Balanus Costa 1778

The joints where the plates overlap are shiny.

This is the scutum (left) and tergum (right) from an individual eaten by a seastar. The tergum is beaked, as can be seen at top.

This is the view of the inside of the tergum (left) and scutum (right).

The wall plates are formed of hollow tubes, the openings of which are visible at the bottom of this photo. Longitudinal striations can be seen on the inside of the wall plates, as seen here. The base of the plates is at the bottom.

Balanus rostratus from about 100 m depth, San Juan Channel, WA (Photo by: Dave Cowles, July 2006)

The beaked terga (one of them in this individual is broken) and the orange-yellow orifice in a partly opened animal are visible here.

Here is a photo of an unbroken individual. Since the movable plates are entirely closed the yellow tissue inside cannot be seen.

Balanus nubilus feeding. Underwater photo by Kirt Onthank July 2007. The snail to the left is Calliostoma ligatum.

Balanus nubilus from about 10 m depth near Rosario. Note how several individuals are attached to each other. (Photo by: Dave Cowles, July 2006)

This group is clustered on a cobble at Ala Spit. Photo by Dave Cowles, September 2005

When individuals become too crowded, as on this rock, they grow in a tall, thin columnar formation. Photo by Dave Cowles, September 2005

When individuals are dislodged from the rock they leave a calcified scar behind. Photo by Dave Cowles, September 2005

Unlike Chthamalus dalli, Balanus glandula frequently grow on other substrates such as the wood of this stump. Photo by Dave Cowles, September 2005.

Balanus glandula is usually white or gray-white, but these individuals growing on a stump are mostly brownish, probably due to overgrowth by diatoms or other algae.

These crowded individuals on an intertidal rock at Seal Beach, Oregon, have grown up to 10 cm tall. Photo by Dave Cowles, September 2010

This large individual (2.5 to 3 cm long) is unusual in several ways. Most barnacles are roughly as long as wide but this individual is nearly twice as long as wide. Also, there are several young barnacles which have settled on the inside surface of the plates, although the original barnacle is still alive.Photo taken by Dave Cowles, June 2011 in the upper midlittoral at Swirl Rocks between two rock walls.

Balanus glandula attached to a cobble at Ala Spit, Whidbey Island. Diameter approximately 1.5-2 cm (Photo by: Dave Cowles, September 2005)

This 1 cm individual is living on the carapace of Cancer magister.

Balanus crenatus living on a bottle collected at 18 m depth, Whidbey Island, WA. About 1/2 cm in diameter. (Photo by: Dave Cowles July 2006)