Nature Field Guide
Giant False Limpet
- Spanish name
- Lapa
- Scientific name
- Siphonaria gigas
What Do Pico & Tati Think?
A cap-shaped shell shelters a snail on the rocky shore.
Species overview
About the Giant False Limpet
Although its shell looks like a little cap rather than a spiral, this animal is a gastropod. It grazes algae on rocks. Siphonaria belongs to a different group from keyhole limpets.
Explorer activity: Draw the shell in side view. How does a low cap differ from a tall spiral? Record your observation without lifting the animal.
Your discovery notes: Record the date, place and habitat, then add a sketch or photograph. If you cannot confirm the species, label it “unidentified shell” and keep your observations.
Identification
Key Features of the Giant False Limpet
Single cap-shaped shell rather than two hinged halves.
Look at the shell outline and raised top.
Compare with a keyhole limpet; a top opening is an important difference.
Habitat & range
Rocky intertidal habitat.
Local observations
Pacific Costa Rica: Punta Mala field-study record. This supports regional inclusion, not a confirmed Tamarindo Beach sighting.
When to observe
Tides and conditions affect visibility. Let an adult or local guide choose a safe observation time; this card does not promise a seasonal sighting.
Conservation & care
Observe and photograph shells where they are. Leave living animals, occupied shells and empty shells in place. Do not pry animals from rocks, dig in mangroves or put fingers into shell openings. Explore with an adult or guide, follow site rules and stay clear of surf and slippery rocks.
Observation activity
Draw the shell in side view. How does a low cap differ from a tall spiral? Record your observation without lifting the animal.