How is the development of sea stars?

Sea Star Embryology. Use these images as you study preserved material (slides) of Sea Star development. Find similar stages on your slide. Then record your observations including sketches of each of the stages. Sketches should be included with your laboratory report. read more

This change includes the formation of a digestive system with two openings (mouth (17) and anus (16)). The larva grows as it feeds on algae and diatoms. After several months the larva undergoes a process called metamorphosis that transforms it into a tiny sea star. read more

During development, the maturing ova are arrested during meiosis I (frequently at diplotene of prophase). Upon contacting sea water, the primary oocytes resume meiosis, the nucleus (germinal vesicle) is degraded, and the first and second polar bodies are formed by 1.5 and 2 hours, respectively. read more

A characteristic feature of the development of Astropecten, i.e., the lack of a brachiolaria stage, is stressed. The term "nonbrachiolarian type" is tentatively proposed to distinguish the development of Astropecten and Luidia, which do not pass through a brachiolaria stage, from the usual indirect type of development. read more