On 04/26/2010 I started a culture of a marine snail species, Calliostoma ligatum. After observing the early cleavage stages in the first ten hours after fertilization, I didn’t look at the culture for a week. By then, the embryos had turned into veliger larvae. Through the dissecting microscope, the veliger’s velum looked irridescent. The effect was generated by the rapid beating of the long cilia along the rim of the velum. I put a veliger under the compound microscope and found that I could not see the rainbow effect under transmitted light.
However, it was really cool to watch the larva retracting its foot and velum and closing its operculum (trap door) to seal itself into its shell. Then after several seconds, it would use its foot to push its operculum open, and evert its foot and velum. I took a series of pictures showing the veliger slowly evert its foot and part of its velum from the shell. Each picture also shows the hexagonal honeycomb-like texture of the shell, which I think looks cool. These larvae are fun to watch and I look forward to observing the continued development of my Calliostoma culture. See more pictures of Calliostoma veligers.