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Unformatted text preview: BIO1500 W07 Fish and vertebrate origins Moving up the food chain: chordate and vertebrate origins CEPHALOCHORDATA: lancelets 1) Old phylum of fish-like marine chordates 2) 1cm - 10cm 3) ~23 species 4) Notochord runs along entire length of nerve chord 5) Lack of head or cephalization 6) Plancton filterers 7) Gills adaptation to filter feeding http://kentsimmons.uwinnipeg.ca/16cm05/1116/chordate.htm CEPHALOCHORDATA: body plan http://en.wikipedia.org/wiki/Lancelet VERTEBRATE PHYLOGENY VERTEBRATES: defining body plan features 1) Neural crest: Considered “fourth germ layer” Considered Ectoderm derivative Neural tube Concentrated between neural tube Neural crest and ectoderm during early development Gives rise to neurons and glia of peripheral nervous system, sceletal muscle, smooth muscle, chondrocytes, osteocytes, melanocytes, cromaffin cells, and a number of endocrine cells Evolutionary origin of neural crest Evolutionary 1) Neural crest
Neural tube Neural crest Evolutionary origin of neural crest Evolutionary 1) Neural crest Evolutionary origin of neural crest Evolutionary 1) Neural crest VERTEBRATES: defining body plan features 2) Internal organs http://www.infovisual.info/02/033_en.html VERTEBRATES: defining body plan features VERTEBRATES: 2) Endoskeleton VERTEBRATES: defining body plan features 3) Complex nervous system VERTEBRATES: defining body plan features VERTEBRATES: 3) Lens eyes FISHES: Basic features 1) >24,600 species 2) 1cm - 18m length 3) non-tetrapod chordates in sea and freshwater 4) Paraphyletic collection of taxa http://www.mblwhoilibrary.org/exhibits/leu ckart/wall_charts/images/slides91_116/L11 4.GIF F I S H: a paraphyletic taxon Paraphyletic groups include some but not all descendendants of the last common ancestor Reading trees: monophyly, paraphyly and polyphyly
A monophyletic clade (Taxon 1 and 2) contains all descendants of an ancestral lineage (internal branch). A paraphyletic group (“Reptilia”) includes most but not all descendants of an ancestral lineage. Polyphyletic groups (Taxon 3) contain only few of all descendants of an ancestral lineage. from Kardong 2005 FISH: Basic body plan features 1) Vertebral column FISHES: Basic body plan features 1) Vertebral column FISH: Basic body plan features 2 ) Jaws http://www.geol.umd.edu/~jmerck/eltsite/lectures/Touroflife/touroflife.html http://news.nationalgeographic.com/news/2003/01/photogalleries/snakes/photo2.html Evolutionary origin of the vertebrate jaw 2 ) Jaws FISHES: Basic body plan features 3) Paired appendages http://myfwc.com/Fishing/Fishes/anatomy.html FISHES: Basic body plan features 4 ) Gills Basking Shark Cetorhinus maximus http://www.marinebiodiversity.ca/shark/english/basking.htm FISHES: Basic body plan features 4 ) Gills http://www.delportdupreez.co.za/diving/sharks/assets/images/sharkgills.jpg FISHES: Basic body plan features 4 ) Gills FISHES: Basic body plan features 5) Single-loop blood circulation Extant “FISH”: classification Extant 1) Myxini: Hagfishes (~30 species) 2 ) Cephalaspidomorphi: Lampreys (~35 species) 3) Chondrichthyes (750 species): sharks, skates and rays 4) Actinopterygii: ray-finned fishes (30,000 species) 5) Sarcopterygii: lobe-finned fishes (7 species) Bruegel Big Fish http://moldychum.typepad.com/moldy_chum/2006/1 1/bruegel_big_fis.html MYXINI: Hagfishes MYXINI: 1) 2) 3) 4) 5) Jawless No paired appendages Scavengers Mostly blind Well-developed sense of smell Members of the class Myxini have a partial cranium (skull), but no vertebrae. Their skeleton is made of of cartilage, as is that of sharks. Hagfish lack jaws, and for this reason used to be classified with the lampreys in a group called the Agnatha ("no jaws") or the Cyclostomata ("round mouth"). http://www.cartage.org.lb/en/themes/Scie nces/Zoology/Biologicaldiverstity/AnimalsI II/AnimalsIII.htm CEPHALASPDOMORPHI: lampreys 1) 2) 3) 4) Jawless No paired appendages Freshwater Parasitic and non-parasitic species http://www.cartage.org.lb/en/themes/Sci ences/Zoology/Biologicaldiverstity/Anima lsIII/AnimalsIII.htm CEPHALASPDOMORPHI: lampreys CEPHALASPDOMORPHI: 1) 2) 3) 4) Jawless No paired appendages Freshwater Parasitic and non-parasitic species http://www.cartage.org.lb/en/themes/Sci ences/Zoology/Biologicaldiverstity/Anima lsIII/AnimalsIII.htm CONDRICHTHYES: sharks 1) 2) 3) Cartilaginuous skeleton No swim bladder Internal fertilization http://www.educationalfossils.com/educational-fossils/shark/shark.htm ACTINOPTERYGII: ray finned fishes ACTINOPTERYGII: 1) Bony skeleton ACTINOPTERYGII: ray finned fishes 2) Swim bladder ACTINOPTERYGII: ray finned fishes ACTINOPTERYGII: 2) Swim bladder
Dorsal aorta To heart Gas Muscular gland valve Swim bladder ACTINOPTERYGII: ray finned fishes 3) Paired fins supported by bony rays ACTINOPTERYGII: ray finned fishes ACTINOPTERYGII: 4) Lateral line system ACTINOPTERYGII: ray finned fishes 4) Lateral line system Scales of the lateral line of the roach (Rutilus rutilus) In fish, the lateral line is a sense organ used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail. Sometimes parts of the lateral organ are modified into electroreceptors, which are organs used to detect electrical impulses. It is possible that vertebrates such as sharks use the lateral organs to detect magnetic fields as well. Most amphibian larvae and some adult amphibians also have a lateral organ.http://en.wikipedia.org/wiki/Lateral_line_system ACTINOPTERYGII: ray finned fishes ACTINOPTERYGII: 4) Lateral line system ACTINOPTERYGII: ray finned fishes 5) Gill cover ACTINOPTERYGII: ray finned fishes ACTINOPTERYGII: 5) Gill cover ACTINOPTERYGII: ray finned fishes 5) Gill cover ACTINOPTERYGII: taxonomy 1 ) Chondrostei 2 ) Holostei 3 ) Teleostei A giant grouper http://upload.wikimedia.org/wikipedia/commons/2/23/Georgia_Aquarium_-_Giant_Grouper_edit.jpg ACTINOPTERYGII: taxonomy 1) Chondrostei: sturgeons, paddlefish, reedfish and bichir Chondrostei: Primarily cartiliginous fish showing some ossification. Structure of the jaw is more akin to that of sharks than other bony fish Gill covers Lack of scales (except for sturgeons Heterocercal tail Paraphyletic Atlantic sturgeon http://en.wikipedia.org/wiki/Chondrostei ACTINOPTERYGII: taxonomy 2) Holostei: bowfins, gars Skeleton ossified with a thin layer of bone covering a mostly cartiliginous skeleton in the bowfins) Tail still heterocercal in gars Scales (thick ganoid in gars, thin and bony in bowfins) Paraphyletic Spotted gar, Lepisosteus oculatus Bowfin, Amia calva http://en.wikipedia.org/wiki/Holostei ACTINOPTERYGII: taxonomy 3) Teleostei ~20,000 extant species in about 40 orders. Modifications in jaw bones and musculature that facilitate protruding jaws outwards from the mouth Caudal fin is homocercal Trout http://en.wikipedia.org/wiki/Holostei ACTINOPTERYGII: famous teleosts ACTINOPTERYGII: Eel American eel, Anguilla rostrata http://en.wikipedia.org/wiki/Eel ACTINOPTERYGII: famous teleosts Sea horses http://www.scubado.co.uk/Wallpaper/Images/640x480/Sea_horse.jpg ACTINOPTERYGII: famous teleosts ACTINOPTERYGII: Guppy ACTINOPTERYGII: famous teleosts Piranhas
Photo by rmhermen, taken at Belle Isle Aquarium, March 30, 2005 http://en.wikipedia.org/wiki/Piranha Zebra fish [Danio rerio] Zebrafish embryo after 24h development http://www.ncbi.nlm.nih.gov/genomes/leuks.cgi Zebra fish development http://zfin.org/zf_info/movies/Zebrafish.mov Puffer fish [Takifugu rubripes] http://www.ncbi.nlm.nih.gov/genomes/leuks.cgi SARCOPTERYGII: lobe-finned fishes Traditionally consisting of lungfish and coelacanths Bony fish with paired rounded fins . Fins similar to limbs
The African lungfish Protopterus http://users.tamuk.edu/kfjab02/Biology/Verte brate%20Zoology/b3405_ch08.htm Latimeria http://en.wikipedia.org/wiki/Image:Coelacanth-bgiu.png AMPHIBIAN ORIGINS: from fins to legs AMPHIBIAN
Humerus Femur Pelvis Tibia Lobe-finned fish Humerus Ulna Shoulder Radius Fibula Pelvis Femur Shoulder Fibula Tibia Ulna Early amphibian Radius ...
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