A quick post on a dive a couple of weeks ago, my first boat dive in Cornwall. Four divers left from Loe Beach in Feock on the Fal Estuary to find the wreck of the Rock Island Bridge at the mouth of the Helford River. On our way we saw a Harbour porpoise which was a first for me, great! The mouth of the Helford is only slightly deeper (nine meters) than it is off Grebe Beach where we usually dive. There is no eelgrass here, just some Divided net weed Dictyota dichotoma and very large Sugar kelp Saccharina latissima lying flat on the bottom. The seabed is an expanse of gravel covered with quite a lot of bivalves: Great scallop Pecten maximus, Rayed artemis Dosinia exoleta, Norway cockle Laevicardium crassum, Dog cockle Glycymeris glycymeris, Common ottershell Lutraria lutraria, Warty venus Venus verrucosa, Pullet carpet shell Tapes corrugata and Hardshell clam Mercenaria mercenaria amongst them. Next time I will collect shells so I can take a good picture of all of them back on land. The place was swarming with starfish feeding on these bivalves, I’d say 90% Common starfish and 10% Spiny starfish. Below a Common starfish Asterias rubens feeding on a clam, a small brittlestar Amphipholis squamata and a Warty venus and Pullet carpet shell.Although the seabed was relatively featureless and we did not manage to find the wreckage, it was fun to watch the Thornback rays Raya clavata (including a large individual with distinctive black headmarkings) and the many Small-spotted catsharks (or dogfish) Scyliorhinus canicula which are very easy to approach. We also saw a Red gurnard Aspitrigla cuculus (see also this old post). However, it is high time we are going to explore some other, deeper dive sites. With the weather deteriorating, I hope we can find some more good days to dive this year though!
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 A lot has happened to the aquarium and some of what I post here is already outdated, but here goes.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:Poor 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:The 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.
In addition to animals, loads of different seaweed species could be found washed up on the beach in Pleneuf-Val-Andre:
Some of the species would look great in the aquarium I am sure. For instance Fine-veined crinkle weed Cryptopleura ramosa:Pestle weed Gigartina pistillata: (EDIT 2017: does not look like this species at all, be very suspiscious of my seaweed ID skills in older posts please!)Maybe a Plocamium species, I am not sure. I really like my Seasearch Guide to Seaweeds of Britain and Ireland, but it does not contain a key and I find it hard to determine some species based on a photograph.What would be great is to have a seaweed key app. I saw a great one this weekend for trees: leaf snap: take a picture of a leaf with your phone or tablet and it automatically gives you a list of best hits based on the outline (and perhaps colour, I don’t know), it worked really well. Seaweeds (actually pretty much all organisms) are too complex in shape, size and color for this. However, I could see an app working where the first screen would give you a number of pictograms, eg ‘dark encrusting reds’, ‘chalky reds’, ‘feathery reds’, ‘fan-shaped reds’ etc. After touching a first pictogram, new ones would appear, for instance to select the branching pattern, ‘irregular’, ‘whorled’, ‘opposite’ or ‘alternate’ and so on. Instead of such a purely dichotomous approach, it could also be possible to be presented with a wide variety of pictograms describing different properties (eg, colour, overall shape, texture, location on the shore), where it is possible to skip properties you are unsure about and still go ahead with the next steps. This would be a brilliant resource and help me identifying weeds such as this one:Anyway, a final seaweed (there were many, many more but this one I immediately recognized): Sugar Kelp Saccharina latissima. It is surrounded by various species of flat and tubular Sea Lettuce Ulva:
The second good rock pooling session in Bretagne was in the little port of Pleneuf-Val-Andre. The rock pools themselves were very similar to those in Erquy. The only interesting find there was a pretty gastropod I had not seen before (a white snail with a dark brown/black shell about 1,5 cm in length).
It looks like a Trophon muricatus, although I am not 100% sure Raphitoma purpurea:
Cuttlebones were scattered everywhere along the shore and we even found a clump of Common cuttlefish Sepia officinalis eggs:
The eggs were quite big and had a weird texture. I don’t know if these egg clumps can survive hours on the beach at low tide, probably not. It would have been cool to take them to an aquarium to see if they would hatch. It is extremely difficult to keep cuttlefish though, they need live food and large aquariums which usually are still too small still to prevent ‘butt burn’ when they jet backwards into the tank wall and their cuttlebone gets exposed right through the mantle. In the next post I will get to the washed up seaweeds.