Helminths, symbiosis and parasitism

The Wedding Present

Along one wall of the museum are a series of mounted and labeled specimens, which unintentionally and exquisitely demonstrate some of nature’s persistent biological interactions: Symbiosis and parasitism.

In the corner, inside a Victorian glass bell jar is a Venus Flower Basket (Euplectella aspergillum) – a light transmitting sponge found in the deep waters around Japan. It is composed of glass fibres that are constructed from silicic acid extracted from seawater. Traditionally, the dried sponge was given as a wedding gift, as inside it is home to a pair of small symbiotic shrimp that live in the body of the sponge and feed on its waste. Young shrimp pairs search for their own basket to live in, and once they have grown they cannot leave.

Two cases along, past the corals and bryozoa and close to the floor are a few taller vessels containing ominous pales stretched forms – Helminths, or parasitic worms.

Pentastomids, or tongue worms, are blood-consuming parasites that live the pulmonary and nasal cavities of predatory vertebrates, usually snakes. When the predator host eats the intermediate host (a fish or small mammal) the nymph of the tongue worm is released into the digestive tract and then bores into the lungs where it matures. They are rare in humans but can be transmitted by eating raw goat or sheep meat, and result in severe itching the ears and throat, and eventual death if not removed or dislodged by coughing or sneezing.

You hope that your gaze will hold them still in their glass coffins.