Overarching Theme Adaptation ANIMALS What characteristics do all animals share?What are the important trends in animal evolution? Big Idea Annelids and Arthropods were first to develop adaptations such as segmentation.PHYLUM ANNELIDA Segmented WormsGeneral Characteristics Bilateral symmetry Three germ layers Coelomates Long, segmented body, each segment separated by internal walls called septa segments allow for specialization of tissue and efficiency of movement longitudinal and circular muscles which help in locomotion Complete digestive tract with mouth and anus at opposite ends: tube-within-a-tube Found in variety of habitats such as moist soil, fresh and salt water have the most developed sense organs seen thus far, especially in marine species sensory cells are receptive to chemical, mechanical and light stimuli most undergo sexual reproduction but some species can reproduce asexually by budding and regeneration TaxonomyClasses

A) Oligochaeta (= few bristles) e.g. earthworm & tubifex worms (fish food)- live in soil or fresh water, some in oceans- setae (bristles) on ventral side of bodyi) Feeding and Digestion- pharynx can extend through mouth- detritus feeders jaws covered in sticky mucus or act like pump to suck up food- earthworms form castings through digestion, this is major component of soil- food goes in mouth -> to crop (temporary storage) -> gizzard (grinds food into small pieces) -> to intestine (enzymes breakdown food) -> digested food absorbed into blood -> waste out anus (castings)

ii) Reproduction- permanent sex organs, hermaphroditic but must cross fertilize- two worms crawl into mating position and release mucus from clitellum, a dorsal, saddle-like swelling to aid in transfer of sperm- transfer sperm to sperm receptacle of each other- worms separate- mature ova and sperm shed in cocoon made by clitellum, fertilization external- zygote develops into microscopic ciliated larvae, then into baby earthworms

iii) Respiration- diffusion through moist skin- secrete a protective coating (=cuticle) to hold in moisture and produce a layer of mucusiv) Circulation- have a closed circulatory system, this is another evolutionary step and first appeared in annelids- two blood vessels run length of body- to head via dorsal vessel and to tail via ventral vessel- ring vessels in each segment supply blood to internal organs- five pairs of pulsating aortic arches (mini hearts) direct blood flow to specific regions of body

v) Excretion - paired nephridia in each segment, these are simple, tube-shape excretory organs that direct metabolic wastes to outside of body through minute pores in the cuticle- solid wastes go out anusvi) Nervous System- paired ventral nerve cord runs length of body- anterior dorsal bi-lobed ganglion (primitive brain)- nerves branch into each segment from nerve cordvii) Movement- two types of muscles longitudinal muscles: front to rear, allow animal to contract and expand in length circular muscles: encircle body, when they contract animal gets skinnier, this allows then to force their way through sediment/soil- setae push into soil and prevent worm from slipping backwardsviii) Ecological Role- break down organic matter- mix and aerate soil- important in composts- are eaten by many birds and other animals

Learning Activity Earthworm Sheet and Dissection

B. Polychaeta (=many bristles) e.g. sand worms, tube worms, clam worms- marine worms - variety of habitats; live in cracks & crevices in coral reefs, sand, mud, piles of rock, open water, burrow, in tubes- paired parapodia (paddlelike appendages) tipped with setae (bristles) on segments- parapodia used for walking, digging, as fins may be precursors of legs seen in later animals- e.g. sea mouse long bristles extend over back of worm (furlike)- well developed eyes, antennae, and sensory palps- mostly predators either by filter feeding (e.g. tubeworms have featherlike structures to sift detritus and plankton from water) or active hunters (sandworms hide in burrows and use powerful jaws to clamp onto prey)- external fertilization forms trocophore (ciliated larvae) juvenile worms adults - exchange gases using gills, e.g. Feather Duster, have large, coloured, feathery gills that protrude from burrow or tube- convert organic debris in oceans into CO2 used by marine plankton for photosynthesis C. Hirudinae (no bristles)- external parasites e.g. leeches, suck blood and tissue fluid- found in moist tropical countries - < 6 cm long, some tropical ones are 30 cm!- freshwater, some marine & terrestrial- are carnivorous not parasites eat invertebrates (snails, worms, larva)- oral chaetae (teeth) are specialized to pierce skin of host- produce and secrete hirudin, a chemical substance that has both anaesthetic and anticoagulant properties- powerful suckers at both ends that help them cling to their host- muscular pharynx sucks blood- can suck up to 10 times its weight in blood in 1 feeding- takes up to 200 days to digest its blood feast (with symbiotic bacterias help)- can live 1 year before next feeding- as with other parasites, do not have significant nervous, digestive, excretory or circulatory systems- reproduce in manner similar to earthworms- can be used by humans to maintain blood flow after microsurgeries, reduce swelling and speed up healing of tissues

PHYLUM ARTHROPODA Arthro=jointed, Poda=feet

General Characteristics 3 cell layers Bilateral Symmetry. Coelom High degree of cephalization Jointed appendages 3 body regions (head, thorax, abdomen) segmented body shows evolutionary relationship with annelids, most clearly seen in Chilopoda, Diplopoda and larval (like caterpillars) stage of some Insecta Exoskeleton of chitin + protein: secreted by the epidermis (pro-good protection, con-only moves at joints, cannot get bigger, so must molt) Most dominant and widespread life form on Earth 70- 85% of all animals are arthropodsi) Respiration - use one of three structures - gills, tracheal tubes, or book lungs (see diagram)- terrestrial arthropods depend on respiratory system with tracheal tubes rather than circulatory system to carry O2 to cells- spiders and other arachnids use book lungs- aquatic arthropods use gills in similar manner to mollusksii) Nervous System Sensory organs are well-developed: compound eyes, tympanum (ear), antenna (touch, smell, chemical reception). dorsal brain, connected by a ring and a double nerve cordiii) Feeding and Digestion Mouthparts usually include pair of mandibles for biting and chewing Digestive system: complete, mouth, intestine and anus. Glands produce digestive enzymesiv) Movement Locomotion: many different adaptations for movement such as walking legs, wings, swimming appendages Quick, active animals with well-developed muscle systemv) Reproduction- dioecious= separate sexes (except for a few such as barnacles)- fertilization usually internal- sexual reproduction vi) Excretion - solid waste out anus, - metabolic waste out malpigian tubules in terrestrial arthropods, out green glands (modified nephridia) in aquatic arthropodsvii) Circulation- open circulatory system - dorsal vessel acts as a heart, which delivers body fluids to tissues throughout body chamberviii) Ecological and Economic Role- Arthropods as Food:- Crab, lobster, shrimp, crayfish many coastal economies rely on these- Foods for birds and insects- Zooplankton and small crustaceans (krill) are food for fish and aquatic mammals- Honey-bee: produces honey and royal jellyBeneficial Arthropods:- Spiders: control aphids- Bees: pollination, wax, honey- Silk: larvae of silkworm mothHarmful Arthropods:- Locusts: destroys crops- Mosquito: carries diseases- Barnacle: foul bottom of ships- Termites: destroys wood- Spiders and scorpions: poisonous bites

Confirm your Knowledge Insect Rsum Assignment, due __________________________

ix) TaxonomyPhylum Arthropoda is so huge that it is divided into four subphyla, which are in turn divided into classes.Subphyla:1. Trilobita -extinct now, fossils show development of exoskeletons, jointed appendages and three body segments2. Chelicerata All chelicerates have a body divided into a cephalothorax (fused head + thorax) + abdomen Unique to chelicerates are two pairs of appendages attached near mouth: chelicerae (spiders use these to bite and paralyze prey, they then inject enzymes that liquefy the prey and they suck the juice out) pedipalps (usually for handling prey; in scorpions, modified into huge claws) All spiders produce silk. Some spin webs using spinnerets, are abdominal appendages Ticks and mites are usually parasites Silk used for webs, protecting eggs and capturing preyi) Class Arachnida Spiders, scorpions, ticks, mites All have 4 pairs of walking legs Most are carnivorous ii) Class Merostomata Horseshoe crabs: living fossils, basically unchanged for 200 million years! Not really crabs (lack antennae and segmented abdomen of crustaceans) Catch food with their chelicerae Eyes on sides of their carapace (shell)

3. Crustacea (subphylum and class) Includes all crustaceans: crabs, prawns, lobster, crayfish, copepods, water fleas, barnacles Primarily aquatic Vary widely in size microscopic to 6m Usually have a very hard exoskeleton reinforced with calcium salts Usually have 2 pairs of antennae and a pair of mandibles 5 pairs of walking legs, with first pair specialized into pincers for grasping Have head, thorax and abdomen Head and thorax can be fused into a cephalothorax Appendages vary greatly; crayfish have claws, walking legs, swimmerets and uropod Have bristles over body, sense organs

4. Uniramia - millipedes, centipedes, and all insectsi) Class Chilopoda 12 | Page

1 pair of legs per segment Centipedes are carnivores poison fangs very fast

ii) Class Diplopoda 2 pair of legs per segment Millipedes are scavengers Fairly slow Moist habitats

iii) Class Insecta Huge group, 76% all animal species All have a head, thorax and abdomen 3 pair of legs attached to the thorax Include herbivores, predators, parasites, scavengers social behavior of many species, division of labour, these allow for success of this class

Learning Activity Stations Lab

Insect Adaptations Insects have structural and functional adaptations that have enabled them to become the most abundant and diverse group of arthropods. About 80% of all arthropods are insects

Metamorphosis: abrupt and pronounced changes in appearance (egg to an adult)4 types of metamorphosis:1. No Metamorphosis: egg, young adulte.g. Silverfish

2. Incomplete Metamorphosis: egg, naiad, adulte.g. dragonfly or mosquito1. Egg: laid in water2. Naiad: is aquatic (grows by molting)3. Adult: aerial (flies)

3. Gradual Metamorphosis:e.g. grasshopper1. Egg2. Nymph3. Adult

4. Complete Metamorphosis:1. Egg2. Larvae (segmented) caterpillars, grubs.3. Pupae (resting period) cocoon4. Adult: no further molting. 90% of insects go through this stage

Molting (occurs in other arthropods as well such as Crustacea and Chelicerata) Epidermis digests inner part of exoskeleton and absorbs much of chitin to recycle Secretes new exoskeleton inside of the old one, then pulls out of old one Often eats the leftovers! Why waste good nutrients? Expands, puffs out to new size Takes a few days to harden, vulnerable Molts several times (depends on species) b/w hatching and adulthood

Legs- adapted to a variety of functions depending on habitat and food source

Wings- insects are only invertebrates that can fly- has allowed them to disperse long distances and colonize wide variety of habitats- wings are outgrowths of body wall made of thin double membrane of chitin (how are these different than vertebrate animal wings?)- for flight, need adaptations for complex coordinated body movements to ensure upward lift, balance and steeringMouthparts- all insects have three pairs of appendages used as mouthparts but these are adapted to type of food insect eats

- grasshoppers have piercing mouthparts to cut plant tissue (mandibles) and other mouthparts to bring food into mouth (palps)- butterflies and moths have long tube that is coiled and uncoiled to draw nectar from flowers, like sipping through a straw- mosquitoes have thin, needlelike tubes to pierce skin to suck liquids into mouth- flies have a fleshy end to their mouthpart that acts like a sponge to mop up foodInsect Societies- insects such as honeybees, termites and ants organize into social groups and cooperate in activities necessary for their survival- within a society, individuals are specialized to perform specific tasks- also have created adaptations for communication techniques; in the honeybee, the waggle dance is used to tell others where food is located in their habitat- other communication can be done visually (e.g. bioluminescence in fireflies), by sound (grasshoppers rubbing legs against wings), touch (ants touching antennae to pass on messages), or chemically (trail pheromones used by caterpillars to create map to food source that others can follow)

Connections to Biological Theme Describe the evolutionary advantage of body segmentation, first seen in annelids.Segmentation of the body plan is important for allowing different regions of the body to develop differentially for different uses. But why should segmentation be so advantageous? Over millions of years, and exposure to changing environmental constraints, it is easier for an animal to specialize a segment into a specific tool in response to a need, than to create a whole new organ from scratch.

In 2010, researchers found that the genes controlling segment formation during embryo development are almost the same in drosophila (an arthropod) and in annelid marine worms, on which they concentrated their studies. These similarities led them to conclude that the genes had been inherited from a common ancestor, which was itself segmented. It also appears that vertebrates inherited this characteristic from an ancestor they share with the arthropods and the annelids.____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Evaluate three adaptations of insects in terms of the role they played in enabling insects to become so diverse and abundant.____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________