Hexactine

A hexactine is a type of spicule found in certain marine sponges. Spicules are microscopic structural elements that form the skeleton of many sponges. Hexactines are characterized by having six principal rays, each of which lies along one of the three axes of a Cartesian coordinate system. These rays are mutually perpendicular and extend from a central point. Each ray is typically divided into two equal parts, creating twelve points in total, although some definitions consider the six rays themselves as the defining feature. The overall shape can be described as a star-like structure. Hexactines are primarily found in the class Hexactinellida, commonly known as glass sponges, which are a group of deep-sea sponges. These sponges often have skeletons composed entirely of silica, and the hexactine spicules contribute significantly to the intricate and often beautiful lattice-like structures that characterize their bodies. The arrangement and complexity of hexactines can vary, leading to diverse forms within the Hexactinellida class. They play a crucial role in providing support and rigidity to the sponge's body.