The weather was not great last weekend and we were too late at the diveshop on Saturday to be back in time to get the tanks refilled for a dive on Sunday but the one dive was (as always) worth the effort! We took dive buddy Chris’s boat from Loe Beach in Feock over to the other side of the Fal Estuary (between St. Just and St. Mawes) to explore the Maerl beds. See an earlier post on a snorkel trip to see this bed of ‘Cornish coral’ for some more background information. After the usual faffing about with equipment on board we plunged in the water. I took a single photo of the boat which turned out quite dramatic:Although we were diving 1-2 hours before high water (the best time, as clear seawater is pushed in the estuary), the visibility was quite bad. After going just a couple of meters down, fields of maerl loomed into view (the dive was really shallow, 5.9 meters max I think!). There were quite a lot of Thornback ray Raya clavata egg cases (foreground first picture) but we did not see the rays themselves. There are two main Maerl genera around here, Phymatolithon and Lithothamnion but their growth forms are varied and there are other encrusting Pink paint weeds that could look similar. We saw a number of golf balls that were completely covered in coralline algae, quite cool.We saw a couple of *very well* camouflaged crabs sitting about. They were completely covered by sponges, coralline algae and seaweeds. There are a number of crab species shaped like this but most of them seem too small. Best guess is th
e Toad crab Hyas coarctatus the Europan spidercrab Maja squinado in a particular extravagant mood. There are lots of little things hiding in the Maerl; gobies (rock gobies I think), squat lobsters, swimming crabs, hooded prawns and things that hide faster than I can identify them. I noticed a dainty little prawn sitting about which is probably Thoralus cranchii, although it could also be Eualus occultus (second picture is cropped). Swimming crabs were common and probably mostly were the Harbour crab Liocarcinus depurator. The first picture was the only one with flash and shows the Maerl colours a bit better. The second photo shows a Velvet swimming crab Necora puber under a snakelocks anemone sitting on top of a bottle. This species can be very commonly seen rockpooling. Lastly an empty shell of the largest European sting winkle Ocenebra erinaceus I have seen so far and probably the largest sponge I have seen so far too (with a human head for scale).
After 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.)This 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.No 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.One 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.
The aquarium was in desperate need of a make-over (again…). I hauled a ton of rocks over from the beach and stacked them up. (I thought at first that I would need something to stick the rocks together (epoxy, superglue or waterfall foam) but that wasn’t really necessary). I also removed most of the gravel and replaced it with sand. So quite a big change but it really looks a lot better. However, my nice burrowing Red-speckled anemones suffered a bit when putting the sand in, and even after siphoning it off again I could not really find them anymore….hopefully they turn up again! The aquarium is still a bit bare and I have to go out and collect things that will live on the rocks, such as anemones and seaweeds. However, there is some progress on the seaweed front. There is a bit of Irish moss Chondrus crispus growing spontaneosly from the back wall. There are also some patches of pink corraline algae; which must be Coral weed Corralina officinalis judging from one outgrowing patch. Having this species grow would be great, but they do not seem like fast growers. Chrysymenia wrighti is still thriving on the circulation pump; I remove a bit every now and then, so it acts as an ‘algae scrubber’, removing nutrients from the water. I have placed a couple of other seaweeds in the aquarium, a bit risky as they can die off and start trouble, but I can’t help it. The red Soliera chordalis below has done well before but unfortunately has started to die off a little already (first pic). I have a big piece of a flat red species that has started to grow from nowhere as well (second pic).One day, the aquarium was full of strings of Painted topshell eggs. I noticed when feeding a day later that the water was not very cold: I had forgotten to switch the pump/chiller back on two days previously! So the trick to breed this species is to increase the temperature, although I am not expecting much to happen with the eggs. Either the Thick-lipped or Netted dogwhelks are also occasionally sticking their egg masses to the glass. I placed a chunk of orange Estuarine sponge in the aquarium; this was devoured by Painted topshells and Cushion stars, so it is a good bit of live food to add. I had planted a little washed-up eelgrass plant to see if it would survive and indeed it has grown more roots. (If you want to try this yourself, please always use washed up plants and don’t dig out any, as eelgrass beds are vulnerable habitats.) It would be great to have a second tank dedicated to eelgrass….The little scallop is still happy (see close-up). I have added another filter feeder: a Leathery sea squirt Styela clavata. Butt-ugly, but that is actually fun too. I am trying it out as they are an invasive species and so probably pretty hardy. A Sting winkle seems to like it (but not eat it). I have never seen my two Sting winkles eat anything actually. They move about very slowly, but they have grown.Now the snakelocks anemones are gone, I have added some more fish. I have caught some juvenile Pollack Pollachius pollachius with my net. At first I caught ones that were less than an inch, but they did not survive. Of the six two-inch or so ones I caught, three dissappeared after one day, but the remaining three are going strong. Very nice looking fish! I also caught a little Tompot blenny Parablennius gattorugine (by hand at low tide). It is quite shy, but is increasingly showing itself. A beautiful little fish! I have one remaining Two-spotted goby. The Common goby is doing very well and eats from my hand. I think I’ll go for another little tompot, more Pollack and Two-spotted gobies. Ideally I would catch some Leopard-spotted gobies with a trap when diving, let’s see….The other fish I would like to have again is the Goldsinny wrasse: very pretty and not as nervous as Corkwing wrasse.
The tide this Sunday in Flushing was as low as it was the day before in Mount’s Bay and the weather was just as great too. We could walk among the Eelgrass and Golden kelp Laminaria ochroleuca. There were lots of Snakelocks anemones Anemonia viridis around; especially striking were patches of what must be clones. The tentacles are much shorter than the ones in my aquarium or those found deeper on kelp, must be due to being less exposed to the waves. Loads of fish as is usual here, a single overturned rock yielded five species alone! Again pictures of the Connemara clingfish Lepadogaster candollei, a Butterfish Pholis gunnellus (very wriggly, hard to get a good shot) and Tompot blenny Parablennius gattorugine eggs:
This site is sheltered and silty and some species are more characteristic for this habitat and much less common in Castle Beach in Falmouth. Examples include the Keyhole limpet Diodora graeca, the Elephant hide sponge Pachymatisma johnstonia and the Yellow-plumed seaslug Berthella plumula:
The diversity of seaweeds was very high and I think the pictures below give a good impression of that. Very low on the shore Bushy noduled wrack Cystoseira nodicaulis can be found; in this case almost as iridescent as is Bushy rainbow wrack Cystoseira tamariscifolia. We found some Beautiful kidney weed Kallymenia reniformis, here David Fenwick is taking a photo of it on his first visit to my local haunt. All in all one of the best rock pooling weekends so far!
For the first time in a while I had time to nip over to Castle Beach to do a little rock pooling. The tide wasn’t the best and the pools did not look to great either actually; this seemed to be due to a mix of some seaweed species dying off, and some not so great-looking species ones blooming: Lots of Wireweed, Ulva and very fine weeds (the latter are often very pretty under magnified and in water, but not so much as a blob on the rocks). What might be Desmarestia viridis (but don’t take my word for it): Still, there was plenty to see: Orange-clubbed sea slugs for instance and one very weird-looking creature I had never noticed before was clinging on in little groups on red seaweeds under overhangs, the annual sponge Sycon ciliatum:
The Breadcrumb sponge Halicondria panicea can be very nicely coloured: There were a lot of tunicates about. Colony-forming Morchellium argum for instance and this beauty, probably Ascidia mentula (determined by helpful folks at the ‘NE Atlantic Tunicata‘ facebook group): One colony-forming tunicate looked superficially like Botryllus but was much bigger and less pretty, it might be Aplidium nordmanni: Quite a lot of Sting winkles Ocenebra erinacea were around as well:Finally, I spotted the orange/yellow egg masses of the Cornish sucker (or Shore clingfish) Lepadogaster lepadogaster (see here for an older post on them). However, I also found some that were greyish and had a speckled band, as well as a red dot between the eyes. Local expert David Fenwick told me these are from the Small-headed clingfish Apletodon dentatus, a species I have not yet seen the adults of (see his site for pictures):
On my way back from rock pooling yesterday in Flushing I turned one last rock on the upper shore and found two species of tiny snails that I had not noticed before. First, a couple of Two-toothed white snails Leucophytia bidentata, one of the few terrestrial, airbreathing snails that have returned to a marine habitat:More numerous was the smaller species Cingula trifasciata. Below a group next to a large wormshaped eggmass that my Seasearch Identifications friends quickly pointed out belonged to the Ribbon Worm Lineus ruber:
We went for a stroll last weekend in between showers: starting from Maenporth beach, following the coastal path south (direction Lizard). We discovered a nice, rocky beach with an abundance of rock pools. Not that much time to explore, but the pools seemed different from those on Castle Beach: filled with sand and with much more bare rock (probably because of scouring).
Pestleweed Gigartina pestillata (not entirely sure but a species tolerant to sand cover so that fits) was common. I found a small (5 mm) jade-coloured egg mass on this seaweed that I could snap using my iPhone olloclip macrolens. According to the SeaSearch Identifications facebook group,
probably from the Green leaf worm Eulalia viridis. from the snail Lacuna vincta.
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:
The number of Slipper limpet Crepidula fornicata (live and dead) was quite amazing, there were whole banks of them:
The little channel from the port to the sea, a mix of sand and rocks, was more interesting than the actual rock pools:
with a variety of organisms washing up, for instance this large (dead) Common spider crab Maja squinado (European shoe size 45 in the background…):
A Dog cockle Glycymeris glycymeris shell:
Egg cases (‘a sea wash ball’) of the edible Common whelk Buccinum undatum:
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.