What is a difference between crab starfish?

Crabs and starfish, while both marine invertebrates, are quite different in several ways:

1. Body Structure:

* Crabs: Have a hard, chitinous exoskeleton, a segmented body with a distinct head, thorax, and abdomen, and ten legs (two large claws and eight walking legs).

* Starfish: Have a central disc with five or more arms, a soft, spiny body covered in a thin, leathery skin, and no distinct head or segmentation.

2. Locomotion:

* Crabs: Walk sideways using their eight legs, and can also swim using their flattened abdomen.

* Starfish: Move by using tiny tube feet located on the underside of their arms. These feet are filled with water and extend and retract, allowing the starfish to grip surfaces and move slowly.

3. Feeding:

* Crabs: Are omnivores, eating a variety of food, including algae, small fish, mollusks, and crustaceans. They use their claws to crush and tear food.

* Starfish: Are carnivores, primarily feeding on bivalves (oysters, clams, etc.) by prying them open with their tube feet and everting their stomachs into the shell.

4. Reproduction:

* Crabs: Most crabs reproduce sexually, with the female carrying fertilized eggs until they hatch.

* Starfish: Can reproduce both sexually and asexually. They release sperm and eggs into the water for fertilization. Some species can also regenerate lost arms or even an entire body from a single arm.

5. Habitat:

* Crabs: Live in a variety of habitats, including coastal areas, estuaries, reefs, and deep sea environments.

* Starfish: Primarily live in marine environments, often found on rocky shores, sand bottoms, and coral reefs.

In summary: Crabs and starfish are distinct creatures with different body structures, movement, feeding methods, reproductive strategies, and habitats.