Shells

I started a Cornish shell collection with my children recently. So yesterday we went to our local beach on Flushing to look for new additions. Lying down I took a really close look and was rewarded with a whole bunch of tiny species. On this photo, 14 species comfortably fit on a square inch. Species names in a clockwise spiral:

Bela powisiana

Tritia incrassata (Thick-lipped Dog Whelk)

Trivia arctica (Arctic Cowrie)

Tricolia pullus (Pheasant Shell)

Bittium reticulatum (Needle Whelk)

Littorina obtusata (Flat Periwinkle)

Calliostoma zizyphinum (Painted Top Shell)

Steromphola cineraria (Grey Top Shell)

Littorina saxatilis (Rough Periwinkle)

Tectura virginea (White Tortoise Shell Limpet)

Rissoa lilacina

Peringia ulvae (Mudsnail)

Nucella lapillus (Dog Whelk)

Steromphola umbilicalis (Flat Top Shell)

Aquarium Update 8

Another long time without a post. A lot has happened to the aquarium and some of what I post here is already outdated, but here goes. My Daisy anemone has buried itself and has not resurfaced but the Red-speckled anemone is growing well. I found the Dahlia anemone I was looking for, but lately it has been pestered by a Purple top shell, which has left a scar on its column, I hope it survives. The most dramatic event was that the Snakelocks anemone managed to kill my Sea scorpion (but not eat it, it was too large). This must have happened when I  removed some of the rocks, startling it and make it swim in the wrong direction:IMG_4963Poor thing (although it had eaten 22 of my mullet so it works both ways I guess…). The good thing was that I could try keeping some other fish again. Using my net, I caught some Two-spotted gobies as well as a Common goby Pomatoschistus microps (I think, there are some very similar species) and a Goldsinny wrasse Ctenolabrus rupestris. The total tally from netting off the Flushing quay is now eleven fish species, not bad. The Goldsinny swims around the tank a lot and does some digging; it seems to be a more interesting fish to watch than the Corkwing:

The Plumose anemones Metridium senile are strange, they can be all shrivelled up for days, be short and squat or all extended. Here three pics of the same individual:Presentation1The Turban top shells Gibbula magus are very nice to watch (the Grey topshell Gibbula cinerarea gives a sense of scale). I found a Sea urchin Psammechinus miliaris and decided to try it out. It spends half its time under the gravel and pops up here and there with shells and pebbles attached to it. Let’s see what it does! Lastly a picture of the tank. I had attached a young Sugar kelp Saccharina latissima to the tunze pump with an elastic band and now it has attached itself to the plastic.IMG_5091

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new year’s resolutions

It has been a while since I last posted about the aquarium, mainly because I had a problem with algae and did not like the look of the tank in general. Combined with being away for two weeks over the holiday season, I decided to remove the rocks and most animals from the tank. Only left are some snails, Cushion stars and a Spiny starfish (who seems to do fine except for being less brightly coloured than when I caught it). The snails made a good start and cleaned up a lot of algae but it was too little too late. Also, (non Spiny starfish-related) mortality was quite high. Of all snails, the periwinkles fared least well (as I had noticed on earlier occasions); the Grey top shells seemed to do best. A main problem is that the snails move out of the water and often die there. Grey top shells can be found in the intertidal but are also common in the subtidal and so might be more suitable for the aquarium.

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Anyway, time for a fresh start in the new year. I have decided to buy a chiller (and pump), mainly so I can switch off the noisy hood fans, but also because a more natural temperature regime might help keeping some of the more difficult species (see eg here and here). I have trawled the internet to find recommendations for the least noisy chiller but to no avail. I will stick with a more expensive brand and hope for the best. I will also invest in LED lighting. LED lights give a nice shimmer effect, generate less heat, use less electricity, need less replacement and are more easily dimmable. I’ve found this interesting Red Sea Max 130D retrofit kit:solderless_rsm130_dimmable__09721.1361404356.640.640I will need to buy a separate dimmer and probably will have to ask my local sparky for help fitting it in the hood but it seems like a good investment. I’d like to supplement white LEDs appropiate for shallow water with some blue ones so I’ll be able to get a deeper water feel as well. This week I saw an inspirational aquarium back in Blijdorp Zoo in Rotterdam: a deep water reef with gorgonians, many brittle stars, Boar fish (or Zulu fish) Capros aper, Snipe fish Macrorhamphosus scolopax and John Dory Zeus faber. A crap photo:

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However, I will go for a more brightly lit seaweed aquarium first. I will switch to finer gravel and reduce the amount of rocks to improve water flow. This time I will also focus more on fish. Marius has a great picture of a Two-spotted goby Gobiusculus flavescens in his Irish rock pool aquarium here and I definitely want to have a couple of these (I had a tiny one recently but it was eaten by one of the Snakelocks…). The other fish I definitely want to have is a bright green juvenile Ballan wrasse Labrus bergylta (although the other species are pretty too):

wrasseSmall wrasse can be caught using a hand net but I reckoned it would be easier using a cast net. After my first trial run with such a net in the Helford river a while back I am not so sure though: loads of leaves and twigs but no fish. Youtube has hundreds and hundreds of ‘how to throw a cast net’ videos but these all use slightly different techniques which sometimes involve a throw whilst holding the led line between the teeth… Anyway, I’ll have to practice!

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sea gherkin

Another ‘lifer’ yesterday: a Sea gherkin Pawsonia saxicola, at Castle Beach in Falmouth. It is a small sea cucumber (a relative of the Cushion star next to it); a very cool find indeed!

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The main aim though was to collect more snails to help out in the grazing project. This was pretty easy of course. I collected a couple more Painted top shells Calliostoma zizyphinum and many, mainly juvenile, Grey top shells Gibbula umbilicalis. I also picked up a beautiful small Spiny starfish Marthasterias glacialis; this fellow will go after the snails but as long as the predation is not too severe that will be OK, let’s see. Finally, using my little aquarium net, I went after some fish high up the shore and caught a tiny Two-spotted goby Gobiusculus flavescens. I need to catch a bunch more of those, hope to post about that soon