Taxonomy
- Kingdom: Animalia
- Phylum: Mollusca
- Class: Gastropoda
- Subclass: Vetigastropoda
- Order: Lepetellida
- Family: Fissurellidae (keyhole limpets)
- Genus: Fissurella
- Species: Fissurella maxima
- Authority: G. B. Sowerby I, 1834
Common name: Giant keyhole limpet
Description
Fissurella maxima is a marine gastropod mollusk characterized by a conical shell with a distinctive apical opening (“keyhole”). Adult shell size ranges from approximately 50 mm to over 65 mm, with the largest recorded specimens reaching about 138 mm. No size‑based sexual dimorphism has been documented.
Distribution and habitat
The species occurs in the Pacific Ocean along the western coast of South America, from Ecuador to Tierra del Fuego. It is most frequently recorded in waters where sea‑surface temperatures are between 10 °C and 15 °C (50 °F–59 °F). F. maxima inhabits the intertidal zone, typically found on algae or the undersides of flat rocks.
Biology and reproduction
F. maxima is dioecious, possessing separate male and female individuals. Primary spawning takes place in late November to December (late spring–early summer in the Southern Hemisphere), with a secondary reproductive peak occurring in July and August (winter).
References
- World Register of Marine Species (WoRMS). Fissurella maxima G. B. Sowerby I, 1834. Retrieved 21 April 2011.
- Bretos, M.; Tesorieri, I.; Alvarez, L. (December 1983). “The Biology of Fissurella maxima Sowerby (Mollusca: Archaeogastropoda) in Northern Chile. 2. Notes on its Reproduction”. The Biological Bulletin 165 (3): 559–568. doi:10.2307/1541465.
- Ocean Biodiversity Information System (OBIS). Fissurella maxima. Retrieved 31 December 2025.
Note: This entry is based on information available from peer‑reviewed literature and reputable marine species databases.