Starfish reproduce both sexually and asexually. Sexual reproduction occurs mainly by spawning, where millions of eggs and sperm are released into the water from the starfish's gonads located in each arm. Fertilization is generally external. During spawning, starfish gather in groups called spawning aggregations to increase the chances of fertilization. This process happens mostly during warmer seasons and high tides. Some species form pairs and engage in pseudocopulation by intertwining arms and synchronously releasing gametes, but fertilization still occurs externally without penetration.
Asexual reproduction happens through two main methods: fissiparity and autotomy (self-amputation). In fissiparity, the starfish splits into two parts including the central disk, each part regenerating the missing parts. In autotomy, a starfish can sacrifice a limb that can regenerate into a new individual if it includes part of the central disk. The offspring from asexual reproduction are genetic clones of the parent.
Thus, starfish have versatile reproductive strategies involving both production of genetically diverse offspring sexually and cloning genetically identical offspring asexually.
