Chordata

• What type of animals are chordates?

  Deuterostomate animals
• What is a characteristic feature of chordates?

  They are bilaterally symmetrical
• What gland do chordates have?

  Endostyle or thyroid gland
• What type of digestive tract do chordates possess?

  Complete digestive tract
• How does blood flow in chordates' hearts?

  Forward ventrally and backward dorsally
• What are the four unique characteristics of chordates during development?

  1. Notochord
  2. Dorsal nerve cord
  3. Pharyngeal slits
  4. Post-anal tail
• What is the notochord?

  A semi-flexible cartilaginous rod
• Where is the notochord located in chordates?

  Dorsal to the gut, ventral to the nerve cord
• What are pharyngeal slits?

  Openings between the pharynx and outside
• What is a post-anal tail?

  A muscular tail extending behind the anus
• What are the three subphyla of Phylum Chordata?

  Cephalocordata, Vertebrata, Urochordata
• What are the classes within the subphylum Urochordata?

  1. Larvacea
  2. Ascidiacea
  3. Thaliacea
• What is unique about urochordate larvae?

  They have notochords in their tails
• How do adult urochordates live?

  They are sessile and can be solitary or colonial
• What do sessile urochordates attach to?

  Rocks and other solid substrates
• What are the two siphons in urochordates used for?

  Water circulation and excurrent water
• What is the tunic in urochordates?

  A gel-like tough covering
• Are urochordates monoecious or dioecious?

  They are monoecious but cross-fertilization is common
• What type of development do urochordates undergo?

  Indirect development with a larval stage
• What are cephalochordates also known as?

  Lancelets
• What is the size of cephalochordates?

  About 5 cm long
• How is the body of cephalochordates described?

  Elongate, laterally flattened, nearly transparent
• What does the notochord in cephalochordates extend from?

  From the tail to the head
• What projects from the anterior end of cephalochordates?

  An oral hood
• What do ciliated cirri do in cephalochordates?

  They are used in feeding
• How do cephalochordates sort food materials?

  At the cirri, large particles are thrown off
• How does water flow in cephalochordates?

  From the pharynx through pharyngeal slits
• What is the reproductive strategy of cephalochordates?

  They are dioecious
• What is the most diverse subphylum in Phylum Chordata?

  Subphylum Vertebrata
• What are the two divisions of Subphylum Vertebrata?

  1. Gnathostomata
  2. Agnatha
• What characterizes members of superclass Agnatha?

  They lack jaws and paired appendages
• What type of skeleton do Agnatha members possess?

  Cartilaginous skeleton
• What are members of Class Myxini known as?

  Hagfishes
• Where are hagfishes found?

  Exclusively marine environments
• What are members of Class Cephalaspidomorphi known as?

  Lampreys
• Where can lampreys be found?

  In both freshwater and marine environments
• What characterizes superclass Gnathostomata?

  Jawed vertebrates with paired appendages
• What are the two major categories of superclass Gnathostomata?

  1. Those that bear fins
  2. The tetrapods
• What are the classes that bear fins in superclass Gnathostomata?

  Class Chondrichthyes and Class Osteichthyes
• What characterizes Class Chondrichthyes?

  Cartilaginous endoskeleton and placoid scales