¿ what anatomical/physiological features distinguish vertebrates?
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¿ What anatomical/physiological features distinguish vertebrates?. ¿ Who are vertebrates related to, and how are they related to each other ?. ¿ In what ecosystems do vertebrates occur ? . ¿ What are the roles of vertebrates in aquatic and terrestrial ecosystems ?. - PowerPoint PPT PresentationTRANSCRIPT
¿ What anatomical/physiological features distinguish vertebrates? ¿ Who are
vertebrates related to, and how are
they related to each other ?
¿ What are the roles of vertebrates in aquatic and terrestrial
ecosystems ?
¿ How many different kinds or species of vertebrates are there ?
¿ In what ecosystems do vertebrates occur ?
There are over 57,000 living vertebrate species
For every extant species there were ~100 that are now extinct
Vertebrates are found in almost all environments on earth, from ocean depth to highest mountains and from pole to pole
Vertebrates range in size from tiny fish, amphibians and reptiles small enough to fit on a coin, to blue whales who are so huge their heart is a big a small car
Vertebrate lifestyle is energetically expensive… obtain energy as both carnivores and herbivores with many specializations in between
The vertebrate story…
Two major groups of vertebrates
1) Non-amniotes:A-gnathans (Myxinoidea & Petromyzontoidea ) (~100 species)
Chondr-ichthians (~1,000 species)
Osteichthians (~27,000 species)
Amphibians (~6,400 species)
The vertebrate story…
The vertebrate story…
Two major groups of vertebrates…
2) Amniotes , which also has two major groups:Sauropsids - Testudinians (~300 species)
Lepido-saurians (~8,000 species)
Crocodilians (~25 species)
Avians (~9,700 species)
Synapsids –Mammalians (~4,800 species)
The vertebrate story…
New species…
¿How many species are there on planet Earth?
Estimates vary by an order of magnitude!
Thousands of species described annually
Most are small and of “other” kingdoms… still some vertebrates being described.
Examples…
AgnathaExtinct: Ostracoderms
*Covered by bony armor
*Mostly small fish 2cm (some up to 2m)
*Small mouth openings
*4 openings on dorsal surface of head
*Extinct after abundance of jawed fishes on the scene
http://universe-review.ca/I10-27-jawlessfish.jpg
AgnathaExtant: “Cyclostomes”Hagfish and Lamprey
*Are not as closely related as might appear
*Hagfish are scavengers that lack the rasping denticles of lamprey
*Most Lamprey are parasitic
http://www.exploretheabyss.com/photo/gallery/gallery/ds_trawl/images/HagfishLR.jpg
http://www.nwrc.usgs.gov/world/images/lamprey.jpg
http://www.glaucus.org.uk/sea-lamprey-sucker-RL.jpg
Extant Jawless fishes…
Agnathans are a Polyphyletic group!
Super class Agnatha (oldest craniates in fossil record) Cambrian or earlier
Most abundant in Silurian and lower Devonian
Fossil fish small <15cm (although some up to 2m)
Sucking or scooping feeding mechanism
Conodonts resemble hagfish (Cambrian to Triassic)
All gill tissue is endodermal in origin
Gill structures, arteries, nerves etc. internal to branchial skeleton
http://tolweb.org/Vertebrata
Extant Jawless fishes…
Hagfish (Myxinoidea) …Class - MyxiniOrder – MyxiniformesFamily – MyxinidaeGenera – 6 from mostly temperate waters
Species - > 40 with Pacific and Atlantic Hagfish most well known.
At least one fossil representative from Carboniferous that resembles modern species.
Only occur in marine habitats
Live on soft bottoms of mud, silt or clay usually from 25 – 600m deep.
http://www.bio.uio.no/akv/english/research/mzk/benthos_pictures.html
http://www.youtube.com/watch?v=g8pONkTyk2c http://www.youtube.com/watch?v=NYRr_MrjebA&NR=1
Extant Jawless fishes…
Hagfish (Myxinoidea) …They burrow and perhaps feed on soft-bodied worms etc. they encounter.
Also scavenge and prey on fishApparently good sense of smell,as they quickly find netted fish.
Unique “knotting” technique allows them to pull meat from carcass.
Eversion and retraction of teeth on each side of mouth pull off/in food
http://bakkouz.net/pix/Hagfish.jpg
http://sophont.blogspot.com/2004_02_01_archive.html
Extant Jawless fishes…
Hagfish (Myxinoidea) …Eyes degenerate and covered by skin
Large tentacles surround nasal opening and mouth
Probably lack a larval stage
http://www.uoregon.edu/~joet/Pictures-Pages/Image5.html
http://a.abcnews.com/Technology/AmazingAnimals/popup?id=4958186&contentIndex=1&page=6&start=false
http://www.gma.org/fogm/myxine_glutinosa.htm
Extant Jawless fishes…
Hagfish (Myxinoidea) … 5 to 15 pairs of gills (depending on species)
Some species have branchial ducts that exit via a single tube and external opening Broad-gilled Hagfish
http://www.austmus.gov.au/fishes/fishfacts/fish/ecirrhatus5.htm
http://www.austmus.gov.au/fishes/fishfacts/fish/ecirrhatus6.htm
Broad-gilled Hagfish
Extant Jawless fishes…
Hagfish (Myxinoidea) …Cartilaginous skeleton not well developed…* No vertebrae* Only a membranous roof of the skull
1 semicircular canal on each side of head (Lamprey have 2 and other vertebrates have 3)
In addition to primitive heart… they also have contractile vascular regions in:* Tail* Cardinal vein* Portal vein
Have red blood cells like other vertebrates… but only one type of WBC.
Extant Jawless fishes…
Hagfish (Myxinoidea) …Females outnumber males 100 to 1
Thought at first to be hemaphroditic
Almost nothing known of their reproductive biology!
Recent studies have verified the presence of neural crest cells.
Extant Jawless fishes…
Hagfish (Myxinoidea) …Well known for a defensive mechanism… SLIME!
Abundant mucous glands secreting mucus and coiled proteins
Proteins straighten in water and trap mucus close to hagfishes body
After danger has left, hagfish ties a knot in tail and pulls it towards its head “squeegie-ing” off the slime.
Extant Jawless fishes…
Hagfish (Myxinoidea) …Some commercial use in Asia as source for leather and meat.
Can cause some Economic loss to commercial fisheries when able to access fish caught in gill netsand/or long lines
“Human exploitationOf natural resources,such as fisheries, typically depletesstocks because no attention is givento the biology of the resource and itsrenewable, sustainable characteristics.For example, we do not know how longHagfish live; how old they are when they first begin to reproduce; exactly how, when or where they breed; where the youngest juveniles live; what are the diets and energy requirements of free-living hagfishes; or virtually any of the other information needed for good management. As a result, eel-skin wallets will probably become as rare as items made of whalebone , tortoise shell and ivory. “(Pough et al . 2009, pg. 59)
http://www.daylife.com/photo/0g1T92TaxK623
http://www.daylife.com/photo/0e9DdRDaeV8qa
Extant Jawless fishes…
Lamprey (Petromyzontoidea) …Class – CephalaspidomorphiOrder – Petromyzontiformes / (Hyperoartia)Family – PetromyzontidaeGenera – 10Species - ~ 40 with Petromyzon sp. and Lampetra sp. most well known.
Superficially resemble Hagfish, but differ in several important ways including vertebrae
Unique in having a nasal opening (single) that leads to the pituitary gland.
http://www.gma.org/fogm/Petromyzon_marinus.htm
Extant Jawless fishes…
Lamprey (Petromyzontoidea) …
Petromyzon marinus Sea Lamprey
Extant Jawless fishes…
Lampreys (Petromyzontoidea) …Most species areparasitic
Use hornified “teeth”on the surface of theoral hood and tongue
Can have a negativeImpact on gameand commercialfisheries
http://www.gma.org/fogm/Petromyzon_marinus.htm
http://en.wikipedia.org/wiki/File:Boca_de_lamprea.1_-_Aquarium_Finisterrae.JPG
http://www.biology.duke.edu/bio217/2005/ncy/sea%20lamprey.html
Extant Jawless fishes…
Lampreys (Petromyzontoidea) … Lampreys have 7 pairs of gill pouches
Do not typically use flow-through ventilation
Rather, they use tidal ventilation
http://www.rsc.org/chemistryworld/News/2005/September/03100501.asp
Extant Jawless fishes…
Lampreys (Petromyzontoidea) … Nearly all species are anadromous
Anadromous species that grow in adult form in the sea are the largest (up to 1m)
A small parasitic species (Lampetra minima) was full grown at less than 10 cm (now extinct)
Spawn in streams
Lay 100,000s of eggs
http://oregonstate.edu/dept/ODFW/NativeFish/Lamprey.htm
Extant Jawless fishes…
Lampreys (Petromyzontoidea) …Larval lamprey are called ammocoetes
Live in gravel beds filtering plankton and organic debris for 3-7 years
Metamorphose and then begin journey to sea or other major water basin where they will grow and mature.
Usually live as adults for less than 2 years.
They migrate back up to their hatching grounds (now spawning grounds)
Mate and then die!
Extant Jawless fishes…
Lampreys (Petromyzontoidea) …
Extant Jawless fishes…
Lampreys (Petromyzontoidea) …
Extant Jawless fishes…
Lampreys (Petromyzontoidea) …
Extant Jawless fishes…
Lampreys (Petromyzontoidea) …
Gnathostomes3 groups appeared in the Paleozoic:
1) Placoderms (ex. Arthrodires) had large boney plates and paired fins
http://www.noaca.org/earlgeo.gif
http://www.cnrs.fr/cw/dossiers/dosevol/imgArt/dioram/PaleozoDevon/Zimg/dicksonosteus.jpg
Gnathostomes3 groups appeared in the Paleozoic:
2) Chondrichthyans (cartilagenous fishes)*Includes sharks, rays, skates, and ratfish
*Cartilaginous skeletons
*Many with placoids
*No bony operculum
http://www.lifeglobe.com/images/product/Sharks/sharks04_r2_c2.jpg
http://www.pangaeadesigns.com/_graphics/page/fish/large/ratfish.jpg
Gnathostomes3 groups appeared in the Paleozoic:
3) Teleostomes (spiny and bony fishes)
*Acanthodians are (spiny fishes) are extinct
*Had skeleton of bone and cartilage
*Had an operculum
http://sps.k12.ar.us/massengale/images/R-acanthodians.gif
OsteichthyansShared ancestors with tetrapods
Have an air sac
Dermal bone
Paired fins… either ray finned (actinopterygii) or fleshy finned (sarcopterygii)
http://www.paleodirect.org/fg009.htm
ActinopterygiiBasal groups include Sturgeon and Paddlefish
http://www.hellscanyonsportfishing.com/images/sturgeon%20pictures/Kevin%20&%20Sturgeon%202.jpg
http://www.digimorph.org/specimens/Polypterus_senegalus/whole/specimen.jpg
ActinopterygiiAdvanced groups include Gars, Bowfins and Teleosts (most other bony fish)
http://www.sdafs.org/laafs/Amazing%20Fish%20Pictures/Big%20Alligator%20Gar%2009-03.JPG
SarcopterygiiHave fleshy lobed fins, internal nares and a bony operculum
2 major clades:
Actinistians, extinct except “coelocanths”
Rhipidistians (and dipnoi)“lungfish”
http://kentsimmons.uwinnipeg.ca/16cm05/1116/34-14-Coelocanth.jpg
http://www.bertsgeschiedenissite.nl/geschiedenis%20aarde/lungfish.jpg
Amphibia*Paraphyletic group… omitting amniote descendants
*Extinct groups include Labrynthodonts (Ichthyostega)
*Extant group (Lissamphibia) includes:
Apoda (caecilians)
Urodela (salamanders)
Anura (frogs)
http://news.siu.edu/news/May05/images/salamander.jpg
http://www.yesnet.yk.ca/schools/wes/webquests_themes/frogs_theme/frogs_K/frog_species/barred/images/
barred_leaf_frog_jpg.jpg
http://www.bbc.co.uk/radio4/science/media/Btaitanus-PC1b.jpg
AmniotesGroup includes Reptiles and Synapsids
Reptilia (paraphyletic)
Chelonia (testudinea) “turtles”
Rhynchocephalians “tuatara”
Squamates “lizards, snakes etc.”
Crocodylians “crocodiles” etc.
Aves “birds”
SynapsidsAmniotes with synapsid skull, hair, mammary glands & nipples (most)
Mammalia
Monotremata
Mammalia
Marsupialia
Mammalia
Insectivora
Mammalia
Xenarthra
Mammalia
Tubulidentata
Mammalia
Pholidota
Mammalia
Chiroptera
Mammalia
Primates
Mammalia
Lagomorpha
Mammalia
Rodentia
Mammalia
Carnivora
Mammalia
Pinnipedia
Mammalia
Perissodactyla
Mammalia
Atriodactyla
Mammalia
Hyracoidea
Mammalia
Proboscidea
Mammalia
Sirenia
Mammalia
Cetacea
• Cloaca/Eggs
• No front teeth (or no teeth at all)
• Opposable thumbs
• Peg-like teeth (African)
• Pouch
• Scaly
• Smooth cerebral cortex/sharp teeth
• Two pairs of incisors (only central growing)
• Wings
• Aquatic ungulates without hind-
limbs
• Aquatic with nostrils on top of
head
• Canine with fins/terrestrial birth
• Growing incisors/hoof-like nails
• Incisors form tusks
• Single pair of growing incisors
• Ungulates with even #
toes/paraxonic foot
• Ungulates with odd # toes
(usually)/mesaxonic foot
• Well developed canines