What Type Of Animal Is A Crawfish

Scientific name: Cambarus sp.
Common name: Crayfish

(Information in this Species Page was compiled by Alicia Fitzgerald in Biology 220W, Jump 2006, at Penn Country New Kensington)

Crayfish (with special reference to genus Cambarus) are extremely distinctive freshwater crustaceans. Their large anterior-nearly pairs of legs have powerful claws which are efficient tools for defense, food gathering, and object manipulation. Their iv pairs of walking legs assist them in rapid locomotion across the bottom substrates of their aquatic habitats. Surprisingly, they are not really capable of swimming although they can use powerful thrusts of their tails to speedily propel themselves (backwards) through the h2o. This latter movement is particularly effective when the crayfish is attempting to elude a predator.

Distribution
Species of crayfish are widely distributed throughout the globe and are institute abundantly in most of the continental United States. They alive in ponds, streams, rivers, and lakes most typically under submerged rocks and logs. Some species are also capable of digging burrows oftentimes topped with tall, distinctive "turrets" that are often located some distance from the h2o'south edge. On our Nature Trail, crayfish are found in the flowing waters of our stream and in the surrounding isolated wetlands.

Environmental Tolerance Limits
Crayfish are extremely hardy animals that can tolerate wide ranges of water temperatures and salinities. They can even survive the drying up and loss of their streams and ponds. They respond to these extreme habitat disruptions by aestivation in burrows or other refugia or by migration to still intact water sources. Crayfish are very intolerant of pollution and other human-generated fouling of their surroundings. A rich crayfish population, then, is a very positive alphabetize of habitat quality. Crayfish are more arable in streams that have acidic water. This affluence may be due more than to the acid-generated absenteeism of fish which prey on crayfish than to a direct, positive influence of the acid on the crayfish itself.

Diet
Crayfish activity centers around food. When food sources are abundant, a crayfish tends to forage (i.eastward. leave its refuge under a rock or log) a very small percentage of the time. When food is deficient, though, crayfish will spend a considerable amount of fourth dimension foraging. Crayfish consume both plant and animate being materials and will, depending upon seasonal and local availabilities, consume a great variety of types of foods. Nearly all aquatic plants, mollusks, insect larvae, mature insects, tadpoles, amphibian eggs, and minor fish are common foods. Likewise taken opportunistically are small rodents and even modest birds. Young crayfish must consume i to 4% of their body weight each day and tend to concentrate upon animal food sources. Developed crayfish, on the other hand, merely require an intake of 0.3 to 1% of their body weight each mean solar day and tend to primarily accept plant materials for their food. If living food sources are not bachelor, crayfish volition, at need, swallow carrion. Crayfish tend to forage for food at night

Moulting
Crayfish, similar all arthropods, have an encasing exoskeleton fabricated out of the structural polysaccharide "chitin." For a crayfish to grow, it must shed its exoskeleton and and so re-grow a new and larger one. This shedding and re-growth process is called "moulting." When a crayfish moults it is very vulnerable to both injury and predation and, so, must spend the 2 or iii days information technology takes to re-abound its exoskeleton relatively inactive in its refugia. Young crayfish moult 6 to ten times during their first year while older crayfish moult 3 to five times during their second (and, typically, final) year of life.

Mating and Reproduction
Crayfish mate in the early spring and females comport the fertilized, developing eggs inside their bodies for 4 to six weeks. These developing eggs are and so transferred to the outside of the female's body and glued via an agglutinative called "glair" to the female's tail. The eggs so hatch by the terminate of spring. Merely 20 to 40% of the eggs, though, really produce young. Failure of these eggs is often due to a low percentage rate of initial fertilization and to a frequent failure of the glair, external adhesive.

Predators, Parasites, Symbiosis and Diseases
Crayfish are eaten past many species of animals including raccoons, ruddy foxes, muskrats, northern h2o snakes, eastern painted turtles, and many types of birds. Crayfish are likewise frequently aggress by parasites and diseases which bear upon their gills, eyes, exoskeletons, and intestines. Many of these infections and infestations do picayune credible harm to the private crayfish unless the animal is stressed or debilitated in some fashion (these contributing stresses are often in the grade of polluted, or in other ways low quality water). Crayfish also announced to have a mutualistic symbiosis with an aquatic annelid called "Cambarincola" which, apparently, helps to clean droppings out of the crayfish's gills thus improving the crayfish'due south respiratory efficiency and fitness.

Ecological Significance
Crayfish are an of import component of our stream ecosystem. They are significant links in the complex aquatic and terrestrial food webs in our ecosystem and, by their feeding, burrowing, and foraging activities, help to maintain a high level of water quality in our stream to the groovy do good of and then many of our Nature Trail species.

Source: https://www.dept.psu.edu/nkbiology/naturetrail/speciespages/crayfish.htm

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