crawfish

Crawfish, crayfish, or crawdads are small freshwater crustaceans in the order Decapoda that resemble tiny lobsters. They inhabit rivers, streams, ponds, and wetlands in many temperate regions. The terms vary by region; "crawfish" is common in the southern United States, while "crayfish" is more widely used elsewhere.

Taxonomy and diversity: Two superfamilies, Astacoidea (true crayfish) and Parastacoidea (Australian crayfish), contain hundreds of species. Overall, about 600 described species are recognized.

Anatomy and biology: Crayfish have a hard exoskeleton, five pairs of walking legs, and two large claws. Body length ranges from a few centimeters to over 10 cm depending on species. They breathe with gills, molt to grow, and rely on antennae and stalked eyes to sense their environment.

Habitat and ecology: They are primarily benthic, living on or near the bottom of freshwater bodies. They are omnivorous, feeding on plants, detritus, invertebrates, and carrion. They are prey for fish, birds, and mammals and can influence vegetation and sediment through foraging. Some species are invasive outside their native ranges.

Life cycle: Reproduction is sexual. Females carry fertilized eggs under the abdomen until hatching; the young emerge as miniature adults after several molts. Life span and maturation vary by species and environment.

Human use and conservation: Crawfish are a popular food in many cuisines, especially in the southern United States, where they are boiled, used in étouffée, or bisques. They are cultured in aquaculture operations and released in some areas for fishing. Habitat loss, pollution, and invasive species pose conservation and management challenges.