Aquarium Essays - Zoology, Nervous System, Arthropod, Animal, Insect

Aquarium Essays - Zoology, Nervous System, Arthropod, Animal, Insect Aquarium Organism 1,2,3,6,7,8,9 and 10 are from the phylum Chordata. All Chordates shared four major characteristics; a notochord, which provides a skeletal support, a dorsal hollow nerve cord, which develop into the central nerve system, pharyngeal slits, which are openings in the pharynx that develop into gills, and a post-anal tail. Organism 2,7 and 8 are the phylum Mollusca. The animals in this category share many characteristics which are bilateral symmetry,two cell layers, tissues and organs, lack a cavity, posses a through gut with a mouth and anus monomeric and highly variable bodies, may posses shell and calcareous spicules, has a nervous system with a circum-oesophageal ring, ganglia and paired nerve chords, open circulatory systems with a heart and an aorta, has gaseous exchange organs called ctenidial gills, reproduce sexually, feed on a wide variety of materials and live in most environments. Organism 4 is an Arthropoda. Arthropods have a body covered in chitinous cuticle that hardens into an exoskeleton, composed of somites (Metamerism), jointed appendages, ventral nerve cord with ganglia at each segment, open circulatory system and a bilateral symmetric body. Most Arthropods reproduce sexually; however some insects are parthenogenetic. Organism 4 was Porifera. Poriferans are commonly sponges which are sedentary by nature, most of them are marine sponges, cylindrical, have radial symmetry, have a body wall called a diploblastic, their middle layer has various wandering amoebocytes, have many ostia on their body, feed on minute organisms and small organic particles which enter the body through the oscula, have exoskeletons, secrete mainly ammonia, and asexual reproduction takes place by budding or sexual reproduction take place through internal fertilization. Organism 5 and 9 are Cnidaria. Cnidarian organisms are radially symmetrical, have bodies with internal cavity and a mouth, reproduction is sexual or asexual, has a simple net-like nervous system, has a distinct larval stage which planktonic, live in aquatic environments, mostly carnivores otherwise filter feeders, and have minimal skeleton of chiton or calcium carbonate. Organism 6 is echinodermata. These organisms free living, exclusively marine forms, larvae are bilaterally symmetrical while the adults are radially symmetrical, have bodies represented by a central disc covered by ossicles with spines called pedicularia, disc may bear extensions called arms, have a complete digestive system, have a water vascular system, posses tube feet for locomotion and respiration as well as feeding, has a central nervous sytem ring with five radiating nerves, sexual reproduction, development is indirect, and posses an ability to regenerate. For organism 3, the subphylum is Crustacea. Crustacea are primarily aquatic arthropods, but also include terrestrial forms, which have a cephalothorax covered by a carapace. They also have mandible mouthparts, gills for respiration, antennae, and biramous appendages.