Anthopleura elegantissima/ sola

Haliotis cracherodii

Lottia gigantea

Mytilus californianus

Chthamalus spp./Balanus glandula

Tetraclita rubescens

Pollicipes polymerus

Pisaster ochraceus


Species Home



Tetraclita rubescens Darwin, 1854

(Previously known as T. squamosa rubescens)

Thatched barnacle

General Description (from Morris et al. 1980):

Diameter usually to 30 mm, rarely to 50 mm; wall consisting of only 4 plates; shell of adult reddish, shell of juveniles white

Habitat and Range (from Morris et al. 1980):

Common, middle and low intertidal zones on rocks exposed to strong surf; occasionally subtidal on hard-shelled organisms such as abalones; San Francisco Bay to Cabo San Lucas (Baja California)


Thatched barnacles are usually found growing as solitary individuals rather than aggregated, as are acorn barnacles (Engle and Davis 1996). Thatched barnacles may live as long as 15 years (Hines 1978). They are effective competitors for space and may influence the distribution of mussels and other species (Foster et al. 1988). In the lower intertidal zone, individuals may grow large enough to avoid predation by sea stars and gastropods (Morris et al. 1980). Thatched barnacles might be sensitive to sewage pollution (Littler and Murray 1975) and recovery from disturbance may take more than 2 years (Murray and Littler 1979).

Tetraclita rubescens (left) and Megabalanus californicus (right) (adapted from Morris et al. 1980)

Can be confused with:

Megabalanus californicus, which is pink and has a smoother operculum and smooth area between plates (Kendall et al. 2002)


Engle JM, Davis GE (1996) Ecological condition and public use of the Cabrillo National Monument intertidal zone 1990-1995. Technical report. Cabrillo Historical Assoc, Cabrillo National Monument, Point Loma, CA

Foster MS, DeVogelaere AP, Harrold C, Pearse JS, Thum AB (1988) Causes of spatial and temporal patterns in rocky intertidal communities of Central and Northern California. Memoirs of the California Academy of Sciences Number 9, San Francisco, California

Hines AH (1978) Reproduction in three species of intertidal barnacles from central California. Biol Bull 154:262-281

Kendall A, Kusic K, Maloney E, Williams M (2002) List of species to be discussed at the 2002 MMS Taxonomic Workshop

Littler MM and Murray SN (1975) Impact of sewage on the distribution, abundance, and community structure of rocky intertidal macro-organisms. Mar Biol 30: 277-91

Morris RH, Abbott DL, Haderlie EC (1980). Intertidal invertebrates of California. Stanford University Press, Stanford

Murray SM and Littler MM (1979)