Chordates and Vertebrates Lab
Introduction/Background:

In this lab students are learning all about chordates and vertebrates and will be viewing examples of them as well. The examples to be viewed in the lab are Tunicates, Lancelets, Lampreys, Rays, a Dogfish shark, a Perch, Catfish, Eels, Toads, Frogs, Lizards, Snakes, Roadrunner (foot), Barn owl (wing), Cotton tail rabbit , and an Opossum. The different types of chordates/vertebrates discussed in this lab are the urochordata, cephalochordate, craniates, gnathostomes, chondrichthyes, actinopterygii, tetrapods, amphibian, amniote, reptilian and aves, and mammals. Students are going to learn how to differentiate the different organisms and the characteristics that make them unique!
d. What is a marsupial?

A marsupial is a mammal of an order whose members are born incompletely developed. At birth, they take a long, arduous journey from the birth canal, driven purely by instinct, grabbing hold of the mother marsupial’s fur which she has cleaned and made easier to traverse with saliva, to reach the pouch. Upon reaching the pouch, they latch onto a teat which swells in their mouth to prevent them from being accidentally dislodged during the mother’s movements. They remain attached for months to continue and complete their development.

Discussion:
Students learned all of the following in the chordates and vertebrates lab. Chordates have four key characteristics. They have notochords, a dorsal, hollow nerve cord, pharyngeal slits or clefts, and a muscular, post anal tail. Two major groupings are Urochordata and Cephalochordata. The urochordata to be observed are the tunicates. Tunicates retain pharyngeal slits, have incurrent and excurrent siphon, and they are suspension feeders. Lancelets are the cephalochordate that will be observed in the lab. The next grouping are the craniates. The craniates have chordate characteristics plus a distinct head. Myxini are craniates, an example of which being the hagfish, but there are no specimen to be observed in the lab. The next major grouping are the vertebrates. These are craniates plus a backbone. The backbone includes vertebrae, they have a more extensive skull, and more elaborate skeletal