Two strange bicycles that never caught on are featured in this segment. On location at the Sun Coast Sea Bird Sanctuary, in St. Petersburg Florida, we discover some of the adaptations and habits of pelicans, a unique species whose existence is being threatened by human encroachment. Of all the sea creatures found in the worlds ocean, sponges have one of the simplest structures and show some of the greatest adaptability to different environments. First appearing in the fossil record in the Pre-Cambrian Eon, over 600,000,000 years ago, sponges have shown little change over time. Currently, about 5000 different species of sponges have been identified ranging from 1 cm to over 200 cm in length.
All sponges have a similar body plan which basically resembles a sac filled with holes.
Water enters the body through these holes where it is kept moving by thousands of microscopic cells which have beating flagella, tiny whip like hairs which move back an forth. Once in the sponge body, the water is filtered of tiny plankton which it uses as a food source. Most sponges are hermaphroditic, meaning that a single organism has both eggs and sperm. One unique feature of sponges is there ability to repair themselves. When a sponge gets damaged, or when cells have been separated from the main body, they re-aggregate to form a healthy individual.