Sea Cucumber
Main Characteristics of Echinoderms
- There are 6,300 species of echinoderms.
- Echinoderms include starfish, brittle stars, feather stars, sea lilies, sea urchins, and sea cucumbers.
- Echinoderms can only be found in the ocean. Most of them inhabit shallow waters on the sea floor.
- Echinoderm originates from Ancient Greek. The term "ekhînos" means "hedgehog" (which is a spiny animal) and "dérma" translates to "skin". In fact, there are spines or thorns on their body.
- In sea urchins, the spines can be quite long. The spines of the black sea urchin can even reach lengths of up to 12 inches (30 cm).
- In contrast, starfish and sea cucumbers usually have very short spines.
- Most starfish have five arms. However, there are also species with 40 arms.
- Echinoderms lack the traditional brain structure. Instead, they possess a sophisticated nervous system that enables them to make decisions and control their movements.
- Echinoderms can be either herbivores or carnivores. Sea urchins are mostly herbivores, feeding on algae. Starfish are often carnivores, consuming clams and other marine creatures.
- The largest sea urchin is the red urchin. It can reach a diameter of 7 inches (18 cm).
- Sea urchins can live for a very long time. The red urchin can even reach over 100 years of age, and some say it can live up to 200 years.
- The flower urchin is the most dangerous type of sea urchin. A touch can lead to not just intense pain, but also breathing difficulties, muscle paralysis, numbness, and confusion. This can result in drowning for divers and snorkelers. This creature inhabits the Indo-Pacific region.
- The heaviest starfish is Thromidia gigas, which can weigh up to 13 pounds (5.9 kg). The largest starfish is Midgarida xandaros, with a diameter of up to 4.5 feet (1.38 meters).
- The crown-of-thorns starfish reproduces rapidly and can cause significant damage by eating corals, which leads to the destruction of reefs. It is also dangerous to humans due to its venomous spines.
- The largest sea cucumber is the snake sea cucumber. It can grow to be 6.5-9.8 feet (2-3 meters) long.
