Cernina fluctuata, common name the wavy moon snail, is a species of marine gastropod mollusc in the family Ampullinidae.

[2] This species resembles the moon snails of the family Naticidae, though it is not related.

One way to differentiate this shell from that of true moon snails is by its lack of an umbilical callus.

The color pattern is one of wavy or zigzag stipes crossing the width of the shell.

[1] This is in contrast to true moon snails, which are predators.