Porifera Cnidaria Lophotrochozoa Ecdysozoa Nematoda and Arthropoda Deuterostomia 2017 Pearson Education Inc Phylum Nematoda Roundworms Found in most aquatic habitats in soils in moist tissues of plants and in body fluids and tissues of animals Body covered by tough cuticle They have an alimentary canal but lack a circulatory system Hemocoel Reproduction usually sexual by internal fertilization Many species are important in decomposition and nutrient cycling Figure 33 27 Encysted juveniles Muscle tissue 50 m Also many parasites of plants animals and humans Trichinellosis Contracted by eating undercooked meat Symptoms include nausea diarrhea vomiting fatigue fever chills headache cough itchy skin aching joints Figure 33 27 Juveniles of the parasitic nematode Trichinella spiralis encysted in human muscle tissue LM Ascaris lumbricoides Major pathology and symptoms Pneumonia associated with migration of larvae in the lungs Obstruction of the intestines Vomiting and abdominal pain May cause malnutrition in children with heavy infections or poor diet Some infections are asymptomatic One of the three most common helminth parasites Neglected Tropical Disease Hookworms Caused by the nematodes Necator americanus and Ancylostoma duodenale Attaches to the intestinal wall and feeds on blood and tissue Anemia lethargic behavior and craving for peculiar foods pica Carried from human feces in soil that contact bare skin Neglected Tropical Disease Phylum Arthropoda Ubiquitous Segmented body with specialized body regions Arthropods have eyes olfactory receptors and antennae that function in touch and smell Arthropods have an open circulatory system Figure 33 30 Cephalothorax Abdomen Antennae sensory reception Thorax Head Exoskeleton Paired jointed appendages Swimming appen dages one pair per abdominal segment Pincer defense Mouthparts feeding Walking legs Phylum Arthropoda Chelicerata sea spiders horseshoe crabs scorpions ticks mites and spiders Myriapods centipedes and millipedes Pancrustaceans insects crabs lobsters shrimp barnacles and other crustaceans Chelicerates Claw like appendages called chelicerae Anterior cephalothorax and posterior abdomen Lack antennae and simple eyes Figure 33 31 Horseshoe crabs Limulus polyphemus Figure 33 32 Arachnids Most modern chelicerates are arachnids which include spiders scorpions ticks and mites Scorpion 50 m Dust mite Web building spider Black Widow Spider Alabama has only five potentially harmful spider species https www aces edu blog topics invasive wildlife control black widow and recluses text In 20Alabama 2C 20five 20species 20of Mediterranean 20recluse 20 Loxosceles 20rufescens Figure 33 34 Myriapods a Millipede 2 pairs segment b Centipede one pair segment Pancrustaceans Crustaceans Marine freshwater and terrestrial Cephalothorax and abdomen Highly modified appendages Isopods terrestrial freshwater and marine species Decapods mostly larger include lobsters shrimp crabs and crayfish Hexapoda Insects and primitively wingless species springtails diplurans and proturans INSECTA Flies mosquitoes beetles wasps bees stink bugs cicadas butterflies moths roaches termites dragonflies fleas Insects Insects live in almost every terrestrial habitat and in fresh water flying insects fill the air They are rare in marine habitats Head thorax and abdomen Six legs Specialized respiratory excretory and digestive structures modified to conserve water The ability to fertilize eggs internally to prevent desiccation of exposed gametes 2017 Pearson Education Inc Figure 33 35 Abdomen Thorax Head Compound eye Antennae Anus Vagina Malpighian tubules Heart Dorsal artery Crop Cerebral ganglion Ovary Tracheal tubes Nerve cords Mouthparts Figure 33 38 Archaeognatha bristletails 350 species Thysanura silverfish 450 species Winged insects many orders Complete metamorphosis Incomplete metamorphosis Coleoptera beetles 350 000 species Hemiptera 85 000 species Orthoptera 13 000 species Diptera 151 000 species Hymenoptera 125 000 species Proboscis Lepidoptera 120 000 species Figure 33 UN05 Porifera Cnidaria Lophotrochozoa Ecdysozoa Deuterostomia Echinoderms and chordates are deuterostomes Echinoderms Living echinoderms are divided into five clades Asteroidea sea stars and sea daisies Ophiuroidea brittle stars Echinoidea sea urchins and sand dollars Crinoidea sea lilies and feather stars Holothuroidea sea cucumbers Figure 33 40 Central disk Digestive glands Short digestive tract Stomach Anus Spine Gills Madreporite Radial nerve Ring canal Radial canal Gonads Ampulla Podium Tube feet Figure 33 41 A sea daisy clade Asteroidea Ophiuroidea Brittle Stars Echinoidea Sea Urchins and Sand Dollars Crinoidea Sea Lilies and Feather Stars Figure 33 44 A feather star clade Crinoidea Figure 33 45 A sea cucumber clade Holothuroidea Chordates Phylum Chordata consists of two subphyla of invertebrates as well as vertebrates Chordates are bilaterally symmetrical coelomates with segmented bodies Which would be a great surprise if found in the body of a sponge a spongocoel b amoebocytes c mesohyl d visceral mass The major difference between the two divisions of annelids the errantians and sedentarians is that a sedentarians are less mobile than errantians b sedentarians are more mobile than errantians c sedentarians contain parapodia d errantians include leeches e sedentarians are all marine organisms Your friend who was setting up a lab on arthropods for your class put out specimens of the following groups Which needs to be removed a chelicerates b myriapods c pancrustaceans d ophiuroids If you wanted to show an example of segmentation to a group of visiting students which phylum would be the best choice a Nematoda b Arthropoda c Mollusca d Chordata e Cnidaria The best example of an animal phylum with enhanced overall surface area is a Cnidaria b Nematoda c Annelida d Platyhelminthes e Echinodermata