Category Archives: crustaceans

Octopus in Porthkerris

Posted on by 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 by 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!

Crabby Camouflage

Posted on by under crustaceans

I am frequently amazed by the ability of animals to be perfectly camouflaged. Here are three examples of local crab species that do an impressive job of blending in. Above, the Furrowed (or Pebble) Crab (Xantho hydrophilus). An abundant species – multiple individuals will hide under every rock you lift up on the shore. Below a Broad-clawed Porcelain Crab (Porcellana platycheles) which also lives under rocks, flat and covered in tiny hairs. (This is actually not a true crab but the product of ‘carcination’ where non-crabs have evolved into a crab-like form. This has happened independently in at least five Crustacean lineages.) Finally a Green Shore Crab (Carcinus maenas) which is abundant in many locations although not so much locally. There are even better examples of crab camouflage around, but I either do not have good photo of them (Spider Crabs decorating themselves with sponges and seaweeds), or have never seen them myself as they live in water deeper than I normally dive (the Sponge Crab).

Macro Rockpooling

Posted on by 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.

The Crack pt. 1

Posted on by under crustaceans, diving, EMWL, fish, Silver Steps
At my local shoredive site Silver Steps here in Falmouth, there is a crack in the rocks, maybe three meters long and not very deep, that is home to an array of interesting species. I have posted pics from this spot before, for instance that of a big conger eel (which has since left it’s hidey-hole, perhaps it swam off to reproduce and die in the Mid-Atlantic?). Anyway, I visited again this week and tried close-up shots with my macrowide angle probe lens. The prawns are much bigger here in the rock pools, but I am not sure if they are Paleamon serratus or P. elegans, as this requires a closer look at the serrations on the rostrum. Regardless of species name, they are stunningly beautiful animals with their blue and yellow legs and black-striped carapace.

Some more pics below (notice that in some another animal is lurking in the background!). Some species are easier to photograph than others, clingfish are very shy for instance. Anyway, there are some more ideas I have, for instance trying to capture multiple species in one frame and post about them in ‘The Crack pt2.’!

Moody Macro

Posted on by under crustaceans, fish, Flushing, Macro, mzuiko60mm, rock pooling
A quick post with some finds from a recent walk on the shores of Flushing, specifically above-water (‘topside’) macro shots with a diffuser. This always leads to my subjects turning out with subdued grey and brown tones, but that is OK. A velvet crab, the amphipod Cymodoce truncata (looks a bit like a trilobite!), a worm pipefish covered in a film of water with some more shots (with descriptions) at the end.

life on a chain

Posted on by 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.

P.S. there are two older posts tagged with ‘buoys‘.

beachcombing after storm Darragh

Posted on by under beach combing, crustaceans, eggs, fish, iPhone, jellies, molluscs
Storm Darragh raged over the UK last weekend – which by itself was not great, apart from the fact that there was a chance interesting stuff had washed up on the beach! As the winds came from the North, we drove to the long beach at Perranporth on the north coast to have a look. It was nice to get sandblasted for a bit and admire the furious crashing waves and icy blue-grey sea. Find of the day was a dead Grey Triggerfish (Balistes capriscus), a generally more southern species that is increasingly observed in the UK. Some other finds in the gallery below (shot with an iPhone; which is actually a lot easier than changing a wide angle for a macro lens on a wet, sandy beach!). Among the finds, Goose Barnacles, a Small-Spotted Catshark eggcase, an unidentified blob and a cuttlefishbone of the Pink Cuttlefish (Rhombosepion orbignyanum).

Scorpion Spider Crabs

Posted on by under anemones, crustaceans, diving, EMWL, photography, Silver Steps
I recently posted on the Crustaceans inhabiting my local shore dive site Silver Steps (see here), but left out one species: the Scorpion Spider Crab (Inachus spp.), which deserves a post on its own. I have blogged about this crab before (see here), specifically in the context of ‘macro-wide angle’ for which this species, perched on- or under a snakelocks anemone, is ideally suited. My previous efforts were based on an affordable inon wetlens, but I have since bought a super-duper nauticam lens. Although very good at macro-wide angle, this lens lets in very little light, which basically gives you three options: 1) lie on some bright white coral sand in the Maldives and shoot upwards to the sun at midday (so actually not really an option), 2) increasingly compromise the exposure triangle to keep a blueish/greenish background (higher ISO>more noise, lower shutterspeed>more camera shake, greater aperture>smaller depth of field), or 3) keep all settings in a ‘normal’ range, resulting in a foreground lit up by strobes on maximum output, but a black background (only if you are shooting critters in rock crevices you can get both fore- and background well-exposed, as strobe light has something to bounce back from – see for some examples the Crustaceans post). I quite like the clean black background and dislike bluer, but grainier images, so have mainly tried option 3. Hopefully, next year in summer I can try going for some blue background shots. Sorry if this blog is occasionally turning into a photography borefest by the way, but I have been really getting into that stuff! ;-). Anyway, these scorpion spider crab pics have turned out quite nicely.