Chordata Flashcards
Gold Packet Exam 3 (42 cards)
Chordata
an animal of the large phylum Chordata, comprising the vertebrates together with the sea squirts and lancelets.
Four Characteristics of the Chordata
Notochord, hollow dorsal nerve, pharynx with gill slits, post-anal tail.
Notochord
Flexible but incompressible rod of tissue-stiffening structure-lost in development in “higher” vertebrates.
Hallow dorsal nerve chord
Runs from anterior to posterior of body, along upper midline of body.
Pharynx with gill slits
Pharynx anterior part.
- Wall consists of gill slits between solid gill bars.
- Often lost through development in “higher” vertebrates.
Post anal tail
Area of tissue behind the anus. Sometimes lost through development.
Subphyla Chordates
Cephalochordata, Urochordata, Vertebrata
Cephalochordata
Lancelets- fish without jaw and obvious organs. Most primitive chordates. Invertebrates.
Urochordata
Tunicates (sea squirts) - marine invertebrates. Adults have no notochord, nerve cord, or tail. Body covered in cellulose tunic, filter feed through pharynx.
Vertebrata
Vertebrates with central and peripheral nervous system. , one heart, kidneys for osmoregulation, a coelom, cephalization, .
Vertebrate axial
skull and vertebral column
Endocrine Glands
all vertebrates have these for hormones.
Vertebrates all have…
tail, vertebral column, skeleton, coelom, head, limbs, kidney, heart, jaws, liver, endocrine.
Tetrapod
a four-footed animal, especially a member of a group which includes all vertebrates higher than fishes. (Frog and up)
Jaws evolved from…
anterior gill arches/bars
Agnatha
Cylindrical, smooth, jawless, cartilaginous skeleton, notochord, simple fishes. (Hagfish and lampreys).
Chondrichthyes
(sharks) Torpedo or flattened, placoid scales, mouth behind anterior, jaws, cartilaginous skeleton, 5-7 pairs of gill slits, buoyancy via pectoral fin and oily liver.
Lateral Line Organ and Electroreceptors
Found in Chondrichthyes for detecting vibrations in the water.
Ampullae of Lorenzini
special sensing organs called electroreceptors, forming a network of jelly-filled pores.
Actinopterygii
The bony fish-tall and torpedo shaped. Floats via the swim bladder with an anterior mouth. Gasses go from blood in and out of bladder.
Gravid
pregnant, carrying eggs or young.
Amphibia
Cylindrical or stout, gills to young, Skin is moist granular, for gas exchange, girdles, carnivorous, worldwide decline.
Girdles
Amphibian- where legs attach. Pectoral (forelimbs) and pelvic (hind-limbs).
Chytrid Fungus
an infectious disease that affects amphibians worldwide.
