Phlebobranchia

Phlebobranchia is an order of sea squirts, also known as tunicates, in the class Ascidiacea. They are filter-feeding marine invertebrates that are typically found attached to rocks, seaweed, and other solid surfaces. Phlebobranchs have a unique body structure and feeding mechanism, which sets them apart from other ascidians.

Common Names

Phlebobranchs are often referred to as "sea squirts" due to their ability to forcefully expel water from their bodies when disturbed. They are also known as "tunicates" because their bodies are covered in a tough, leathery tunic made of cellulose. Other common names for Phlebobranchia include "sea grapes" and "sea peaches," which refer to their shape and texture.

Characteristics

Phlebobranchs are characterized by their sac-like body structure and two siphons: an incurrent siphon and an excurrent siphon. The incurrent siphon draws in water containing food particles, while the excurrent siphon expels filtered water. They have a simple circulatory system with a heart that pumps blood through a single, closed loop.

Phlebobranchs possess a unique feeding mechanism. They use a pharynx lined with cilia to filter food particles from the water. The cilia create a current that draws water into the incurrent siphon. The food particles are trapped in a mucus net on the pharynx and then transported to the digestive tract.

Environments

Phlebobranchs are found in a variety of marine environments, from shallow intertidal zones to deep ocean trenches. They are typically attached to rocks, seaweed, and other solid surfaces. Some species are solitary, while others form colonies of individuals that are connected to each other.

References

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