Chapter 38

Section 2

Invertebrate Chordates

Phylum Chordata• Chordates- animals with a

vertebrate (backbone)

• Have a notochord, pharyngeal pouches, dorsal nerve cord, & postanal tail

Evolution & Classification

• Phylum Chordata is separated into three subphyla

• Vertebrata

• Cephalochordata

• Urochordata

Subphylum Cephalochordata

• Lancelets- notochord, dorsal nerve cord, pharyngeal pouches, & postanal tail

• Live in warm shallow waters in the sand

• Water leaves body through an opening called the atriopore

Subphylum Cephalochordata

• Lancelets can swim weakly

• Segmented body

Subphylum Urochordata

• Tunicates- “sea squirts”- shoot out water when touched

• Most are sessile & live on sea bottom

• Filter-feed

• Hermaphrodites

REVIEW!!!• What are the three subphyla of the

phylum chordata?

• Name an animal from each subphyla.