Horniman Museum and Aquarium on a trip to London which features lots of stuffed animals and diorama’s which I find quite fascinating. The aquarium part is small; there is some behind the scene coral (sexual) propagation research going on which sounds very interesting. There were two or three coldwater tanks too, the larger tanks were not much too look at (I know how hard it is…) but I really liked the Victorian fountain-style aquarium. A quick snap here; see this video for a nice overview. I would like to collect some Black brittlestars Ophiocomina nigra next year, they can be very abundant at slightly deeper sites.I also visited the National Marine Aquarium in Plymouth for a second time. It features the deepest aquarium in the UK, complete with plane wreck and some Sandtiger sharks. I was more interested in the coldwater stuff, of which there was quite a bit. I especially liked the Lesser weever Echiichthys vipera which can be caught on sandy shores; their venomous sting would make handling a bit tricky though. There were some cute pipefish (these need live food and I do not want to commit to that) and a round display with loads of Snakelocks anemones (see the first picture posted on this blog). I have placed a couple of these in my aquarium again, perhaps I need to get a few more, as they are so pretty and easy to keep. I did not manage to get a good shot of the very impressive Wreck fish or Stone bass Polyprion americanus in the large coldwater display unfortunately. Next up a washed up sponge in Falmouth (species unknown) and a live one (Aplysilla sulfurea) under a rock, both taken in Falmouth with my iPhone. I have only been diving a couple of times this year and did not post about the rocky shore dives (here some photos of the maerl and eelgrass beds). I have seen a variety of interesting animals, including cuttlefish, a conger eel and lobsters but next year I hope to go out a bit further and dive a bit deeper to finally see jewel anemones and dead man’s fingers. I am not sure I want to commit to a flash and strobes though, instead I’d like to practice my rock pool (seaweed) photography.
A short update on the aquarium; I have collected some more anemones and hope to collect a lot more now spring has started (I went for my first dive of the year this Friday; it was really nice to be back in the water but the visibility was really bad and it was only 9 degrees!). I do not have a decent full tank shot (FTS as it is called on aquarium fora…) but decided to post some quick iPhone pics anyway. The first photo shows three species: top left is a Diadumene cincta or lineata, bottom left a Dahlia anemone Urticina felina and the two on the right are Strawberry anemones Actinia fragacea. Next a Plumose anemone Metridium senile followed by a white variety of the Red-speckled anemone Anthopleura ballii. I feed the anemones a couple of times a week by hand with pieces of defrosted shrimp. The anemones readily take up the shrimp, especially the Dahlia anemone is very quick to grab food and close up. The Plumose anemones are more difficult as they are often closed (they slowly open up when they sense food in the water but often they don’t) and have very fine tentacles not suited to feeding on larger particles. They would be better fed with zooplankton from a turkey baster but I have been too lazy to do that. When they are fully extended they are beautiful, white or orange but often they are flat as a pancake and shift shape a bit, leaving behind pieces of tissue that sometimes develop into tiny anemones. I have some beadlet anemones and a small orange and white species I am not sure of too. There are a whole bunch of other species (I can recommend this excellent guide) and many are very beautiful (see here for a gallery of photos by Paul Kay). The plan is to try to find more Dahlia anemones, as these come in many colour variations, but they are not very common in the rock pools here. A common species when snorkelling in the Helford is the Mud sagartia, which would also be nice to have. I am doubting about getting some Snakelocks again: they are very pretty and I could get the commensal spider crab as well, but they are also quite deadly…
Long time no post, just been too busy! The aquarium is doing reasonably well at the moment, especially considering the fact that I have not done any water changes since the last update and I have added a bunch of new organisms. I have added two Beadlet anemones Actinia equina. They are a dullish brown (except for a nice blue band around the base); I have not found the bright red or green individuals yet. Very similar but more striking are Strawberry anemones Actinia fragacea of which I have collected three. They are voracious, I could easily feed them a shrimp a day. The same goes for the Sea scorpion. I am afraid of sticking my hand in now as it comes after me! Time to let this buddy go. This will also give me the opportunity to add some other things such as squat lobsters.I have taken a break from experimenting with seaweeds and am focusing on anemones instead. I have added a bunch of small Plumose anemones Metridium senile that I scraped of the side of a pontoon. Weird fellas, they can fill up with water to be quite large, or just reduce to a crumpled little pancake. I have four white ones; I could only find very small ones of the orange variety and these were all devoured by Cushion stars (interesting). I’d like to have a large orange one as well, but I have to wait half a year until I can go diving again (they are very common in deeper water).
On the sheltered, silty shore of Flushing I found two small anemones attached to rock and half buried in the maerl sand. My excellent Seasearch Sea Anemones and Corals guide told me they were a Daisy anemone Cereus pedunculatus (uniform greay with many very short tentacles) and a Red speckled anemone Anthopleura balli (purplish and speckled, for a better picture of a different colour variant see this old post). Both quickly half buried/half nestled themselves under a rock so only the tentacles and the mouth are visible. They take pieces of shrimp and so hopefully they’ll be able to grow; these species should reach a decent size:
My friend marine biologist Chris gave me a snakelocks anemone that he had cured from its symbiotic algae. A very cool, bright white individual but it has returned to its original purplish colour so it must have taken up symbionts again. The snakelocks I already had, grew big, split into two and grew some more. Interestingly, one of the individuals seems to be turning from the green- to the purple colour variety:So six anemone species in all. I would really like to have some Dahlia anemones, they are very colourful, large, and not uncommon (old pic here). I need to go anemone hunting at a good low tide soon (I have not been out in ages).
I had the Chryseminia seaweed growing attached to the Tunze for a while and it worked OK, but it looks a bit messy and so I will remove it. However, I see that little Chryseminia plants have started to grow from the rock in many places (see top picture). I have to give the glass a weekly clean (with a tooth brush) and the rocks have turned a bit too greenish recently. I have noticed however that near the Snakelocks anemones, tufts of filamentous algae have appeared, as the grazers do not want to come too close to their tentacles (this reminds me of a work by an ecologist friend of mine who studies how seedlings can be protected from grazers when growing close to thorny shrubs, I’ll have to tell him of this observation!).
There has been some snail mortality. I mainly have Grey top shells but there are less than half of them left. I do not know why, part might be predation (which is not all bad as at least they serve as food for other inhabitants). I need to collects some more in any case. The Netted dog whelks are doing well. They are usually hidden below the sand, but as soon as they smell a defrosted shrimp, they come up like a Shai-Hulud. Their plowing through the sand is definitely good in preventing mats of diatoms to appear. Their little cousins the Thicklipped dog whelks are also doing fine. They tend to creep up the Daisy anemone to steal its food. I still have a Sting winkle Ocenebra erinacea which moves slowly but is very pretty. There are a variety of other species such as Blacklined- and Rough periwinkles. The best species however are the truly sublittoral large Turban top shells Gibbula magus (some of which have died as well, one of the shells has been taken over by a hermit crab, wich are also doing fine):
OK, part two of my list of fun and easy species to keep in an unchilled native marine aquarium (see here for numbers 10-6). I will later post about species to avoid, and of course also about easy seaweeds to keep.
5: juvenile crabs
Crabs are active and interesting to watch, however, in a community tank they should not be too large as they can be quite destructive as well. Juvenile Shore crabs Carcinus maenas are an option, or a variety of crab species that stay small, such as Pirimela denticulata (I am not too sure what species the above pictured crab is, but it is still doing well four months after collecting it).
4: Squat Lobster Galathea squamifera
Squat lobsters Galathea squamifera can be a bit shy but are entertaining to watch as they scuttle about. Very common under rocks in silty areas.
3: Snakelocks Anemone Anemonia viridis
Very pretty and common anemones that are easy to keep. Beadlet anemones Actinia equina and Strawberry anemones Actinia fragacea survived in my aquarium as well but they seemed to shrink a bit over time rather than grow and these species can retract their tentacles which looks less nice. I did not specifically feed my anemones by dropping artemia or food pellets on them. The photosynthetic capabilities of Snakelocks anemones due to their algal symbionts probably makes it easier for them to thrive when food is relatively scarce. Beware for the tentacles of larger individuals though, as they can sting!
2: Common prawn Palaemon serratus
Prawns* have been a rage in tropical freshwater aquariums for years but people forget that there are very pretty ones right in our seas. I must admit I have not got round to checking rostrum (the ‘nose’) structures to differentiate between several closely related Palaemon species, but I think I have the Common prawn. They are always foraging and flock to any new object in the aquarium to check for edible bits. If the pumps are switched off they will swim and compete with the fish for food.
* or shrimp, these two names can mean different things in different English-speaking countries. In other languages ,like my native language Dutch, we only have a single word (garnaal) for these critters
1: Cushion star Asterina gibbosa
My numbers 2, 3 and 4 could have been number 1 as well, but I ended up picking the very common Cushion Star. Although grey and just an inch in size, these quintessential rock pool inhabitants are active, hardy and just plain cool!