Halloween Crab
Hartnollius quadratus
Spanish: Cangrejo de tierra de patas rojas

Halloween Crab (Hartnollius quadratus) is a species recorded near La Saladita, Guerrero, Mexico, with 30 research-grade iNaturalist observations within about 50 km of La Saladita (the survey box also takes in Zihuatanejo, Ixtapa and Troncones).
- 2026-05-20 — observation by daniel_brito
- 2026-05-15 — observation by jepg
- 2026-05-15 — observation by naturazihua-24
- 2026-02-01 — observation by viridelao
- 2025-12-16 — observation by ecologorey
- 2025-12-08 — observation by hallet
Interactive card with more photos, sounds and similar species Shore life guide iNaturalist
Cite as: “Halloween Crab (Hartnollius quadratus) at La Saladita”, La Saladita Field Guide, lasaladita.com/species/hartnollius-quadratus/, updated 2026-09-26. Observation counts and months come from iNaturalist research-grade records within about 50 km of 17.8375°N, 101.7606°W (the survey box also takes in Zihuatanejo, Ixtapa and Troncones); summary text from Wikipedia where present.