Brissus
Brissus is a genus of heart urchins, echinoids belonging to the family Brissidae. Heart urchins are characterized by their heart-shaped bodies, and Brissus species are particularly distinguished by their flattened, oval test (shell). They are found in various marine environments worldwide, predominantly in warm, tropical and subtropical waters.
Common Names
Members of the Brissus genus are commonly known as "heart urchins," reflecting their heart-shaped bodies. Specific species may have additional regional names, such as the "common heart urchin" for Brissus unicolor.
Characteristics
Brissus species share several key characteristics:
- Heart-shaped test: The test is flattened, oval, and somewhat heart-shaped.
- Ambulacral grooves: The test exhibits distinct ambulacral grooves, running along the oral (bottom) surface.
- Tubercles: The test is covered in numerous tubercles, which are small, rounded projections.
- Spines: The spines are short and relatively uniform in size.
- Mouth and anus: The mouth is located on the oral surface, while the anus is positioned on the aboral (top) surface.
Environments
Brissus species are typically found in sandy or muddy bottoms in coastal areas. They are often found in shallow waters, although some species can occur at depths of up to 100 meters. These urchins play an important role in their ecosystems, contributing to nutrient cycling and sediment turnover.
References
World Register of Marine Species (WoRMS)
The Echinoid Fauna of the Eastern United States