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1  of 13 BIO203 - Animal Diversity Lecture 1 - Evolution • Zoology is the scientific study of animals • Science is the acquisition of knowledge guided by hypotheses that are explanatory • Scientific method; hypotheticodeductive • A testable hypothesis for which there is a lot of supporting data is called a theory • Darwin presented the first credible explanation for evolutionary change; evidence derived from 5 year voyage. • Darwinism is made up of;" Perpetual Change; the notion that the earth is always changing" Common descent; all organisms descended from a common ancestor" Multiplication of species; Allopatric - overcoming reproductive barriers geographically; Adaptive radiation is proliferation of many adaptively disparate species." Gradualism; small changes over a long period of time" Natural selection; survival of the fittest, the strongest reproduces • Microevolution; Genetic change in a population and a change in the relative frequency of alleles." Processes for genetic change are…" 1. Mutation" 2. Genetic drift" 3. Non-random mating" 4. Migration" 5. Natural selection • Macroevolution is the large scale events and processes. • Speciation links micro and macro evolution. Lecture 2 - Animal architecture and class-action and phylogeny • 5 levels of organisation" 1. Protoplasmic (Eg protozoans)" 2. Cellular (Eg metazoa; sponges)" 3. Cell tissue (Jellyfish)" 4. Tissue-organ (Platyhelminthes)" 5. Organ-System (Simplestl nemeterean) • Body symmetry can be…" 1. Spherical - mirrored when body is cut any way through the centre." 2. Radial - can be divided into similar halves by more than one plane." 3. Bilateral - Divided in the middle and mirrored • Cephalisation refers to the concentration of nervous tissues and sense organs up one a bilateral animal. This results in a distinct head often. It’s efficient for information gathering and sensing. Normally the mouth is associated with the head. • Embryology zygote>blastomeres>blastula>gastrula • Cell cleavage in embryos can be either;" Radial - where cells are symmetrically cleaned around a polar axis. This produces tiers of cells and occurs with regulative development." Spiral cleavage - Where cells cleave obliquely and occurs with mosaic development. • Regulative development refers to each blastomere developing independently " Mosaic development refers to the notion that blastomeres cannot survive independently • Blastocoel = fluid filled cavity inside blastula • The components of a Gastrula is the ectoderm (outer germ cell layer); endoderm (inner germ cell layer); gastrocoel • Body cavity exposes more cells to O2. Allows for greater body flexibility and space for organs. • Three body cavities;" 1. Coelomate - Organs and gut are embedded within a parenchyma. (flatworm)" 2. Pseudocoelomate - Cavity surrounding gut; absent of peritoneum (nematodes)" 3. Eucoelomate - Body cavity with peritoneum that is derived from mesoderm. (annelids/insects/ chordates)

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1. Protostome > spiral cleavage > mosaic development > mouth is first opening (molluscs/ annelids)" 2. Deuterostome > radial cleavage > regulative development > any is first opening (echinoderms/chordates) Metameism refers to the creation of repeated body segments. Each segment is a meatier or somite. Occurs in annelida, arthropoda, chordata. Metazoan bodies have cellular components derived from ectoderm, mesoderm, endoderm and extracellular tissue." Cellular components = tissues" Extracellular = fluid/structural elements (bone/cartilage/cuticle/plasma/lymph/interstitial fluid) Tissue types;" 1. Connective tissue" 2. Nervous tissue" 3. Epithelial tissue" 4. Muscle tissue Phylogeny : the evolutionary relationships among organisms Systematics: science of classification Classification: grouping of organisms based on similarities and differences; reflecting evolutionary relationships." Taxonomy: Naming organisms Linnaeus developed current hierarchical classification system. With latin genus and species name. Zoological nomenclature;" 1. Kingdom" 2. Phylum (subphylum, infraclass)" 3. Class (subclass)" 4. Order (suborder)" 5. Family (subfamily)" 6. Genus" 7. Species (subspecies) The criteria for species;" - Common descent; members of a species traced to common ancestral population" - Smallest distinct groupings" - Reproductive community What are the three concepts of species?" 1. Biological Species Concept (BSC) Interbreeding/common descent/same niche" 2. Evolutionary Species Concept (ESC) common descent/asexual & sexual/ evolutionary context" 3. Phylogenetic Species Concept (PSC) common descent/asexual & sexual/geographically disjunct populations may be judged separately. Ancestral character state = common to a group of organisms and more recent ancestors Derived character state = characteristic developed since ancestral character state Outgroup (Eg birds when discussing reptiles) Clade = group of organisms that share a derived character state Homology = morphological characteristics occurring as a result of common ancestry

Lecture 3 - Sponges/Radiate/Acoelomate & Pseudocoelomate animals • (Porifera) Sponges are the simplest multiceullar animals • Sponges are of cellular level organisation, they are filter feeders, have no nervous system or sense organs or muscles. Their bodies are mass of cells embedded in a gelatinous matrix and held together by a skeleton of spicules. Mostly marine, some freshwater. Sessile. • Four classes of sponge;" 1. Calcarea - spicules are calcium carbonate" 2. Hexactinellida - spicules of silicon, rigid, 6 pointed" 3. Desmospongiae - silicon & spongin (most common sponge and used as bath sponges)" 4. Homoscleromorpha - spicules absent or small

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• General structure of porifera; outer covering of flat pinacocyte cells, middle layer acts a s a supporting skeleton, inner layer contains collar, cells are for food absorption.

• Three types of canal systems;"

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1. Asconoid; simplest tubular form" 2. Syconoid; more complex; folded" 3. Leuconoid; ball shaped, most complex Venturi effect - shape of sponge distorts the current so water flows faster at the top which pulls it up through pores and out osculum. Reproduction of porifera; sexual and monoecious, but also asexual Phylum Cnidaria; widespread marine environments and some freshwater; corals/jellyfish/ anemones, have cnidocytes (stinging organs), sessile and free living, some are symbiotic, coral reefs are important structures. Life cycle of Cnidarians; either a polyp or medusa form as adults. Polyps are sessile, asexual and can form colonies; medusas are free swimming and have various kinds of reproduction including a polyp phase. Feeding and digestion; mouth opens into gastrovascular cavity and is connected to the cavity in the tentacles. Prey are drawn into gastrovascular cavity and enzymes are discharged. Body layers;" 1. outer epidermis" 2. middle mesoglea" 3. inner gastrodermis Nematocysts are stinging cells, there are 20 differen types and the most common is a capsule contained by a coiled, barbed thread, covered by a lid. Under high osmotic pressure to flick our and barb prey. Classes;" 1. Hydrozoa - chitin and protein, asexual and sexual (bluebottles)" 2. Scyphozoa - cup and bell shaped, true jellyfish" 3. Cubozoa - square bell with a tentacle at each corner (box jellyfish)" 4. Anthozoa - corals and sea anenomes, brightly coloured in warm shallow water" 5. Staurozoa - solitary polyp Phylum Ctenophora; comb jellies, all marine, transparent, drift in warm seas, luminescent at night, sticky tentacles. Acoelomates have organ-system level organisation, bilateral symmetry and a distinct head. They have a dorsal and ventral surface. Three phylums;" 1. Platyhelminthes (flatworms) - dorso-ventrally flattened; incomplete digestive; simple nervous; simplest animals with excretory systems; often involve many hosts" 2. Nemertea (ribbon worms) - first to evolve separate mouth and anus, mostly marine but a few freshwater and terrestrial. Predators, can fragment to reproduce but also sexual." 3. Gnathostomulida (jaw worms) - wormlike, scrape bacteria and fungus" 4. Micrognathozoa; only one species in greenland Phylum rotifera - large ciliated crown, eat phytoplankton Phylum Acanthocephala - spiny headed worms, parasitic, has cylindrical probiscus Phylum Cycliophora - 3 species only, parasitic on cray fish Phylum nematoda, parasite, roundworms, hookworms, pinworms, filarial worms. Smooth, featureless, lack of specialisation allows them to occupy a lot of habitats. High hydrostatic pressure. Phylum Nematomorpha - gordian worms Phylum Tardigrada - water bears, can survive desiccation, extreme temperatures, radiation and vacuums of space.

Lecture 4 - Molluscs • Coelomate, possible shared ancestry with annelida, ancestral molluscs in pre Cambrian oceans, bilaterally symmetrical, ovoid, dorsal surface covered with a shell. First shell tough cuticle, then calcium carbonate. Organ-system, definite head, often with tentacles, well developed sense organs, many have radula, varied respiration, most have kidneys, most dioecious

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• Generalised body plan; visceral mass (mantle, shell, mantle cavity), head & foot (for anchorage and movement)

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1. Aplacophora: Wormlike, without shell" 2. Monoplacophora: Until recently, only fossils, deep sea, low rounded shell, creeping foot." 3. Polyplacophora: chitons, sedentary, marine, 8 dorsal plates" 4. Scaphopoda: Tusk or tooth shells" 5. Gastropoda: snails, limpets, slugs, whelks, conchs, sea slugs; shell one piece, bilateral symmetry. Coiling of shell is the spiral winding for balance and compactness. Torsion shell, twisting shell 180 degrees anti clockwise." 6. Bivalvia: Laterally compressed with two valves; mussels, clams, oysters, shipworms" 7. Cephalopoda: Cuttlefish, squid, octopus. Marine predators, tentacles, arms. Bivalve feeding: water enters through inhalent siphon and exits through exhalent siphon. Ciliar create water currents. Food passed down to groom and then to mouth. Bivalve repro: sexes usually separate, external fertilisation Glochidia can attach to gills or fins of fish and can be specific to particular species. Cephalopod characteristics; well developed brain and eyes, colour changes, locomotion by expelling water, sexes separate, courtship behaviour.

Lecture 5: Annelids • Are eucoelomate • CNS, complex circulatory system, metamerism, digestive tract and blood vessels entire length, outer layer flexible cuticle, respiration through skin, gills, prarpodia. Each segment contains fluid filled coelom. • Errantia: free living polychaete • Sedentaria: sedentary polychaetes, oligochaetes Lecture 6: Arthropods • So many arthropods because;" 1. Versatile exoskeleton - procuticle mad of chitin, very tough" 2. Segmentation - allow for articulation" 3. Joint appendages - rapid and versatile movement" 4. Oxygen piped directly to cells via trachea" 5. Highly developed sense organs - balance/chemo reception" 6. Complex behaviour patterns" 7. Metamorphosis - allows different habitats and food etc • Class: Merostomata - giant water scorpions • Class: Pycnogondia - long legged sea spiders • Class: Arachnida - Aranea: spiders, 4 legs, 8 simple eyes, pair pedals, poison glands, sping ailk." Scropionida - scorpions; pedipalps are claws." Pseduoscorpionida - no stinging tail" Opiliones - harvestmen, no pedicel separating thorax and abdomen" Acari - ticks and mites, mouthparts sit on protruding capitulum" Solpugida - sun or camel spiders, voracious, non venomous" Crustacea - strongly segmented, brood and care for young, first walking leg with chela, 2 antennae, 2 maxillae, respiration via gills, excretory organs in head • Class Branchiopoda - fairy shrimp, tadpole shrimp, filter feeders • Class Maxillopoda • Class Malacostraca - Isopoda (strongly segmented); Amphipoda (scuds)" Decapoda: crabs, lobsters, fish, 5 pairs of legs • Subphylum myriapoda: chilpoda (predators/each segment 1 pair of appendages/flattened torsoventrally) and diplopoda (generally herbivores/cylindrical/ two sets per segment) • Subphylum Hexapoda" Class Insecta • Class Insecta; 3 body segments, 3 pairs of legs, 1-2 pairs of wings, legs and wings attached to thorax, large compound eyes, mouth pats complex

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• Flight can happen in two ways and is controlled by thoracic muscles;" •

1. Direct flight muscles attached to wings (locusts/dragonflies/cockroaches)" 2. Indirect flight muscles, move by modifying shape of thorax Feeding is specialised to diet and there are three main types;" - Chewing: well developed mandables and strong toothed plates" - Sucking: tube for sucking pollen or sponge mop " - Piercing mouthparts - needle like stylets"

Lecture 7 - Echinoderms • All marine; starfish/brittle stars/sea urchins/sea cucumbers • Particle feeders, grazers and predators • General; ambulacral grooves radiate from mouth for feeding; Tube feet and spines project from tubes; upper surface with spines, ossicles (plates under epidermis); anus and water sieve (madreporite), eucoelomate, radially symmetrical, unique water vascular system, canals lead off to rows of tube feed, ampullae have sucker on the end for grip. • Classes;" 1. Asteroidea - sea stars and star fish, skin heavily armed with ossicles, tube feet have suckers to grip prey." 2. Ophiuroidea - Brittle stars, marine, each arm has slits at the base - respiratory and genital functions, tube feet produce sticky mucous for grip, arms extremely long and agile, no anus" 3. Echinoidea - sea urchins, marine, cylindrical bodies encased in a tough shell. Artistotle’s lantern for mastication (five bony toothed section and muscular retractors)" 4. Holothuroidea - sea cucumbers, marine, bottom surface with tube feet for crawling along sea floor. Mouth surrounded by 10-30 tentacles, covered in mucus to catch plankton, long digestive tube that opens into a swollen chamber. Trunk of respiratory tree opens into cloaca." 5. Crinoidea - feather stars/sea lilies - live in depths of up to 4000m, free living adults, attached to sea bed during larval stage, bright crowns, flexible stalks. 5-200 feathery arms. • Most echinoderms are carnivorous, sea star has a two part stomach, unselective, tube feet used to catch food. • Echinoderm reproduction: " - Most separate sexes" - Pair of gonads" - External fertilisation" - Arms can regenerate" - Free swimming bilateral larvae • Water-Vascular system: unique to echinoderms, it is a combination of canals, tuber feet and dermal ossicles that form a hydraulic system. The functions of which include locomotion, feeding, respiration and excretion. It opens through the medreporite. Process;" 1. Madreporite" 2. Stone canal" 3. Ring canal around mouth" 4. Radial canals" 5. Ambulacral groove in arms" 6. Lateral canals" 7. Tube feet • Phylum Hemichordata - marine, gill slits and dorsal nerve chord (as so, was previously classified as chordate, but is actually not related, this is not homologous.) Eg acorn worms. Lecture 8 - Fishes and Vertebrate beginnings • Phylum Chordata, at some stage in their lives chordates all have…" 1. Notochord - Flexible, rodlike, length of body, fluid filled sells, hydrostatic, primary purpose is to stiffen the body." 2. Dorsal nerve chord - anterior end enlarged to form a brain " 3. Pharyngeal pouches and slits - cavities that have given rise to tonsils, ear cavity, perforated pharynx for filter feeding and development of gills"

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4. Postanal tail - motility for swimmng, waggle tail for communication etc, vestige in humans" 5. Endostyle or thyroid, secretes mucous to trap food. Subphylum; Urochordata - Sea Squirts, marine, shallow-deep water, headless, larvae have notochords Subphylum,; Cephalochordata - lancelets, small, slender, translucent, marine, has simple nerve chord Subphylum Craniata (Vertebrata) all have" 1. Skulls" 2. Endoskeleton" 3. Efficient respiration" 4. Well developed head" 5. Coelom" 6. Paired limbs Evolution vertebrata: Earliest were small, jawless, fish like creatures, lacke paired fins, had bony armour, descendants include today’s jawless fishes. Evolution of jaws came from gill arch, hardened gill arches (placoderms; the first jawed vertebrates that were heavily armoured, appeared in Devonian but became extinct with no descendants) What is a fish?" - Lives in water" - Has fins instead of limbs" - Cold blooded" - Scales" - Gills" - Lateral line" - Vertebrae" “An aquatic vertebrate with gills throughout life and limbs in the shape of fins.” " Ichthyology is the study of fish. Diversity of fishes; most numerous group of vertebrates, over 28,000 living species. Diversity of extremes;" - Habitat; some live in the heart of a large shark (Simenchelys parasiticia)" - Size; 8mm-20m" - Temp; 1.8-40 degrees" - Altitude; 8km deep, 7km above sea level" - Adaptions; camouflage, attractants, predator avoidance, prey ambush Why have fish been so successful in exploiting aquatic environments?" - Gravity is less important, allows for efficient locomotion" - Water is a better conductor than air so detection of prey is more efficient" - Less temperature extremes than in air Swimming;" - Most economical form of animal locomotion" - Trunk muscles are myomeres" - Body shape and fins are closely tied with life history Neutral buoyancy;" - Many fish are weightless in water" - gas filled swim bladder; evolved from lungs of primitive devonian fishes Lateral line" - detects mechanical disturbance Respiration" - Gills, counter current flow" - Operculum, negative pressure Osmotic regulation" - Freshwater fish: higher blood salt concentration than freshwater, so water enters their bodies via osmosis and excess water is pumped out via kidneys, salt absorbing cells in gill epithelium. “Hyper-osmotic regulators”"

7  of 13 - Marine fish: lower blood salt concentration than seawater, water loos from bodies, salts gained via osmosis. Drink water, salt-secretory cells in gills. “Hypo-osmotic regulators” • Scales function as a barrier against disease, infection and predators and also aids in ion exchange. • Reproduction;" Oviparous - eggs released by female, development occurs outside maternal body" Viviparous - eggs develop within female body which supplies nutrition " Ovoviviparous - eggs develop within female body, without additional nourishment from parent. • Bony fishes - Actinoptergyii (ray finned fishes) and…. Sacropterygii - lobe finned fishes might have given rise to land vertebrates because the have a modified swim bladder that is like a lung and fleshy lobed fin legs. • Why are Actinoptergyii so successful? 96% of all living fish species" - thin, flexible cycloid and ctenoid scales" - Buoyancy; swim bladder" - Symmetrical shape of homocercal tail" - Elaboration of fins" - Changes in jaw suspension" - Increased mobility and speed for predator avoidance and feeding efficiency • Chondrichthyes: cartilaginous fish (sharks and rays) • Sharks" - cartilaginous skeleton" - 5-7 gill slits" - No swim bladder" - upper jaw not fused to cranium • Rays" - Dorsoventrally flattened bodies" - Gills, mouth, lateral line on underside of bodies" - Teeth; crushing plates • Lampreys; Petromyzontida" - No jaw Lecture 9 - Amphibians and Reptiles • Difference between life on land and water" - Oxygen content greater in air and diffuses rapidly" - Temperature fluctuations are much greater on land" - Desiccation is a problem" - Support structures need to be stronger on land" - Different food resources" - Reproduction challenges, especially for those that have lived in water up until now. • Early tetrapods and amphibians" - Two important features; lungs and legs • Lungs; in dry periods, water bodies disappeared, fish that survived had lungs that were an outgrowth of the pharynx which led to the evolution of the circulatory system; heart and lungs. Confident with" - Lowest oxygen levels" - Max plant diversification " - Changing landscape" - Decaying plant matter" - Deoxygenating water bodies " - Progressive increase in s...