Pronunciation: [ˈɛt͡ʃɪnˌə͡ʊdəm] (IPA) 
"Echinoderm" is a term used to describe a phylum of marine animals, such as starfish and sea urchins. The spelling of this word can be broken down using IPA phonetic transcription as "ɛˈkɪnədɜːm". The "echino" part of the word comes from the Greek word "echinos" meaning "hedgehog" and the "derm" means "skin". The correct spelling of this word is important when discussing these animals in a scientific context.
An echinoderm is a marine invertebrate belonging to the phylum Echinodermata, characterized by a distinct spiny or calcareous exoskeleton. Derived from the Greek words "echinos" meaning "hedgehog" and "derma" meaning "skin," the name perfectly encapsulates their spiky appearance. Echinoderms include various familiar organisms such as sea stars, sea urchins, sea cucumbers, and sea lilies.
These animals typically possess a radial symmetry, meaning they can be divided into equal halves through multiple planes passing through a central axis. They have a water vascular system, a unique feature that allows them to move and feed. This system consists of a network of water-filled canals that function in locomotion, suction feeding, gas exchange, and excretion.
The exoskeleton, often called a test or shell, provides protection and support to the echinoderm's body. It is composed of calcareous plates or spines, which vary in size, shape, and arrangement depending on the specific species. Some species have the ability to regenerate lost body parts, such as arms or spines.
Echinoderms exhibit various feeding strategies, depending on their specific morphology. While sea stars and sea cucumbers are generally scavengers or filter feeders, sea urchins are mainly herbivorous, using specialized jaws called Aristotle's lantern to scrape algae from rocks.
Echinoderms are found in oceans across the globe, from shallow coastal waters to the deep sea. They play crucial roles in marine ecosystems, acting as both predators and prey, and contributing to nutrient recycling and overall community structure. Additionally, echinoderms have significant economic importance, as they are exploited for food, pharmaceuticals
The word "echinoderm" is derived from the Greek words "echinos" meaning "hedgehog" and "derma" meaning "skin". It refers to a phylum of marine animals characterized by their spiny skin, resembling the spines of a hedgehog. Echinoderms include starfish, sea urchins, sand dollars, and sea cucumbers.
