| Elephant | Oyster | Flamingo |
| Ξ Poem | Oyster Notes |
cloistered: Oysters are bivalves, mollusks with two close-fitting half-shells that, when closed, completely enclose the shellfish within a protective bone-hard case.
burly shell: Compared to other bivalve mollusks, the shell of an oyster is unusually rough on the outside, providing ideal purchase for spat (baby oysters) to anchor themselves to with their byssal threads. In this way, generations of oysters build up a reef, or bed, of sturdy oyster shells, where the crowding pressure of other oysters causes the characteristic burls in the oyster's shell.
foisted in … dust: Cultured pearls form around a grain of sand or similar small irritant introduced by hand into the oyster.
her: Although oysters begin their lives as males, most eventually change into females, so among mature oysters, females predominate. But, at the time I wrote it, a more compelling reason for this choice of pronoun was that my daughter, for whom I wrote this poem, was in her mother's womb.
inmost: Pearls are usually created deep inside the oyster, between the digestive organs, reproductive organs, and adductor muscle.
sequestered: Unlike surf-loving clams and mussels, oysters prefer a calm habitat with a steady current, typically settling at a depth of 3 to 80 meters.
paste-encrusted: The oyster's innards are enveloped by its mantle, a thin but tough membrane that secretes a pasty substance called nacre, which hardens into the mother-of-pearl constituting the oyster's shell. Chemically, nacre is composed mainly of calcium carbonate, like our bones, but in an orthorhombic crystalline form known as aragonite. The aragonite crystals are fixed in a matrix of the proteins conchiolin and perlucin.
whorl: Oysters and several other shellfish build up their shells (and pearls) one layer a day, accumulating over the years to thousands of ultrathin and uniform layers of nacre.
festering: In nature, pearls are formed when an oyster encases a parasite in nacre to wall it off and render it harmless. A similar process occurs in humans when lung tissue protects itself from tuberculosis bacteria by encasing them in calcium carbonate, which shows up as clouds of granulomae in x--rays of healed patients.
lustrous: The highly uniform spacing between the semitransparent layers of nacre in a pearl or oyster shell is often within the range of the wavelength of visible light, producing an enchanting iridescent sheen, or orient, as the regular layers reflect different colors of light from different angles.
For more information on oysters, see the Wikipedia Oyster article.