Callinectes

Callinectes is a genus of swimming crabs in the family Portunidae, commonly known as blue crabs. The genus is widely distributed along the Atlantic coast of North America, the Gulf of Mexico, and the Caribbean Sea. Callinectes species are economically important as a food source and for recreational fishing. They are also important predators in their ecosystems, playing a role in regulating populations of other invertebrates and fish.

Callinectes exasperatus

Common Names

The most common name for members of the genus Callinectes is "blue crab." This name is derived from the bluish color of the carapace, particularly in mature males. Other common names include "Atlantic blue crab," "Chesapeake blue crab," and "Gulf blue crab." The specific common names often reflect the geographic region where the species is found.

Characteristics

Crabs in the genus Callinectes are characterized by several distinctive features, including:

  • Flattened carapace: The carapace is broad and flattened, with a smooth, slightly convex surface.
  • Sharp, pointed rostrum: The rostrum, or snout, is a prominent, pointed projection on the front of the carapace.
  • Wide, paddle-like fifth pair of legs: The fifth pair of legs is modified into broad, flattened paddles that the crab uses for swimming.
  • Prominent eyes: The eyes are large and prominent, located on stalks that can be rotated independently.
  • Color variation: The color of the carapace can vary depending on the species and the age and sex of the crab. However, most Callinectes species have a bluish or greenish tint.

Environments

Callinectes crabs are found in a variety of marine environments, including:

  • Estuaries: They are particularly abundant in estuaries, where they inhabit shallow, brackish waters with a mix of fresh and saltwater.
  • Coastal bays: They are also found in coastal bays and lagoons, where they can tolerate a range of salinities.
  • Shallow marine waters: Some species, such as the blue crab (Callinectes sapidus), can be found in deeper, marine waters along the continental shelf.

References

Wikipedia: Callinectes
NOAA Fisheries: Blue Crab
Mississippi Department of Wildlife, Fisheries, and Parks: Crabs