Silver Steps Round-up

Posted on August 29, 2026 by An Bollenessor under crustaceans, diving, fish, nudibranchs, Silver Steps

I realised I still had photos on my hard disc from a bunch of dives taken at local haunt Silver Steps in Falmouth this summer that could do with posting, as some came out quite nicely. Several photos were taken at my secret spot ‘The Crack‘ (I have now labelled all posts with photos taken in this small spot with that tag). I took some with my trusted Olympus 60mm lens and others with my new 30mm lens. The latter worked well with a large aperture to give a nice blurry background, as seen with the Tompot Blenny (Parablennius gattorugine) above (and further below). I also managed to take a good ‘full frontal’ shot of a Connemara Clingfish (Lepadogaster candolii) showing of the sucker with which they attach to the rocks.

During one dive something caught the corner of my eye: a small Spiny Lobster (Palinurus elephas) – a very nice surprise as I had not seen one here for quite a few years! These are tricky customers to take a photo of I find: their antennae are so long that you need a wide angle scene to have them in the frame, as getting close up gets you only part of the animal. Also a photo of a prawn (Palaemon, not sure which of the two possible species); such beautiful animals! Below that a block of some more good photos.

At the end of one dive I came across a nudibranch I had not seen before: a Yellow Skirt (or Venus) Seaslug (Okenia elegans). Extravagant in its colours and proportions this was one of my finds of the year. Unfortunately I could not give it the full photographic treatment I had in mind as I was running low on air when I found it. Finally a bunch of not-so-good photos but they show a range of common local species and so I have added them for completeness. You can read descriptions when you click on individual pics.

Shells

Posted on August 23, 2026 by An Bollenessor under molluscs, photography, shells

Another short post with some pics I took earlier in the year at the kitchen table. I was an avid shell collector when I was young and, since I am at the beach or underwater a lot, I still pick up and take home shells (never live molluscs). I found that it is actually quite hard to take decent macro shots of shells. Ideally you take photos at an angle while the shells are underwater on a black background, but I had trouble with glare and gave up on that approach. The photos here were all taken above-water on a white background (which will be overexposed with the shells being underexposed so that is something I need to figure out). Shells tend to lose their lustre so I have used baby oil to restore their gleam. Above the Pheasant Shell Tricolia picta (previously UK specimens were considered to be T. pullus), a favourite macro topic of mine as well when alive, see here. I have pasted a few more photos below, including the five species of Topshells common in Cornwall, but I am too lazy to add all species names! (feel free to comment if you are curious about a specific species and I will do my best to answer). Something to experiment more with in winter when I cannot go out.

Octopus in Porthkerris

Posted on July 5, 2026 by An Bollenessor under bryozoans, crustaceans, diving, echinoderms, fisheye, molluscs, photography, Porthkerris, wide angle

This is the second year of an ‘octopus boom’ here in Cornwall. One of our two native species (Octopus vulgaris) has become much more common, probably due to warming waters. They wreak havoc on the crab pots (it is a big local story), but have made many snorkellers and divers very happy! Although I have spotted them once or twice before, this week I headed down to Porthkerris to have a proper look. Porthkerris is one of the best known shore dive sites in the country, and the only shoredive site in Cornwall I know of that let’s you get a bit deeper than ten meters. Those extra few meters make the difference in spotting things like Cuckoo Wrasse and Sea Fans, and also make it more likely to spot octopus (although these also occur in shallow water; one was even found in a rockpool in Falmouth). Armed with my 8mm fisheye lens I drove down on a Tuesday for two (solo)dives. It wasn’t long before I spotted the first octopus, however it quickly jetted away from me – either they have different personalities or different moods (or both) but not every octopus reacts the same to a passing diver. I managed to get a bunch of shots of several cooperative individuals shown below. Some individuals looked a bit ropey as they were nearing the end of their life-span and I even spotted a dead individual.

I managed shots of some other animals as well, see the gallery below (click on pics for legends). I have done much more macro- than wide-angle photography lately, as it is quite hard in murky English waters. When using strobes it is easy to get backscatter, moving very close to the subject minimises that but makes it hard to get any light between the dome and the subject, often resulting in an unlit centre of the shot and/or blown out spots at the sides. I went back on Friday for another two dives. Fewer octopuses (octopi is incorrect!) and the viz wasn’t as good but it was enjoyable all the same. A selection of critters below. I found a nudibranch new to me (Acanthodoris pilosa) that was so large I could take a halfdecent photo of it using the fisheye lens!

Early Spring Macro

Posted on March 29, 2026 by An Bollenessor under crustaceans, eggs, fish, Flushing, Macro, molluscs, mzuiko60mm, nudibranchs, rock pooling, seaweeds, shells, snorkeling, worms

High time for a quick update. Spring has not started in earnest yet and so the number of days in the water have been limited. As is usual, I have practiced taking pics of Flat Periwinkles (Littorina obtusata or L. fabialis) on a bank of the Penryn River. Below that another set of pics taken in Flushing and Falmouth when it was too windy and choppy to get in the water. These were all taken with my cygnustech diffuser which give the pictures a quite distinctive, slightly subdued look.

I did go in the water a few days in a row when the weather and tides allowed it, which was great. I think one time I stayed in for three hours – my core temperature took some time to recover! No special finds and only a few good pics as my strobe placement had become quite rusty but here are the best and/or the most interesting ones. (Species names in the photo captions.) Bring on proper spring weather and flat seas!

What is a seaslug?

Posted on January 15, 2026 by An Bollenessor under Macro, molluscs, nudibranchs, worms

A nudibranch, a snail and a seaslug crawl into a bar…no seriously, what actually is the difference between these three types of molluscs? According to Kerney and Cameron (1979), those animals that cannot fit into their shell are called slugs, and those that can are called snails (definition brought under my attention by Ian Smith, see his amazing species accounts of British molluscs on flickr: Morddyn). Seaslugs either have an outer shell in which they cannot retract, an internal shell or no shell at all. The Solar-powered seaslug (Elysia viridis) pictured above is a species without a shell that is an example of a seaslug. Nudibranchs are a type of seaslug with ‘naked’ (nudi) gills (branchs) on their back. Nudibranchs never have a shell (although many have one when they are a larva). Books on nudibranchs often include seaslugs and sometimes they even feature snails! This happens when these species are related to seaslugs (the ‘lathe acteon’ or ‘beer barrel’ Acteon tornatilis is an example of that – a goal of this year is to take a good photo of that species). I have posted a range of photos on here as an illustrations of seaslugs (or not!); read the captions for species info.

Candy striped flatworm Prostheceraeus vittatus

Macro Rockpooling

Posted on December 30, 2025 by An Bollenessor under anemones, cnidarians, crustaceans, echinoderms, Macro, molluscs, photography, sponges, tunicates, worms

I realised I had not posted (much) about this year’s rockpool snorkels so I am taking the opportunity to post a ‘picdump’ with a whole array of tiny species. These photos were taken with a macrolens, and for most a wetlens was used for even greater magnification. Above the White Tortoiseshell Limpet *Tectura virginea*, a tiny species living on calcified red seaweed. I have added species names to the photos below.

Some Silver Steps Molluscs

Posted on November 29, 2025 by An Bollenessor under diving, molluscs, shells

After posting about the fish and crustaceans of my local dive site Silver Steps in Falmouth, it is time to give molluscs some love! The photos in this post were all taken at 5-10 meter depth at a gravelly bottom this year. Above (and at the end) the Turban Topshell (*Gibbula magus*) which is common subtidally. However, this was the first time I noticed that they have pretty sky-blue eyes! It is one of my challenges to take a pic of it with both eyes in the frame next year. Below, another favourite species of mine: the Pheasant Shell (*Tricolia picta*, previously *P. pullus*). This was a large individual (close to a centimetre?) with a candy cane striped pattern that I’d never seen before.

Next up a juvenile Dog Whelk (*Nucella lapillus*) on top of a Saddle Oyster and the Common Keyhole Limpet (*Diodora graeca*). The latter might be called ‘common’ but I do not see it very often. Going from the Gastropods to a Bivalve: a King Scallop (*Pecten maximus*) with its many eyes and a Cephalopod: the Common Cuttlefish (*Sepia officinalis*). This was a very large individual covered in many small white lesions, probably near the end of its life. It was fine in my presence and let me take some photos. It is sometimes strange to think that these intelligent creatures are more closely related to a clam than to a fish! Some bonus photos at the end.

Seagrass Macro

Posted on October 26, 2025 by An Bollenessor under anemones, bryozoans, eelgrass, Flushing, Macro, molluscs, mzuiko60mm, nudibranchs, photography, tunicates

I had a couple of good snorkels at the end of summer in the seagrass beds off my local beach in Flushing. The water at the end of summer is warm enough to go without wetsuit – I just had a weightbelt to let me sink down on the sand at low tide, no fins needed. I managed to do what I normally find very difficult: spot nudibranchs! Mainly one of the more common species, Polycera quadrilineata, but that was fine by me, as they are very beautiful, especially the black colour morph pictured above. I spotted one other species, the egg-eating Favorinus branchialis (with its own eggs also visible). Not great photos, but in my defense they are very small!

Shelled molluscs are easier to find. Below 1) the ubiquitous Grey Topshell Steromphala cinerarea, 2) the Grooved Topshell Jujubinus striatus and 3) the tiny Rissoa membranacea (faecal pellets on show, even within the shell). The latter two species are strongly associated with seagrass.

Some assorted macro photos below and at the end a view at a very low tide of the Flushing seagrass site this October.

life on a chain

Posted on September 20, 2025 by An Bollenessor under buoys, crustaceans, molluscs

The rain has been hammering down and I am in accute underwater withdrawal… Just a bit of the ole bloggin then! These are some pictures from April, when the phytoplankton had not kicked in and the water was still quite blue. Out of curiousity I swam out to the marker buoys off Castle Beach in Falmouth to see if there was anything interesting growing on them. There was! Lots of mussels, including on the chain going down to the bottom (10ish meters deep). I took my fisheye lens and after much adjusting of strobes (holding the housing sideways for portrait mode, and also up, meaning that the lower strobe needed to be pulled back) I got the nice shot above. Mussels are not a favourite of underwaterphotographers (this is an understatement!) but they are beautiful upclose, the white mantle contrasting with the blueish black shell.

A few days later I returned with my probe lens, as i thought this would offer an original perspective. It was a tricky thing to do as this lens lets in very little light. The difference between foreground and background seems slightly off as well! These photos show that the mussels were crawling with the tubedwelling amphipod Jassa marmorata, a prominent fouling species. I planned to return to try again a few days later, but the chains had been replaced by ‘fresh’ ones, bad luck! I will go back to have a look at them as soon as the weather allows it.