Lobsters & Crayfishes belong to the infraorder Astacidea, a well-known group of decapod crustaceans valued both for their culinary importance and interesting biology. Currently, more than 600 species have been described within this infraorder, including both marine and freshwater species. What unites all these animals is a very visible feature: the presence of a pair of large front claws used for defense, feeding, and, in some cases, digging.
From a morphological point of view, lobsters & crayfishes have a robust body divided into a cephalothorax (fused head and thorax) covered by a hard carapace, and a segmented abdomen that allows them to swim backward quickly. Their first two pairs of legs are modified into claws, often with one claw larger than the other, adapted for cutting or crushing. Unlike spiny lobsters, these crustaceans lack long spiny antennae.
The infraorder Astacidea is divided into several important families and genera, including:
- The family Nephropidae, which groups the true lobsters and marine lobsters. This group includes species such as Homarus americanus (American lobster), abundant along the North American Atlantic coast, and Homarus gammarus (European lobster), found in the northeastern Atlantic and the Mediterranean Sea.
- The family Astacidae, composed of European and Asian freshwater crayfish. An example is Astacus astacus (European crayfish), which inhabits rivers and lakes in Europe and is sensitive to water pollution.
- The family Cambaridae, with more than 400 freshwater crayfish species in North America, including the genus Procambarus, to which belongs Procambarus clarkii (red swamp crayfish), a widespread invasive species.
- The family Parastacidae, which includes freshwater crayfish of the Southern Hemisphere, especially in Australia, New Zealand, and South America. Some species in the genus Astacopsis reach impressive sizes.
- Finally, the family Nephropsidae includes Norway lobsters or langoustines, such as the well-known Nephrops norvegicus (Norway lobster or Dublin Bay prawn), highly appreciated in European cuisine. This species lives buried in muddy bottoms of the northeastern Atlantic and the Mediterranean.
Lobsters & Crayfishes are carnivorous or omnivorous. They feed on molluscs, worms, small fish, other crustaceans, or even dead animals. Thanks to their powerful claws, they can capture, tear apart, and crush their prey. Some species, like Norway lobsters, also feed on organic matter found in the sediment.
Regarding reproduction, these crustaceans have separate sexes. During mating, the male transfers a sperm package to the female, who stores it until egg laying. The female attaches the eggs to her abdomen and protects them for several weeks or months, depending on the species. Once hatched, the young go through several stages before reaching the adult form.
Lobsters & Crayfishes have a wide geographic distribution. While true lobsters and Norway lobsters inhabit cold or temperate marine waters, freshwater crayfish are found in fresh waters on every continent except Africa. Many of them have great economic and ecological importance but are also threatened by overfishing, habitat loss, and invasive species.
