Little Brown Barnacle

Chthamalus dalli

Order: 

Thoracica

Family: 

Chthamalus

The Chthamalus dalli is a small barnacle that can grow up to 8mm within diameter.  The shell has a smooth surface that is a brown-grey color. While the general habitat remains the upper and middle rocky intertidal zone, the geographic distribution ranges from San Francisco, CA to Baja California (1).  Food sources include microplankton since the small brown barnacle is classified as a filter feeder.  In respect to predators, snails and sea stars are regarded as a danger to the little brown barnacle.  To counteract, the Chthamalus dalli will occasionally grow a slight curve on its shell as a defense mechanism.  For reproduction, the barnacle produce both sperm and egg simultaneously and do not self-fertilize.  Rather than self-fertilizing, the barnacles utilize self-fertilization (2).

 

(1) "Chthamalus/ Balanus | MARINe.” UC Santa Barbara Ecology and Evolutionary Biology, Reagents of the University of California, https://www.eeb.ucsc.edu/pacificrockyintertidal/target/target-species-chthamalus-balanus.html

(2) “Chthamalus dalli.” Race Rocks Taxonomy, http://racerocks.ca/racerock/taxalab2/2011/chthamalusd/chthamalusd.htm

Habitat:

  • ​​​​​​​Rocky Intertidal Zone