Animal Diversity II: Protostomes II Ecdysozoa Objectives: • Be able to identify specimens from the main groups in Ecdysozoa: Nematoda, Onychophora, and Arthropoda. • Be able to classify Arthropods as Chelicerates, Myriapods, Hexapods or Crustaceans. • Be able to describe the major body divisions of Arthropods. Ecdysozoa The ecdysozoa are a monophyletic group of protostomes joined by the synapomorphy of molting, or shedding their outer skin or exoskeleton at least one in their lifetime. This is the most diverse group of animals on the planet, by virtue of containing the insects, and thus the leaf-eating beetles, which make the order of the beetles, the Coleoptera, the most diverse of all described organisms. The Ecdysozoa includes many phyla, including the Kinorhyncha (mud dragons), Priapulida (penis worms), Nematoda and nematomorpha (pin worms and related), the Onycophora (velvet worms), Tardigrada (water bears) and the most speciose Arthropoda. In this laboratory you will see examples of Nematoda and Arthropoda. Draw at least one specimen from each specimen, unless more are instructed. 2 Animal diversity II PHYLUM Arthropoda SUBPHYLUM Chelicerata ORDER Xyphosurida FAMILY Limulidae Horseshoe Crab Scorpion PHYLUM Arthropoda SUBPHYLUM Chelicerata CLASS Arachnida ORDER Scorpiones 3 Animal diversity II Pseudoscorpion PHYLUM Arthropoda SUBPHYLUM Chelicerata CLASS Arachnida SUBCLASS Dromopoda ORDER Pseudoscorpionida Spiders PHYLUM Arthropoda SUBPHYLUM Chelicerata CLASS Arachnida ORDER Araneae Draw at least 3 spiders. 4 Animal diversity II Ticks PHYLUM Arthropoda SUBPHYLUM Chelicerata CLASS Arachnida SUBCLASS Acari ORDER Ixodida Look at preserved specimens and slides. Millipede PHYLUM Arthropoda SUBPHYLUM Myriapoda CLASS Diplopoda How many legs per segment do you see? 5 Animal diversity II Centipede PHYLUM Arthropoda SUBPHYLUM Myriapoda CLASS Chilopoda How many legs per segment do you see? PHYLUM Arthropoda CLASS (SUBPHYLUM) Crustacea ORDER Decapoda Draw at least 2 members of the Decapoda, which includes crayfish, lobsters, crabs and shrimp. We have lots of specimens to choose from. Make sure you choose at least one crab and one shrimp. Why do you think this order is called Decapoda? 6 Animal diversity II Fairy shrimp – Not true shrimp, but an important component of the oceanic food chain. PHYLUM Arthropoda SUBPHYLUM Crustacea CLASS Branchiopoda SUBCLASS Sarsostraca ORDER Anostraca Daphnia – an important planktonic crustacean. PHYLUM Arthropoda SUBPHYLUM Crustacea CLASS Branchiopoda ORDER Cladocera FAMILY Daphniidae GENUS Daphnia 7 Animal diversity II Insects can be divided into the wingless and winged, or the Apterygota and Pterygota, respectively. The Apterigota includes the orders Archaegnatha (the bristletails) and the Thysanura (the silverfish). PALEOPTERA Order Odonata (Anisoptera/Dragonflies and Zygoptera/Damselflies) Suborder Anisoptera, the dragonflies. Dragonfly adult. Label the dorsal and ventral regions, and then identify the head, thorax, abdominal regions. Identify and label the antennae, eyes, mouth, forewings and hindwings. Draw a leg separately, and label the coxa, tibia, femur and tarsi, and tarsus. NEOPTERA Today we will see specimens in the Neoptera or “new wings”. No single species can be said to be representative of the whole group (usually taxonomic Order, but refer to the discussion we had during lecture about this), so please draw at least two specimens from each group. Select specimens that have morphological disparity, e.g. for the Hymenoptera, do not draw two bees, but instead a bee and a wasp or a bee and an ant, etc. SIPHONAPTERA 8 Animal diversity II NEUROPTERA – The “lacewings”. Pay special attention to the netted wing structure, the mountparts and the peculiar antennae. COLEOPTERA – The beetles. Notice that all beetles have a hardened pair of wings, called elytra. Many things that are not normally called beetles, are actually members of this order, e.g. fireflies and ladybugs. Always look for the leathery, hardened wings and you can ID it as a beetle. 9 Animal diversity II HEMIPTERA – The “true bugs”. There is a lot of debate concerning the monophyly of this group, as it might include the Homoptera (cycads and leafhoppers). For now, look at the examples presented to you in lab and pay special attention to the mounthparts, always long and looking down, which they use to pierce the tissue of plants and animal prey. DIPTERA - The flies and mosquitoes. Pay special attention to the wings. Although they have two large wings, look closely where you would expect a second pair of wings to be, and you will see a tiny pair of rudimentary wings called the halteres. These are very important in the stabilization during flight. 10 Animal diversity II LEPIDOPTERA – the moths and butterflies. Look at the structure of their wings, covered with scales, and to their long proboscis. ORTHOPTERA – The grasshoppers and crickets. This order might be paraphyletic. 11 Animal diversity II DYCTIOPTERA: Mantodea – The mantids. DYCTIOPTERA: Blattaria – The cockroaches. One of the most beautiful and elegant group of insects. 12 Animal diversity II DYCTIOPTERA: Isoptera – The termites. This group is in question, as recent research suggests that they are highly modified cockroaches. PHASMIDA – The walking sticks. Look at their fantastic camouflage! 13 Animal diversity II Phylum Nematoda Roundworms Phylum Onychophora velvet worms Phylum Tardigrada water bears Phylum Arthropoda Subphylum Trilobitomorpha – trilobites (extinct) Subphylum Chelicerata Class Merostomata Order Xiphosura Horseshoe crab Class Pycnogonida Sea “spiders” (not true spiders) Class Arachnida Spiders, scorpions, ticks and daddy-long-legs Subphylum Myriapoda Order Chilopoda Centipedes Order Diplopoda Millipedes Class Insecta Order Siphonaptera – Fleas Order Neuroptera – Lacewings Order Coleoptera - Beetles Order Hymenoptera – Wasps; Bees; and Ants Order Isoptera – Termites Order Homoptera – Cicadas & others Order Trichoptera – Caddisflies Order Lepidoptera – Moths & Butterflies Order Orthoptera – Grasshoppers; Crickets & Locusts Order Hemiptera – True Bugs Order Diptera – Flies Class Crustacea Subclass Malacostraca Order Stomatopoda – Mantis shrimp Order Isopoda Order Amphipoda – Scuds Order Decapoda – Shrimps; Lobsters; & Crabs Subclass Branchiopoda Order Anostraca – Brine shrimp (Sea Monkeys) Order Cladocera – Water fleas (e.g. Daphnia) Subclass Ostracoda – Seed shrimp Subclass Copepoda Subclass Cirripedia – Barnacles .