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Unformatted text preview: 82 Phylum Arthropoda Members of this phylum are bilaterally symmetrical, segmented, eucoelomate protostomes that have a chitinous exoskeleton, open circulatory system, complete (with anus) digestive tract, dorsal brain with ventral nerve cord, and paired jointed appendages. Typically, the body is divided into three regions: the head, thorax, and abdomen, although some regions may be fused. Arthropods are the most numerous and diverse of all the animal phyla. The phylum is further subdivided into 4 Subphyla. Subphylum 1: Cheliceriformes Chelicerates have 4 pairs of legs plus 2 pairs of head appendages: one pair of chelicerae and one pair of pedipalps ; they lack antennae. Chelicerae are pincerlike and used for feeding; pedipalps are mainly sensory but can be used in feeding, locomotion, or reproduction. Class Arachnida (spiders, mites and ticks, scorpions) Terrestrial, with characteristics of subphylum; spiders with bulbous and legless abdomen (hindbody), mites and ticks with abdomen fused with leg-...
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This note was uploaded on 12/27/2011 for the course BSC 1020 taught by Professor Danmoon during the Fall '11 term at UNF.
- Fall '11