Hawaiians used many fishing methods. Hook and line were used to catch medium-sized fish as well as sharks, squid and octopus. The most reliable line was made from olona, one of the world's strongest plant fibers. Hooks were shaped from a single piece of human, bird, or dog bone, pearl or turtle shell, whale ivory, or wood; composite hooks combined two or more pieces lashed together. Stone, coral, or shell tools were used to shape the hooks. Hook shapes ranged from straight to nearly circular, often including one or two carved barbs. The largest hooks were built for sharks. Made of wood or a composite of wood with a bone point, they measured seven to 11 inches long. Fishermen stored lines and hooks in gourd containers. Stone sinkers took many shapes. The plummet form, or pohakialoa, is unique to Hawai`i and was made to carry lines to the bottom of deep fishing grounds. While in shallower water a fisherman could easily see the sandy or rocky bottom, it was more difficult to get visual bearings in deep water. Oil from roasted kukui nuts, chewed and spat on the surface, increased visibility to six fathoms (120 feet). Hawaiians made lures as well as hooks. The most striking are cowrie shell lures for catching squid and octopus. One or two cowrie shells and a stone sinker were lashed to a wooden shaft that also supported a bone hook; the lure might also include a hackle of ti leaf strips. Different cowrie shell lures were used to fish at particular times of day, depending on color, ocean conditions and the sea floor. Some lures passed down through generations became famous in stories and chants. Some were named for ancestors or relatives. Kamakau wrote that some lures were so powerfully attractive that they would simply be shown over the side of the boat and "squids came climbing in." Fishermen used fish, shrimp or crab to bait their hooks. They used live bait to attract and hold a school of fish. Ground bait - cut pieces of fish pounded soft - was wrapped in a cloth package along with a baited hook, the whole bundle weighted and lowered to the sea bottom. The line was then jerked free and the hook swallowed by fish attracted to the bait. Squid ink bait made from the roasted ink sac mixed with plant ingredients was put on the fish hook tip to catch small fish near shore.