Animal Kingdom Ch 30 31 32 Kingdom Animalia

Animal Kingdom - Ch 30, 31 & 32. Kingdom - Animalia Topics • Animal – definition • Body organization and classification • Monophyletic groups and Phyla • Major representatives of Phyla

Animal Kingdom - Ch 30, 31 & 32. pp. 622 -623. Who are Animals? • Very diverse with some common characteristics – – – Multicellular eukaryotes Heterotrophs Cells are specialized - for various functions Most - capable of locomotion Most - nervous systems and muscles Most - reproduce sexually • • Haploid gametes form zygote that cleaves In embryogeneis, a ball of cells, blastula Undergoes gastrulation (infolding of cells making germ layers) Complex levels of differentiation, some metamorhosis

Animal Kingdom - Ch 30, 31 & 32. pp. 625 -627. Classification • Earliest fossils ~600 mya; land ~440 mya • <5% of all animals are vertebrates – Includes fish, amphibians, reptiles, birds, mammals • Invertebrates lack backbone – Includes sponges, jellyfish, worms, mollusks, insects, crustaceans

Body Symmetry Animals - Ch 30, 31 & 32 pp. 626 -628. • Parazoa (sponges) and Eumetazoa • Eumetazoa - radial or bilateral symmetry – Radial: body arranged as spokes in a wheel – Bilateral: body arranged as mirror-image along a central axis • Most Eumetazoans - bilaterally symmetric – Each half identical, or very similar at least – Tendency toward cephalization - head with sensory structures, neural integrating systems located – Diploblastic or triploblastic – Triploblastic – acoelomates, pseudocoelomates, coelomates

Animals - Ch 30, 31 & 32 p. 627 -630. Embryonic Germ Layers • Ectoderm: outer layer - makes outer covering, nervous system • Endoderm: lining of the digestive tube and digestive organs – Cnidarians and ctenophores are diploblastic • Mesoderm: muscles, skeleton, and circulatory system – All animals besides the Cnidara and Ctenophora are triploblastic

Triploblastic Body Plans • Acoelomates • Pseudocoelomates (probably evolved by simplification of coelomates – not monophyletic) • Coelomates Animals - Ch 30, 31 & 32 pp. 628 -630.

Animals - Ch 30, 31 & 32 pp. 630 -631. Protostomes and Deuterostomes • During gastrulation - cells move, blastopore forms • Protostomes – Blastopore becomes mouth – Spiral cleavage in embryo – Determinate cleavage - Embryonic cells develop into fixed body parts • Deuterostomes – Blastopore becomes anus, second pore - mouth – Radial cleavage – Indeterminate cleavage - Each cell can make an adult

Animals - Ch 30, 31 & 32 p. 629.

Animals - Ch 30, 31 & 32 p. 632. 6 main animal clades based on molecular data Parazoa, Radiata, Biradiata, Lophotrochozoa, Ecdysozoa, Deuterostomia.

Six animal clades and their phyla 1. PARAZOA – – specialized cells, but no tissues no germ layers, no muscle tissue, no nervous tissue Phylum PORIFERA – sponges 2. RADIATA - radial symmetry - diploblastic (two germ layers) – ectoderm, endoderm - muscle and nervous tissue present - nervous system a “nerve net” Phylum CNIDARIA – jellyfish, sea anemones, corals, etc.

3. BIRADIATA phylum PTINOPHORA – comb jellies 4. LOPHOTROCHOZOA phylum PLATYHELMINTHES - flatworms phylum MOLLUSCA – squids, octopi, oysters, clams, snails, slugs, conchs, etc. phylum ANNELIDA – segmented worms - bilateral symmetry - triploblastic (3 tissue layers – ectoderm, mesoderm, endoderm) - protostome pattern of development (spiral cleavage, blastopore develops into gut)

5. ECDYSOZOA – these animals must molt (ecdysis) in order to grow phylum NEMATODA - roundworms phylum ARTHROPODA - arthropods 6. DEUTEROSTOMIA - bilateral symmetry - triploblastic (3 tissue layers – ectoderm, mesoderm, endoderm) - deuterotostome pattern of development (radial cleavage, blastopore develops into anus) Phylum ECHINODERMATA – sea stars, sea cucumbers, sea urchins, sand dollarrs, etc. Phylum CHORDATA – lancelets, sea squirts, lampreys, vertebrates, etc.

Phylum PORIFERA -sponges -specialized cells but no tissues -sessile as adults -no nervous system, no muscles -plankton filter feeders -skeleton consists of spongin and inorganic spicules

Phylum CNIDARIA – basic morphological features • • radially symmetric diploblastic (ectoberm + endoderm) possess a gelatinous layer (=mesoglea) specialized defensive cells on tentacles (=cnidocytes) • “nerve net” type nervous system • gastrovascular cavity

“cnidocyte” – specialized cell that discharges poisons-tipped barb into prey or potential predator

Two body forms in Cnidaria The Polyp is sessile with tentacles oriented upwards and outwards: - sea anemone - corals - Hydra The Medusa is free-swimming with tentacles dangling downwards: - jellyfish

Phylum CNIDARIA - classes • class HYDROZOA – Portuguese man-o-war – Hydra – other colonial forms • class SCYPHOZOA – jellyfish • class ANTHOZOA – sea anemones, corals Physalia – “Portuguese Man-o-war” a colony (zoon) of specialized zooids

Class SCYPHOZOA – adults are “jellyfish” medusa body form

Class ANTHOZOA – sea anemones

Phylum PLATYHELMINTHES classes • class TURBELLARIA – free living flatworms • class CESTODA – tapeworms – intestinal parasites of vertebrates – body of adult tapeworm consists of scolex and string of zooids called proglottids • class TREMATODA – flukes – organ parasites of vertebrates – an oral sucker and a ventral sucker present

Class TURBELLARIA – free-living flatworms

Class - CESTODA scolex hooks acetabula (suckers) proglottid (not segments)

Class TREMATODA flukes

Phylum ANNELIDA - segmented worms • body consists of metameres or “segments” – repeated identical body units • triploblastic • coelomates • closed circulatory system consisting of series of “pumps” or ostia • ventral nervous system • complete digestive system (mouth and anus present)

Phylum ANNELIDA classes • class OLIGOCHAETA – earthworm, etc. no appendages, clitellum evident • class HIRUDINEA – leeches – external blood-sucking parasites of vertebrates oral and posterior suckers, segments divided into annulets • class POLYCHAETA – marine worms, plume worms, sandworms, etc. unsegmented parapodia usually present

Class OLIGOCHAETA - earthworms

Class HIRUDINEA - leeches

Class POLYCHAETA In plume worms and fan worms, parapodia are modified as plankton-trapping structures

Phylum MOLLUSCA • • • coelomates bilateral symmetry triploblastic open circulatory system complex nervous system mantle and mantle cavity – flap of tissue covering the visceral organs - highly modified in some groups • mantle secretes calcium carbonate exoskeleton in many mollusks • muscular “foot” – highly modified in some groups

Phylum MOLLUSCA - classes • class POLYPLACOPHORA – chitons – 8 overlapping platelike shells • class BIVALVIA – bivalved mollusks – clams oysters, mussells, scallops, etc. – shell in two symmetrical parts, hinged along one edge • class GASTROPODA - snails, slugs, nudibranchs, conchs, etc. - coiled shelled mollusks • class CEPHALOPODA – squids, octopi, cuttlefish, chambered nautili, etc – muscular foot modified as ring of tentacles and arms around mouth.

Class POLYPLACOPHORA

freshwater mussell Class BIVALVIA oysters giant clam of the great barrier reef

Class GASTROPODA

Class CEPHALOPODA cuttlefish octopus squid chambered nautilus

Phylum NEMATODA – roundworms – morphological features • they are not segmented • they possess an external cuticle • they are pseudocoelomates • they must undergo ecdysis like arthropods large intestinal roundworm

many nematodes are parasaites of humans and other vertebrates heartworm hookworms whipworms filarial worms

Phylum Arthropoda

Phylum ARTHROPODA subphyla and classes • subphylum Myriapoda – classes, Chilopoda (centipedes) and Diplopoda (millipedes) • subphylum CHELICERATA – classes, Merostoma (horseshoe crabs) and Arachnida (spiders, scorpions, ticks, mites, horseshoe crabs) • subphylum CRUSTACEA – Classes, Malacostraca (crayfish, lobsters, shrimp, crabs, isopods) and Cirripedia (Barnacles) • subphylum Hexapoda – Class, Insecta (insects)

Subphylum - Myriapoda Diplopoda - millipedes – 2 pairs of legs per segment Chilopoda – centipedes - 1 pair of legs per segment

Subphylum - Chelicerata Class - Arachnida walking legs • 4 pairs of walking legs • 2 tagmata (cephalothorax + abdomen) • pedipalps • chelicerae (=“fangs”) • antennae absent pedipalps chelicerae abdomen cephalothorax

Subphylum - Crustacea Class - Malacostraca • 5 pairs of walking legs • 5 pairs of swimming legs • 5 pairs of mouth appendages • 2 tagmata (cephalothorax + abdomen) • 2 pairs of antennae cephalothorax abdomen

Subphylum - Hexapoda Class - Insecta • 3 pairs of walking legs • Wings usually present • 3 tagmata (head + thorax + abdomen) • 1 pair of antennae