Balanus rostratus, the rostrate barnacle, is a species of acorn barnacle found primarily in the North Pacific.
Classification.
"Balanus rostratus" was first scientifically described under its present name by in 1883, in the eighth volume of the "Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873–76". The species' type locality is in Japanese waters near Kobe; the species was discovered in 1875, taken attached to a rock along with specimens of "Balanus trigonus" and "Balanus amaryllis". Hoek thought the new species related to "Balanus glandula" and "Balanus crenatus." The type specimens were relatively small. In English, "B. rostratus" is commonly called the "rostrate barnacle", while in Russian it is called "Клювоносный морской жёлудь" ().
Besides the implicit nominotypical subspecies, "Balanus rostratus rostratus", four subspecies, "B. r. alaskensis", "B. r. apertus, B. r dalli", and "B. r. heteropus" were described by Henry Augustus Pilsbry; first "apertus" in 1911 and then the remaining three all at the same time in 1916.
Fossil record.
Fossils of "Balanus rostratus" have been recorded from several Pliocene deposits near Nome, Alaska.
Interactions with humans.
As food.
"Balanus rostratus" is fished for and eaten in Japan. In some markets, a kilogram of rostrate barnacles can fetch , and there is some domestic trade for them. Aquaculture specifically for rostrate barnacles is done only by small-scale farms.