crayfish

The spiny lobster, excessively called crawfish or crawdad, is a lively irrigate spineless that declinations in the Kingdom Animalia. They be arthropods that break down to the largest crustacean hostel, the Decapoda, and atomic number 18 related to the brine lobster. This order constitutes the families Astacidae ( northerlyern Hemisphere), Parastacidae, or Austroastracidae (S come to the forehern Hemisphere). There be legion(predicate) diametric genera of the crawdaddy put all everywhere the world. The to a great extent or less common genera of North the States take on Procambarus, Orconectes, Faxonella, genus Cambarus, Camb bellus, and Pacifastacus. The most probable crawdad to be set in motion at Rice Creek would be the Cambarus robustus. Austropotamobius is the most common genus of Europe.         crawdad occur in a wide-cut mannequin of freshwater habitats and argon (or were) naturally general in all continents of the world except Antar ctica and, surprisingly, Africa (Sutcliffe, 2002, p297). There ar more(prenominal) than 500 species of crayfish, more than half of which occur in North America alone. ecrevisse be also entrap in Europe, New Zealand, and East Asia. These creatures are nocturnal so they befog in mud burrows or under rocks and fag end detritus during the day and they search for food at night. Their provender at Rice Creek, as well as round the world, includes snails, oligochaetes, humiliated fish; such as minnow, guppies, and goldfish; aquatic insects, aquatic plants, and dead or decaying organisms. The crayfish is the largest mobile macroinvertebrate in equable freshwater ecosystems (Holdich & Lowery, 1988, p.1). Crayfish are normally 3-4 inches in length. The smallest crayfish, Cambarellus diminutus are about 1 inch long and are found in the southeastern United States. Astacopsis gouldi on the another(prenominal) pot is one of the largest found in Tasmania which has a length of 40 cm (15 inches) and has a weight of abo! ut 3.5 kg (8 pounds) (Daniel, 2002). The cylindrical-shaped ashes of the crayfish is covered by a thick exoskeleton, which molts hitch it grows. There are advantages and disadvantages to having an exoskeleton. The exoskeleton protects the animal from other crayfish and predators equal trout and bass, but when it is molted the animal is very vulnerable until the new exoskeleton hardens. more or less other predators include eels, pike, chub, perch, herons, mink, otters, snakes, and people. The crayfish is usually characterized by having a head attached to the thorax, which is called a cephalothorax. The cephalothorax is so connected to the abdomen, which is connected to segmented tail. The abdomen is approxi geminately thirty percent of the buckler length (Hobbs, 1987, p.31). The tail can be used to quickly dart backward if threatened. On the cephalothorax at that distinguish are deuce compound eyes, which are attached to transportable stalks. These stalks help t he animal protect its eyes by retracting them if risk of infection approaches. The crayfish also has a pointy nose and a concord of sensory antennae on its head. There are four pairs of manner of walking legs attached to the thorax. asunder from walking backwards, forwards, and sideways, these legs help the animal poke into food in crevices betwixt rocks. Crayfish also support a pair of strong pinchers, which are very stabilising in raw and capturing food, as well as defense. They retain five pairs of swimmerets that are located under the abdomen; bailers, which are used to clog up water over the gills; and many an(prenominal) specialized, food-handling legs. All of the legs on a crayfish can regenerate, or grow back if lost. Crayfish have been known to fuck in a variety of colors including green, sandy yellow, pink, white-hot or dark brown. Crayfish have a tone expectancy of about 2 years and rely on mass reproduction for the subsequence of the species(Dani el, 2002). Crayfish reproduce sexually and mate in f! all through winter. A potent attracts a female by touching her with his antennae and his claws. He thusly turns the female on her back, holds her pinchers in his, and then positions his abdomen over hers. He continues to insert the ischial hooks on his pereiopods into coxal membranes of the pereiopods of the female (Page, 1985, p.343). This is basically the way in which the crayfish are locked together to mate. after the sperm is in the female, the male places a plug in her so other males wint try to mate with her.

When the eggs are fertilized, she glues them to her swimmerets and then finds a safe place to stay. After a fewer weeks, hatching takes place and the ball up crayfish stay with their mommy for weeks before going out on their own. Crayfish are important to the environment and simulated military operation a very epoch-making role in their ecosystems. Since they are omnivorous, they process organic question and transform capacity between different levels of the food chain. Their biomass is extravagantly in comparison with other consumers(Holdich & Lowery, 1988, p.128). Most animals cannot readily implement detritus and living phytology and so they transfer energy from the producer directly to higher(prenominal) trophic organisms. They are practically referred to as rubbish collectors because they diversify waste into protein. Over the years, over-fishing, water pollution, irrigation demand, and disease has decreased the commonwealth of these important animals. Man is accordingly negatively affecting the freshwater ecosystem. There are many efforts being made by co nservation biologists and Fish and Wildlife do ecosy! stem teams to stop the deduction of crayfish throughout the world. Bibliography Butler, S.R., DiStefano, R.J., Schuster, G.A. (2003). Crayfish: an overlook fauna. Endangered Species Bulletin, 28, 2, 10-13. Daniel, P. (2002). Crayfish Background. Retrieved October 10, 2003, from Hofstra University web site: http://people.hofstra.edu/ force/peter_c_daniel/Animal_Physiology/special_topics_spring2002/Ken/Topic_1.html Hobbs, H.H. (1987). A review of the crayfish genus Astacoides (Decopoda: Parastacidae). Wahsington, D.C: Smithsonian Institution Press. Holdich, D.M.,&Lowery, R.S.(1988). freshwater crayfish: biology, management, and exploitation. Potland, Oregon: Timber Press. Page, L.M. (1985). The crayfishes and shrimps (Decapoda) of Illinois. Champaigne, Illinois: University of Illinois Press. Sutcliffe, D. (2002). biological science of freshwater crayfish. Fisheries Research, 59,1,297-299. If you essential to get a fu ll essay, order it on our website: OrderCustomPaper.com

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