Daphnia magna Essays

Daphnia magna Essays Daphnia magna Paper Daphnia magna Paper This chapter provides an overview of the biology of waterless of the genus Daphnia. It describes basic aspects of Individual physiology and nutrition, Including some remarks about Immunity. It summarizes the typical life cycle and development of Daphnia. The modes of reproduction and the induction of resting egg production in cyclic and obligate parthenogenesis forms are discussed. Finally, population biological aspects, such as behavioral ecology, habitat preferences, population genetics, and population dynamics, are introduced. Go to: Introduction The following introduction summarizes the key aspects of the natural history of the genus Daphnia. It is far from exhaustive. Because much of the biology has been studied over the past 250 years and is considered to be common knowledge, I give no references to specific studies In most cases. The Interested reader may consult Fryer (1991), Steer (Bibb Lambert and Simmer (1 999), and Peters and De Bernard (1987), from which much of the information was taken. A search on the Internet using the term Daphnia or Clamored will also bring up a large body of information. Of particular interest is the Clamored Web page of the university of Gullah in Canada. The reader familiar with Daphnia may skip this chapter and move on to Chapter 3. Daphnia are platonic crustaceans that belong to the Payload (sometimes called Bronchiolar), which are characterized by flattened leaf-like legs used to produce a water current for the filtering apparatus. Within the bronchioles, Daphnia belong to the Clamored, whose bodies are enclosed by an unqualified shell (Figures 2. 1 and 2. 2), known as the carapace. It has a double wall, between which hemolytic flows and which Is part of the body cavity. The carapace Is largely made of chitin, a polysaccharide. Clamored have up to 10 pairs of appendages, which are (from front to back): untangles, antennae (the second antennae, used for swimming): maxillae: and mandibles; followed by 5 (as in Daphnia) or 6 limbs on the trunk. The limbs form an apparatus for feeding and respiration. At the end of the abdomen is a pair of claws. The body length of Clamored ranges from less than 0. 5 mm to more than 6 mm. Males are distinguished from females by their smaller size, larger untangles, modeled post-abdomen, and first legs, which are armed with a hook used in clasping. It describes basic aspects of individual physiology and nutrition, including some remarks about immunity. It summarizes the typical life cycle and development of references to specific studies in most cases. The interested reader may consult Fryer (1991), Steer (1993), Lambert and Simmer (1999), and Peters and De information. Of particular interest is the Clamored Web page of the University of and which is part of the body cavity. The carapace is largely made of chitin, a to back): untangles, antennae (the second antennae, used for swimming); maxillae; modified post-abdomen, and first legs, which are armed with a hook used in clasping.