INVERTEBRATE ZOOLOGY

Three Domains of Life Three large groups called domains Three large groups called domains Bacteria - prokaryotes Bacteria - prokaryotes Archaea - prokaryotes Archaea - prokaryotes Eukarya - eukaryotes Eukarya - eukaryotes Prokaryotic – cells lack a nucleus Prokaryotic – cells lack a nucleus Eukaryotic – cells possess a nucleus and membrane bound organelles Eukaryotic – cells possess a nucleus and membrane bound organelles

Classification is continually changing Classification is continually changing Some scientists don’t subscribe to the three domain method of classification Some scientists don’t subscribe to the three domain method of classification Some still use the Five Kingdom method Some still use the Five Kingdom method Domain Bacteria Domain Archaea

Domain Eukarya Domain Eukarya consists of several kingdoms Domain Eukarya consists of several kingdoms Protista - single celled (several kingdoms) Protista - single celled (several kingdoms) Plantae - multicellular Plantae - multicellular Fungi - multicellular Fungi - multicellular Animalia - multicellular Animalia - multicellular

Protists Kingdom PlantaeKingdom Animalia Kingdom Fungi

Diversity of Life DNA is the molecule responsible for diversity DNA is the molecule responsible for diversity Specific regions of DNA (genes) code for specific types of proteins Specific regions of DNA (genes) code for specific types of proteins Speciation occurs several ways Speciation occurs several ways Allopatric Allopatric Adaptive radiation Adaptive radiation Sympatric Sympatric If reproductive barriers arise between populations, speciation will occur If reproductive barriers arise between populations, speciation will occur Prezygotic barriers Prezygotic barriers Postzygotic barriers Postzygotic barriers

Invertebrate Zoology Study of invertebrate animals Study of invertebrate animals Inverts make up at least 99% of all extant (living) animal species on the planet Inverts make up at least 99% of all extant (living) animal species on the planet Over 1,000,000 described spp. (species) on the planet (mostly insects) Over 1,000,000 described spp. (species) on the planet (mostly insects) Estimated 10 to 30 million spp. have yet to be described Estimated 10 to 30 million spp. have yet to be described We will cover 19 (time permitting) of the approx. 35 animal phyla We will cover 19 (time permitting) of the approx. 35 animal phyla

Preview of Phyla Protozoa – animal-like protists Protozoa – animal-like protists Do not belong to kingdom animalia, and thus are not considered to be invertebrate animals Do not belong to kingdom animalia, and thus are not considered to be invertebrate animals Important evolutionary link between prokaryotes, and everyday plants and animals Important evolutionary link between prokaryotes, and everyday plants and animals Volvox

Phylum Porifera Sponges Sponges

Phylum Cnidaria Jellyfish, Anemones, and Corals Jellyfish, Anemones, and Corals Portuguese Man O’ War

Phylum Ctenophora Comb Jellies Comb Jellies

Phylum Platyhelminthes Flatworms Flatworms

Phylum Nemertea Ribbon Worms Ribbon Worms

Phylum Mollusca Chitons, Clams, Snails, Slugs, Squids, and Octopi Chitons, Clams, Snails, Slugs, Squids, and Octopi Banana Slug

Phylum Annelida Segmented Worms Segmented Worms

Phylum Echiura Spoonworms Spoonworms

Phylum Sipuncula Peanut Worms Peanut Worms

Phylum Tardigrada Water Bears Water Bears

Phylum Arthropoda Horseshoe Crabs, Arachnids, Crustaceans, Myriapods, and Insects Horseshoe Crabs, Arachnids, Crustaceans, Myriapods, and Insects

Phylum Gastrotricha Name means “stomach hair” Name means “stomach hair”

Phylum Nematoda Roundworms Roundworms Caenorhabditis elegans = good Ascaris lumbricoides = bad

Phylum Rotifera Wheel bearers Wheel bearers

Phylum Phoronida A lophophorate A lophophorate

Phylum Brachiopoda Lamp shells, another lophophorate Lamp shells, another lophophorate

Phylum Bryozoa Bryozoans, the largest phylum in the superphylum Lophophorata Bryozoans, the largest phylum in the superphylum Lophophorata

Phylum Echinodermata Starfish, Brittle Stars, Urchins, and Sea Cucumbers Starfish, Brittle Stars, Urchins, and Sea Cucumbers

Phylum Chordata Phylum Chordata is the only phylum containing vertebrate animals, however, there are some invertebrate chordates Phylum Chordata is the only phylum containing vertebrate animals, however, there are some invertebrate chordates

Taxonomy Linnean system (Kingdom, Phylum, Class, Order, Family, Genus, Species) is almost abandoned Linnean system (Kingdom, Phylum, Class, Order, Family, Genus, Species) is almost abandoned Genus species (binomial nomenclature) is still used Genus species (binomial nomenclature) is still used Lumbricus terrestris Lumbricus terrestris Scientists are more interested in evolutionary relationships (how are organisms similar / different), as opposed to what “What class do shrimp belong to?” Scientists are more interested in evolutionary relationships (how are organisms similar / different), as opposed to what “What class do shrimp belong to?” Taxonomic names, and proposed evolutionary relationships change frequently Taxonomic names, and proposed evolutionary relationships change frequently

Cladistics Method embraced by the authors of your text for constructing evolutionary relationships in the form of phylogenetic trees, or cladograms Method embraced by the authors of your text for constructing evolutionary relationships in the form of phylogenetic trees, or cladograms May be assembled according to morphology and/or molecular data (nucleic acid or amino acid sequences) May be assembled according to morphology and/or molecular data (nucleic acid or amino acid sequences) Can be used to infer a great deal about evolutionary relationships Can be used to infer a great deal about evolutionary relationships But it is easy to make mistakes But it is easy to make mistakes Homology – good indication of a relationship Homology – good indication of a relationship Analogy - misleading Analogy - misleading

Morphological Vs. Molecular Data Body Plan DatarRNA Data

Ground Plan For each Phylum we cover, you want to understand that group’s ground plan (basic set of characteristics) For each Phylum we cover, you want to understand that group’s ground plan (basic set of characteristics) These characteristics are useful for determining differences / similarities between phyla These characteristics are useful for determining differences / similarities between phyla Ground plan for Phylum Arthropoda (example): segmented body, chitinous exoskeleton, periodic molts, and jointed appendages Ground plan for Phylum Arthropoda (example): segmented body, chitinous exoskeleton, periodic molts, and jointed appendages