Toxopneustidae
Toxopneustidae is a family of sea urchins in the order Temnopleuroida. The family includes the commercially important edible sea urchin, Strongylocentrotus droebachiensis, commonly known as the green sea urchin. They are found in a wide range of marine environments, from shallow rocky shores to deeper waters, and are primarily herbivores, grazing on algae and detritus. The family is characterized by a number of distinguishing features, including a globular test, a peristome (mouth) located centrally on the oral surface, and a periproct (anus) located on the aboral surface. The test is typically covered in spines, which can vary in size and shape depending on the species. Toxopneustidae are important members of marine ecosystems and play a role in nutrient cycling and the maintenance of marine biodiversity.
Common Names
The common names for members of the family Toxopneustidae vary depending on the species and region. Some of the most common names include:
- Green sea urchin (Strongylocentrotus droebachiensis)
- Purple sea urchin (Strongylocentrotus purpuratus)
- Red sea urchin (Strongylocentrotus franciscanus)
- Sea egg (various species)
Characteristics
Toxopneustidae sea urchins are characterized by several distinct features, including:
- Globose test: The test is the hard, calcareous shell that encloses the sea urchin's body. It is typically globular in shape, meaning it is round and somewhat inflated.
- Peristome: The mouth, or peristome, is located centrally on the oral surface (bottom) of the test. It is surrounded by five teeth, which are used for grazing on algae and other food sources.
- Periproct: The anus, or periproct, is located centrally on the aboral surface (top) of the test. It is surrounded by a ring of plates and is typically covered in spines.
- Spines: The spines are sharp, pointed projections that cover the test and provide protection and locomotion. The spines can vary in size and shape depending on the species.
- Pedicellariae: These are small, pincer-like appendages that are located among the spines. They help to defend the sea urchin against predators and keep the surface of the test clean.
Environments
Toxopneustidae sea urchins are found in a wide range of marine environments, including:
- Intertidal zones: Some species of Toxopneustidae sea urchins can be found in the intertidal zone, which is the area between high and low tide marks.
- Subtidal zones: The majority of Toxopneustidae sea urchins are found in the subtidal zone, which is the area below the low tide mark.
- Rocky reefs: Many species of Toxopneustidae sea urchins prefer to live on rocky reefs, where they can find a variety of food sources.
- Kelp forests: Some species of Toxopneustidae sea urchins are found in kelp forests, where they graze on the algae that grow on the kelp.
- Sandy bottoms: A few species of Toxopneustidae sea urchins are found on sandy bottoms, where they feed on detritus and other organic matter.
References
For more information on Toxopneustidae sea urchins, see these reliable references: