Spectember 4: Junk Rat

One million years in the future, the world is still in the iron grip of humanity's destructive reign. Most of the large terrestrial animals-- and a number of the aquatic ones too-- have long since died out, and those that remain are critically endangered. Global warming has melted the world's ice caps, and the oceans, lakes, and rivers are extremely polluted. Yet some animals have adapted to these hellish conditions. The caddisflies are a group of aquatic insects that thrived mainly in clean water; with the rise of pollution, many of them became extinct. But one species has evolved a unique adaptation to survive.

The Microplastic Caddisfly (Ultimotrichopteryx plastiferus) is similar to its relatives in that it has an aquatic larval stage, which protects itself with a casing made out of debris it finds. While most caddisflies make this casing out of rocks and pieces of shell, the Microplastic Caddisfly uses man-made objects-- small beads of plastic that float in the water column. It is one of the smallest caddisflies, measuring less than a centimeter long in its larval stage, and even smaller as an adult, so the microscopic flecks of plastic found in the water are sufficient to form a shell for it.

While it is unique in being able to withstand and even thrive in polluted water, the Microplastic Caddisfly is in most other ways a typical member of its group. It spends up to a year as a larva, before pupating and emerging as an adult to mate and lay eggs. Adults do not feed and live for less than a week before dying after they reproduce. As one of the few insects able to tolerate the polluted water of this world, the Microplastic Caddisfly is important prey for many of the other water-dwelling animals of its time.