Sunday, 15 January 2017

Buried Treasure!

Spent the afternoon on the beach with Aimée. Not sunbathing, not holding hands whilst walking in the surf, not building sand castles, not even beachcombing. No, we were digging for worms! We were armed with a spade, a rake, a hand trowel and an empty ice cream tub. The tide was out as far as I've ever seen it and, wonder of wonders, there was a lovely flat sandy area free of rocks and rubble. We made a beeline for it and followed the tide all the way out. 

I started digging and Aimée started raking the soft muddy sands. A mother and her couple of young kids materialised nearby, seemingly intent on seeing what we were up to. So far we'd seen nothing, then a sudden jet of water shot out of the sand by my feet! I dug the spade in and cleverly sliced a large bivalve shell into two halves, just in time for the mum to ask, "did your spade do that?" Flippin great, at least I had brilliant views of the animal inside. We showed the kids a few worms, showed them the broken shell and let them have a go with the rake. Turns out they live just next to the beach and the mum told me about the urchins that lay exposed in the weeds at low tide just off from Staffin, big purple ones (ie Edible Sea Urchin, one I've yet to see!) They were a nice bunch, I'll probably bump into them again seeing as I'm often on this beach. 

Back to the digging - this is the large bivalve (well, what's left of it...) that I dug up

At least the animal itself wasn't damaged. Might need a new side wall though.....
The siphon that caused the jet of water. Impressive!
This is the Sand Gaper (Mya arenaria) and a lifer for me. Sadly I have destroyed half of the shell which will allow predators an easy access. This mollusc's days are numbered, I feel quite bad about that. Apparently they are good eating, not something I was tempted to try. Talking of good eating, these are locally collected for the pot too - this is the Striped Venus (Chamelea gallina) and a lifer.

The best-marked one we could find, most here are really quite plain shelled
Other bivalves found in the sand included Common Mussels (Mytilus edulis) and quite a few Thin Tellins (Angulus tenuis). But what of the worms, I hear you cry! Calm down, I was just getting there. 

We dug up loads of worms, mostly small slender things that I really didn't fancy trying to identify. But we found absolutely masses of Sandmason Worms (Lanice conchilega) including this one of which I managed to take a truly awful image.

Seen here with the beginnings of its latest tube
The biggest worms by far were this big fat Blow Lug (Arenicola marina)  

Three (not two) annulations between the 2nd and 3rd chaetigers
and this big brute, eventually identified as Arenicolides ecaudata with its feathery gills and tail end as fat and robust as the head end. Note the lugs have head ends much fatter than their tail ends. 

A rather moribund Arenicolides ecaudata back indoors, fully 6 inches long.
Plenty of these smaller worms in the mud, this is what's known as a Catworm or Nephtys hombergii. Catworms have a hugely diagnostic means of locomotion when swimming, they thrash the tail back and forth which sets up an ever-increasing wave up the body towards the head. These things can disappear into soft sand as if it wasn't even there! It took a bit of microscope work combined with habitat knowledge to come to that ID. Note the lovely pearly iridescence along the upperparts

  Nephtys hombergii - much paler and pearlescent in real life!
There was this distinctive-looking thing too. No clear annulations, I did wonder if it was a sea cucumber and not a worm at all. I still don't know, it has yellow tubercules very similar to the huge Arenicolides so may be a young one of those? Maybe. 

Ugly bugger whatever it is. A tad over 2 inches in length.
Also found were numbers of sand eels. I'm not sure which species yet, but suspect Lesser Sand Eel

Most were less than a quarter the size of this one
And how did we find all of these magnificent creatures, I hear you ask. We dug holes and trenches (which was most successful) and raked the top couple of inches of wet sand (which was less successful). Here's a pic of me doing just that - soon after this I ripped the carapace off a crab. I never knew this sort of thing could be so destructive!

It had been mizzling on us for some time and the tide had turned against us. We headed further up the beach and had a look around what looks like an old disused slipway. There are lots of rocks there and huge numbers of Common Mussels all over the place. There were a good many patches of a yellow encrusting sponge, but without a compound microscope to check the spicules it's a bit pointless trying to figure out which species. Beadlet Anemones were new for the year and a sudden wriggle between rocks turned into a very dapper Butterfish (Pholis gunnellus) which was quickly followed by a second individual. They lay their eggs amongst rocks in shallow water at this time of year so these may have been gravid females.

I've only seen a couple of these fantastic fish before, so it was a real treat to find more!
We were wet but happy to have finally found a few things in the sand. I plan on doing plenty more sand digging in the near future. Hopefully Aimée will too - once we get her some proper wellies!

1 comment:

  1. Inspiring stuff! That unidentified ugly thing might once have belonged to John Wayne Bobbitt.