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Re: Sea-hares

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  • Douglas Herdson
    Hi Since Cornwall WT put this out I have had reports of a further 4 large specimens caught in Poole Bay, Dorset. I am also keen to hear of any other records of
    Message 1 of 5 , Oct 30, 2007
      Hi
      Since Cornwall WT put this out I have had reports of a further 4
      large specimens caught in Poole Bay, Dorset.

      I am also keen to hear of any other records of these two large
      species of Aplysia. The only ones I am aware of for Aplysia
      fasciata prior to August of this year are:

      1800s - several in the Channel Islands
      15/02/1949 - Salcombe Estuary
      8/07/1971 - Galway Bay, Ireland
      2/08/1971 - Killary Bay, Ireland
      Late 70s or early 80s - Exmouth Beach, Devon
      1990 - Gillan Creek, Helford, Cornwall
      1997? - Saltstone, Salcombe Estuary, Devon

      i.e. only six in the last hundred years.

      You may be interested in the info I have gathered for the media -

      Aplysia fasciata at the National Marine Aquarium

      A specimen of 30 to 35 cm and weighing 1.5 kg was caught in Poole
      Bay, Dorset, just outside of Poole Harbour on 14th October 2007, in
      a trammel net by John Green of the FV. Serendipity. It was caught
      in 3 - 4 m of water on sand on a flooding tide, while fishing for
      sole and bass. Subsequently a further four large sea hares have
      been caught by fishermen in the same area.

      It was brought into the National Marine Aquarium where it is now on
      show as our "Feature Creature" in our recently refurbished Shallow
      Waters, Hidden Depths exhibit, where it is devouring very large
      quantities of sea lettuce Enteromorpha latuca.

      Aplysia fasciata is the largest and the rarest of the three species
      of sea hare found in the British Isles. It is an Atlantic species,
      found from the Channel to Angola (South west Africa and to Brazil)
      and also throughout the Mediterranean. It appears to reach its
      northern limit in Ireland and along the Channel coast of England.
      It is one of the largest sea slugs in the world. The other two
      British species are the relatively common Aplysia punctata variable
      in colour and growing to 20 cm; and the uncommon Aplysia depilans
      with different shaped back lobes, brown or green and growing to a
      maximum of 30 cm.

      There were several in the Channel islands in the mid 1800s, but the
      first one in mainland Britain was found on the Saltstone in Salcombe
      Estuary, Devon, at extreme low water in February 1949. Another was
      found at the same place in 1997. They are very rare but have also
      been found in Ireland and Cornwall. This year from late August to
      mid October, a number of individuals have been found from south west
      Cornwall to Dorset and in Jersey. Several were washed up on two
      beaches on the south Devon coast (described as "purple, slug-like,
      up to the size of a rugby ball"), and egg masses have been found in
      a sheltered inlet.

      They are impressive animals growing to 40 cm and weighing up to 2
      kg. Most found in Britain have been smaller, but the specimen from
      Poole was a large one of 30 to 35 cm and 1.5 kg.

      While called sea slugs they are very different from garden slugs,
      being some of the most spectacular and beautiful of molluscs.

      The sea hares have a small thin internal shell, largely covered by
      the large wing-like body flaps (parapodial lobes) which also protect
      their gills. These give it a bat-like appearance when swimming.
      They vary from bright red to brown in colour, have a clear head,
      tiny eyes and have two pairs of tentacles, the larger of which look
      like rabbit's ears. It is these tentacles along with its large size
      and rounded body shape that give it a rabbit-like look and
      consequently its common name. When stressed they release a purple
      ink into the water which is contains the toxin opaline. The animals
      are said to be mildly toxic but are eaten in some areas of the
      world.

      Most sea slugs feed on other animals including sea anemones, but the
      sea hares are vegetarians preferring seaweed.

      They come inshore to breed, most usually in the Spring. Each sea
      hare is both male and female being a simultaneous hermaphrodite.
      They are known to form long mating chains each animal being a male
      to the one in front of it and female to the one behind. The penis
      is on the side of the head just below the right anterior (cephalic)
      tentacle. They then lay a pink to orange chain of eggs forming
      large spaghetti-like masses at the bottom of the shore or in shallow
      water. The young hatch from these, spend some time as a veliger
      larva in the plankton and them settle on algae as a tiny 1-2 mm sea
      hare. They grow rapidly reaching full size in a year, before
      breeding and dying.

      They are a rare southern species but a combination of climatic
      conditions appear to have brought quite a few to our southern shores
      this year. This is probably a one-off occurrence. There is no
      reason at present to link it to climate change, though it could be
      related to changes in oceanic currents.

      regards, Doug

      This email is just to let you know about the new article about Large
      Helford
      > Sea-hares is now available on the Helford Voluntary Marine
      Conservation Area
      > web site at http://www.helfordmarineconservation.co.uk/news.htm
      >
      > All sightings of these larger species would be of great interest
      and
      Dr Paul
      > Gainey would try to visit any find within range or as far as
      practicable
      > Tel: 01326 372 840.
      >
      > Best regards
      > Jayne Herbert
      > On behalf of Dr Pamela E Tompsett, Helford Voluntary Marine
      Conservation
      > Area
      > www.jayne-herbert.co.uk
      >
    • glaucus25
      Hello, I did not realise the Sea Hare in the October Torpedo Bulletin was the rarer species*. I have amended the web pages. (*I have been preoccupied
      Message 2 of 5 , Oct 30, 2007
        Hello,

        I did not realise the Sea Hare in the October Torpedo Bulletin was
        the rarer species*. I have amended the web pages. (*I have been
        preoccupied recently.)

        http://www.glaucus.org.uk/Torpedo2007Oct.htm

        Cheers
        Andy Horton.
        glaucus@...
        ><< ( ( ( ' >
        British Marine Life Study Society (formed 6 June 1990)
        http://www.glaucus.org.uk/
        ----------------------------------------------------------------------
        Marine Wildlife of the North-east Atlantic Ocean Yahoo Group
        New Group: http://uk.groups.yahoo.com/group/Glaucus

        MARINE LIFE NEWS BULLETIN TORPEDO
        http://www.glaucus.org.uk/Torpedo2.htm
        New Image Uploading Service:
        http://www.flickr.com/groups/glaucus/
        ><< ( ( ( ' >


        --- In Glaucus@..., "Douglas Herdson"
        <douglas.herdson@...> wrote:
        >
        > Hi
        > Since Cornwall WT put this out I have had reports of a further 4
        > large specimens caught in Poole Bay, Dorset.
        >
        > I am also keen to hear of any other records of these two large
        > species of Aplysia. The only ones I am aware of for Aplysia
        > fasciata prior to August of this year are:
        >
        > 1800s - several in the Channel Islands
        > 15/02/1949 - Salcombe Estuary
        > 8/07/1971 - Galway Bay, Ireland
        > 2/08/1971 - Killary Bay, Ireland
        > Late 70s or early 80s - Exmouth Beach, Devon
        > 1990 - Gillan Creek, Helford, Cornwall
        > 1997? - Saltstone, Salcombe Estuary, Devon
        >
        > i.e. only six in the last hundred years.
        >
        > You may be interested in the info I have gathered for the media -
        >
        > Aplysia fasciata at the National Marine Aquarium
        >
        > A specimen of 30 to 35 cm and weighing 1.5 kg was caught in Poole
        > Bay, Dorset, just outside of Poole Harbour on 14th October 2007, in
        > a trammel net by John Green of the FV. Serendipity. It was caught
        > in 3 - 4 m of water on sand on a flooding tide, while fishing for
        > sole and bass. Subsequently a further four large sea hares have
        > been caught by fishermen in the same area.
        >
        > It was brought into the National Marine Aquarium where it is now on
        > show as our "Feature Creature" in our recently refurbished Shallow
        > Waters, Hidden Depths exhibit, where it is devouring very large
        > quantities of sea lettuce Enteromorpha latuca.
        >
        > Aplysia fasciata is the largest and the rarest of the three species
        > of sea hare found in the British Isles. It is an Atlantic species,
        > found from the Channel to Angola (South west Africa and to Brazil)
        > and also throughout the Mediterranean. It appears to reach its
        > northern limit in Ireland and along the Channel coast of England.
        > It is one of the largest sea slugs in the world. The other two
        > British species are the relatively common Aplysia punctata variable
        > in colour and growing to 20 cm; and the uncommon Aplysia depilans
        > with different shaped back lobes, brown or green and growing to a
        > maximum of 30 cm.
        >
        > There were several in the Channel islands in the mid 1800s, but the
        > first one in mainland Britain was found on the Saltstone in
        Salcombe
        > Estuary, Devon, at extreme low water in February 1949. Another was
        > found at the same place in 1997. They are very rare but have also
        > been found in Ireland and Cornwall. This year from late August to
        > mid October, a number of individuals have been found from south
        west
        > Cornwall to Dorset and in Jersey. Several were washed up on two
        > beaches on the south Devon coast (described as "purple, slug-like,
        > up to the size of a rugby ball"), and egg masses have been found in
        > a sheltered inlet.
        >
        > They are impressive animals growing to 40 cm and weighing up to 2
        > kg. Most found in Britain have been smaller, but the specimen from
        > Poole was a large one of 30 to 35 cm and 1.5 kg.
        >
        > While called sea slugs they are very different from garden slugs,
        > being some of the most spectacular and beautiful of molluscs.
        >
        > The sea hares have a small thin internal shell, largely covered by
        > the large wing-like body flaps (parapodial lobes) which also
        protect
        > their gills. These give it a bat-like appearance when swimming.
        > They vary from bright red to brown in colour, have a clear head,
        > tiny eyes and have two pairs of tentacles, the larger of which
        look
        > like rabbit's ears. It is these tentacles along with its large
        size
        > and rounded body shape that give it a rabbit-like look and
        > consequently its common name. When stressed they release a purple
        > ink into the water which is contains the toxin opaline. The
        animals
        > are said to be mildly toxic but are eaten in some areas of the
        > world.
        >
        > Most sea slugs feed on other animals including sea anemones, but
        the
        > sea hares are vegetarians preferring seaweed.
        >
        > They come inshore to breed, most usually in the Spring. Each sea
        > hare is both male and female being a simultaneous hermaphrodite.
        > They are known to form long mating chains each animal being a male
        > to the one in front of it and female to the one behind. The penis
        > is on the side of the head just below the right anterior (cephalic)
        > tentacle. They then lay a pink to orange chain of eggs forming
        > large spaghetti-like masses at the bottom of the shore or in
        shallow
        > water. The young hatch from these, spend some time as a veliger
        > larva in the plankton and them settle on algae as a tiny 1-2 mm sea
        > hare. They grow rapidly reaching full size in a year, before
        > breeding and dying.
        >
        > They are a rare southern species but a combination of climatic
        > conditions appear to have brought quite a few to our southern
        shores
        > this year. This is probably a one-off occurrence. There is no
        > reason at present to link it to climate change, though it could be
        > related to changes in oceanic currents.
        >
        > regards, Doug
        >
        > This email is just to let you know about the new article about
        Large
        > Helford
        > > Sea-hares is now available on the Helford Voluntary Marine
        > Conservation Area
        > > web site at http://www.helfordmarineconservation.co.uk/news.htm
        > >
        > > All sightings of these larger species would be of great interest
        > and
        > Dr Paul
        > > Gainey would try to visit any find within range or as far as
        > practicable
        > > Tel: 01326 372 840.
        > >
        > > Best regards
        > > Jayne Herbert
        > > On behalf of Dr Pamela E Tompsett, Helford Voluntary Marine
        > Conservation
        > > Area
        > > www.jayne-herbert.co.uk
        > >
        >
      • Douglas Herdson
        ... Hello, I did not realise the Sea Hare in the October Torpedo Bulletin was ... Yes, Andy If you compare it with the fantastic photos by Tony Sutton in
        Message 3 of 5 , Oct 31, 2007
          --- In Glaucus@..., "glaucus25" <Glaucus@...> wrote:

          Hello,

          I did not realise the Sea Hare in the October Torpedo Bulletin was
          > the rarer species*. I have amended the web pages. (*I have been
          > preoccupied recently.)
          >
          > http://www.glaucus.org.uk/Torpedo2007Oct.htm
          >
          > Cheers
          > Andy Horton.
          > glaucus@...
          > ><< ( ( ( ' >
          > British Marine Life Study Society (formed 6 June 1990)
          > http://www.glaucus.org.uk/
          > -------------------------------------------------------------------
          ---
          > Marine Wildlife of the North-east Atlantic Ocean Yahoo Group
          > New Group: http://uk.groups.yahoo.com/group/Glaucus
          >
          > MARINE LIFE NEWS BULLETIN TORPEDO
          > http://www.glaucus.org.uk/Torpedo2.htm
          > New Image Uploading Service:
          > http://www.flickr.com/groups/glaucus/
          > ><< ( ( ( ' >
          >
          Yes, Andy

          If you compare it with the fantastic photos by Tony Sutton in
          Pamemela Tompsett's article, you can clearly see the difference
          between the two larger British species of Aplysia. Tony's photos
          are A. depilans while Steve Potter's is A. fasciata; and this is the
          species we have at the NMA. I will try to load a photo of our
          beasty.

          regards, Doug
        • Andy Horton
          Hello Aplysia fasciata at the National Marine Aquarium by Doug Herdson Photograph on Flikr http://www.flickr.com/photos/shoreham/1809880792/ & BMLSS Aplysia
          Message 4 of 5 , Oct 31, 2007
            Hello

            Aplysia fasciata at the National Marine Aquarium
            by Doug Herdson

            Photograph on Flikr
            http://www.flickr.com/photos/shoreham/1809880792/
            &

            BMLSS Aplysia
            http://www.glaucus.org.uk/Aplysia.htm

            Cheers


            Andy Horton.
            glaucus@...
            ><< ( ( ( ' >
            Marine Wildlife News of the North-east Atlantic Ocean
            (British Marine Life Study Society)
            http://www.glaucus.org.uk/News2007.htm
            http://www.glaucus.org.uk/News2006.htm
            http://www.glaucus.org.uk/News2005.htm
            http://www.glaucus.org.uk/News2007Autumn.htm


            ----- Original Message -----
            From: "Douglas Herdson" <douglas.herdson@...>
            To: <Glaucus@...>
            Sent: Wednesday, October 31, 2007 9:52 AM
            Subject: [Glaucus] Re: Sea-hares


            --- In Glaucus@..., "glaucus25" <Glaucus@...> wrote:

            Hello,

            I did not realise the Sea Hare in the October Torpedo Bulletin was
            > the rarer species*. I have amended the web pages. (*I have been
            > preoccupied recently.)
            >
            > http://www.glaucus.org.uk/Torpedo2007Oct.htm
            >
            > Cheers
            > Andy Horton.
            > glaucus@...
            > ><< ( ( ( ' >
            > British Marine Life Study Society (formed 6 June 1990)
            > http://www.glaucus.org.uk/
            > -------------------------------------------------------------------
            ---
            > Marine Wildlife of the North-east Atlantic Ocean Yahoo Group
            > New Group: http://uk.groups.yahoo.com/group/Glaucus
            >
            > MARINE LIFE NEWS BULLETIN TORPEDO
            > http://www.glaucus.org.uk/Torpedo2.htm
            > New Image Uploading Service:
            > http://www.flickr.com/groups/glaucus/
            > ><< ( ( ( ' >
            >
            Yes, Andy

            If you compare it with the fantastic photos by Tony Sutton in
            Pamemela Tompsett's article, you can clearly see the difference
            between the two larger British species of Aplysia. Tony's photos
            are A. depilans while Steve Potter's is A. fasciata; and this is the
            species we have at the NMA. I will try to load a photo of our
            beasty.

            regards, Doug
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