Porthkerris
Category Archives: molluscs
Back to Silver Steps
With the camera housing back, I have been in the water again lately, taking quite a few photos. I am lagging behind with posting quite a bit (this will allow me to post when I cannot get in the water later in the year) but should occasionally maintain the blog over summer, so here is! My local haunt Silver Steps provided during two dives with the macro lens. Above a Twin Fan Worm (Bispira volutacornis). These are quite shy (i.e. they retract into their parchment-like tube when their composite eyes detect a curious diver) but also are attached to cluttered rock walls. To blur this unappealing background, I used a very shallow depth of field (f 2.8); this also has the advantage of letting a lot of light in so ISO can be decreased to 100 – sorry non-photographers!). Below a collage of other ‘usual suspects’ (names under the photos) but ALSO I SPOTTED AN OCTOPUS! Crouched in a crevice and with only a macro lens I could not do it justice but it was still a very nice encounter.
Periwinkles
Long time no post – the idea was to spend time taking photos during spring and summer and enjoy the underwater world vicariously by blogging in autumn and winter. However, something terrible happened on my only dive of 2025: my underwater housing sprung a leak! The housing was not flooded to an extent that it damaged my camera but it needed to be repaired before I could get back underwater. Unfortunately there is only one place that can do that, backscatter all the way in California, and even more unfortunately, U.S. customs decided to keep my package on a shelf for over a month. I have never seen an octopus in my decade of diving but of course people reported eight or so per dive last month so I was feeling very sorry for myself!* Anyway, I have been confined to the shoreline so far. To cope with that, I bought a weird chinese macro-wide angle lens to play with which I will post about later. I also used my ‘normal’ 60mm macro lens (sometimes with a Raynox lens attached to the front for extra magnification) and took some time to focus on periwinkles.
At the top and below a Flat Periwinkle (Littorina obtusata or maybe L. fabialis – distinguishing is very hard as it requires investigating differences in penis shape!). As you can see the locations are not always glamorous, but if you zoom in you can still find beauty!
Flat periwinkles tend to be most active above-water, followed by the smaller Rough Periwinkle (Littorina saxatilis – below) with the Common Periwinkle (Littorina littorea – below that) only occasionally moving about.
Finally, a tiny species the Small Periwinkle (Littorina Melharaphe neritoides). Probably overlooked by most, as it is tiny (up to 8mm, usually smaller) and hidden between barnacles (or even nestled in empty barnacle cases) high on the shore.
* and no, I could not bring myself to go diving without a camera…
A Gray Seaslug
There have been a few finds lately at my local spot in Falmouth (and in other places in Cornwall) of the fantastically coloured Rainbow Slug Babakina anadoni. I have tried in vain so far to find it, but I did manage to find another species of Seaslug last Friday: Aeolidia filomenae. It is the opposite of the Rainbow Slug; large, not small, drab, not extravagant, and common instead of rare. More of an understated beauty I guess, and still a nice find! This species feeds on anemones (mainly Beadlet Anemones but also Snakelocks Anemones) rather than the Candelabrum hydroids the Rainbow Slug prefers. I am not very good at spottting nudibranchs so the plan is to keep looking this spring and find more species!
Rockpools from the top
I tried my hand today at taking photos of rock pools above water – tricky! I used my Leica wide angle lens with a polarizing filter and a handheld strobe in a diffuser. It was fun playing around, although felt my back after an hour or so trying! It is difficult to keep the reflection of the flash out of the shot. The tide was not low so these are small, mid-shore pools dominated by coralline algae and some (fine) red seaweeds. Beadlet and snakelocks anemones, limpets, periwinkles, thick- and purple topshells are the most common animals. Some sunshine and blue sky – let’s see when I can try my hand at underwater photos again!
P.S. two extra pics taken a day later (without flash) near Bream Cove featuring an anemone-eating Aeolidia nudibranch.
beachcombing after storm Darragh
A Late October Snorkel
Many other critters were found too and I took shots of a selection. First, a Sea Spider, all legs and crawling away. A tiny mat of colonial tunicate that looked like a persian rug on drugs. A quick shot of the ubiquitous (if you know where to look – on kelp fronds) blue-rayed Limpets and a stalked jellyfish. Finally, I spent a lot of time taking shallow-depth-of-field AND slow shutter-speed photos of a scorpion spider crab in a snakelocks anemone to get some sort of ‘artistic’ shot. It did not really work, but it was fun nonetheless and I will have a go at it again. After almost 2,5 hours in the water I stumbled back to the car to get changed – an afternoon well-spent!
Pheasant Shells
The Pheasant Shell is one of my favourite little critters in the rockpools in Falmouth. It is a bit weird to refer to these organisms as ‘shells’ actually, as they are living things and the nonliving shell is ofcourse only a part of them. The confusion extends to its scientific name: this species was previously known as Tricolia pullus, but has recently been split into a Southern European T. pullus species and a Northern European T. picta species. Perhaps the dust needs to still settle on that one.
I have taken these photos, on different occasions, with the mzuiko 60mm macrolens and the nauticam cmc-1 wetlens. The extra magnification the latter lens (screwed onto the housing) offers is great; although somehow I always want to get even CLOSER! I have not nailed the Pheasant Shell shot either. Reflecting on these pics I think I need to use a shallower depth of field to get rid of cluttered backgrounds. Next time.
The calcified operculum (the little door to close the shell) is clearly visible in the first photo above, as are the tentacles. On the second photo above you can even see that the left ‘neck lobe’ is more deeply digitated (fingerlike) than the right one. For more detailed (studio)shots of this and other molluscs please see Morddyn’s flickr account. I will post more macroshots of other mollusc species soon!
Dog Whelks at Kynance Cove
A trip to one of our favourite places today: Kynance Cove on the Lizard Peninsula. The weather was such that snorkeling was a big no, but after some wind and rain, luckily the sun came out for a bit (which it should, it is July!). I took some macro shots of the rocks at low tide using my new Cygnustech diffuser. This contraption makes the flash light much less harsh, and is pretty much essential when taking (non-natural light) macro shots. This is one of the best diffusers out there and I can highly recommended it (are plenty of reviews are available online). Some of the shots were taken with the Raynox DCR-250 macro attachment in front of the macro lens for a little bit of extra magnification.
Anyway, there is not a lot of animal diversity on this battered coast of green and red serpentine rock: barnacles, dog whelks, mussels and limpets mainly. Above a selection of photos highlighting some small Dog Whelks (Nucella lapillus). This predatory species can come in many more colour varieties than we found today (see here for example). The limpets are either the Common Limpet (Patella vulgata) or the Blackfooted Limpet (P. depressa); you need to be able to see the animal to be sure. The barnacles are Montagu’s Stellate Barnacles (Chthamalus montagui) (I might have this wrong; I must confess I never really gave barnacles the attention they deserve). Not too spectacular but you gotta try something when you cannot take photos underwater!
New Nudibranch Book
Last week I had a very special delivery in the post: the second edition of Nudibranchs of Britain, Ireland and Northwest Europe by Picton and Morrow (available HERE amongst other (web)shops). I received a free copy because I contributed photos for two not so commonly encountered egg-eating seaslugs: Calma glaucoides and Calma gobioophaga. I was really chuffed with this, as apart from the authors, many real experts contributed photos (including Cornwall’s very own David ‘aphotomarine‘ Fenwick). Although sea slugs might seem ‘niche’ to some, they are among the prettiest and most diverse marine creatures and I am sure many divers, snorkelers and rockpoolers (and readers of this blog) will really enjoy this book (see also this review)!
The funny thing is that I have actually not taken many photos of nudibranchs at all…. I have only been serious about macro (and in the possession of strobes that actually work…) for a few years but moreover, I am not very good at finding them! This publication has really spurred me on to go look for nudibranchs and learn more about them though. What is also exciting is that I bought (secondhand) scuba kit a few weeks ago, so i will be able to go back to diving and see a wider range of things. Now if only the wind dies down!
