Tuesday, November 12, 2019

№ 724: Parasite Paradise

Parasites are going extinct in droves – and we should be very worried (Paywall)

They cause deadly diseases and brainwash crickets to leap into ponds, so why are conservationists fighting to save parasites from extinction?


Andrew Dobson at Princeton University [says], “Parasites are as fundamental to an ecosystem as predators are,” he says. In nature, parasitism is the most common way to get food, shelter and other resources – so common that parasites far outnumber free-living organisms. For example, the 45,000 known vertebrates are home to more than 75,000 parasites.

“There are more animals being eaten from the inside out than the outside in,” says Dobson. At least 70 per cent of food-web interactions are between a parasite and its host, says Carrie Cizauskas at the University of California, Berkeley. “Parasites are the glue that holds an ecosystem together.”

Take the camel cricket. Like many crickets, it can be infected by a parasite called a horsehair worm. After the worm matures in the cricket’s body, it needs to reach fresh water to reproduce. Instead of waiting for the cricket to take an accidental bath, the worm compels its host to make a suicidal leap into a stream or pond, where it can then bore a hole and slither into the water. In doing so, the worm provides a crucial delivery service: crickets account for more than half the food eaten by trout in some areas. . .

THE WAY IT IS (November 11)

Existence, in fact, is just about eating.
Bacteria, amoebæ, seeds and blue whales
are on the menu for something or other.
(No need to go in to gory details.)

Come dinner time there are no winners,
saints are every bit as tasty as sinners.
“From sperm to worm” (a rhyme from Sondheim*)
everything feeds something, sometime.

The basic fact of this living condition:
if you exist you are nutrition.
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*West Side Story, “Quintet”