conchiolin

This shell layer is composed of a type of protein known as conchiolin.

The distinct peripheral belt demonstrates that a conchiolin keel was present.

Natural pearls are nearly 100% calcium carbonate and conchiolin.

Corneous opercula are made out of the protein conchiolin.

The combination of aragonite and conchiolin is called nacre, which makes up mother-of-pearl.

Chemically speaking, this is calcium carbonate and a fibrous protein called conchiolin.

Both genera are characterised by partially uncalcified (conchiolin) shell portions.

The layers usually incorporate a substance called conchiolin, often in order to help bind the calcium carbonate crystals together.

The teleoconch is composed of conchiolin, a transparent cartilaginous material, and its surface lacks sculpture.

In the mantle, tiny tubes excrete the almost invisible specks of mineral salt that cement to the conchiolin.

On the teleoconch whorls, the peripheral belt on which the conchiolin keel was attached is very clear.

Recent specimens of Oxygyrus keraudreni have an uncalcified shell of conchiolin in the adult stage.

The gastropod shell has several layers, and is typically made of calcium carbonate precipitated out into an organic matrix known as conchiolin.

The conchiolin keel is glass-like and has a truncate anterior edge that ends at the shell aperture.

Finally, the foot is lifted off the capsule and the wall of conchiolin hardens still further in contact with sea water (Fretter and Graham, 1962).

The periostracum, a layer of protein (conchiolin) that is the outermost part of the shell surface, is yellowish-brown.

These semi-rigid structures are part of the periostracum, a thin protein layer (conchiolin) secreted by the snail to cover the calcareous shell.

Conchiolin (sometimes referred to as conchin) are complex proteins which are secreted by a mollusc's outer epithelium (the mantle).

In other words, the shell plate in this species is oval in shape, solid and calcareous (chalky), with a transparent conchiolin (horny) base.

In many, but by no means all, species of molluscs, the epidermis of the mantle secretes calcium carbonate and conchiolin, and creates a shell.

The shells of most molluscs are made of calcium carbonate (the main constituent of limestone and chalk), and of conchiolin, a protein.

The presence of a subperipheral belt much the same as in Protatlanta souleyeti, on the other hand, demonstrates that a conchiolin keel has been present in this species.

With X-rays it is possible to see the growth rings of the pearl, where the layers of calcium carbonate are separated by thin layers of conchiolin.

The shell's structure is distinctive: sinuous bands of blue, green, and rose iridescence are delineated by dark brown lines of conchiolin, a proteinaceous material that holds the shell together.

The mollusk, being irritated by the intruder, forms a pearl sac of external mantle tissue cells and secretes the calcium carbonate and conchiolin to cover the irritant.