Sand dollars are actually the skeletons of marine echinoderms and take their off-white, chalky form after the animal dies. They are closely related to flat sea urchins, starfish and sea cucumbers. When alive, they are covered in short, fine spines and range in color from yellow to blue and purple.Know More
Sand dollars get their name from their size, shape and the coloring of their skeletons. They are 2 to 4 inches across and coin-shaped. The round shape and bleached white color of their skeleton on the beach at low tide is reminiscent of silver dollars.
Sand dollars in their living form exist in marine environments on the sandy ocean floor, usually in shallow waters. They use their spines to burrow into the sand as well as to move over it. In tranquil waters, they stand on end, partially buried in the sand. As ocean currents increase, they flatten out or burrow completely into the sand. They can also grow heavier skeletons by ingesting sand in order to weigh themselves down.
There are male and female sand dollars. The animals reproduce sexually by releasing eggs and sperm into the water. The eggs are fertilized and form larvae, which eventually settle to the ocean floor and slowly change into the flattened, spine-covered creature. They can live anywhere from 6 to 10 years.Learn more about Zoology
The peregrine falcon, or Falco peregrinus, is the fastest bird and the fastest member of the animal kingdom. When swooping or diving, it reaches speeds of up to 200 miles per hour. It is native to North America and historically known as the duck hawk.Full Answer >
Given the timescales involved in animal evolution and the difficulty of identifying new species as their first members emerge, there is no single species that could be said to have evolved most recently. Some animals, however, have populations that do not breed together and could be regarded as emergent species.Full Answer >
Maxim magazine places the hyena at the top of its list of the filthiest beasts in the animal kingdom. It cites the hyena's reputation as a grave robber, its mating habits and its method of marking its territory as evidence to support the hyena's nomination to the filthiest beast list.Full Answer >
A fish is an animal. It is a multicellular organism with eukaryotic cells arranged into tissues and organs. Eukaryotic means that fish cells have nuclei and other structures that are protected by membranes.Full Answer >