more macro rockpooling

Another quick, brisk trip to the rocky shore in my village of Flushing today to practice my macro photography with the 60mm lens. I used the highest F-stop, varied the output of the flash and let the camera decide the shutterspeed and ISO. I did not find anything too special, but the very common organisms are just as pretty as the rarer species. Above and below juveniles of the Flat topshell Gibbula umbilicalis and the Grey topshell Gibbula cineraria on pink encrusting algae. Still not quite used to not having optical zoom as with my old Canon Powershot but quite happy with the shots, especially as all were hand-held. As I am lazy, these are JPEGs with some  tweaking using Windows photoviewer.

Below a Black-footed limpet Patella depressa, a more ‘atmospheric’ shot of a periwinkle, might be the ‘normal’ Littorina littorea but not 100% sure, and a baby Edible crab Cancer pagurus. Really looking forward to go into the water again, but not only is it still cold and grey, it is very windy and choppy so bad viz. Probably another rockpooling post next weekend!

tiny critters

IMG_1646A nice low tide at Falmouth’s Castle Beach today. The weather was not great but at least it was not raining (I still managed to get quite soaked, including my wallet…). Quite a lot of brittlestars, urchins, worm pipefish and porcelain crabs around. I did some collecting for the aquarium: beadlet and strawberry anemones, snails and urchins. Otherwise I focused on the smaller stuff and took pictures with the olloclip macrolens on my iPhone. First two tiny crustaceans that I have not attempted to identify and what I think is a tiny Edible crab Cancer pagurus. The nicest find was a white colonial tunicate that at very first sight looked like an eggmass. I could not readily identify it using the usual websites, so hope that the NE Atlantic Tunicates facebook page members can help me out (Note: they did, it could be a ‘regressed’ Diplosoma spongiforme). On Sunday I had a quick look in Flushing and for the first time found some juvenile Candy-striped flatworms Prostheceraeus vittatus (see here for adults), very pretty!IMG_1680 IMG_1687IMG_1672IMG_1697IMG_1712IMG_1706IMG_1743

animals that did not do that well in my aquarium…

A while back I wrote two posts on my personal top ten animals for the (unchilled) aquarium (here and here). Of course, there were also organisms that were not such a success. Animals can be unsuited for the aquarium for many reasons, and of course this depends on the size of aquarium, the combination of animals and what you define by ‘unsuited’; so please keep in mind that the following is a personal account!

Aggressive species: Another reasons that makes animals unsuitable for a community tank is that they are bullish. (Animals becoming too big is not a real problem for the native aquarium as you can release them again and replace with smaller individuals.) Crabs often get rowdy for instance. I kept a small (5 cm carapace width) Edible crab Cancer pagurus for a little while (his name was Barry). It would bury (Barry!) itself during the day, but as soon as the lights turned off it would go about and rearrange the tank. Rocks weighing over a kilo were knocked against the glass and I found a Cushion star cut in two. It was quite an operation to remove it from the tank using a net (but during all that rummaging I interestingly saw bioluminescence in the tank which was very cool). Shannies like to feed on snails and hermit crabs and so in a relatively small aquarium at least, so sometimes you have to choose between one or the other:

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Truly littoral species: I had a couple of limpets Patella vulgata in the aquarium that just sat in the same place on the glass for months. At this time, algal growth was a problem, so I should have known if they had moved during the day or night by the tracks they would have made but they did not move a millimeter. The animals seemed a bit thinner in their shell, but seemingly they can survive for very long periods without food. Not being able to emerge from the water as they do normally seems to be a big problem for these animals.

Secretive species: Other animals simply are too shy or live underneath rocks; no point really in putting them in the aquarium if you cannot see them. This happened with Broad-clawed porcelain crabs, a Shore rockling and also a Shore clingfish (although hidden, all of these animals did survive for a long time). I have seen Brittle stars in a Mediterranean aquarium but the ones found in the intertidal here tend to live under rocks and I never saw one back in the aquarium. A Sand star Astropecten irregularis quickly buried itself in the gravel:

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Filter feeders: I quickly realized that filter feeders, mussels or tunicates for example, were very difficult. There simply were not enough algae growing in the water to feed them (unfortunately, at times there were plenty of algae growing on the rocks and on the glass). One way to keep filter feeders is to separately cultivate algae for food. A really nice blog describing such a project can be found here. Another solution might be to feed these animals with artificial plankton, which is available commercially. This requires very good skimming to get rid of excess nutrients though. Both options I find too cumbersome at the moment. Having said all this, one filter feeder managed to survive for many months in my aquarium: the variegated scallop.

Other fussy eaters: Worm pipefish did OK in the aquarium, but that was probably because I regularly brought in new seaweeds housing fresh zooplankton. Unlike Mullet, Gobies or Blennies, I have never seen them take frozen food and therefore I will not keep them again until I can provide them regularly with live brineshrimp or similar. Snakelocks anemones always did well in the aquarium, but Beadlet and Strawberry anemones didn’t (they actually did not die but seem to shrink rather than grow over time). The former are able to grow because of their symbiosis with photosynthesizing algae and so do not rely as much on food. I must say that the latter two  species are probably relatively easy to keep when you make the effort to regularly dunk a piece of dead prawn on them. The European cowrie Trivia monacha feeds on tunicates which I had trouble keeping alive and so they are unfortunately not an option yet:

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Unknown reasons: On a few occasions a species just died and I had no idea why. The only thing this taught me was to not try that species again. This happened to a Common starfish Asterias rubens:

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castle beach

Although cold and rainy on the bank holiday Monday, the weekend weather was glorious (and low tide was ‘low’), so it was off to Castle Beach in Falmouth:

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To me this looks as good as a coral reef! Loads of Harpoon weed Asparagopsis armata, Thong weed Himanthalia elongata and Oarweed or Tangle Laminaria digitata (there are two similar kelp species, but these remain more erect when above water my guide tells me). Also quite some of my favorite Bushy rainbow wrack Cystoseira tamariscifolia shining blue:

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Also iridescent: a tiny (<5 mm) Blue-rayed limpet Helcion pellucidum. Normally found on Laminaria kelp, this one sat under a rock:

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Especially on the middle shore, there was quite some change in seaweed composition, with lots of Ulva and similarly bright green, slimey algae in the rock pools. The abundant Shore clingfish Lepadogaster lepadogaster had been laying eggs under rocks everywhere:

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You can even see the embryo eyes, I am very happy with my olloclip macrolens (although photography in the bright sun is difficult, especially if you do not want to disturb the animals/eggs too much). There were a couple of quite big Edible crabs Cancer pagurus around. The combination of a trembling crab and a trembling hand resulted in a sub-optimal macro photo of its carapace but it is still a neat pattern:

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Strangely (and mostly, annoyingly), the second pump of the aquarium broke down before the weekend and I ordered two new ones. The aquarium has not improved without filtration of course. I will be traveling quite a bit over summer so I will not experiment much with it in the near future.

quick rockpooling session

Went to Castle Beach in Falmouth after work this week for a bit of rock pooling. I saw a beautiful grey-red Sea scorpion Taurulus bubalis; I could not tell the difference) or but it was gone before I could even attempt to catch it. Below the much easier to spot Shanny Lipophrys pholis Giant goby Gobius cobitis (after lifting up a rock):

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I spotted a small Eel Anguilla anguilla for the first time on the beach; it was quick but I could scoop it up from a very shallow sandy pool. Nice, but not of interest for the aquarium!

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Also spotted for the first time: a European sting winkle Ocenebra erinacea. This I took home for the aquarium:

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A tiny white Edible crab Cancer pagurus. I do not know if it is an albino or whether juveniles are generally white. I had a bigger one in the aquarium (carapace width 6 cm or so), but every night the light went out it came out of its burrow and started to rearranging the tank, knocking big rocks against the glass. This one is only one cm so I hope it will be better behaved:

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