Just a Common Whelk Shell (3)

Lots of barnacles on a whelk shell

Whelk shell with an encrustation of mostly acorn barnacles – some complete with all plates and in other areas only the basal plate remains

Acorn Barnacles (Cirripedia) settle on almost anything in the sea or on the seashore. These images show the empty shell of a Common Whelk (Buccinum undatum) that I picked up on the beach at Rhossili on the Gower Peninsula in South Wales – it has proved to be an ideal substrate for them.

The outer surface of the shell is almost entirely covered with barnacles. The majority are intact with the lateral and also the terminal plates. Many specimens are mature but there are juveniles too. In one area, the barnacles have been knocked off but you can still see the basal plates by which they were attached. Some barnacles may have been living on this common British seashell while it was still alive. However, it is equally possible that the shell became colonised by barnacles once it was empty. The few calcareous tubes of marine worms which are stuck on the inner surface of the aperture or mouth of the shell would have settled there once the whelk flesh had disappeared.

The close-up shots reveal the details of the structure of the barnacles, made up generally from six fixed lateral plates overlapping each other to form the shell for the animal, with four articulating terminal plates forming the lid to the chamber. The whole barnacle shell is in this instance securely attached to the whelk shell by a basal plate that often remains in place even when the barnacle becomes detached. Not all species of barnacle have a basal plate.

The macro-photographs also show the intricate pattern and texture of the whelk shell surface with a regular criss-crossing of ridges. This gives an almost lattice-like effect where the growth lines intersect with the natural ornamentation or sculpturing of the shell. In close-up, it is also possible to see small areas of the colonial microscopic animals called Bryozoa or Sea Mats (resembling fragments of lace) which are clinging to the bases of some of the barnacle shells.

Macro-photograph of growth lines and natural sculpturing on a whelk shell

Close-up image of pattern and texture in a barnacle-encrusted whelk shell

Barnacle encrustation on a whelk shell

Whelk shell with mature and juvenile barnacles attached

Macro-photograph of growth lines and natural sculpturing on a whelk shell

Close-up image of growth lines and natural sculpturing in a barnacle-encrusted whelk shell

Apertural view of epibiont encrustation hard parts on a Common Whelk shell

Whelk shell with barnacles attached to the outside and calcareous tubes inside

COPYRIGHT JESSICA WINDER 2014

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Mother of Pearl 1

Ornamental iridescent veneer of mother-of pearl on an 18th century  bureau-bookcase

Mother of pearl is a wonderful iridescent material that is frequently used for artistic purposes. It comes from the inner surface of certain shells, sometimes gastropods like the Button Top Shell, and other times from bivalves such as the Freshwater Pearl Mussel. The inner or nacreous layer of certain shells is composed of crystals which are arranged in layers that reflect light in an attractive way. The colours reflected, and the intensity of the sheen, depend on the type of shell from which it has been obtained and also on the quality of light to which it is exposed. The same piece of mother of pearl can look different in different lights.

The photographs here show the details of the decorative veneer on a bureau-bookcase probably made in Mexico between 1780 and 1820. This is one of many fine items of antique furniture displayed in the Victoria and Albert Museum in London. The veneer is composed of about 7,000 individual pieces of shell, each piece from a separate individual shell (most likely freshwater mussel), and each one having taken about 40 minutes to prepare and shape. The shape of every shimmering piece is highlighted to great effect by a very narrow border of contrasting dark wood.

Ornamental iridescent veneer of mother-of pearl on an 18th century  bureau-bookcase

Ornamental iridescent veneer of mother-of pearl on an 18th century  bureau-bookcase

COPYRIGHT JESSICA WINDER 2014

All Rights Reserved

Just a Common Whelk Shell (2)

Study of a Common Whelk shell

Close-up, even the most common seashell picked up on the beach has a wealth of detail in its colour, pattern, and texture that tell the story of what it is and the life it has led, stage by stage: the shape and form, the size, the inherent sculpturing, the fine growth lines, breaks, scarring, and staining. Unusually, this Common Whelk shell (Buccinum undatum) has no attached epibiont organisms like barnacles or sea mats, or evidence of boring organisms like marine worms and sponges. Its black and orange staining show that it has spent some time buried in the sand near the top of the boundary from 5 – 15 cm deep that is a gradation between the anoxic black sediment where mostly only anaerobic bacteria thrive – and the yellow sand above which has enough free oxygen to support the life of immense populations of micro-organisms and to decompose their waste products.

Detail of growth lines and pattern in a Common Whelk shell

Study of a Common Whelk shell

Close-up image of seashell texture

Study of a Common Whelk shell

COPYRIGHT JESSICA WINDER 2014

All Rights Reserved

Lyme 4

Large Jurassic ammonite fossil in a beach boulder

An abundance of Jurassic ammonites – seen on a single walk along the shore at Monmouth Beach in Dorset, England, a few years back. There were large ones and small ones; embedded in beach boulders and forming rock pavements; in limestone and shale; some crystallised and others just impressions; some with other fossils preserved alongside or even inside the chambers.

Large Jurassic ammonite fossils embedded in a rock platform on the beach

Small ammonite fossil in Jurassic limestone

Impression of a small ammonite fossil

Large Jurassic ammonite fossil in a beach boulder

Large Jurassic ammonite fossils embedded in a rock platform on the beach

Large Jurassic ammonite fossils embedded in a rock platform on the beach

Large Jurassic ammonite fossil in a beach boulder

Ammonite fossil on Monmouth Beach at Lyme Regis

Ammonite fossil on Monmouth Beach at Lyme Regis

Large Jurassic ammonite fossil in a beach boulder

Large Jurassic ammonite fossil in a beach boulder

Monmouth Beach at low tide

COPYRIGHT JESSICA WINDER 2014

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Sea Campion

Sea Campion (Silene uniflora) a common British seashore flower

Sea Campion (Silene uniflora) on Chesil Beach shingle

Sea Campion (Silene uniflora) is a common British seashore flower. I photographed these yesterday where they were growing on the pea-sized pebbles of Chesil Beach between Abbotsbury and West Bexington in Dorset, England.

COPYRIGHT JESSICA WINDER 2014

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Ringstead Sea Kale

Young curly leaf of Sea Kale just opening

Close-up of a young red and purple leaf of Sea Kale

Sea Kale, Crambe maritima Linnaeus, grows on the shingle beaches in Dorset, England. When the leaves first sprout, they are a delectable colour of purple but as the plant matures the leaves become grey-green. However, the leaf veins and the curly edges of the leaves remain pink/purple but not as intense a colour as in the young shoots.

Sea Kale leaf becoming greener as it develops but with purple veins and edges

Close-up of a semi-mature Sea Kale leaf with leaf veins and curly edges still coloured purple or deep pink

Close-up of well developed Sea Kale leaf showing pink/purple leaf edges

Close-up of well developed Sea Kale leaf with grey-green blade and just the edges pink

Sea Kale (Crambe maritima) growing on the beach

A Sea Kale plant growing on seashore shingle at Ringstead Bay

Sea Kale (Crambe maritima) growing on the beach

Sea Kale (Crambe maritima) growing on the beach

Young purple shoots at the base of Sea Kale (Crambe maritima) growing on the beach

Young purple shoots sprouting at the base of Sea Kale (Crambe maritima) growing on the Ringstead Beach

COPYRIGHT JESSICA WINDER 2014

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