Scientific Name: Cyerce nigra
Common Name: Black-spotted Cyerce

Adult Size: 15 mm
Depth Range: 2 – 20 m; often found in shallow lagoons, seagrass meadows, and coral rubble areas
Biotope / Habitat: Prefers areas with abundant green algae (Caulerpa spp.), on which it feeds and hides among the fronds for protection
Diet: Herbivorous sacoglossan that feeds on Caulerpa algae, extracting and storing chloroplasts (kleptoplasty) within its cerata, allowing it to use sunlight as an additional energy source
Reproduction: Simultaneous hermaphrodite; mates flank-to-flank and lays gelatinous, coiled egg ribbons on algae. The eggs hatch into free-swimming veliger larvae that drift before settling on suitable algae
Fun Fact: Cyerce nigra is famous for its beautiful body and leaf-like cerata edged with iridescent hues. When disturbed, it can shed its cerata in a process called autotomy—a clever escape strategy against predators!

Graceful and mesmerizing, Cyerce nigra is one of the most photogenic sacoglossans. Its shimmering cerata and unique movement make it a favourite subject for underwater macro photographers—and an unforgettable find for any diver lucky enough to spot it.