Speiro

Speiro is a genus of marine gastropod mollusks in the family Drilliidae. The genus was first described by the French naturalist Jean-Baptiste Lamarck in 1816. The name "Speiro" is derived from the Greek word "speiros," meaning "seed," reflecting the spiral shape of the shells.

Species within the genus Speiro are characterized by their conical, spirally coiled shells with a smooth surface and a distinct aperture. The shells are typically small to medium-sized, ranging from a few millimeters to about 20 millimeters in height. The color of the shells can vary, often being white, cream, or brown, sometimes with a slight iridescence.

Speiro species are found in various marine environments, including coral reefs and rocky substrates. They are known to feed on small invertebrates and algae, using their radula to scrape food from surfaces. The genus is relatively diverse, with numerous species described worldwide, particularly in tropical and subtropical regions.

The taxonomy of the genus Speiro has undergone revisions over the years, with some species being reclassified or redescribed based on new morphological and genetic studies. Despite these changes, the genus remains an important group within the family Drilliidae, contributing to our understanding of marine biodiversity and evolution.