Lecture 4: Ecdysozoan Protostomes PDF

Chapter 31 Lecture 4: Ecdysozoan Protostomes: Lineages that undergo ecdysis – Nematoda, Onycophora & Arthropoda Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated,...

Chapter 31 Lecture 4: Ecdysozoan Protostomes: Lineages that undergo ecdysis – Nematoda, Onycophora & Arthropoda Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  31.7 Ecdysozoan Protostomes Copyright reserved: Slides prepared by Prof. C. Simon Protective external covering that they shed (ecdysis) regularly All reproduce sexually, sexes usually separate, fertilization usually internal Three phyla: Nematoda Onychophora Arthropoda Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Phylum: Nematoda, the Round worms Copyright reserved: Slides prepared by Prof. C. Simon If all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable, and if, as disembodied spirits, we could then investigate it, we would find mountains, hills, vales, rivers, lakes and oceans represented by a thin film of nematodes. The location of towns would be decipherable, since for every massing of human beings there would be a corresponding massing of certain nematodes… N.A. Cobb. 1914. yearbooks of the United States Department of Agriculture, 1914 nematodes are extremely abundant and found everywhere Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Nematodes in swim bladder of an eel Nematode diversity Ecological importance Copyright reserved: Slides prepared by Prof. C. Simon Nematodes infecting insect grubs Free-living species break-down organic material & recycle nutrients Agricultural importance Parasites damage plant roots and infest farm animalsNematodes infesting the Medical importance Beer mat nematodes Nematodes forming galls on roots of Swelling caused by nematodes in human eye lymphatic system rose bushes Hook worms (digestive system) Nematodes what they affect infesting locusts W. bancrofti (lymphatic system) https://youtu.be/fGmXD7NPftY?si=RR_ebC10rsyX-Qle (from lady‘s brain) Russell, Biology: The Dynamic https://images.theconversation.com/files/417777/original/file-20210825-17- Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be 1irjp2u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=926&fit=clip scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Phylum Nematoda Copyright reserved: Slides prepared by Prof. C. Simon Nerve cords Anterior ganglion Longitudinal only Open circulatory system, no respiratory system Shed regularly, protection Locomotion: https://www.youtube.com/watch?v=SpgjnXEFadg Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Phylum Onychophora Copyright reserved: Slides prepared by Prof. C. Simon Velvet worms: Live under stones, logs, and forest litter in tropics and moist temperate habitats Segmented bodies, multiple pairs of excretory organs, numerous pairs of unjointed legs Flexible cuticle, open circulatory system, specialized respiratory system, large brains, jaws, and tiny claws on their feet Many produce live young Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Phylum Arthropoda Copyright reserved: Slides prepared by Prof. C. Simon >50% animal species on Earth Multiple jointed appendages Rigid chitinous exoskeleton Advantages Protective Attachment site for muscles Waterproof Disadvantage Can’t expand, limits growth → ecdysis (shedding skeleton) O2 can’t be taken up across the skin Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Phylum Arthropoda (cont.) Copyright reserved: Slides prepared by Prof. C. Simon Body segments No internal separation Often fused, reducing number of segments Head, thorax, and abdomen Cephalothorax and abdomen Open circulatory system Heart pumps haemolymph from the haemocoel Respiratory systems vary by group Complete digestive system Cephalisation & highly organized central nervous system Brain, nerve cord touch receptors, chemical sensors, compound and or simple eyes, hearing organs Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Phylum Arthropoda Copyright reserved: Slides prepared by Prof. C. Simon Extinct group: Trilobita Extant groups: Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Class: Trilobita this body form is considered the ancestral Copyright reserved: Slides prepared by Prof. C. Simon body form of anthropoda Extinct since Permian: among the earliest arthropods Head Deep longitudinal grooves divide the body into three lobes Ovoid, dorsoventrally flattened, heavily Thorax and abdomen armored Three body sections Head includes a pair of chemosensory antennae and two compound eyes Thorax and abdomen with pairs of walking legs Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Subphylum Chelicerata: Classes Arachnida and Merostomata Copyright reserved: Slides prepared by Prof. C. Simon Two major body regions: cephalothorax and abdomen Appendages on head/cephalothorax: Chelicerae = fanglike structures for biting prey Pedipalps = grasping organs, sensory organs, or walking legs 4 pairs walking legs on cephalothorax Respiratory structures derived from ancestral appendages on abdomen Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Marine Chelicerata Merostomata (horseshoe crabs): Carnivorous bottom feeders in shallow coastal waters Horseshoe-shaped shell Photographsbydee/Dreamstime.com Gills modified walking legs Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Terrestrial Chelicerata Copyright reserved: Slides prepared by Prof. C. Simon Arachnida: Highly modified chelicerae & pedipalps Spiders & scorpions = predators Scorpions with 1 pair walking legs modified Mites feed on plants or animals; ticks feed on blood Important in agriculture and disease transmission https://www.unr.edu/main/images/news/201 8/Feb/Tick1180x560.jpg?width=675&height= 675&mode=crop (C) iStock.com/Willem Van Zyl; (D) Andrew Syred/Science Source; (E) Cathy Keifer/Shutterstock.com Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Spider Cephalothorax Abdomen Geza Farkas/Shutterstock.com Simple https://www.sciencemag.org/news/2018/11/spider -silk-five-times-stronger-steel-now-scientists-know- why# B https://cdn.britannica.com/14/55014-050-99FFE87D/section- A book-lung.jpg Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Subphylum Myriapoda Centipedes and millipedes: Copyright reserved: Slides prepared by Prof. C. Simon All are terrestrial Two body regions: (A) Sandra Standbridge/Shutterstock.com; (B) Audrey Snider-Bell/Shutterstock.com head with one pair of antennae, and simple eyes Mandibles trunk with many segments with walking legs Centipedes have one pair of legs per segment & are fast predators with powerful toxins Millipedes have 2 pairs of legs per segment & are slow but powerful herbivores or scavengers Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  “Crustaceans” Copyright reserved: Slides prepared by Prof. C. Simon Almost all are extremely active aquatic (marine and freshwater) animals Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Anatomy of “Crustaceans” (Lobster) Copyright reserved: Slides prepared by Prof. C. Simon Compound 1 pair mandibles, 2 pairs maxillae (= pincer) Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Examples of Crustaceans Copyright reserved: Slides prepared by Prof. C. Simon Decapoda: Crabs, lobsters, shrimps Mostly in marine and freshwater habitats Larger species (up to 60 cm long and weigh 20 kg!) are benthic Extreme specialization of appendages: chelipeds, walking legs, swimmerets etc. Chaumeton/Agence Nature (A) EcoPrint/Shutterstock.com; (B) Herve Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Examples of Crustaceans Copyright reserved: Slides prepared by Prof. C. Simon Copepoda: small species, plankton Very abundant, important part of aquatic food webs web at the bottom of the food Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Examples of Crustaceans Cirripedia: Barnacles all other crustaceans are mobile Adults are sessile & live in a sit on rocks, don't move https://upload.wikimedia.org/wikipedia/common strong, calcified cup-shaped s/7/72/Chthamalus_stellatus.jpg shell Filter feeders Hermaphroditic have a long penis which helps with sexual intercourse iStock.com/ankh-fire Gooseneck barnacles Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Subphylum Hexapoda Copyright reserved: Slides prepared by Prof. C. Simon Insects (class Insecta) and their relatives: The most diverse and successful animals on Earth Elliotte Rusty Harold/Shutterstock.com St/Shutterstock.com; (F) Michael Durham/Minden Pictures; (G) iStock.com/bpperry; (H) Biosphoto/Bartomeu Borrell; (D) Henrik Larsson/Shutterstock.com; (E) Mi (A) Pajjai Sapwattanapaisarn/Shutterstock.com; (B) aaltair/Shutterstock.com; (C) Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Anatomy of Hexapoda (Grasshopper) Copyright reserved: Slides prepared by Prof. C. Simon Tracheal system Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be (excretory system) scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Insect Sensory Systems Copyright reserved: Slides prepared by Prof. C. Simon Insect sensory systems are diverse and complex: Image-forming compound eyes and light-sensing ocelli Touch & chemical receptors Hearing and sound-producing organs Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Specialized Mouthparts have different diets Copyright reserved: Slides prepared by Prof. C. Simon Diverse mouthparts for feeding, including the mandibles, maxillae, labrum and labium Fly feeding: https://www.youtube.com/watch?v=N23E4jYTExk Butterfly feeding: https://www.youtube.com/watch?v=MYWPWTme_YI Mosquito feeding: https://www.pbs.org/video/deep-look-mosquitoes/ Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Insect Development Copyright reserved: Slides prepared by Prof. C. Simon Developmental stages separated by ecdysis Three basic patterns of development first group doesn't show metamorphisis second group, offspring looks like adult when it hatches, but is missing certain characteristics these characteristics grow incrementally third group, undergoes extreme organisation until it emerges as an adult Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Importance of arthropods Copyright reserved: Slides prepared by Prof. C. Simon Agricultural & economic importance May destroy vegetable crops (mites, locusts), stored food (weevils), wool (moths), paper (fish moths) and wood (borer beetles) Some parasitise animals that are pests Essential for pollinating crops Make silk (moth species), honey & wax, beauty products (bees) Essential parts of food-chains (food for other animals including humans, fly larvae break down decaying animals) Medical importance Transmit diseases, clean wounds, forensics Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Copyright reserved: Slides prepared by Prof. C. Simon Morphological characters of Arthropoda Merostomata Vericrustacea Oligostraca Xenocarida Myriapoda Arachnida Hexapoda Plot the following characters on the tree Compound / simple eyes Sensory appendages on head 1 pair “Crustacea” 2 pairs Feeding appendages Chelicerae + pedipalps Mandibles Chelicerata Pancrustacea No appendages on abdomen Mandibulata 2 pairs of walking legs per segment Mainly aquatic 3 body regions Mainly terrestrial Many unspecialised appendages, 1 pair per segment Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  STUDY BREAK 31.7 Copyright reserved: Slides prepared by Prof. C. Simon 1. What part of a parasitic nematode’s anatomy protects it from the digestive enzymes of its host? 2. Which characteristics of Onycophora are similar to Annelida, and which are similar to Arthropoda 3. If an arthropod’s rigid exoskeleton cannot be expanded, how does the animal grow? 4. How do the number of body regions and the appendages on the head differ among the four groups of living arthropods? 5. How do the life stages differ between insects that have incomplete metamorphosis and those that have complete metamorphosis? Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.