Zeeegels

Zeeegels, or sea urchins, are marine invertebrates belonging to the class Echinoidea within the phylum Echinodermata. They are characterized by their globular shape and a hard, calcareous shell called a test, which is covered with movable spines. These spines serve multiple purposes, including protection from predators and aiding in locomotion. Sea urchins are primarily herbivores, feeding on algae by using specialized structures called pedicellariae and teeth (called Aristotle's lantern) to scrape algae from rocks. They are found in a variety of marine habitats, from shallow coastal waters to deep-sea environments. The reproductive biology of sea urchins is notable; they are gonochoric, meaning individuals are either male or female, and they release gametes into the water column for external fertilization. Some species are commercially harvested for their roe, which is considered a delicacy in many cultures. Sea urchins play an important ecological role as grazers, helping to control algal growth and maintain the balance of marine ecosystems.