Watch a spider shed its skin under the microscope!

Posted by Graeme Lyons , Thursday 28 March 2019 16:32

Yesterday, as well as four species of ladybird beaten from one branch of a Douglas Fir, there was also a sub adult male Araneus (either triguttatus or sturmi). Now sturmi usually favours evergreens and trigutattus deciduous trees according to the texts. So you would think that it's more likely to be sturmi. Being a young male though, it wasn't possible to tell. I fed him some springtails from the garden today to see if he would grow. An hour later I checked to see if he had eaten any of them and it appeared dead. No, wait, it's just started shedding its skin. So I dashed to the microscope and set up the camera and recorded it shedding its skin! So cool...

Turns out it is Araneus triguttatus which is much commoner in Sussex than sturmi. I have never seen one with this particular colour pattern as they are usually much more orange with a distinctive pattern, not these three pale dots. My 125th spider for the year and another new species for Burton Pond. I would have missed this if I had looked 10 minutes later, so feeling pretty lucky.

A ladybird in the tray is worth four in the bush

Posted by Graeme Lyons , Wednesday 27 March 2019 16:39

No, that doesn't work or make any sense but it's too late now, I've said it. I'm ashamed of myself. I think I've been watching too much Alan Partridge. Jane Willmott and I spent half an hour recording at the Warren today, part of our Burton Pond reserve. I saw a beatable branch of Douglas Fir and thought it worth a tap. A girl band's worth of ladybird species popped out instantly. Three of the four ladybirds above were new to the site! From Left to right we have Eyed, Cream-streaked, Larch and Pine Ladybirds. Pine was the only one we had previous records for.

We had a quick go with the suction sampler in a recently cleared and scraped area that is regenerating into a heathy/acid-grassland glade. We were amazed to witness a song fight between THREE singing Marsh Tits that descended into a massive rumpus. Agonum sexpunctatum, Arctosa perita and Anoplius viaticus were all present.

This nationally scarce spider was new to the site, Euryopis flavomaculata. I have very few records of this spider. It has the English name of Ant-tiger, which I really like. The 'wild card' names that don't fit a formula really appeal, it is in a genus of of its own though. It doesn't make a web and predates ants.

Also new to the site (and the year for me) was Enoplognatha thoracia. Another spider that wouldn't keep still.

Bathyphantes approximatus and (finally!) Erigone dentipalpis make my spider year list up to 124 and the site up to 107.

"Are we in Avatar now?"

Posted by Graeme Lyons , Saturday 23 March 2019 09:43

So after work yesterday I went straight back to the Pound for an even lower tide (the lowest of the spring). It was however at 18:40 and was pushing dark. Torches were essential by this point but it was mild an calm. I met up with James Harding-Morris and Robert Jaques, both pan-species listers that I had never met. Everyone was buzzing after last night's haul but it was the Snakelocks Anemone photo that gets pride of place. This is taken under water with the TG4 with James' UV torch shining on it. The title of this post comes from a quote by Robert that I had to rip off. I really appreciated the amount of nonsense these guys came out with, a really fun evening. And I didn't have to turn any rocks again.

Now I think Polycera quadrilineata was on top of everyone's list after my post yesterday so we started sweeping sea weed with pond nets. On my first attempt, I got another lifer!!! Not a nudibranch but still a sea slug, and more closely related to terrestrial molluscs than sea hares (thanks to Cynthia Trowbridge for this info!), here is the incredible Solar-powered Sea Slug Elysia viridis.

And whilst I was taking these photos, James found Polycera quadrilineata effortlessly. Four in all in fact. And another two Elysia viridis! A really nice shot of the rhinophores here showing the detail, these are the 'chemoreceptors' of nudibranchs. You've got no chance of seeing this detail unless the animal (and camera!) is under water. The Olympus TG4 is just brilliant for this stuff. Just remember this and the above specimen were about 5 mm long.

Check out this shot of a Sea Lemon found by Robert crawling through weed.

Early on we spotted a few Dahlia Anemone.

And a Wentletrap!

A couple of White Tortoiseshell Limpets.

And a huge crustacean which must be Common Prawn Palaemon serratus (and not Crangon crangon as I originally labelled it - thanks Evan).

As for the fish, we wracked up (see what I did there) a whopping seven species (or eight in two days). Long-spined Sea Scorpion showing the diagnostic spines at the side of the mouth which are so easily visible when the animal is under water.

And beyond the kelp zone, Ballan Wrasse and Tompot Blenny were the commonest fish. This huge wrasse took some team effort to catch. It was cathartic because in this same area two years ago I bungled something that looked exactly like this and given how many we saw here last night, I was convinced that that was also a Ballan Wrasse but now I am not sure it's not a huge Corkwing thanks to Evan. The wrasse is the one on the left. Not sure what the other vertebrate is.
So in favour of Ballan: Smooth preoperculum, huge size (25cm), no black tail spot, lots of smaller Ballans present beyond the kelp zone. In favour of Corkwing: black kidney mark behind eye, larger scales that do not appear pale centred, blue fins beneath.  OK, a third opinion is needed but Evan has started to sway me into thinking this is actually a massive Corkwing...

UPDATE: It looks like this is a big Corkwing male. Thanks to Evan and people from the Seasearch Facebook group for commenting. I'm amazed how different it is to all the other Corkwings I have seen, I really take the point that divers must see these animals much more frequently than I do. Amazing!

One the way back in I turned over a tiny rock (that's literally all I can do) and I found a clingfish! Now we have four clingfish species and I knew it wasn't Cornish Sucker or Connemara Clingfish. So it's either Two-spotted (the common one) or Narrow-headed (the scarcer one). I am not convinced I can tell which from these photos or even if it is possible at all. Using the Handbook of the Marine Fauna of North-West Europe it's about the relative placement of the fins but this doesn't seem to be a character used in more recent field guides. If it had two big spots then that's easy to ID as a male Two-spotted. Females are apparently not separable in the field. I think the head is about 1/3rd the length of the body and not the 1/4 required for it to be Small-headed. So I think this is likely to be a female Two-spotted Clingfish. And in hindsight, I believe all the individuals I have seen of this species pair are likely to be that too.

Beyond the kelp zone, I spotted a piece of red sea weed dancing around in a rock pool. It was clearly a crustacean. What a strange creature. I have just keyed this out and I believe this is a type of skeleton shrimp called Caprella linearis. Other marine crustaceans new for me were Siriella armata and Gammarellus angulosus.

Another incredible evening's natural history. I was amazed that there wasn't a soul there again yesterday. If you want to get a big list of species it's really key to hit the lowest tides of the year.

A real highlight was walking back up the cliffs into the back of Eastbourne. The Alexanders was covered in moth and beetles. Upwards of 20 Oedomera femoralis feeding on the flowers but also Common Quaker, Satellite, Dark Chestnut, Bloxworth Snout, Double-striped Pug, Agonopterix heracliana and Digitivalva pulicariae, better than the moth trap at Woods Mill on Thursday morning. And I got two new spiders new for the year. Amaurobius ferox (116) and Dysdera croccata (117).

The Spectacular Sea Slugs of Sussex!!!

Posted by Graeme Lyons , Thursday 21 March 2019 22:06

Sometimes you go rock-pooling on one of the lowest tides of the year and it pays off. Then there was this evening, it was just off the scale. WOW!!! I can't get over what just happened. I've seen more sea slugs this evening than I have ever seen in my whole life. I believe this is the insanely cool Polycera quadrilineata. Just look at this video and you get an idea of how excited I am. This animal is about 5 mm long, this gives you a flavour of how great this camera is given it's also submerged under sea water.

It's like something from the tropics. I found two rather effortlessly by sweeping sea weed with a pond net. Have some more of this incredible animal.

Wow. WOW! I actually don't know what to say.

How about even more amazing sea slugs?! Evan found this Facelina bostoniensis under the second stone he turned over!!! I was only talking about how I'd like to see this at work today, we didn't see another one. When a Broad-clawed Porcelain Crab crawled over it, the appendages suddenly straightened into narrow points. Wish I had caught that on film.

But it didn't stop there! Evan found this under the FIRST rock he turned, which we now think is Lamellaria perspicua (not Pleurobranchus membranaceus as originally stated). A sea slug like mollusc.

We also saw these sea slugs. Three Goniodoris nodosa (and not the Acanthodoris pilosa that I initially claimed it was - saw that there a few years ago) under one rock with eggs! Sorry I was rushing to get the blog out last night. Thanks for spotting that Evan.

To give some context here tonight, I had not seen ANY of the above four species until tonight. These were abundant, we saw at least four. Berthella plumula.

And Sea Lemon eggs! They are huge!

Other molluscs included: Northern or Arctic Cowrie.

Bearded Mussel.

And a living Variegated Scallop!

Wow. Just wow. It didn't stop there though. I had this Long-legged Spider Crab.

And four fish. Rock Goby was the commonest. Evan found a batch of eggs too.

A single Tompot Blenny.

And one each of Corkwing Wrasse (above) and Ballan Wrasse (below). Only the second time I have seen this species. You can see the difference in the shape of the head. Corkwing is much commoner down here.

That was one of the best days natural history I have ever had, utterly mind blowing. A massive thanks to Evan Jones for turning so many rocks and finding sea slugs so effortlessly.

I'm going back tomorrow evening for what is going to be another extremely low tide!!!

UPDATE: I was so excited I forgot to say where I was. This is at the Pound, Eastbourne, East Sussex.

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