American Oceans

The Difference Between Lobsters and Crawfish

a lobster in an aquarium

Lobsters and crawfish, also known as crayfish, are both crustaceans, a group of primarily aquatic invertebrate animals characterized by their hard exoskeletons and specialized appendages. Though they may share some similarities in appearance and habitat, there are distinct differences between the two marine animals that make them unique.

Lobsters are larger in size and commonly found in saltwater environments, such as oceans and seas. There are numerous types of lobsters, including clawed lobsters and spiny lobsters, which belong to the families Nephropidae and Palinuridae, respectively. On the other hand, crawfish predominantly inhabit freshwater environments like rivers and lakes and belong to the Astacidea and Parastacidae families. These smaller crustaceans are equipped with strong claws that they use for defense and foraging.

In comparing lobsters and crawfish, it becomes evident that their physical characteristics, habitats, and distribution vary significantly. These differences contribute to their unique roles within the ecosystems they inhabit and the culinary preferences of those who consume them.

Physical Characteristics and Habitats

Body ShapeLarger and heavierSmaller and lighter
ColorGreenish-brown, blue, or orangeReddish-brown, green, or blue
Average Length12 to 25 inches3 to 6 inches
ClawsLarger and more robustSmaller and weaker
Legs10 legs, including 3 pairs of swimming legs10 legs, including 1 pair of short swimmerets
Nearness to GroundCloser to the ground, with body almost parallelHeld at a more elevated angle

Both lobsters and crayfish belong to the same family and share some physical characteristics. They both have a hard exoskeleton, a cylindrical body, and a segmented abdomen with rings. They also have long antennae, legs, powerful tail, and large claws for grasping their prey.


Lobsters and crayfish also differ in the habitats they call home. While both species are often found in rocky and sandy environments, lobsters are mainly found in oceans and seas, whereas crayfish inhabit freshwater environments such as rivers, lakes, streams, and ponds.

Lobsters typically reside in saltwater habitats, where they prefer colder temperatures ranging from 2 to 16 degrees Celsius (35-61°F). They are mostly found near the coastal areas of the Atlantic ocean, and they prefer to hide in rocky crevices to avoid predators.

On the other hand, crayfish are freshwater creatures and can be found in a wide range of temperatures depending on the species, from 8 to 25 degrees Celsius (46-77°F). They often inhabit muddy bottoms in rivers, ponds, and streams as well as hiding under rocks, logs, and aquatic vegetation for protection.

Diet, Behavior, and Predation

a crawfish walking along the bottom of a lake

Lobsters and crayfish, both belonging to the crustacean family, exhibit similar diets and behaviors. They are primarily omnivorous creatures, consuming plants, insects, worms, small fish, and mollusks, such as clams, snails, and mussels. Lobsters also feed on sea urchins, algae, and other marine plants, making their diet quite diverse.

Both species are more active at night, making them nocturnal feeders. Their nocturnal behavior allows them to scavenge for food with reduced risk of predation. Lobsters and crayfish not only rely on the food available in their ecosystems but also turn to detritus when necessary.


Various predators target lobsters and crayfish at different stages of their life cycle. Common predators include fish, birds, and eels. Raccoons are also known to prey on crayfish. Larger marine species, such as crabs, have been observed preying upon juvenile lobsters.

As crayfish inhabit freshwater ecosystems, they tend to encounter fewer predators than their marine relatives, the lobsters. However, it does not mean crayfish are free from threats. They have been observed exhibiting behavioral responses to fish predators, adjusting their movements and hiding patterns for protection.

Lobsters, on the other hand, face a myriad of predators in their marine environment. In response to predation, lobsters, particularly juveniles, have been found to use shelter and hiding to reduce the risk of predation. Predation pressures can vary significantly between species and life stages, with juvenile lobsters and crayfish at a higher risk due to their smaller size and vulnerability.

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