Mother lode of flame shells discovered off Scotland

January 1, 2013 • 5:22 am

Here’s a bivalve mollusc I didn’t know existed. The day before Christmas, the BBC News reported a stupendously large assemblage of living flame shells (Limaria hians, also known as the “gaping file shell”) living off the coast of Scotland.

A huge colony of an elusive and brightly coloured shellfish species has been discovered in coastal waters in the west of Scotland.

The extensive bed of at least 100 million flame shells was found during a survey of Loch Alsh, a sea inlet between Skye and the Scottish mainland.

That’s about 20 flame shells for every person in Scotland! (I haven’t been able to find a photograph of a huge grouping.) They’re bizarre looking creatures, seemingly more suited to tropical than temperate waters:

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The article continues:

The Scottish environment secretary said it could be the largest grouping of flame shells anywhere in the world.

The colony was uncovered during a survey commissioned by Marine Scotland.

It was conducted as part of work to identify new Marine Protected Areas (MPAs).

The small, scallop-like species has numerous neon orange tentacles that emerge between the creatures’ two shells.

Flame shells group together on the sea bed and their nests create a living reef that supports hundreds of other species.

It was conducted as part of work to identify new Marine Protected Areas (MPAs).

The small, scallop-like species has numerous neon orange tentacles that emerge between the creatures’ two shells.

Flame shells group together on the sea bed and their nests create a living reef that supports hundreds of other species.

The story also gives a few “flame shell facts”:
  • Flame shells build “nests” by binding gravel and shells together with thin wiry threads.
  • About 4cm long, they group together in such numbers that the sea bed is covered by a felt-like organic reef of material several centimetres thick.
  • Flame shell beds are found at only eight sites in Scottish waters.

They have a restricted distribution, all around England and Northern Ireland:

uklimhia

The Marine Life Information Network gives some information about lifestyle and habitat

Distribution: Patchy records from off Plymouth Sound, Skokholm, southern Isle of Man, western coasts and lochs of Scotland, and Mulroy Bay, Northern Ireland.

Habitat: Found from low water to ca 100 m on coarse sand, gravel, broken shells and stones. It may occupy ‘nests’ of byssus threads among rubble, under stones or in the holdfasts of laminarians. When abundant, the ‘nests’ may coalesce to form a carpet or reef over shell-sand, which may provide a substratum for kelps.

Description: The edge of the fleshy mantle bears numerous conspicuous, red and orange filamentous tentacles. The shell is thin, solid, equivalve and oval in outline, tapering towards the beaks, and usually about 2.5 cm in length but occasionally reaching 4 cm. The beaks bear an ‘ear’ like projection on each side, the anterior ‘ear’ being more prominent. The shell gaps on both sides. The shell is white in young specimens becoming whitish-brown with age. The shell bears clear growth steps and ca 50 radiating ribs that extend to a crenulate margin. When disturbed this species can swim actively using jets of water expelled by ‘clapping’ its shells together and a rowing motion of its tentacles.

Here’s a photo from the Wikipedia site:

800px-Flame_shells

For more on flame shells, including a diver’s experience with them, go here.

h/t: Chris

27 thoughts on “Mother lode of flame shells discovered off Scotland

  1. “They have a restricted distribution, all around England and Northern Ireland”

    Hey, whats that splotch of the coast of Pembroke then?

    We Taffs are always being ignored (sulks)

    1. Rod: I was thinking the same thing. Maybe I’m too cynical, but I can just imagine someone saying “But there’s a 100 million of them! It won’t hurt to harvest some. The economy!”

      1. And what are the local fishermen likely to say? Apart that is from “Gerroorf Moi Seee!”
        They’re very, if you’ll pardon the pun, clannish out on the West Coast. For an inshore fishery like this, It would be a spectacularly stupid (or brave) non-local fisherman who tried to mussel (sorry!) in on the area.
        The reef is described as 0.75 Ha. That’s an area equivalent to 75m by 100m. Good luck on finding that without local assistance.
        I can’t find my dive guide for the area, but some of the parts of Loch Alsh and surrounding lochs are well beyond normal diving limits, and some beyond abnormal diving limits. That also implies significant submarine topography (really bad for trawling equipment, if your gear didn’t get “accidentally” cut away by another boat, anyway), and as the ferryman to Skye (either ferry) would often show, there are some real tidal rips around there. Not as bad as the Corrievreckan, but pretty good nonetheless.
        If they’ve survived this long, that probably means that they’re not economical to fish for anyway, even as bait for some other, more valuable fish stock.

        1. These are wonderful! I spent a couple of years in my youth creel fishing the west coast of Scotland, and never heard of these. Of course, we wouldn’t catch them in the creels, and the trawlers, as you say, would keep well clear of that kind of ground. When creeling for Nephrops, which live in sand, we could co-exist with the trawlers only by shooting creels along the edge of the sand, where the trawlers were too scared to work, so they are unlikely to get to these creatures. Clam dredgers (a very destructive method) would be more of a problem.

  2. Is it sad that the first thought to raise its head was that someone had found a previously undiscovered weapons cache left over from WWII?

    1. Well, there was tons and tons of ordnance of all kinds, ranging from submarines to small arms ammunition dumped in the sea off Scotland from ’45 to about the mid-50s.
      Not an unreasonable question to ask.

      1. Don’t forget the thousands of tonnes of mustard gas, chlorine gas shells and phosgene shells that have been dumped in various parts of the British (and French, and American, and German) seabed, mostly after World War 1.
        Most of the British dumping for which detailed records exist are further south – under the Larne-to-Cairnryan ferry route (because there were harbours nearby – “Doh!”). But almost certainly there will be other, unrecorded, dump sites.
        It’s a perfectly normal year when one or several of the harbour towns along this side of the country has the harbour shut down while the bomb-disposal people come in and deal with the unwelcome contents of a trawl. So, “what’s this ‘ere?” always includes a frisson of “I hope it’s not a bomb.”

    1. Wrong – we Scots are part of the redhead Celtic Fringe (poor pun intended), just more handsome than the Irish. These shellfish have beards many a Scot would be proud of.

      1. Well, lesson learned. I suppose I’ll have to cue off of something other than hair color to tell all y’all apart…fifes versus bagpipes, perhaps?

        b&

            1. Next time you’re in Scotland I’ll split a bottle of Macallan over your head, sorry, with you. Reflex comment deleted – it would be Bell’s or Haig blended if I split it over your head.

  3. If you think mere flame scallops are cool, check out the electric flame scallop (Lima sp.)

    FYI: you can find both versions in your local aquarium store. They’re pretty common.

  4. Reblogged this on sciencekitty and commented:
    These look like the ultimate kitty happy meal – snack and a toy all in one! Where can I get some for my research? I need to categorise the flavour on my chicken-tuna scale. Vital research!

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