Nudibranch

Posted on June 5, 2022 by An Bollenessor under nudibranchs

Two entries back I posted photos of the Goby egg-eating seaslug Calma gobioophaga. Last week I was lucky enough to spot its cousin, Calma glaucoides, who is a bit less fussy and eats different types of fish eggs, as well as cephalopod eggs. I found it by turning over a rock whilst snorkeling in a very shallow (<50 cm!) pool. Next to a depleted patch of clingfish eggs, it was circling around, busily depositing eggs of its own. A fantastic surprise, and I really need to get on with recording such findings.

new strobe

Posted on May 2, 2022 by An Bollenessor under echinoderms, eggs, Macro, molluscs, nudibranchs

Long time no post! Due to a combination of not-so-good weather and work I have not been in the water much the last few months. I attempted some seaweed photography but most times the viz was bad; the one time the conditions were great, somehow all my photos turned out to be a bit meh and I could not be bothered to post them. (For some older shots on seaweed diversity see here, and many older posts as well.) Anyhow, my exciting news is that I finally bought a new strobe (an INON D-200 for those who are interested) because my old Sea&Sea strobes just proved to be too temperamental. Something I should have done a long time ago, but the thrifty Dutchman in me just never pulled the trigger. I have now taken it out twice this weekend and it works like a charm! Now I just need to practice, as it is actually still very hard to go from an OK photo to a truly good pic. Above a shot of a baby urchin Psammechinus miliaris. The true stars of the weekend however were nudibranchs.

A very special find (shown to me by fellow rockpool photography enthusiasts Martin and Greg) were two Goby egg-eating seaslugs Calma gobioophaga. This tiny species can only be found on the goby eggs it eats. With such a ‘niche niche’ and with very good camouflage it is no wonder that reports of this species are rare. A fun fact: its protein-rich diet means it does not have to poo and it therefore does not have an anus…The rock with the eggs and nudis was very shallow and so it was a challenge to get the port of the camera housing under water. Luckily Greg assisted with pointing out the nudi and holding my strobe in place. Freshly hatched goby fry could be seen hovering above the eggs (the fact that a predator was munching through their brothers and sisters might have triggered some of the hatching). The cerata (the fleshy lobes on the nudi’s back) seem to have two goby eyes in them to make them better blend in!

Finally, two other nudibranch species, neither very colourful. Both are predators of anemones: first the largish Grey sea slug Aeolidia papillosa and second the smaller species Aeolidiella alderi. Both adequate shots but I need to practice to make them truly good. I will probably buy a second INON strobe so I can practice wide angle shots as well when diving. I hope to go out a lot more during summer and will make sure to post here about my finds and progress!

Silver Steps Diving III

Posted on September 2, 2019 by An Bollenessor under diving, molluscs, mzuiko60mm, nudibranchs, Olympus OM-D E-M5 Mark II, Silver Steps

I will keep this post short, as my third Silver Steps shoredive of the year was a week ago. As you can see above, my dive was made by encountering the beautiful nudibranch Antiopella cristata (although I prefer the old name Janolus cristatus…). My camera battery strangely gave up straight after taking these pics (argh!), otherwise I would have bothered it for at least another ten minutes! The 60mm lens is great. Look at the European cowrie Trivia monacha below which is less than a centimeter in length. Not a great shot but it shows that it is possible. Finally, a common Phoronid worm Phoronis hippocrepia (Thanks Allison, please check out her great blog Notes from a California naturalist). I hope the wind will die down and I can go back soon.

Posted on May 6, 2019 by An Bollenessor under molluscs, nudibranchs, Olympus OM-D E-M5 Mark II

Because of the plankton bloom (see the last post), I decided to try my hand again at some above-water macrophotography. Above and below a Flat periwinkle Littorina obtusata on bladder wrack. More subjects: a Red Doris Rostanga rubra, a Painted topshell Calliostoma zizyphinum, Cornish sucker (or Shore clingfish) Lepadogaster purpurea eggs (they must not be laid long ago and so the tiny fish are not yet visible, although if you zoom in you can see an outline forming) and some layers of Coral weed.

First attempts at macro photography

Posted on March 26, 2017 by An Bollenessor under Canon G16, crustaceans, eggs, Macro, nudibranchs, tunicates, worms

I recently posted my first photos taken with the nauticam CMC macro wetlens using stalked jellyfish as a subject. I since lost my lens, which I in large part blame on the bad fit of the adapter with which it is attached to the housing. The best thing in these cases is not to agonize over it too much, order a new one straight away and keep going, so that is what I did (also I am now a bit more careful of course). Here some more photos of macro subjects. Above a very easy subject as it is very common this time of year and also it does not move….Paddle worm egg capsules (probably Eulalia viridis). The individual eggs can be just made out in the gelatinous blob. Below, one of the more common nudibranch species Polycera quadrilineata. Nudibranchs come in all kinds of stunning colour variations and are very species rich and so are a favourite of macro photographers (see this old post hunting for them with David Fenwick in Newlyn, and check out the NE Atlantic Nudibranch facebook page for lots of eye candy). Tricky with the narrow depth of field to get the whole animal in focus. Mysid shrimp are quite common and beautiful little animals hovering about in small groups. They need dissection to determine which species it is, but this might be Leptomysis lingvura (around 10 mm). Finally, the colonial star Ascidian Botryllus schlosseri; these form colonies (‘systems’) where zooids have individual inhalant openings and a shared exhalant opening. They are common, sessile, flat, and come in a range of colours so they make ideal subjects for a beginning macro photographer. Not only that, apart from fish they are our closest relatives in rock pools, which is most obvious in the tadpole-like larvae which have a dorsal notochord (a cartilage rod functioning as a backbone). I hope to devote a post to them later in the year.

Photography Update

Posted on February 11, 2017 by An Bollenessor under anemones, Canon G16, eggs, molluscs, nudibranchs, seaweeds, snorkeling, sponges, tunicates

More photography practice lately. I have started to use Photoshop to post-process images, which is hard. I have sat with Thomas Daguerre for a session which was very helpful. For some images, the twiddling is of not much use; the image above of a Bull huss egg case for instance I am pretty happy with as is. Below I have pasted some before and after-Photoshop photo’s. Mostly adjusting highlights and contrast, cropping and playing around with sharpness (in the RAW files), most images tend to be a bit reddish. I have not bothered to tackle the ‘marine snow’ with the Spot Healing brush tool. First, Snakelocks anemones, next, Cocks’ comb Plocamium, then Harpoonweed Asparagopsis armata and an old kelp holdfast covered in feeding Grey topshells Gibbula cineraria. On and under the seaweeds I encounter many interesting tiny animals, but it is hard to take good photo’s without a macrolens. I have pasted a couple photo’s below (none have been edited in any way): the Stalked jellyfish Haliclystus octoradiatus (these can also be reddish or brownish, and can be found on a wide variety of seaweeds), a sponge, a juvenile Snakelocks anemone Anemonia viridis (next to a Flat top shell Gibbula umbilicalis) and the Star ascidian Botryllus schlosseri where I later noticed the fecal pellets underneath. Pooping tunicates, that is what we need more pictures of!Finally, some more before- and after- Photoshop images. The first is the nudibranch Rostanga rubra (‘Red doris’) which was only 5mm or so (see also the tiny Daisy anemone in the background). I shot it today, very cold: 4 degrees, and the water might have been only 8 degrees, brrrr! Next, a closeup of the seaweed Osmundea (see the first photo of this post) which shows its interesting pigmentation. The photo’s are nothing special yet, but I notice I am making progress. Excitingly, I just have ordered a macro wetlens and so hope to get some proper macro photography going soon!

Oregon

Posted on July 7, 2016 by An Bollenessor under anemones, Canon G16, Canon Powershot D30, crustaceans, iPhone, non-Cornwall, nudibranchs, public aquarium, rock pooling

Last month we had a great holiday travelling from San Francisco to Seattle. Nature here is awe-inspiring for the average European; we saw snowcapped volcanoes, giant redwoods, dunes, beaches, mighty rivers and temperate rainforest. This is not the place for a travelogue, however, rock pools were of course checked and that is prime blog material! We had a bit of a happy-go-lucky approach to travelling and I had not checked tide times beforehand. Turns out that the tides on the Pacific West coast work very differently than those in Western Europe: instead of two almost equally low tides a day, there is a proper low tide and a not so low tide, how inconvenient! (This page has a good overview of tide types, including another type with only one low- and one high tide a day.) In the end I had two early mornings on the Oregon coast for rock pooling: Bob’s Creek Wayside south of Yachats (pic above) and Seal Rock north of Waldport (see map). (I actually prefer the more appropiate American term ‘tide pooling’ as of course there are also (freshwater) rock pools that do not experience tides.) The coast in most of Europe is so much more densely populated it is almost strange to see that vast stretches of pristine coastline with hardly any people around, brilliant. Also, the vast amounts of driftwood and logs is almost unseen in Europe, as thewhole continent is pretty much deforested (especially in the UK, my guess is only places like Norway could be comparable in that respect).Being at the Pacific Northwest tide pools made me feel like a kid in a sweetshop: I could not decide to stick with a beautiful find or try to move on to the next exciting thing. It seemed a bit useless to just start documenting all the different species in the short amount of time I had. Instead I mainly enjoyed just looking around, especially admiring the Green surf anemones Anthopleura xanthogrammica (above). I know this species mainly from the Coldwater Marine Aquarium Owner group on facebook which has many North American members. Although the diversity of animals and seaweeds in the South West of the UK is amazing, I must admit I am always a bit jealous of the critters in Pacific Northwest tanks! The Green surf anemones are not only strikingly coloured and large, but also incredibly common, along with the Aggregating anemone Anthopleura elegantissima forming dense carpets on the rocks, inhabiting gulleys low on the shore to tide pools quite high on the shore.

I had taken the plunge and ordered a new camera for this holiday, a Canon G16 with a Fantasea underwater housing (see this post). However, I did feel comfortable with it in its bulky housing yet and so reverted to the more basic Canon powershot D30 and my iPhone for these sessions instead. I saw a couple of the large nudibranchs Hermissenda crassicornis as well as a Janolus fuscus, very pretty. Also below a Lined (or striped) shore crab Pachygrapsus crassipes and an unidentified prawn. Otherwise, most of the photo’s turned out to be not that great; I was just too hasty!Although all species were different (except for the Plumose anemones Metridium senile I saw on some pontoons), it was interesting to see the parallels with Cornish rock pools. For instance, all seaweed colours, shapes and textures I knew from home were present here, just in different combinations in each species. There were noticeable differences too. For one, many of the American organisms (chitons, isopods, anemones) are much bigger. The rocks were almost completely covered in barnacles and mussels (again both huge). Seagrass (Phyllospadix) was growing from the rocks!

Two mornings of rock pooling in a three week holiday was not enough, but all that was manageable unfortunately. We however also visited the Oregon Coast Aquarium in Newport on the single rainy day we had and that was pretty good. I am not a big fan of the generic aquarium displays (sharktunnels, ‘nemo’s’, scary Moray eels etc) so it was nice to see mainly coldwater aquaria, especially the nanoaquariums that housed a jumble of sponges, anemones, barnacles, chitons and strange fish, such as one of my favourites, the Grunt sculpin Rhamphocottus richardsonii which camouflages as a giant barnacle (first photo, see also here). A touch pool contained sea cucumbers, huge abalones and the largest chiton species in the world, the Giant Pacific (or Gumboot) chiton Cryptochiton stelleri, humongous! I hope one day to be back in this beautiful part of the world.

Nudibranchs

Posted on October 4, 2015 by An Bollenessor under nudibranchs, pontooning

This Saturday I was at the marina in Newlyn, where local natural history expert David Fenwick was kindly showing me how he obtains the samples he finds so many creatures in (worms, copepods, tunicates, forams and many other things). Todays focus was on nudibranchs, arguably the most beautiful group of little critters. David has recorded an amazing 46 nudibranch species from these pontoons alone! As this is the most Southwesterly pontoon in the country, it is a bit of a ‘sentinel site’ for southern species with northward-shifting ranges. Indeed David has found a species new to the UK that has also been discovered in the south of Spain and possibly off the coast of Morocco. He often sends samples away to (inter)national labs for sequencing and further investigation and frequently shares his finds on facebook (see the links page for relevant facebook groups). For all things marine in Cornwall see his website: Aphotomarine, an edicational resource dedicated mainly to the photography and diversity of marine life that is found in the coastal waters and rockpools of south-west England. Also check out his Aphotofungi, Aphotoflora, Aphotofauna and Stauromedusae.uk. Luckily for me, I can show off some of David’s images in this post too.

The drill: scrape off seaweeds (mainly kelps) covered in tunicates, hydroids, other seaweeds and silt (very mucky business, especially when collected lying on a pontoon covered in seagull-excrement). Next, vigorously wash the seaweeds in a bucket. Sieve the resulting silty water, pick out larger objects (sea squirts etc) from the sieve and gently wash the silt away in a fresh bucket. Then transfer the material to a white tray for preliminary inspection. Some nudibranchs can be observed this way, but the bulk of the animals only show themselves after the sample has been brough home. In warm weather, samples can get deoxygenated, so a battery-powered airpump is a good thing to have. To avoid sloshing, plastic vessels are filled to the brim by opening the lid slightly when held underwater.Back home, samples are placed in the fridge and subsamples are periodically checked under the stereomicroscope. Most animals are a bit more active in the cooled water but some are not. Some come out in the dark, others in the light, so changing the conditions is necessary to see everything that is hidden in the debris. David processed the samples that same afternoon and indeed a lot more came crawling out! From top to bottom: Cuthona amoena, C. foliata, Doto sp., Eubranchus farrani, Facelina annulicornis, F. auriculata, Polycera faeroensis, Elysia viridis (juvenile), Palio nothus, Aegirus punctilucens (juvenile) and Polycera quadrilineata (same species at the top of the post). For more beautiful nudibranch photos see the relevant Aphotomarine section. A very cool activity indeed, although at this point in my life I have not enough time at my disposal to do it justice…However, there definitely will be some smaller olloclip-iPhone sessions at Mylor marina soon!

shark!

Posted on July 17, 2015 by An Bollenessor under diving, fish, Helford, nudibranchs

It has become almost a tradition to go for a dive at Silver Steps (rocky coast) one day and at Helford (eelgrass beds) the next (I rent my equipment for 24 hours, I could squeeze in a third dive maybe but I never really have time for that). So following the Silver Steps dive featured in the previous post, here the Helford one. We found many of the same creatures as described in recent Helford post so I will not get into these. Worth mentioning was the beautiful nudibranch Facelina bostoniensis, but I did not get a shot in focus unfortunately. The highlight of the dive was a Small-spotted catshark Scyliorhinus canicula, around 60-70 cm in length. Very pretty and very easy to approach, I was able to shove my camera almost up its nose!

Diving the Helford

Posted on June 16, 2015 by An Bollenessor under anemones, Canon Powershot D30, crustaceans, ctenophores, eelgrass, eggs, Helford, molluscs, nudibranchs

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.