1. Did you know that cephalopods, (octopuses, squids, and cuttle fish), can see just as well as us, if not better? It's true. Even though their eyes are designed differently than ours, they achieve the same results. We have a flexible lens in our eyes that stretches and shrinks to focus. The lens of a cephalopod, on the other hand, is stiff and not very flexible at all. Instead, the lens is attached to a movable apparatus that transports the entire lens back and forth within the eye in order to focus. This type of eye has some advantages that our eyes don't. For example: As we grow older our lenses become stiff and can't focus as easily. A cephalopod doesn't have this problem because their lenses are already stiff, and don't need to be flexible to focus.
2. Have you ever wondered why certain clams make pearls? The answer is simple. Pearls are formed when an irritating piece of sand, a parasite, or other particle becomes lodged between the clam and its shell. To solve this problem, the clam secretes shiny layers of calcium carbonate that coat the irritating particle, and viola, you have your precious pearls! Now you know that that shiny pearl necklace is just a calcium carbonate coated string of sand and dead parasites.
3. Do you know that horseshoe crabs are not really crabs at all? They're actually the only four living species of a group, class Merostomata, that are largely represented by fossils. Horseshoe crabs are in fact living fossils, resembling creatures that went extinct thousands of years ago!
4. Insects are the largest and most diverse group of animals on earth, as you could probably guess, but did you know that only one species of insects is marine? It's true! Insects have taken over the land, and some species can live in the marshes and rivers and other places that are close to land, but only the marine water strider, (Halobates sericeus), can live any large distance from land. The marine water strider skates on the surface of the water by taking advantage of its elongated legs and the water's surface tension.
5. Did you know that the blue whale, the largest animal on earth, is a filter feeder? The blue whale, along with all other kinds of baleen whales, feed on the plankton. These whales eat mostly krill, that grow to around six centimeters long.
