Nature Field Guide
Pacific White Sea Urchin
- Spanish name
- Erizo blanco del Pacífico
- Scientific name
- Tripneustes depressus
What Do Pico & Tati Think?
Pico notices a rounded shape on the seabed. Tati wants to compare its small details with other urchins.
Species overview
About the Pacific White Sea Urchin
Tripneustes depressus is an eastern Pacific sea urchin also known as the white sea urchin. Short spines give it a different appearance from long-spined species. Record the features visible on the individual you see; lighting and underwater conditions can change how colors appear.
Identification
Key Features of the Pacific White Sea Urchin
A rounded body
Relatively short spines
Confirm the species with a correctly labeled reference image
Habitat & range
Suitable underwater coastal habitat. Use a permitted guided snorkeling or viewing activity appropriate to your family; do not enter the sea just to find this animal.
Local observations
Documented in Guanacaste. Also recorded at Isla del Coco (Oceanic Pacific); the museum checklist uses Ophiocoma alexandri for Ophiocomella alexandri. Region tags represent documented locations, not an exhaustive range or a promise of occurrence at every beach. Additional regional assignments require locality evidence.
When to observe
Visibility depends on the site, conditions and the animal. Ask a local guide about an appropriate visit; no fixed encounter season is promised.
Conservation & care
Watch without touching, lifting, feeding or collecting. Keep fingers and equipment away from spines and other surface structures. Leave the animal submerged and its habitat undisturbed.
Observation activity
Compare photographs of this species and a long-spined urchin. Write one similarity and one difference.