My son’s favourite place in Cornwall is the small nature reserve Windmill Farm on the Lizard peninsula (probably named after the Cornish “Lys Ardh”, meaning “high court” rather than being named after its lizards). The small pools in the heathland here are good for dragonflies in summer but the main attraction for us here are the reptiles and amphibians. The UK is not blessed with a very diverse herpetofauna but this is a pretty good place to go ‘herping’. Grass snakes are rare here and I do not know of people seeing them here, but adders can be found in the right places. The female pictured above was tiny, not longer than 20 cm but still very feisty, striking at me. The 60mm lens meant I had to come up close but it was more cute than threatening. Slow worms are quite common here. They usually creep away when discovered but some stay put and are easy to photograph. It is also possible to spot viviparous lizards here (‘proper’ lizards with legs) but a pic has to wait for another post.
This is a weird little hydroid and so only has a Latin name to go by: Candelabrum cocksii. It was first described by Cocks in his ‘Contributions to the fauna of Falmouth’ in the 1850s and it is quite common locally. I find them mostly as pictured here, but sometimes I see them with their foot extended, going from a centimetre to 8 centimetres or so in length. This allows them to rove over the rock surface in search of tiny (crustacean) prey. Their mouth is located at the end of the trunk which is covered in ‘capitate’ tentacles (see the pic below for anatomical labels). The white spheres are gonophores used for reproduction. It should be possible in summer when these hermaphrodites reproduce to see dedicated clasper tentacles holding the embryos, that would be cool (to me at least!). Btw, I remembered I posted about this species not even that long ago! See here and also see this link and this link from fellow enthusiasts across the pond who likewise have been fascinated by Candelabrum.
This seems like a familiar way to start a blog post but here I go again: ‘the weather has been terrible lately and I have not been in the water!’. March used to be my favourite time for snorkeling because the seaweeds look at their best, but the last three years it has been windy and wet, surely because of climate change…
To keep the blog going (a bit), I have dug out some images from a few dives last year featuring Inachus spider crabs. There are three species, I. phalangium, I. dorsettensis and I. leptochirus, which can be told apart by the arrangement of tubercules on their carapace, but these are often obscured by epiphyte growth, and so I am keeping it to Inachus sp. All species are associated with Snakelocks Anemone (Anemonia viridis) hosts. The photo above is taken using a weird ‘wide angle macro’ wetlens (INON UFL-M150 ZM80). This perspective always fascinated me but it is difficult to achieve. This lens does the job, although it is incredibly ‘soft’, especially around the edges. The close focusing also makes it difficult to direct the strobe light on the subject. So there is a tradeoff between getting the surroundings in view and sharpness. Below first some sharper shots using my 60mm macrolens, followed by some macro wide angle shots (they happen to be each of the different Anemonia colour morph):
I will leave you with the following interesting bit on the biology of these crabs by Diesel (Ethology, 1986):
I. phalangium females are site-constant, and live in the protection of one anemone or group. Males travel frequently between anemones harbouring females due to spawn; they copulate and guard the females until spawning, after which the male leaves again. A male operates in a patrol area containing 3-8 anemone groups and up to 8 females, visiting each female in turn repeatedly just before it is due to spawn. Patrol areas of different males may overlap, with resulting competition to fertilize a female’s next brood. Large males have higher reproductive success than small ones. Females live up to 8 months after the moult of puberty and hatch up to six broods, and males live up to 7 months as adults. A male could fertilize a calculated 26,000 eggs, whilst a female’s reproductive potential is ca. 4,200 eggs. Mortality risks are higher for males than for females, probably because of increased predation while leaving the protection of anemones in order to visit females. Males learn the positions of anemones harbouring females in their patrol areas, and when these are due to spawn. This allows a male to travel with a target and arrive punctually to fertilize the next brood due in his circuit. I. phalangium is the first marine invertebrate reported to use a “schedule” of localities and times for visiting prespawning females. In this way males minimize searching time and mortality risk, and maximize the number of broods fertilized.
A happy 2024 to all followers and readers, may you enjoy the Ocean the coming year in one form or another! This is just a quick post as I have neglected this blog a bit (I have posted these photos on instagram last year though). It is a completely battered Aequorea forskalia at the end of a bloom in September. The images look a bit like oil paintings to me!
Earlier last year I also took some macro shots of another Aequorea species (perhaps A. victoria but these animals are not easy to identify in the field), below two shots showing the mouth (‘manubrium’).
On the same snorkel I also pointed my macrolens at blue jellyfish Cyanea lamarckii; it was fun to capture more detail, although ideally I’d like to capture detail AND the whole animal…. Maybe more luck with a new (or rather secondhand) wide angle lens this year – I cannot wait for the weather to improve and to go back into the water! More posts to follow soon I hope.
Last Sunday we made the trek to Sennen Cove beach in the far west of Cornwall. I have not been in the water for weeks due to the windy weather (and it might be a few weeks before conditions improve), so the only way to get my fix is by going beach combing… With strong westerlies, this spot jutting out into the Atlantic seemed a safe bet, although when we arrived the strandline appeared quite sparse and I did not have hope of finding much. A single find by my eagle-eyed son however made the trip all worth it!
The photos above show the amphipod Phronima sedentaria inside its home, a hollowed-out salp. These small crustaceans use their claws to carve a home out of their barrel-shaped gelatinous host. This offers protection, and a space to rear their young. They occur worldwide in the open sea and are believed to vertically migrate from depths up to a kilometer to the surface each night. Although it was still actively wriggling about, it was essentially doomed after being washed up, so it was taken back in a margarine container filled with seawater and handed over to David Fenwick (www.aphotomarine.com) for further examination. He made some excellent photos of it, making clear why it provided inspiration for the ‘Alien’ movie! As I suspected from the size, this was a female, and brood was found in the salp tunic as well.
These things have been found before a few times in the UK (in Sennen and in the Scillies) but not commonly (4 records on the NBN Atlas and 0 on iNaturalist). I have recorded mine on the latter database (which means it can make its way to NBN as well). Let’s see what else the sea throws up this winter!
We met up with friends in Anglesey (Cymru/Wales) last week. The weather was beautiful, but the viz was milky and the rock pools quite bare. However, there were some interesting animals to see in the pools on the upper shore: rafts of springtails (Anurida maritima). These are tiny but fascinating animals that hide in crevices or under seaweed at high tide but that live in groups on the water surface when it is still. This is helped by bristles that make them highly hydrophobic, a circatidal rhythm and pheromones that allow them to aggregate. Springtails are extremely abundant and important in terrestrial ecosystems but have made a home in the sea as well (and fun fact: although they have six legs, they are not insects). Anurida scavenge on dead animals but themselves fall prey to mites. This tiny raft (the larger springtails are only 3mm) houses two species: a Red Snout Mite (Neomolgus littoralis) a Bdella species (thanks for ID Matthew Shepherd!) and several smaller Halotydeus hydrodomus. The raft in the photo is about the size of a stamp but there is quite a lot going on!
These photos were taken with the 60mm macro lens and the Raynox 250D macroadapter and a cygnustech diffuser (dipping into the water).
During an otherwise uneventful macro-dive at Silver Steps this week I looked under a small rock overhang around 8 meters deep and noticed an unusual little fish. At first glance it resembled a Tompot Blenny (see pic of a showboating individual below), only darker, more skittish and, upon closer inspection, with much smaller tentacles on top of the head. I knew this must be a Variable (or Ringneck) Blenny, Parablennius pilicornis, as we’d seen many of them on holiday on the Basque coast this summer. It is a southerly species that was first recorded in Britain in 2007 but is increasingly spotted. Not a first for Cornwall, but there are still few observations and so I have recorded it on iNaturalist (making it available for later inclusion on the NBN Atlas, the UK’s largest repository of publicly available biodiversity data). Another warmer water species joining our shores due to climate change…
Last Friday I had a really enjoyable rockpool/snorkeling trip with my rockpool buddy David Fenwick (see his website aphotomarine for all your marine ID questions). Dave suggested we go far west, down to Sennen Cove where he knew about some interesting mini sea caves with jewel anemones and other things to explore. That is what we did, see the photo below!
Jewel anemones were indeed found in this spot….the water was too shallow to take a good photo though. I therefore jumped in the water where at first I got a bit seasick of all the waving Furbelows kelp. The water was noticeably colder than on the South Coast too. I discovered a nice deep gully with a whole variety of sea anemones growing on the vertical rock face. Orange, purple and green Jewel Anemones (Corynactis viridis) were common from 6 meters deep (at low tide). Very tricky for this middle-aged man to take good photos on one breath though! I was stumped by one white anemone but as Dave pointed out it looked like a Dahlia Anemone (Urticina felina) (and multiple ‘normally’ coloured individuals lived nearby so that makes sense). Finally a Sandalled Anemone (Actinothoe sphyrodeta) (my photos of the White-striped Anemone Anthothoe albocincta were unfortunately out of focus).
We had a blast and David found a Nemertean worm which might be new to the UK, or even new to science! It will find its way to aphotomarine eventually I am sure (check for ribbon worms here). I certainly like to go back snorkeling here some (windstill, swell-less) time.
I recently bought (2ndhand) scuba gear and did a refresher dive; with the nice weather this week it was high time to get back under the waves and take some photos! I dived Thu/Fri/Sat at the main local shoredive site ‘Silver Steps‘. I went in by myself, but with a maximum depth of around 10 meters and good conditions this is not risky. The dives did not disappoint, the viz was excellent! Although I spotted cuttlefish every dive, I still opted for the macro lens, as I suspected I could not get great shots of them with my fisheye lens at 1.5 meter distance (I might have been wrong!). Instead of heading out to sea as some divers do, I always stick to the gullies by the rocks, diving below the kelp to see what happens beneath the rocky overhangs. There are three usual suspects hiding there, each with a very different personality. First, Leopard Spotted Gobies (Thorogobius ephippiatus) inhabit cracks in the rocks and are quite shy:
Second, Tompot Blennies (Parablennius gattorugine) are extremely inquisitive, often coming very close to check out what is going on in front of their domain:
Third, Black-face Blennies (which are not true blennies but triple fins) that only ever live under overhangs, usually head-down. I did not see males in breeding colours (black face, yellow body) but this colour form is even prettier I think:
When inspecting the rock walls carpeted in sponges, seasquirts, algae, worms and other things, I kept my eyes out for nudibranchs. Apart from a tiny crested aeolis, I spotted a good number of Discodoris rosi, busy mating and laying eggs. This species has only been observed in the UK for a decade or so but the population now is booming, with many reports coming in from all over Cornwall:
All in all a great enjoyable three dives! Silvery schools of sandeels and sprat/herring, many wrasse, cuttlefish, small and very big lobsters and a greater pipefish were also spotted. Unfortunately the weather has made a turn for the worse this week, however, there are still a few diveable months left this year…
A quick post, again of macro shots on-land using the cygnustech diffuser. A Montagu’s Blenny (Coryphoblennius galerita) and a Shanny (Lipophrys pholis) (check its teeth, it is a combtooth blenny). Due to the recent storm I did not venture into the water but had a wander down the shore here in Flushing. The fish were gently placed on some wet seaweed where they lay still before hopping back in their rockpool. The diffuser really gives the photos a moody atmosphere! I hope one day I can find a Tompot blenny on a very low tide to complete the set.
An Bollenessor 