There are several different species of both freshwater and saltwater crayfish. Freshwater ones are also referred to by the names crawfish , crawdad , and crawdaddy.
Use of these terms varies by region. The first records of the word crayfish come from the s. Crayfish are mostly small, lobster-like creatures. But use of the terms varies by region. Crawdad and crawdaddy are most often used in Midwestern states and along the West Coast. Crawfish is the prevalent term in much of the South, whereas crayfish is the preferred term in the Northeast.
What are some synonyms for crayfish? What are some words that may share a root or word element with crayfish? Check out the 55th issue of the Cape Chronicle e-newsletter! Image: Burrowing crayfish found on Hatteras Island after a recent rainstorm.
In California, fishermen trap coolwater crawfish in rivers that feed the Sacramento Delta. Fishermen in the Midwest trap the species in lakes. Limited amounts are farmed in Europe. Scientific Name: Procambarus clarkii, P.
Market Name: Crawfish, crayfish. Common Name: Crawdad, red swamp crayfish, mudbug, crayfish. French Name: Ecrevisse. German Name: Flusskrebs. Italian Name:. Japanese Name: Zarigani. Spanish Name: Cangrejo de rio. Product Profile: Crawfish meat is sweet like lobster meat but more tender and not quite as rich. In This Article Expand. What Are Crawfish? How To Cook.
Crawfish Vs. Where to Buy. Best Places to Buy Seafood Online in Featured Video. Read More. Your Privacy Rights.
To change or withdraw your consent choices for thespruceeats. At any time, you can update your settings through the "EU Privacy" link at the bottom of any page. These choices will be signaled globally to our partners and will not affect browsing data. During this phase, crawfish feed actively and increase their tissue and energy reserves. Preparation for molting takes place in the pre-molt stage. This includes the formation of the new, underlying soft exoskeleton while a re-absorption of the calcium from the old shell occurs.
During the late pre-molt period, crawfish cease feeding and seek shelter or cover. Molting is usually accomplished in minutes. The brittle exoskeleton splits between the carapace head and abdomen tail on the back side, and the crawfish usually withdraws by tail flipping. Hardening calcification of the new exoskeleton takes place during the post-molt period, which can be divided into two phases. Initial hardening occurs when calcium stores within the body are transported to the new exoskeleton.
These stones disappear during the initial hardening period after molting. The second phase of hardening is by absorption of calcium from the water. As crawfish resume feeding, further hardening of the new shell occurs.
Molting is hormonally controlled, occurring more frequently in younger, actively growing animals than in older ones. The increase in crawfish size during molting, and the length of time between molts, can vary greatly and are affected by factors such as water temperature, water quality, food quality and quantity, population density, oxygen levels and to a lesser extent by genetic influences.
Under optimum conditions, crawfish can increase up to 15 per cent in length and 40 per cent in weight in a single molt. In culture ponds, frequent molting and rapid growth occur during spring because of warming waters and adequate food sources. The appearance of mature crawfish increases as the season progresses. Rapid increases in temperature above 80 F may stimulate onset of maturity at smaller sizes, especially under conditions of overcrowding and food shortages.
Crawfish have been known to ingest living and decomposing plant matter, seeds, algae, epiphytic organisms, microorganisms and an assortment of larger invertebrates such as insects and snails. They also will feed on small fish when possible.
These food sources vary considerably in the quantity and quality in which they are found in the aquatic habitat. Living plants, often the most abundant food resource in crawfish ponds and natural habitats, are thought to contribute little to the direct nourishment of crawfish. Starchy seeds are sometimes consumed and may provide needed energy, but intact fibrous plant matter is mostly consumed when other food sources are in short supply.
Aside from furnishing a few essential nutrients, living plant matter provides limited energy and nutrition to growing crawfish. Decomposing plant material, with its associated microorganisms collectively referred to as detritus is consumed to a much greater degree and has a higher food value.
The ability of crawfish to use detritus as a mainstay food item, however, appears to be very limited. Fortunately, in a typical crawfish pond environment numerous animals besides crawfish rely on the microbe-rich detritus as their main food source. Mollusks, insects, worms, small crustaceans and some small vertebrates depend on detritus Figure 6 and, when consumed by crawfish, these animals furnish high-quality nutrition.
Scientists have realised that for crawfish to grow at their maximum rate, they must feed to a greater extent on these high-protein, energyrich food sources.
Sufficient evidence has been established to indicate that although crawfish must consume high-protein, high-energy sources to achieve optimum growth, they can sustain themselves for some time by eating intact and decomposing plant sources and even bottom sediments containing organic debris. Supplemental feeds are not routinely provided to crawfish aquaculture ponds.
Commercial culture of crawfish relies on a self-sustaining system for providing nourishment to crawfish, as occurs in natural habitats where crawfish are abundant. An established or at least encouraged vegetative forage crop provides the basis of a complex food web Figure 7 that ultimately fuels production of crawfish with harvests that typically average pounds per acre and can often exceed 1, pounds per acre.
As a result, the main means of providing nutrition to crawfish in aquaculture is through establishing and managing a forage crop. Ideally, once ponds are flooded in the fall, a constant and continuous supply of plant fragments fuels the food web from which crawfish derive their nutrition.
Key government officials reiterated their support for the growth of the shrimp industry, one of the major aquaculture co….
0コメント