Bay Barnacle- Balanus sp.
Habitat- Marine water areas, attached to rocks, shell, boats, and any other solid object that they can cement to. Some can even live on other organisms such as mollusks and whales.
Range- Atlantic and Pacific shorelines
Description- Can be small but can range up to 25mm in diameter. Sessel, use calcareous shell to cement to hard substrates near water level. Have 6 white-gray plates on the outter shell, opening to organism is tear drop shapped. Just as other barnacles it used sexual reproduction and has an extremely long penis in order to reach neighboring barnacles. Balanus are commonly used as a classic example for competition with Chthalamus as in the article below. A majority of the research done on these organisms was during the 50's-70's and not very much further research has been done.
Ecological Notes- Seen in Manteo sound during kayaking on mussel shells as well as on pier slightly above and below water level. Also seen encrusting on spartina stalks in the salt marsh
Journal Articles To learn about Balanus sp., please see:
Wethey, D.S. (1983). GEOGRAPHIC LIMITS AND LOCAL ZONATION: THE BARNACLES SEMIBALANUS (BALANUS) AND CHTHAMALUS IN NEW ENGLAND. Biol. Bull. 165: 330-341.
Discusses competition and zonation in intertidal zone. 
Connell, J. H. (1961). Effects of Competition, Predation by Thais lapillus, and Other Factors on Natural Populations of the Barnacle Balanus balanoides. Ecological Monographs 31:61–104. 
Discusses balanus predators and environmental controls on balanus populations.
References- Fish, J.D., Fish, S. A Student's Guide to the Seashore. Barnacles pg. 309
Contributed by Amanda Kriner- 2012