THE "ECDYSOZOA" - molting animals

1. THE "ECDYSOZOA" - molting animals a sub-group of the Protostomes, including arthropods and nematodes (round worms), as well as less -well-known groups like the nematomorphs (gordian worms), onycophorans (velvet worms), tardigrades (water bears) and rotifers (wheel animalcules) all of them have rigid exoskeletons, usually made of chitin (a polysaccharide, similar to cellulose) in order to grow, ecdysozoans molt their old cuticles, and produce a larger cuticle in the layer below between the arthropods (the most speciose animal phylum BY FAR) and the nematodes (possibly the most numerous animal on the planet), it seems that this molting life style is very successful. Why? chitin cellulose

2. Nematodes - the round worms http://www.ucmp.berkeley.edu/phyla/ecdysozoa/nematoda.html

3. typical round worm life cycle and internal morphology http://martin.parasitology.mcgill.ca/jimspage/biol/nema.htm Warwick, Nicholas L. The Biology of Free-living Nematodes. Clarenden Press, Oxford; 1984.

4. ...involves similar molecular machinery as molting in arthropods molting in nematodes... Masako Asahina et al. (2000) The conserved nuclear receptor Ftz-F1 is required for embryogenesis, moulting and reproduction in Caenorhabditis elegans. Genes to Cells5: 711 Marta Kostrouchova et al. (2001) Nuclear hormone receptor CHR3 is a critical regulator of all four larval molts of the nematode Caenorhabditis. PNAS 98: 7360-5 crawling movie! http://www.bio.unc.edu/faculty/ goldstein/lab/crawl.mov embryogenesis movie! http://www.bio.unc.edu/faculty/ goldstein/lab/celdev.mov mating movie! http://www.its.caltech.edu/~wormlab/ movies/Rene_mating_movie.mpg http://cal.nbc.upenn.edu/merial/ Nematodes/nems_7.htm

5. annual infection rate said to be 1500 million cases! egg “L1” http://www.path.cam.ac.uk/ ~schisto/Nematodes/Ascaris.html 4th xxx these worms are not very oxygen-tolerant....so how do they survive in their hosts? They have special hemoglobins that bind O2 25,000X stronger than human hemoglobin, using NO to “soak up” the oxygen, thus protecting themselves. (Minning et al. 1999. Nature 401: 497-502.) (1.5 mm long “L4”) (250 µm long “L2”) http://www.biosci.ohio- state.edu/~parasite/lifecycles/ ascaris_lifecycle.html

6. more on Ascaris lumbricoides “L2” hatching from the egg adult worm http://www.dpd.cdc.gov/dpdx/HTML/ImageLibrary/Ascariasis_il.htm

7. Nannophya pygmaea from Malaysia. World’s smallest dragonfly (15 mm)!! The stomatopod Odontodactylus scyllarus picture by Don Trowbridge http://www.ups.edu/biology/museum/UPSdragonflies.html CRUSTACEA INSECTA TRILOBITA† The five classes of arthropods the Goose Barnacle, Pollicipes polymerus http://www3.ocn.ne.jp/~kmitoh/ zaturoku/ebosigai/e_ebosigai.html MYRIAPODA CHELICERATA Neoasaphus http://www.aloha.net/ ~smgon/eyes.htm Hadrurus arizonensis pallidus http://www.creature-creations.com/g6c40.html http://www.desertusa.com/oct96/du_scorpion.html

8. (3%) (18%) (5%) (4%) (9%) (5%) (56%) numbers of described species of plants and animals after: Groombridge, B. 1992. Global Biodiversity: Status of the Earth's Living Resources. London, Chapman & Hall.

9. numbers of species out there.... * after: Groombridge, B. 1992. Global Biodiversity: Status of the Earth's Living Resources. London, Chapman & Hall. * % described = #described / #estimated

10. the insects [including the orders Collembola (springtails) and Thysanura (silverfish)] [including the orders Orthoptera (grasshoppers & crickets) and Blattodea (cockroaches), Hemiptera (aphids, the "true" bugs), Isoptera (termites), Phasmida (leaf insects, walking sticks), Ephemeroptera (mayflies); possibly including the order Odonata (dragonflies and damselflies)] [including the orders Diptera (flies and mosquitoes), Lepidoptera (moths and butterflies) Hymenoptera (bees wasps and ants), Neuroptera (lacewings, ant lions, dobson flies) and Coloeptera (beetles and weevils) I. the ancestrally wingless insects II. the "hemimetabolous" (non-metamorphosing) insects III. the "holometabolous" (metamorphosing) insects

11. PHOTOS ON THE PREVIOUS SLIDE: SPRINGTAIL: http://www.ext.vt.edu/departments/entomology/factsheets/springta.html SILVERFISH: http://ohioline.osu.edu/hyg-fact/2000/2108.html (all of the color photos were from the Tree of Life insect pages) MAYFLY: by T. W. Davies BUG: by Jean-François Cornuet GRASSHOPPER: by Joseph L. Spencer DAMSELFLIES: by Jo-Ann Ordano BEE: by Joseph L. Spencer BEETLE: by Robert Potts

12. crustaceans most are marine(some terrestrial, some fresh water, some all 3!) 5 pairs of appendages on head almost all develop via a "nauplius" larval stage subclass Copepoda subclass Malacostraca subclass Branchiopoda subclass Cirripedia subclass Ostracoda

13. PHOTOS ON THE PREVIOUS SLIDE: (all photos, except the ostracod and the nauplius, were from the Tree of Life crustacean pages) COPEPODS: illustrations by Ernst Haeckel [Augaptilus filigerus male (Calanoida: Augaptilidae); Corycaeus venustus female (Poecilostomatoida: Corycaeidae)] MALACOSTRACANS: Button isopod, Sphaeromene polytylotos (South Africa) by Branch, GM, Griffiths, CL, Branch, ML and Beckley, LE; Pacific red hermit, Elassochirus gilli (Decapoda: Anomura) Juneau, Alaska.by William Leonardamphipod, Hyalella azteca (Peracarida: Amphipoda) by Scott Bauer BRANCHIOPOD: Tadpole shrimp, Lepidurus packardi (Notostraca) Shasta County,CA by William Leonard. OSTRACOD:Gigantocypris sp. (http://www-biol.paisley.ac.uk/courses/Tatner/biomedia/pictures/gigan.htm ) CIRRIPEDES: Barnacle, Semibalanus cariosus (Thecostraca: Cirripedia), Ketchikan, Alaska, by Gerald & Buff Corsi; Nauplius larva of a Barnacle( http://www-biol.paisley.ac.uk/biomedia/graphics/jpegs/Nauplrv.jpg ) NOTE:there are other sub classes of crustaceans - see Pechenik