Red Abalone (also known as Giant Abalone)
Phylum: Mollusca, Class: Gastropoda, Order: Vetigastropoda, Family: Haliotidae, Genus: Haliotis, Species: H. rufescens · Haliotidae (Abalone family) · Gastropod (univalve), whole shell, ear-shaped (auriform) or oval spiral shape
Species
Haliotis rufescens
Shell Type
Gastropod (univalve), whole shell, ear-shaped (auriform) or oval spiral shape
Family
Haliotidae (Abalone family)
Size
Estimated length of approximately 6 to 7 inches, which is large and typical for a mature specimen of this species. Adults commonly range from 5 to 10 inches, with some reaching up to 12 inches.
Color & Pattern
The exterior exhibits a heavily weathered and encrusted appearance with dull brick-red, brownish, and tan tones. Where the outer layer is worn or exposed, hints of a pearlescent mother-of-pearl lustre show through, particularly near the margins. The surface is heavily speckled with tiny white calcareous tubes and encrustations.
Rarity
Common within its natural range, but heavily regulated and restricted due to conservation laws and overfishing; finding unpolished, natural specimens with encrustations in good condition requires dedicated searching or diving.
Habitat
Found in shallow marine waters from the intertidal zone down to depths of about 60 feet (though sometimes deeper). They inhabit rocky coastal areas, kelp forests, and rocky reefs where they can cling tightly to boulders and feed on drift algae, particularly giant kelp.
Geographic Range
Northeastern Pacific Ocean, ranging from the coast of Oregon down through California to Baja California, Mexico.
Description
This is a magnificent, weathered specimen of a large marine abalone. The shell is broad, oval, and ear-shaped, featuring a flattened dorsal profile with a prominent, slightly elevated spire near the posterior margin. The exterior is heavily textured with rough growth lines, deep corrugations, and natural marine encrustations including numerous tiny spirorbid worm tubes. The outer margin shows a scalloped edge conforming to the respiratory pores typical of the Haliotis genus.
Key Features
Distinguished by its large, ear-shaped (auriform) morphology, rapid expansion of the final body whorl, a flattened spire offset to one side, and a series of open respiratory holes (though obscured or worn down in this heavily encrusted wild specimen).
Collector Value
Moderate collector value. While highly prized for their size and beautiful internal nacre, raw specimens heavily encrusted with marine growth are often valued more for natural display or by craft artisans who polish them to reveal the iridescent nacre underneath. Polished museum-grade specimens command higher prices.
Condition Notes
Fair to Good collector condition for a natural, uncleaned beach- or dive-collected specimen. The shell is structurally intact with no major fractures, but it exhibits heavy natural bio-encrustation (calcareous tube worms), weathering, and loss of the pristine exterior layer, which is very common for wild-taken or cast-up abalones.
Interesting Facts
Abalones are famous for their interior nacre, commonly known as mother-of-pearl, which displays brilliant iridescent blues, greens, and pinks. Their muscular foot is considered a high-end culinary delicacy, and their shells have historically been used by Indigenous peoples for jewelry, fishhooks, and ceremonial items.
Ecological Role
Abalones are important herbivorous grazers in kelp forest ecosystems, helping to control algae growth and maintain balance in rocky reef habitats. They are prey for sea otters, octopuses, large fish, and crabs. Due to historical overharvesting and disease, many abalone populations are strictly protected or monitored by conservation authorities.
Similar Species
Pink Abalone (Haliotis corrugata) which has more strongly corrugated margins and a distinct deep furrow near the holes, and Green Abalone (Haliotis fulgens) which features a smoother shell with striking dark green and brown flames.
Beach Finding Tips
Finding a whole abalone shell while beachcombing is quite rare because they generally inhabit deeper rocky subtidal zones rather than sandy shores. They are more commonly found by scuba divers, freedivers, or occasionally washed ashore intact following severe winter storms along rocky California or Pacific Northwest coastlines.