Crayfish<<<< Back to marine animals
- Kingdom: Animalia
- Phylum: Arthropoda
- Class: Malacostraca
- Order: Decapoda
- Suborder: Pleocyemata
- Superfamily: Astacoidea
- Conservation status: Least concern
- Areal: brooks and streams, swamps, ditches, and rice paddies
- Habitat: freshwater
- Food: mollusks, aquatic insects, plants and worms
- Length: 20 centimetres (6.9 in)
- Weight: 3.5 kg (8 pounds)
- Lifespan: 2 - 3 years
- Reproduction: 100 - 500 eggs per hatch
The European crayfish, noble crayfish and broad-fingered crayfish are the most common species of crayfish in Europe, and a traditional food. Like other species, they live only in freshwater rivers and lakes. They can be found in France, all of Central Europe, the Balkans, the British Isles, Scandinavia and western Russia.
Other names: Crayfish, also known as crawfish, crawdads, freshwater lobsters, or mudbugs.
Most crayfish cannot tolerate polluted water.
Crayfish are omnivorous like shrimps and lobsters. That means they eat almost anything. The crayfish feeds on mollusks, aquatic insects, plants and worms, etc. They grab the food with their tongs.
The amount of food consumed depends on how often they shed. When they shed they will eat the shell for calcium.
Crayfish feed on living and dead animals and plants.
The crayfish body consists of the cephalothorax and the abdomen. On the cephalothorax there are two pairs of antennae, with which the crayfish smells and touches, and two compound eyes, made up of hundreds of visual cells. The eyes are located at the tip of the extensions, that move in all directions. The mouth is equipped with powerful jaws.
On the back of the cephalothorax there are 5 pairs of jointed legs: the first pair ends with large and powerful claws, used for catching prey, pairs 2 and 3 have smaller pincers, and the last two pairs end with claws.
The abdomen consists of seven segments. The first five have on the ventral side a pair of legs. Segment 6 shows on the lateral side, two flattened parts which, together with segment 7 form the tail fin.
The crayfish moves forward on the water’s bottom, using its legs. When in danger, it pushes the water in front of him, with the help of the caudal fin blades and the abdomen is moved to the front side.
So it swims backwards.The crayfish breathes through gills. These are placed at the base of the legs and are feather-shaped. The gills are constantly bathedby a stream of water, flowing from back to front, ensuring gas exchange at their level.
- Cambarellus montezumae
- Cambarellus patzcuarensis
- Procambarus acanthophorus
- Procambarus allenii
- Procambarus clarkii
- Procambarus cubensis
- Procambarus enoplosternum
- Procambarus sp. Marble
- Procambarus pubescens
- Procambarus spiculifer
- Procambarus toltecae
- Procambarus vasquezae
- Procambarus versutus
- Astacus astacus — noble crayfish
- Astacus leptodactylus — Danube crayfish
- Astacus pachypus
- Austropotamobius pallipes — white-clawed crayfish
- Austropotamobius torrentium — stone crayfish
- Pacifastacus fortis — Shasta crayfish
- Pacifastacus leniusculus — signal crayfish
- and many more ..
Crayfish hide under rocks or logs. They are most active at night. Crayfish adults (over one year) are more active than young crayfish. Usually they move slowly and cautiously, but if they get scared thet swim backwards quickly to escape the danger. The wild predators of crayfish are alligators, turtles, otters, some birds, etc.
Like most animals crayfish are either male or female, but in most cases they are males. In the mating process the males place the sperm, in the form of a small ball of wool, on the lower abdomen of the female. She undulates her tail after passing the eggs through the sperm to keep them glued to the tail for four weeks. These periods increases if the crayfish live in areas with colder waters.
For this reason, and others, there are variations in the gestation period. In general reproduction occurs in spring. The tropical crayfish reproduce all year long because the environmental temperature is more stable. Unlike saltwater crayfish, freshwater crayfish have larger eggs.
They become adults after 3-4 years.
Did you know that:
As they grow crayfish moult several times.
The octopus can break the crayfish shell using their strong maxillas.
Crayfish hide under rocks or logs.
Crayfish are omnivorous like shrimps and lobsters.