Aquarium Update 14: anemones

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 deadlyIMG_2436 IMG_2191IMG_2165

Diving the Helford

IMG_8454After the success of last weeks snorkelling session, it was high time for a proper dive! Again the Helford did not disappoint. In the end, my Sea hare stroking proved a bit inconclusive; also, my estimate of 30 cm long individuals might have been a slight exaggeration, 20-25 cm is more likely for the larger individuals. My guess is that it might be Aplysia punctata after all, and perhaps this is just a very good year where they reach their maximum size. (Note that three individuals can be seen in the first photo and two in the second photo.)IMG_1081IMG_1014This was not the only Ophistobranch activity going on, as I spotted a small nudibranch sitting on the eelgrass. Probably Eubranchus farrani, although it could well be something that is deserving of a new name, there is a lot of (cryptic) species discovery and taxonomic revision ongoing in nudibranch biology. I also spotted several largish egg masses on the eelgrass that are likely to be from a larger, shelled Ophistobranch; I am waiting for suggestions from various facebook groups *could be Haminoea navicula*. I found a beautiful Wooden canoe bubble shell Scaphander lignarius, these animals live buried in the sand so are not commonly spotted. Next time I’ll bring a small garden rake to see what is hidden below the sand (I am serious!), lots of echinoderms and molluscs to be sure. Pelican’s foot shells Aporrhais pespelecani live in sand, but I found some on top of the sand too, so full of muck that they were barely recognizable. I have found empty shells of this species washed up on holidays before, but it was cool to see them alive for the first time.IMG_1012IMG_1065IMG_1058No cuttlefish in sight this time, but loads of eggs so it is likely that this is an important breeding ground for this species. We encountered one Thornback ray Raya clavata, which, like cuttlefish, are not very shy. These species occur in very shallow waters (we probably did not dive deeper than 7 meter) and the influence of the surrounding woodland is clear, with decaying oak leaves and pine cones amidst the seaweeds and eelgrass.IMG_1083IMG_1085IMG_1032IMG_1031IMG_1039One very well-camouflaged species is the Scorpion spider crab Inachus dorsettensis. Medium-sized Common hermit crabs Pagurus bernhardus are common, running around in Turban top shells covered with hydroids. Although present in the last post, another pic of a Mud sagartia Sagartia troglodytes anemone Red speckled anemone Anthopleuris ballii. Filterfeeding worms are abundant too, including the beautiful¬† Fan worm Myxicola infundibulum as well as a large tube-dwelling worm and worms in white calcareous tubes with bright red bristles that I could not identify. As we got out of the water, we saw a Comb jelly Beroe cucumis, very pretty but hard to photograph. The next dive will have to wait two weeks or so, but then I hope to finally play around with my GoPro.IMG_1041IMG_1035IMG_1019IMG_1026IMG_1072IMG_1048IMG_1090

snorkelling in the Helford

A nice long snorkel in the Helford ‘River’ from Grebe Beach today. The weather was great and so was the water temperature. The timing was good too, close to low tide, so the Eelgrass beds started at only about one meter depth. There were a lot of cool new finds. What was most striking was the extremely large number of Sea hares Aplysia. There was almost one every other square meter, ranging from 5 to 30 cm, and from grey to light brown to very dark brown. The common species Aplysia punctata ususally reaches 7 cm (occasionally up to 20 cm), so the size and often reticulated veining probably make it A. depilans. From David Fenwicks aphotomarine site: “An easy way to distinguish this species from (a third species) Aplysia fasciata is to run a finger from front to back on the dorsal surface. If the finger cannot travel all along the animal from head to tail then it is A. depilans.” This I did not know so I need to go back and stroke some slugs! I see that these large (up to 40 cm!) beasts have been found here before. A not particularly large individual on my hand, as well as an orgy, with some orangy strings of eggs visible:

IMG_0923 IMG_0925Another interesting mollusc to see was the predatory Necklace shell Euspira catena (not a very good shot, would be nice to go back diving soon so there is more time to take pictures). Other nice finds include a Mud sagartia Sagartia troglodytes anemone (I think!) and a small Sagartiogeton undatus anemone. Finally, at only 2 meters depth, we found a good-sized cuttlefish Sepia officinalis, lying still trusting its camouflage. In places, black Sepia eggs could be seen attached to the Eelgrass. Some of us also spotted a juvenile thornback ray in the shallows:IMG_0905

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