Strongylocentrotus droebachiensis

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Strongylocentrotus droebachiensis is a species of sea urchin belonging to the family Strongylocentrotidae. Commonly known as the green sea urchin, it is found in the North Atlantic Ocean and the Arctic Ocean. This species is notable for its ecological role in marine environments and its economic importance in the seafood industry.

Description

Strongylocentrotus droebachiensis has a spherical body covered with long, sharp spines that can vary in color from green to purple. The test, or shell, is composed of fused plates of calcium carbonate. The mouth, located on the underside, contains a specialized feeding structure known as Aristotle's lantern, which is used to graze on algae and other food sources.

Habitat and Distribution

This species is typically found in cold, temperate waters. It inhabits rocky substrates, kelp forests, and seagrass beds from the intertidal zone to depths of around 1,200 meters. The green sea urchin is distributed along the coasts of the North Atlantic, including the eastern coast of North America, the western coast of Europe, and the Arctic regions.

Ecology

Strongylocentrotus droebachiensis plays a crucial role in its ecosystem. It is a primary grazer of kelp and other macroalgae, which can influence the structure and composition of marine habitats. In areas where sea urchin populations are high, they can create "urchin barrens," where the overgrazing of kelp leads to a significant reduction in kelp forest density.

Reproduction

The green sea urchin has a complex reproductive cycle that includes external fertilization. Spawning typically occurs in the spring and summer months. The larvae are planktonic and undergo several developmental stages before settling to the ocean floor and metamorphosing into juvenile urchins.

Economic Importance

Strongylocentrotus droebachiensis is harvested for its roe, which is considered a delicacy in many cultures, particularly in Japan, where it is known as uni. The fishery for green sea urchins is economically significant in regions such as Maine and Nova Scotia.

Conservation

Overfishing and habitat destruction pose threats to Strongylocentrotus droebachiensis populations. Conservation efforts include the establishment of marine protected areas and the implementation of sustainable harvesting practices to ensure the long-term viability of this species.

See Also

• Sea urchin
• Kelp forest
• Aristotle's lantern
• Marine protected area