A sea cucumber is a marine animal that belongs to the phylum Echinodermata. They have a cylindrical body with soft, leathery skin and are typically found on the ocean floor. Sea cucumbers play a crucial role in marine ecosystems as they help recycle organic matter and maintain the health of the seabed. They feed on detritus and other organic particles, filtering them from the surrounding water. Sea cucumbers are known for their ability to expel their internal organs as a defense mechanism, which can be regenerated later. Some species of sea cucumbers are also harvested for human consumption and are considered a delicacy in certain cultures.