Nature Field Guide
Giant Ark Clam
- Spanish name
- Chucheca
- Scientific name
- Larkinia grandis
What Do Pico & Tati Think?
A large ark shell has deep spaces between its strong ribs.
Species overview
About the Giant Ark Clam
Chucheca is an ark clam with broad, strongly inflated valves and prominent ribs. Costa Rican sources may label it Grandiarca grandis or Anadara grandis; current references use Larkinia grandis.
Explorer activity: Draw a rib and the groove beside it from a reference photograph. Compare the whole outline with the two smaller piangua species.
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 Ark Clam
Broad, nearly square outline.
Strong ribs separated by deep grooves.
Prominent raised area near the hinge.
Habitat & range
Pacific estuarine and mangrove-associated coastal habitat.
Local observations
Guanacaste records list this species under current and older names. 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 a rib and the groove beside it from a reference photograph. Compare the whole outline with the two smaller piangua species.