BIOL 3360L Vertebrate Comparative Anatomy Lab -- “Protochordates”
Name:
As you work through the lab guide provided (Kardong & Zalisko 2006) realize that italicized words are general biological
terms that you will be responsible for knowing. In addition, the terms below are bold-faced words from the lab that you
will be expected to know AND to recognize visually (on provided visual references such as specimens, prepared slides
etc.). Furthermore, you will be expected to know the function of any structures with an asterisk(*).
Hemichordata- “Acorn Worm” or Balanoglossus sp. (slides B20-E/F, preserved specimen, photos).
The prepared slides we currently have are marginal… you will have difficulty seeing many of the structures listed. Rely
on the diagrams, whole specimen and online image sources as necessary
Proboscis*
Collar
Trunk
Pharyngeal slits*
Branchial pouch
Branchial pore*
Urochordata- Tunicates/Sea Squirts/Ascidiacea (slides B20-G, B20-H, preserved & plastimounted specimens,
larvae – lab text imagery pgs. 18-20)
You should be able to see many structures on the “plastimounted” ascidian/tunicate and/or B20-G. The “tadpole”
larvae are on slides B20-H. Rely on diagrams, whole specimen and online image sources as necessary
Body
Tail
Tubular nerve cord*
Notochord*
Intestine*
Branchial basket*
Pharygeal slits*
Incurrent siphon*
Excurrent siphon*
Stomach*
Anus*
Adhesive papillae*
Otolith/Statocyst*
Ocellus*
Tunic
Endostyle*
Cephalochordata- Amphioxus (Slides: lateral view/whole mount B20-A, cross section oral/pharyngeal
regions B19-A, cross section intestinal region B18-A, preserved specimens)
Working individually or in pairs, use a camera, iPhone etc. to capture the necessary images to depict the
structures listed below. Import the image(s) into PowerPoint or similar software and then label each of the
structures below with a number or letter. Provide a typed key that identifies the structure represented by each
letter/number, and include a brief description of the function(s) for the asterisked structures. Email this
assignment to me ([email protected]) . Please include names of both team members.
Oral hood
Buccal cirri*
Caudal fin
Dorsal fin*
Myomeres*
Notochord*
Dorsal/tubular nerve cord*
Wheel organ*
Velum
Velar tentacles*
Pharynx*
Pharyngeal slits*
Esophagus*
Midgut cecum*
Hindgut
Anus*
Atriopore
Branchial/pharyngeal
arches/bars
Epibranchial groove
Endostyle
Cilia*
Gonads
Questions
Answer the following questions
Who are the “protochordates” and why aren’t they a proper taxonomic group (use terms monophyletic, paraphyletic
and/or polyphyletic as appropriate)?
Why can’t we think of the species we saw in lab as ancient when their phylogenetic position is ancient?
What phylum/order of animals has a feeding strategy very similar to acorn worms (Balanoglossus sp)? Hint: think back
to your gen. bio. days and consider ALL animal phyla!
Are Urochordates in the phylum Chordata or not? Why (provide rationale)?
How is it that tunicates do NOT have specialized excretory organs?
What is unique about the innervation of cephalochordate myomeres?
How do eggs exit the body (leave what hole/opening) of cephalochordates?