Pelagic Barnacles, Goose Barnacles – Alepas pacifica

The Pelagic Barnacles, Goose Barnacles, scientifically known as Alepas pacifica, are a fascinating species of barnacle with a unique lifestyle. These creatures are filter feeders that inhabit the open ocean, a characteristic that sets them apart from their more sedentary relatives. Their distribution across the globe is extensive, making them a common sight in various marine ecosystems.

Description & Characteristics

Alepas pacifica is a type of barnacle that exhibits a distinct morphology. They are characterized by their elongated, stalked bodies, which can reach a maximum size of approximately 20 centimeters in length. The stalk, or peduncle, is flexible and serves as an anchor, allowing the barnacle to attach itself to various substrates, including marine organisms like whales, sea turtles, and even floating debris. The upper portion of the barnacle, known as the capitulum, houses the feeding apparatus and reproductive organs.

Habitat and Occurrence

Alepas pacifica is a pelagic barnacle, meaning it inhabits the open ocean, specifically the epipelagic and mesopelagic zones. These zones are characterized by varying depths, extending from the surface to approximately 200 meters. Alepas pacifica thrives in these regions, where they readily attach themselves to a variety of hosts, including marine mammals, sea turtles, and even floating debris.

Taxonomy

Alepas pacifica belongs to a distinct group within the crustacean family. It is classified under the class Thecostraca, an order known as Scalpellomorpha, and specifically within the family Heteralepadidae. This family encompasses a range of barnacle species, each with its own unique adaptations and ecological role.

Feeding

Alepas pacifica are filter feeders, a feeding strategy that relies on capturing tiny organisms suspended in the water column. Their feeding apparatus, located within the capitulum, is equipped with specialized appendages known as cirri. These cirri are feathery and constantly move, creating a current that draws in plankton, the primary food source for these barnacles.