The Fenced Ascidian – Botryllus closionis, also known scientifically as Botryllus closionis, is a colonial tunicate belonging to the class Ascidiacea. These fascinating creatures are commonly found in various marine environments, displaying a unique and intricate structure. Botryllus closionis exhibits a distinct, almost fence-like appearance, hence its common name.
Description & Characteristics
Botryllus closionis colonies are typically found in clusters on solid surfaces, such as rocks, piers, and even boat hulls. Each colony is composed of numerous individual zooids, tiny, filter-feeding organisms, which are connected to one another by a shared tunic, a leathery outer layer that provides structure and protection. The zooids themselves are typically small, with maximum sizes reaching just a few millimeters. These colonies can range in size from a few centimeters to several inches across, depending on their specific environment and conditions.
Habitat and Occurrence
The Fenced Ascidian – Botryllus closionis is a common inhabitant of the intertidal and shallow subtidal zones. These zones are characterized by fluctuating water levels and varying salinity, making Botryllus closionis quite adaptable. They are often found attached to solid substrates in areas that experience moderate wave action, facilitating their filter-feeding activities. The species can be found in a variety of marine habitats, including rocky shores, piers, and even on the hulls of ships. They are particularly common in temperate and tropical waters, thriving in environments with water temperatures ranging from 10°C to 25°C. Due to its adaptable nature, Botryllus closionis is often considered an indicator species, reflecting the overall health and condition of its surrounding ecosystem.
Taxonomy
Botryllus closionis belongs to the class Ascidiacea, a group of marine invertebrates that are commonly known as sea squirts or tunicates. Within this class, Botryllus closionis is classified under the order Stolidobranchia, a diverse group of ascidians that are characterized by their distinctive morphology and feeding mechanisms. The species is further classified within the family Styelidae, a family that includes numerous species of colonial ascidians, many of which exhibit similar colonial growth patterns and feeding strategies.
Feeding
Like most other ascidians, the Fenced Ascidian – Botryllus closionis is a filter feeder. It relies on tiny particles suspended in the water column for nourishment. Each zooid within the colony possesses a siphon through which it draws in water, filtering out food particles such as phytoplankton, bacteria, and organic debris. The filtered water is then expelled through a second siphon. This constant filtration process allows the colony to thrive in nutrient-rich environments, contributing to the overall ecosystem’s health and balance.
Image References