A Quick Guide to the Crayfish Life Cycle
The crayfish life cycle refers to the tracking of the development of the crayfish from its birth as an egg through it maturing into an adult fish.
Crayfish, also sometimes referred to as crawfish or crawdads, belong to the families Astacoidea and Parastacoidea and are freshwater crustaceans. They look like lobsters in a smaller scale and are sometimes even referred to as freshwater lobsters.
The crayfish breathe through feather-like gills and tend to inhabit water bodies that do not freeze all the way through to the bottom. They prefer freshwater and are found in streams and brooks where there is enough shelter to hide from predatory creatures.
Crayfish are usually brown, red or off-white in color and they have a distinctive pair of pincers which are useful as a defense mechanism and for finding food.
The crayfish has a life span of two years and its life cycle is, therefore, fairly accelerated.
Adult crayfish mate in open water and this is usually in late spring or early summer. The female of the species is known to mate with more than one male.
The male’s sperm is stored in a receptacle on the female’s underside during mating. This happens before the female makes a burrow in which she will spawn. The burrow is usually near the water’s edge.
While the female is building her burrow, the eggs in the ovary develop and are ready for release through the oviducts.
The sperm which was stored earlier will fertilize the newly released eggs and they become attached to the swimmerets which are found on the underside of the female’s tail. Not all the eggs that are released get fertilized; this is dependent on the size of the sperm.
Crayfish eggs have an incubation period of around three weeks; this is dependent on ambient temperature with 74˚F being recommended as the optimal temperature.
The crayfish eggs hatch and the hatchlings continue to stay attached to the mother fish’s swimmerets for a few more weeks.
After the hatching, with her brood still attached, the female emerges from the burrow to find food. The female is known to eat the hatchlings if she stays on in the burrow and food becomes an issue.
Once the fish is in open water, the chances of the hatchlings detaching from the mother increase dramatically.
Another important stage in the crayfish lifecycle is the molting stage. This is when the juvenile fish shed its hard exoskeleton to make room to grow. This can be a frequent exercise during the growth period.
It is important to note that the rate of growth of crayfish juveniles is greatly impacted by variations in the environment. This includes:
Amount of food available
Dissolved oxygen level in the water
Typically, a crayfish molts about 11 times before reaching sexual maturity; this takes about one year.
A crayfish that reaches sexual maturity will stop growing. They will have the distinctive darker coloring and larger pincers associated with maturity. Males will have the hooks at the base of the third and fourth pair of walking legs and females will have the seminal receptacle for holding the sperm after mating. At this point, the adult fish are ready to start the crayfish life cycle all over again.
Understanding the patterns of the crayfish lifecycle can be useful for those who keep these creatures as pets and for anglers who target these freshwater creatures.