The collection contains images of temporary whole-mount preparations of sea urchin larvae. The images were taken by confocal laser scanning microscopy. The preparations were created using immunohistochemical staining of nervous elements (serotonin) and ciliary elements (alpha-tubulin). The collection contains images of neurons in the apical organ and neurons located along the locomotory ciliary bands, at different stages of larval development: from prism to late pluteus. The species included in the collection are Paracentrotus lividus, Mesocentrotus (Strongilocentrotus) nudus, Echinocardium chordatum, and Scaphechinus mirabilis. The collection is constantly being expanded by new preparations showing new stages of larval development and the architecture of nervous elements. This collection is intended for those who want to learn more about the developmental dynamics of nervous elements containing serotonin and dopamine, and the locomotory structures present in larvae of sea urchins (individual cilia and ciliary bands). The collection was created at the Institute of Developmental Biology RAS. The images are available from the authors.