Ladd's Cerith, Small Horn Shell
Phylum: Mollusca, Class: Gastropoda, Order: Caenogastropoda, Family: Cerithiidae, Genus: Cerithium, Species: C. ladda · Cerithiidae (Cerith or Horn Shell family) · Gastropod (univalve); whole specimens; turreted/spiral shape
Species
Cerithium ladda (Identification confidence: 85%)
Shell Type
Gastropod (univalve); whole specimens; turreted/spiral shape
Family
Cerithiidae (Cerith or Horn Shell family)
Size
4-7mm in length. These are very small (microshells) compared to larger Cerithium species which can reach 50mm+.
Color & Pattern
Creamy white to light beige base; dark purple or brown protoconch (tips) and apical whorls. The color appears natural but slightly matte due to beach wear.
Rarity
Common (locally abundant in shell grit), but overlooked due to their tiny size.
Habitat
Shallow tropical marine waters, typically found in sandy patches near coral reefs or seagrass beds. Intertidal to shallow subtidal.
Geographic Range
Indo-Pacific region, frequently found in beach drift in areas like Hawaii, Fiji, and the Philippines.
Description
Small, robust, turreted shells with distinctive stepped whorls. The spire is tall and conical, ending in a darkened tip. The body whorls often feature subtle spiral ribbing or granules, though these specimens show some beach smoothing.
Key Features
Contrasting dark purple/brown apex; heavy, stepped sutures; small size (micromollusk); thickened outer lip area on the body whorl.
Collector Value
Minimal monetary value ($1-2 for a set). They are primarily of interest to 'microshell' specialists or those who create shell art and jewelry.
Condition Notes
Good to Fine. The shells are intact with no major breaks, though the surface shows light erosion (beach-worn) and have lost some luster. No periostracum remains.
Interesting Facts
Cerith shells are often the first homes for very tiny juvenile hermit crabs. The dark tip is actually the 'protoconch,' which is the embryonic shell the animal was born with.
Ecological Role
Dethritivores; they crawl along the substrate feeding on algae and organic debris, helping to clean the reef environment. They are prey for larger carnivorous snails and crabs.
Similar Species
Cerithium interstriatum (lacks the same stepped whorls) and various Rissoidae species (which usually have different aperture structures).
Beach Finding Tips
Look in 'shell hash' or high-tide drift lines. Use a magnifying glass or a fine-mesh sieve on sandy beaches near coral reefs during low tide.