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39 Cards in this Set

  • Front
  • Back
five characteristics of chordates
1. pharyngeal slits
2. dorsal hollow nerve cord
3. notochord
4. postanal tail
5. thyroid gland or endostyle
protostome groups
molluscs, annelids, arthropods
also line of coelomates
deuterostome groups
echinoderms, hemichordates, chordates
also line of coelomates
phylum chordata divisions (3)
subphylum hemichordata
subphylum cephalocordata
subphylum vertebrata (craniata)-largest
earliest chordate fossils
from the Cambrian period and were of chordates that likely had soft bones
vertebrate characteristics
endoskeleton of bone or cartilage for locomotion, support, protection of organs, many terrestrial, most have jaws
cephalochordate and urochordate characteristics
marine animals, none terrestrial, lack bony or cartilaginous skeleton, suspension feeders
slender rod dorsal to the coelom but beneath and parallel to the nervous system. Composed of core of cells and fluid encased in tough sheath of fibrous tissue-hydrostatic organ with elastic properties that resist axial compression
pharyngeal slits
part of digestive tract posterior to the mouth-(gills for respiration); can appear in early life, later life, or persist throughout.
Have one way flow of water
when associated with gills the water that passed through the pharyngeal slitsl could also participate in gas exchange
primitive chordates pharyngeal slits
slits expanded to a branchial basket and slits increase dramatically in number, increases SA. Cilia produce the water current
endostyle or thyroid gland
iodine metabolism; endostyle (urochord, cephalchord, larval lamprey) is predecessor of thyroid (adult lamprey and other vertebrates)
dorsal and tubular nerve cord
lies above gut and hollow the whole length
invertebrates have nerve cord in ventral position
postanal tail
posterior elongation of body beyond the anus' locomotor apparatus composed of segmental musculature and notochord; tail gives extra SA for thrust and maneuvering
Extra chordate characteristics
bilaterally symmetrical
show segmentation
myomeres on body and tail
as larva, prochordates live in open water between the surface and the bottom
larva have little locomotor capability so they are moved place to place primarily by currents and tides not their own efforts
living on or within the bottom marine substrate
when protochordates go into a substrate or are attached to it
attached to a substrate
two houses, gonads for male and female are in two individuals
both male and female gonads are in one individual
hemichordata characteristics
pharyngeal slits, dorsal nerve cord although sometimes solid, lack notochord and postanal tail
larval hemichordates
tornarian larva-like the larva of echinoderms
mouth forms opposite to blastopore
2 division of hemichordates
eneteropneusts (burrowing)-acorn worm and pterobranchs(sessile)
acorn worm
three coelom-proboscis-locomotion and feeding, collar, trunk
embryological outpocket of the roof of the gut anterior to the pharynx
urochordata characteristics
all five chordate
branchial basket
Taxonomic division of urochordata
ascidiacea-larva free swimming then attach, larvacea and thaliacea-both pelagic
ascidiacea-sea squirts
larva planktonic and adults are sessile
larval form of ascidiacea
ascidian tadpole-few days without feeding, then attach
characteristics of larva
notochord, tail, dorsal and tubular nerve cord
characteristics of adults
tunic made of tunicin, incurrent and excurrent siphons
hermaphrodites (monoecious) but rarely self fertilize-reproduce by budding
jawless fishes that lack a biting apparatus
vertebrate fishes with bony armor
hagfishes and lampreys whcihare round and mouth-most primitive of vertebrates
myxini, no vertebrae, teeth, and reduced eyes, dioeceious, lack bone or surface scales
petromysoniformes- single medial fin but lack paired fins and lobes; cartilage to form simple vertebral column, lack bony skeleton
larval lamprey
ammocoete larva-suspension feeder buries itself in the bottom then after metamorphosis becomes parasitic