Styela clava

Styela clava

Styela clava is a species of ascidian or sea squirt, belonging to the family Styelidae. It is commonly known as the clubbed tunicate due to its distinctive club-like shape. This marine invertebrate is native to the Northwest Pacific Ocean, particularly around the coasts of Japan, Korea, and China. However, it has become an invasive species in various parts of the world, including the North Atlantic Ocean and the Mediterranean Sea.

Description

Styela clava has a tough, leathery outer covering called a tunic, which is often encrusted with various marine organisms such as barnacles, algae, and bryozoans. The body is cylindrical and can grow up to 20 cm in length. The tunic is typically brownish in color and has a rough texture. The species is characterized by its two siphons: the oral siphon at the top, through which water is drawn in, and the atrial siphon on the side, through which water is expelled.

Habitat

Styela clava is commonly found in shallow coastal waters, often attached to hard substrates such as rocks, shells, and man-made structures like piers and boat hulls. It can tolerate a wide range of salinities and temperatures, which contributes to its success as an invasive species.

Life Cycle

The life cycle of Styela clava includes both sexual and asexual reproduction. The species is hermaphroditic, possessing both male and female reproductive organs. Fertilization occurs internally, and the larvae are released into the water column. The free-swimming larvae eventually settle onto a suitable substrate and metamorphose into the adult form.

Impact as an Invasive Species

Styela clava is considered a significant invasive species in many parts of the world. Its presence can disrupt local ecosystems by outcompeting native species for space and resources. It can also cause economic damage by fouling aquaculture equipment, boat hulls, and other marine infrastructure.

Control Measures

Various methods have been employed to control the spread of Styela clava, including mechanical removal, chemical treatments, and the use of biological control agents. However, these methods have had varying degrees of success, and the species continues to pose a challenge to marine management efforts.

Related Pages

• Ascidiacea
• Invasive species
• Marine biology
• Aquaculture
• Ecosystem