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147 Cards in this Set
- Front
- Back
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What defines Kingdom Animalia?
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A.multicellular heterotrophs
B.no cell walls C.monophyletic group (evolved from ancestral protist like modern choanoflagellates) |
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What characteristics are associated with animals?
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A.more than 1 million animal species have been described
B.diversity in form – invertebrates (no backbone; 99% of animals) and vertebrates C.sexual reproduction (few exceptions) |
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typically complex embryonic development for most animals
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1.zygote à morula (solid ball of cells)
2.morula à blastula (ball becomes hollow) 3.blastula à gastrula (ball folds in to form a hollow sac with one opening, the blastopore) 4.interior of gastrula eventually forms gut (tube in many) 5.blastopore becomes mouth or anus |
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Subkingdom Parazoa – Phylum Porifera
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the sponges
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What are some characteristics of Sponges
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A.asymmetrical
B.actually appears to be a grade C.cellular level of development – a loose confederation of cells D.spicules (calcium carbonate or silica) form scaffolding or “skeleton” E.larvae free-swimming (motile) F.adults sessile G.filter feeders H.5150 species, most marine |
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1.body has numerous small pores – water comes in through these to the interior spongocoel cavity
2.water leaves the spongocoel through a large pore, the osculum 3.tubes lined with choanocytes (flagellated cells also called collar cells) that move water using their flagellae What are these? |
filter feeders
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a protein - also supports body in some sponges
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spongin
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Form scaffolding or "Skeleton"
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Spicules
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Flagellated cells also called collar cells
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Choanocytes
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What are some characteristics of Subkingdon Eumetazoa?
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1.all with tissue layers
2.diploblastic – have two cell layers in embryo •ectoderm – outer layer; source of outer covering(epidermis) and nervous system •endoderm – inner layer; becomes gut (gastrodermis) •found in grade Radiata (radially symmetrical – Phyla Cnidaria and Ctenophora) 3.triploblastic – have three cell layers in embryo •mesoderm – middle layer between ecto- and endoderm; most organs form from mesoderm tissue •found in all of clade Bilateria (animals with bilateral symmetry at some point in their life cycle) |
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have two cell layers in embryo
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diploblastic
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outer layer; source of outer covering(epidermis) and nervous system
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ectoderm
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inner layer; becomes gut (gastrodermis)
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endoderm
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radially symmetrical – Phyla Cnidaria and Ctenophora
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Radiata
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have three cell layers in embryo
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3triploblastic
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middle layer between ecto- and endoderm; most organs form from mesoderm tissue
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mesoderm
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animals with bilateral symmetry at some point in their life cycle
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Bilateria
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Eumetazoa have undergone 4 key transitions in body plan during the course of evolution.
What are they? |
A.development of bilateral symmetry
B.development of the body cavity C.development of protostomes and deuterostomes (both appear to make clades) D.development of a segmented body plan (segmentation) in different groups |
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(found in grade Radiata) any plane through the central axis of the animal will produce two halves that are approximately mirror images of each other
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radial symmetry
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(found in clade Bilateria) body has left and right halves that are approximately mirror images of each other
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bilateral symmetry
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What is the Dorsal region?
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Back
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What is the Ventral region?
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Front
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Where is the Anterior region?
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Head
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Where is the Posterior region?
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Rear
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no cavity
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acoelomate
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have fluid-filled cavity between mesoderm and endoderm
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pseudocoelomate
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Name of the Fluid Filled cavity in the Pseudocoelomate
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Pseudocoel
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have fluid-filled cavity within mesoderm and surrounded by mesodermal tissue
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coelomate
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Name of the fluid fileld cavity in the Coelomate
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Coelom
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epithelium lining outer wall of coelom
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parietal peritoneum
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lining covering organs in coelom; also lines inner wall
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visceral peritoneum
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“first mouth”; blastopore becomes mouth
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protostomes
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“second mouth”; blastopore becomes anus
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deuterostomes
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Why is a coelom better than a pseudocoelom?
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endoderm and mesoderm are better able to communicate and coordinate during development because they are in direct contact
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What are some advantages of a segmented body plan?
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-redundancy
-more flexible locomotion -more opportunity for specialization |
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Information about grade Radiata
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A.radial symmetry
B.Phyla Cnidaria and Ctenophora C.tissues, but no true organs |
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stinging-celled animals: corals, hydras, anemones, and jellyfish
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Phylum Cnidaria (clade)
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Characteristics of Phylum Cnidaria
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A.internal digestion in gut cavity
B.life cycle based on three stages C.polyps can reproduce asexually, sexually, or produce medusae that reproduce sexually D.mostly marine, some hydras and jellyfish in freshwater E.have distinct tissues, but no organs F.simple nerve net G.carnivorous, but largely sessile H.many are bioluminescent I.capture prey with cnidocytes |
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barbed projectiles that penetrate the flesh of prey and inject prey with a toxin
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nematocysts
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usually develops from planula; most have a holdfast to anchor to the ocean floor
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polyp
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typically umbrella-shaped and motile (both float and swim)
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medusa
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the hydroids
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Class Hydrozoa
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the jellyfish
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Class Scyphozoa
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box jellyfish
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Class Cubozoa
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sea anemones and corals
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Class Anthozoa
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comb jellies or sea walnuts
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Phylum Ctenophora
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Description of Class Hydrozoa
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1.both polyp and medusa stages
2.most marine and colonia 3.Hydra - small, freshwater 4.Portuguese man-of-war - a colonial hydroid |
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Class Scyphozoa
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1.medusa dominant; polyp small and inconspicuous (sometimes no polyp)
2.muscular ring of epithelial cells pulse rhythmically to propel animal 3.separate sexes 4.larvae are free-swimming planulae 5.planula attaches to substrate and forms a polyp 6.polyps produce multiple medusae |
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Class Cubozoa
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1.medusae are box-shaped
2.tentacle or group of tentacles at each box corner 3.polyps are inconspicuous, some not known 4.stings of some fatal to humans |
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Class Anthozoa
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1.anthos = flower, zoa = animal
2.largest class of Cnidaria (by number of species) 3.solitary or colonial 4.polyp dominant; usually no medusae are formed 5.most harbor symbiotic algae – mutualism where anthozoan provides protection and algae provides food via photosynthesis 6.anemones - fairly free-moving, heavily muscularized 7.corals – hard ones produce calcium carbonate exoskeletons |
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A.radially symmetrical, but more complex than Cniderians
B.have anal pores (two openings – water passes through) C.no cnidocytes; some use tentacles to capture prey D.move using comb-like plates of fused cilia (largest animals to use cilia for locomotion) E.most are bioluminescent |
Phylum Ctenophora
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A.have bilateral symmetry at some point in their life cycle
B.all are triploblastic C.all the rest of the animal phyla that we will cover are in this group |
Bilateria
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A.~70 living species; abundant predators in marine plankton
B.coelomate C.translucent D.centimeter size range E.arrow shape with head, trunk, and tail segments and septa between these F.large eyes and powerful jaws in some G.date back to 500 MYA in fossil record |
Phylum Chaetognatha
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A.most have spiral, determinate cleavage; coelom form from splits within mesoderm; and blastopore become mouth
B.made up of two “sister taxa”: Ecdysozoa (molting) and Lophotrochozoa (non-molting) |
Protostomia
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A.grow by extending the size of their skeletons; do not molt
B.group is unified mostly by genetic similarities and lack of molting C.name comes from two things found in some animals in the group |
Lophotrochozoa
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•feeding structure of ciliated tentacles with coelom within them
•found in three phyla: Ectoprocta, Brachiopoda, and Phoronida |
lophophore
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•larva with a ring of cilia around its middle
•used for swimming and feeding •found in many lophotrochozoan phyla, such as Annelida and Mollusca |
trochophore
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1.Ectoprocta (or Bryozoa; clade)
2.Platyhelminthes (clade?) 3.Rotifera (clade) 4.Annelida (clade) 5.Nemertea (clade) 6.Brachiopoda (clade?) 7.Phoronida (clade) 8.Mollusca (clade) These are all involved in which Clade? |
Lophotrochozoa
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A.~4500 living species
B.coelomate C.aquatic, mostly marine D.use lophophore for feeding E.secrete and live in a chitinous chamber (zoecium); also may be reinforced with calcium carbonate F.adults are sessile and colonial; communicate chemically through pores in zoecia G.some non-protostome characteristics: radial cleavage, secondary mouth, deuterostome-style coelom H.appear to be a sister group to rest of the lophotrochozoans |
Phylum Ectoprocta
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the flatworms (must exclude Acoelomorpha to have any hope of having a grade or clade; acoelomorphs are interesting though, feel free to look up information about them on your own)
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Phylum Platyhelminthes
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A.~20,000 living species
B.acoelomate C.ribbon-shaped, soft-bodied, flattened D.most are parasitic, some are scavengers and carnivores E.non-parasitic forms far more active than cnidarians or ctenophores F.those with a digestive cavity have an incomplete gut (only one opening) G.excretory system - small tubules lined with ciliated flame cells (move water and waste into tubules and out of body) H.no circulatory system – oxygen and food must diffuse to all cells I.some have nerve cords and simple central nervous system J.reproduction |
Phylum Platyhelminthes
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1.only free-living flatworms
2.use ciliated epithelial cells for movement 3.have eyespots; usually move away from light 4.have sensory pits or tentacles for detecting food, chemicals, and nearby movement 5.use pharynx (muscular throat) in feeding 6.abundant in many aqueous environments 7.some occur in moist terrestrial areas 8.include planaria |
Class Turbellaria
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1.all parasitic; resistant to digestive enzymes and host immune responses
2.use mouth to feed 3.1 mm to 8 cm long 4.attach via suckers, anchors or hooks 5.usually have two or more hosts (larvae almost always in snails, final host almost always a vertebrate) 6.important pathogens of humans |
Class Trematoda
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1.human pathogen – beef tapeworm
2.all parasitic; resistant to digestive enzymes and host immune responses 3.absorb food through skin (no mouth, no digestive tract or digestive enzymes) 4.scolex - attachment organ with several suckers and possibly also hooks 5.neck – unsegmented; connects scolex to proglottids 6.proglottids - complete hermaphroditic units, making sperm and eggs ****TAPE WORMS**** |
Class Cestoda
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attachment organ with several suckers and possibly also hooks
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scolex
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complete hermaphroditic units, making sperm and eggs
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proglottids
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A.~1800 species;
B.pseudocoelmate C.common, small (most <1mm), mainly aquatic animals D.mostly free-living and found in freshwater environments; some are parasites; some terrestrial E.corona - ciliated, food-gathering organ at tip of head (filter-feeders) F.sometimes called “wheel animals” because of appearance of beating cilia G.true digestive tract with separate mouth and anus H.jaws in pharynx I.hydrostatic skeleton with rudimentary circulatory system J.separate sexes; some species with parthenogensis – development of unfertilized eggs K.appear to group with true Platyhelminthes and others in a clade called Platyzoa ****Rotifers***** |
Phylum Rotifera
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ciliated, food-gathering organ at tip of head (filter-feeders) of rotifers
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Corona
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development of unfertilized eggs
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parthenogensis
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A.3 classes: Polychaeta (polychaetes), Oligochaeta (earthworms), and Hirudinea (leeches)
B.most have setae – bristles of chitin used to anchor the worm to a substrate (“bristleworms”) C.closed circulatory system has some enlarged vessels that serve as hearts D.gases are exchanged at skin (no gills or lungs) E.excretory system includes nephridia (like in mollusks) F.~16,500 species in marine, freshwater and terrestrial systems G.coelomate H.includes polychaetes, earthworms, and leeches I.unquestionably segmented ***Segmented Worms**** |
Phylum Annelida
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1. many unusual and colorful forms; include plumed worms, peacock worms, fan worms, and many others
2. ~10,000 living species, mostly marine 3. often live in burrows 4. usually filter-feeders, sometimes carnivores or parasites |
Class Polychaeta
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1. mostly terrestrial (in moist soil); a few aquatic species
2. eat their way through soil (usually eat own weight in soil each day; most soil has passed many times through worm guts) 3. 100-175 segments, with mouth on first one and anus on last one 4. no eyes, but some light-sensitive organs near end of body 5. reproduction • hermaphroditic • join in opposite directions at the clitellum (obvious thickened band), which secretes mucus that holds the pair together during copulation • exchange sperm, and then each lays eggs in mucous cocoon surrounded by chitin that is secreted by the clitellum (this cocoon protects the fertilized eggs) ****EARTHWORMS****** |
Class (or subclass) Oligochaeta
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1. mostly freshwater species; some marine, some terrestrial
2. hermaphroditic with clitellum (only during breeding season) 3. reduced segmentation (34 segments), and coelom is reduced and continuous (septae lost) 4. usually dorsoventrally flattened (resemble flatworms) 5. all but one species have no setae 6. have suckers at one or both ends of body 7. includes parasites, predators, and scavengers 8. many suck blood (external blood-sucking parasites) ****LEECHES***** |
Class (or subclass) Hirudinea
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A. ~ 900 living species; mostly marine
B. partially coelomate/partially acoelomate C. similar to free-living flatworms D. often large (up to many meters) E. proboscis – long muscular tube covered by a sheath, thrust out quickly to capture prey F. excretory and nervous systems similar to flatworms G. complete digestive system (two openings, mouth and anus) H. closed circulatory system (blood vessels) ***THE RIBBON WORM****** |
Phylum Nemertea
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long muscular tube covered by a sheath, thrust out quickly to capture prey
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proboscis
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A. 20 living species
B. coelomate C. marine; many burrow into sea bed D. use lophophore for feeding E. U-shaped gut; secrete and live within a chitinous tube *** The horseshoe Worm****** |
Phylum Phoronida
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A. 335 living species
B. brachiopod “clams” – have two calcified shells, superficial resemblance to clams C. use lophophore for feeding D. most are anchored via a unique stalk E. were very common and diverse in the Paleozoic F. decimated in the “Great Dying” (end Permian mass extinction event ~250 mya) G. form a clade with Phoronida |
Phylum Brachiopoda
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A. very successful phylum: over 93,000 named, living species
B. largest number of living species for animals after Arthropoda C. mostly aquatic, but over 35,000 terrestrial species (more than all terrestrial vertebrates) D. includes snails, slugs, clams, oysters, chitons, cuttlefish, octopi, etc. E. from microscopic to 21 m (giant squid – largest invertebrate) F. economically important (food, ornamentation, currency, pests) ***MOLLUSCS***** |
Phylum Mollusca
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used for locomotion, food capture, attachment (In Molluscs)
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muscular foot
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contains most of the internal organs
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visceral mass
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rasping “tongue” with rows of microscopic, chitinous “teeth” used to scrape or drill for food
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radula
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tubular structures that gather wastes from coelom
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nephridia
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ciliated free-swimming larva of many marine mollusks
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trochophore
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second stage in development of most marine snails and bivalves; has beginnings of foot and mantle
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veliger
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secreted by mantle, usually on outside, but on inside in some snails, squid, and cuttlefish, and lost in slugs, nudibranchs, and octopi
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shell
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1. ~1000 living species
2. marine; shell is segmented with 8 overlapping, calcareous plates 3. body beneath shell is not segmented 4. head is greatly reduced 5. foot used for locomotion and for holding onto substrates ***Chitons**** |
Class Polyplacophora
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1. name means “stomach foot”
2. ~70,000 living species 3. mostly marine, but abundant in freshwater, and many are terrestrial 4. most have a shell ****SNAILS AND SLUGS***** |
Class Gastropoda
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found in most marine gastropods – a horny plate that forms a covering “door” when the snail withdraws into its shell
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operculum
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(spiral twisting) of shell due to one side of larva growing faster than the other side
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coiling
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1. includes clams, oysters, scallops, and mussels
2. ~20,000 living species 3. 2 shells (valves) hinged together 4. strong adductor muscles used to pull shells together 5. typically with siphons - most are filter feeders (food trapped on mucus on gills) 6. complex folded, ciliated gills 7. no distinct head or radula 8. most have a strong muscular foot (many different adaptations) 9. some can move by clapping their shells together (scallops) ***THE BIVALVES*** |
Class Bivalvia
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1. includes octopi, squids, cuttlefish, and nautilus
2. ~800 living species 3. 0-1 shells, internal or external • octopi – no shell • squid and cuttlefish – internal shell remnant used for support • nautilus – chambered shell, superficially resembling snails 4. highly developed nervous system • giant axons –great for research • elaborate eyes (some up to 40 cm across – largest known eyes) • most intelligent invertebrates; complex behavior • many are skillful hunters 5. foot modified into grasping tentacles with suckers 6. built for speed – jet propulsion using siphons (they are fast-moving predators) 7. most have a closed circulatory system (only mollusks with this) 8. strong beak for biting; radula used to pull prey in 9. squid and octopi can release a dark “ink” to cloud water for escaping predators or even for trapping prey 10. cuttlefish are famous for changing color to match background or for messaging, using chromatophore pigment pouches; most octopi and squid can do this as well ****THE CEPHALAPODS**** |
Class Cephalopoda
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A. defined primary by molecular evidence
B. synapomorphy is ecdysis, or molting, of cuticle |
Ecdysozoa
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1. Scalidophora
• Phylum Priapulida (clade) • Phylum Loricifera (clade) • Phylum Kinorhyncha (clade) 2. Nematoida • Phylum Nematoda (clade) • Phylum Nematomorpha (clade) 3. Panarthropoda • Phylum Onychophora (clade) • Phylum Tardigrada (clade) • Phylum Arthropoda (clade |
Ecdysozoa
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A. clade of three phyla: Priapulida, Loricifera, and Kinorhyncha
B. basal branch within Ecdysozoa C. all are pseudocoelomate or acoelomate D. have spiny, evertable proboscis that is used for feeding |
Scalidophora
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A. marine; 16 living species, all with phallic appearance
B. range from near microscopic to about 20 cm in length C. fossil record back to the Cambrian period, were likely major predators during Cambrian D. named for Greek fertility god Priapos *****PENIS WORM***** |
Phylum Priapulida
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A. ~100 living species
B. live in marine sediment C. tiny (less than 3 mm long) D. can telescope most of body into lorica, a protective 6-plate pocket |
Phylum Loricifera
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A. ~150 living species
B. live in marine sediment C. tiny (less than 1 mm long) D. segmented body, with head, neck, and trunk with 11 segments |
Phylum Kinorhyncha
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A. clade containing two phyla: Nematoda and Nematomorpha
B. sister group to Panarthropoda C. pseudocoelomate |
Nematoida
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A. "If all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable…we should find its mountains, hills, vales, rivers, lakes, and oceans represented by a thin film of nematodes
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N.A. Cobb
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B. ~25,000 living species (maybe as many as 500,000)
C. most soil-dwelling and microscopic (< 1 mm) D. covered with flexible, thick cuticle E. muscles extend along length (longitudinal), not around F. feeding: 1. many are parasites 2. mouth often has stylets for piercing 3. muscular chamber in throat (pharynx) used for sucking up food G. many are important plant parasites H. about 50 species parasitize humans I. Trichinella - causes trichinosis, females in digestive tract of pigs produce young which make their way to muscle tissue where they form cysts - cook well and you are fine, but 2.4% of people in U.S. carry the worm (don’t eat raw pork!) J. Caenorhabditis elegans – important lab animal; adult has exactly 959 cells; complete developmental cellular anatomy known K. no cilia or flagellae, even on sperm L. reproduction – sexual, with separate sexes (dioecious ****NEMATODES AND ROUNDWORMS***** |
Phylum Nematoda
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A. ~320 living species
B. similar to nematodes in physiology C. adults average ~1 meter long D. all are parasitic 1. famous example – the cricket brain takeover 2. larva develops within Orthopteran host 3. when the nematomorph reaches adulthood, it causes the host to drown itself 4. adult emerges and lives the rest of its life in water ***HORSEHAIR WORM**** |
Phylum Nematomorpha
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A. clade containing three phyla: Tardigrada, Onychophora, and Arthropoda
B. all have legs, claws, ventral nervous system, and segmented body C. all have coelom, but it is mostly associated with gonads; main cavity is instead the hemocoel D. all have open circulatory system with hemolymph (associated with hemocoel) |
Panarthropoda
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A. ~150 described living species
B. once marine, forms living today are all terrestrial C. mostly limited to humid forests in the Southern hemisphere D. (segmented) worms with legs 1. many repetitious body segments, some similarity to caterpillars 2. legs are internally hollow and not jointed; sac-like 3. 13-43 pairs of legs E. average 5 cm long as adults; some as long as 20 cm F. thin, chitinous cuticle G. predatory, mainly on arthropods and mollusks 1. often squirt fast-drying glue-like slime to catch and trap larger prey 2. toxic saliva injected into victim to kill it and begin digestion ***VELVET WORMS**** |
Phylum Onychophora
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A. over 1000 living species
B. aquatic or on other organisms; easiest to find on lichens and mosses 1. many feed on plants or algae 2. some feed on bacteria 3. some hunt smaller animals C. mostly microscopic D. body with head, then 4 segments 1. covered by a chitinous cuticle 2. 4 pairs of lobe-like legs with claws 3. rounded, stubby appearance and slow, lumbering gait E. very hardy animals; able to enter a state of dormancy where they can 1. can survive extreme cold or heat 2. can survive very high radiation doses 3. can survive up to a decade without water ****WATER BEARS*** |
Phylum Tardigrada
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A. includes spiders, insects, lobsters, and others
B. very diverse and important group 1. ~1 million named species (about 2/3 of all named species) 2. probably at least 10 million living species still unnamed 3. dramatic impact (for good and bad) on environment 4. major impact (for good and bad) on economy and human health |
Phylum Arthropoda
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cuticle composed primarily of chitin
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exoskeleton
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• cephalothorax and abdomen
• have one pair of chelicerae (pinchers or fangs); after that, one pair of pedipalps (sensory appendages) • 4 pairs of walking legs (from cephalothorax) |
Cheliceriformes
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• head with and multisegmented trunk
• head has one pair of antennae, then one pair of mandibles and other mouthparts • trunk has pairs of walking legs • appendages are unbranched (uniramous) • tracheal system for respiration |
Myriapoda
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• cephalothorax and abdomen
• head has two pair of antennae, then one pair of mandibles and other mouthparts • cephalothorax has various numbers of pairs of walking legs • abdomen also often has appendages • appendages are branched (biramous) |
Crustacea
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• head, trunk, and abdomen
• head has one pair of antennae, then one pair of mandibles and other mouthparts • trunk has 3 pairs of walking legs and often 2 pairs of wings • appendages are unbranched (uniramous) • tracheal system for respiration |
Hexapoda
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A. spiders, horseshoe crabs, and sea spiders
B. lack jaws; first pair of appendages are mouthparts called chelicerae (fangs in some) C. second pair of appendages are pinchers or feelers (pedipalps) D. rest of appendages are legs; 4 pairs of legs E. three classes: Merostomata, Arachnida, and Pycnogonida F. we will only cover the first two; leaving out Pycnogonida (sea spiders) |
Subphylum Chelicerata
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A. 4 living species considered “living fossils”; same form in fossil record back to 220 MYA
B. pedipalps appear like legs (as do chelicerae to some extent) – appear to have extra legs C. 5 pairs of book gills D. shell called a carapace E. long “tail” spine called telson |
Class Merostomata
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A. include harvestmen, scorpions, spiders, mites, and ticks
B. their chelicerae are fangs, often attached to a poison gland C. two body segments: prosoma (cephalothorax) and opisthosoma (abdomen) D. usually with book gills or book lungs E. four pair of walking legs (8 legs) from prosoma |
Class Arachnida
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1. over 6000 living species
2. oval, compact body with extremely long, slender legs 3. most are predators of insects and arachnids 4. females have an ovipositor for laying eggs |
Order Opiliones
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1. ~2000 living species
2. pedipalps are pinchers 3. stinger in last segment of abdomen 4. most ancient group of terrestrial arthropods (425 MYA) 5. young born alive |
Order Scorpiones
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1. ~40,000 living species
2. produce silk from a protein fluid forced out of spinnerets • modified appendages at rear of opisthosoma • up to six pairs 3. predators • important in controlling insect populations • hunt or use webs for prey capture, or in some cases both • venom glands are connected to fangs, used to paralyze prey • black widow and brown recluse venom particularly lethal to humans 4. webs used for many purposes, capturing prey, wrapping prey or sperm or eggs, gossamer threads as parachutes 5. mating • many have elaborate courtship where male puts female into a trance • pedipalps used in copulation to transfer and deposit sperm • after mating, male is often eaten |
Order Araneae
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1. ~30,000 described living species, estimates are that there are over 1 million actual living species
2. chelicerae fused into a capitulum; used for piercing 3. most mites have cephalothorax and abdomen fused, many live on us 4. some mites are serious pests of crop and house plants 5. ticks are blood-feeding ectoparasites that transmit many diseases in vertebrates |
Order Acari
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A. millipedes and centipedes and their relatives
B. head with and multisegmented trunk C. uniramous mandibulates 1. have paired jaws (mandibles) as mouthpart appendages after the antennae 2. all appendages are basically uniramous (“single-branched”) appendages D. have a tracheal respiratory system E. have Malpighian tubules for excretion Myriapoda form a clade with Chelicerata F. four classes; we will cover two: Chilopoda and Diplopoda |
Subphylum Myriapoda
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A. ~3000 living species described
B. body with head and multisegmented trunk C. carnivorous, eat mainly insects D. venomous E. poison claws on foremost trunk segment F. one pair of legs per trunk body segment ***CENTEPEDES**** |
Class Chilopoda
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A. ~8000 living species described
B. body with largely inconspicuous head and multisegmented trunk C. two pairs of legs per trunk body segment starting with the 2nd segment after the head D. each segment is a tagma that is a fusion of two ancestral segments E. most millipedes are herbivores or detritivores; NOT venomous F. secrete a variety of noxious fluids and gases to ward off attackers |
Class Diplopoda
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A. include shrimp, lobsters, crayfish, crabs, isopods, barnacles, etc.
B. have two pair of sensory antennae as first appendages C. biramous mandibulates 1. have paired jaws (mandibles) as mouthpart appendages after the antennae 2. all appendages are basically biramous (“two-branched”) D. ~35,000 described living species - most marine, many freshwater, some (sowbugs) terrestrial E. nauplius – similar larva shared by all (unifies group) F. decapods – shrimp, lobsters, crayfish, crabs 1. 10 walking legs 2. exoskeleton usually reinforced with calcium carbonate 3. cephalothorax covered in carapace (a dorsal shield) 4. some have swimmerets on abdomen (for swimming, reproduction) 5. some have uropods and/or telson at end of abdomen (for swimming) G. others include sowbugs (terrestrial isopods), Daphnia (freshwater plankton), barnacles (sessile shelled filter-feeders), etc. |
Subphylum Crustacea
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similar larva shared by all (unifies group)
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nauplius
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shrimp, lobsters, crayfish, crabs
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decapods
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A. insects and their relatives
B. head, trunk, and abdomen C. three body segments: head, thorax, abdomen 1. head has one pair of sensory antennae 2. three pairs of legs on thorax only (never head or on abdomen) D. uniramous mandibulates 1. have paired jaws (mandibles) as mouthpart appendages on head after the antennae 2. all appendages are basically uniramous (“single-branched”) appendages E. have a tracheal respiratory system F. have Malpighian tubules for excretion G. insects plus some minor groups (Collembola, Protura, and Diplura) of uncertain classification within the subphylum H. we will focus only on insects (class Insecta) |
Subphylum Hexapoda
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A. terrestrial and freshwater, few marine; extremely diverse and successful group
B. date back in fossil record to 300 MYA; considerable coevolution with flowering plants likely C. ½ of all named species; about a 1018 individuals alive at any given time D. size range from 0.1 mm to 30 cm fat body in hemocoel E. sound production often well developed F. nearly all communicate within their species using pheromones G. instead, learn about these selected, important insect orders – listed in descending order by number of named, living species H. classification within Insecta is an area of very active research and revisions; we won’t try to cover it extensively ***INSECTS**** |
Class Insecta
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A. defined primary by molecular evidence
B. some defining developmental traits (see previous notes), but those can get fuzzy C. clade includes the following phyla that we will cover: 1. Phylum Echinodermata (clade) 2. Phylum Hemichordata (clade) 3. Phylum Chordata (clade) |
Deuterostomia
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A. six classes, all apparently monophyletic
B. sexual reproduction - form free-swimming larvae that are bilaterally symmetrical C. asexual reproduction - many will regenerate if a broken part contains part of the central nerve ring, sometimes they will break on purpose D. coelom – relatively large; used for circulation and respiration E. pentaradially symmetrical - derived trait, larvae are bilaterally symmetrical F. water-vascular system - hydraulic system for moving, feeding G. marine; ~7000 living species; in fossil record back to over 650 MYA H. name means “spiny skin”, reference to their endoskeleton |
Phylum Echinodermata
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1. water enters though madreporite, opening typically opposite mouth
2. water from madreporite moves though stone canal 3. water then enters the ring canal that encircles the esophagus 4. radial canals extend from ring canal into the 5 body parts, establishing basic symmetry 5. radial canals branch out into tube feet 6. contraction of muscular sac (ampulla) at base of tube foot causes fluid to be forced into tube foot, extending it – used for movement |
water-vascular system
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derived trait, larvae are bilaterally symmetrical
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pentaradially symmetrical
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relatively large; used for circulation and respiration
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coelom
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1. mouth and anus on same side
2. 5-200+ arms, filter feeders 3. primitive, sessile 4. sea lilies – have calcareous stalk 15-30 cm long (20 m in some fossils) • “living fossils” • once much more common one of the dominant forms of life in the marine fossil record of the Paleozoic era (both in numbers and size) 5. feather stars - no stalk ***SEA LILIES*** |
Class Crinoidea
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1. 1 cm - 1 m across
2. to 10,000 m deep 3. groove runs along each arm bordered by rows of tube feet 4. tube feet are like little suction cups and create an impressive force 5. feed mainly on bivalves • attach to either side of shell with tube feet • wait until bivalve fatigues • extrudes stomach into opening and digest prey ***SEA STARS OR STARFISH*** |
Class Asteroidea
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1. look like sea stars, but more flexible, move via serpentine motion of arms, groove closed below arms
2. tube feet used to capture small prey and as sensory structures ***BRITTLE STAR*** |
Class Ophiuroidea
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1. no arms
2. usually move via spines operated by tube feet 3. vegetarians ***SEA URCHINS*** |
Class Echinoidea
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1. elongate
2. often with leathery skin 3. mouth surrounded by 8-30 modified tube feet called tentacles 4. other normal tube feet move animal 5. will extrude their foul-smelling stomachs when frightened ***SEA CUCUMBERS*** |
Class Holothuroidea
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1. recently discovered
2. no arms 3. tube feet on edge of disc, instead of along radial lines ***SEA DAISIES*** |
Class Concentricycloidea
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A. ~90 living species; all marine
B. centimeter to meter size range; burrowing; proboscis, collar, and trunk C. name means “half chordates”; transitional group to phylum Chordata D. ciliated larvae resemble sea star larvae E. form a clade with Echinodermata (group called Ambulacraria) F. share with chordates: 1. dorsal nerve cord as well as ventral nerve cord 2. part of dorsal nerve cord hollow in some 3. throat with pharyngeal gill slits ***ACOM WORMS*** |
Phylum Hemichordata
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A. key traits: deuterostomes with notochord, jointed appendages, and segmentation
B. four key features present at some point in life cycle of all chordates: 1. dorsal, hollow nerve cord – becomes brain and/or spinal cord 2. notochord - flexible, fibrous rod along back (replaced by vertebrae in advanced vertebrates) 3. pharyngeal gill slits - openings in the throat region 4. postanal tail – most other animals with tails near the anus have anus at end of tail 5. these features may each be lost or altered in the adult 6. three subphyla: Cephalochordata, Urochordata, and Vertebrata |
Phylum Chordata
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• internal structure filled with air (usually via gases released from blood)
• amount of air can be adjusted, used to regulate body density and thus depth in water • derived from lung, a primitive structure used to breathe air |
Swim Bladder
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• found in other jawed fishes, but most prominent in bony fishes
• system of pores along body • used to sense vibrations in water; both moving and still objects can be detected |
Lateral Line System
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• allows greater diversity in food capture and preparation
• increases breathing effectiveness (throat muscles aid in breathing) • can breath without swimming, unlike sharks |
operculum
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1. most fishes alive today
2. no fin bones or muscle outside of body ***RAY-FINNED FISHES*** |
Subclass Actinopterygii
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1. coelacanth and lungfishes
2. bone and muscle exit body wall into fins 3. gave rise to tetrapods (four-limbed vertebrates with 5- fingered limbs) |
Subclass Sarcopterygii
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A. earliest amphibians - Ichthyostega
1. basically a fish with legs 2. numerous digits on hands, feet 3. tail fin with fibrous rays like a fish 4. 370 MYA, Greenland 5. one of the best transitional series in the fossil record is from fish to amphibian 6. Carboniferous Period (354-290 MYA) – amphibians diversify and are the dominant terrestrial carnivores (Age of Amphibians) B. modern amphibians 1. tend to rely on cutaneous (skin) respiration more than lungs, some without lungs 2. most still require water for early life stages and/or reproduction 3. have 3-chambered heart with pulmonary veins (two-loop system) 4. over 4200 living species in three orders: C. Order Anura – frogs and toads – very derived, lost tail, modified vertebral column for jumping D. Order Urodela (Caudata) – salamanders – elongated body with tail; moist, smooth skin E. Order Apoda (Gymnophiona) – caecilians – lost limbs, look like worms, terrestrial or purely aquatic; burrowing |
Class Amphibia
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frogs and toads – very derived, lost tail, modified vertebral column for jumping
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Order Anura
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salamanders – elongated body with tail; moist, smooth skin
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Order Urodela
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caecilians – lost limbs, look like worms, terrestrial or purely aquatic; burrowing
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Order Apoda
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