Say you find yourself, as one occasionally does, in need of incubating some baby cuttlefish. Say you don't have a lot of money, as one occasionally does not, to do the incubating of said cuttlefish.
Over at the Monterey Bay Aquarium, marine biologists and curators found themselves in exactly this situation as they were preparing for their upcoming special exhibition: "Tentacles," which will feature cephalopods like octopi, squid, and, yes, cuttlefish. They had mother cuttlefish. They wanted to maximize the number of healthy hatchlings that could result from a given clutch, or collection of eggs. And nature, they realized, isn't always the best way to do this survival-maximization: Mothers can forget where they leave their eggs—or, even when they remember, neglect them. Which, if you're trying to increase cuttlefish populations, is not ideal. Removing the eggs and raising them separately, the aquarist Bret Grasse points out, "allows mom to focus on what she does best: laying more eggs."
So, again: Say you need to incubate some baby cuttlefish. Say you'd prefer to do so without buying commercial incubators that can cost hundreds of dollars a pop. Say you'd prefer a more DIY solution.
Well, here is that solution! All you'll need are soda bottles, netting material, plastic tubing, and silicone glue. Oh, and some cuttlefish eggs.
In an Aquarium Tumblr post, Grasse describes his MacGyver-y methods for cuttlefish maturation. First, drink the soda. (Or, you know, empty the bottle of it.) Second, cut the bottle in half, and then affix a screen between the two pieces and also at the open end. (The idea is to create a water-permeable barrier between the inside and outside of the bottle.) Place your cuttlefish eggs into the screen-contained section of the bottle. Plunge the bottle underwater, eggs-side down. Then attach a tube that will inject air into the top half of the bottle, turning it into a "bubbler." The tube will draw water up through the whole device, aerating the eggs.