Rat dissection labs start next
week and continue for three
weeks total (Labs 10-12)
Dissection kits are provided
(check your drawers now),
but you are welcome to bring
your own kit
Lab 9:
Animals III: Deuterostomes
TODAY YOU HAVE A
HAND IN
FOR YOUR EXIT ACTIVITY
Task C-2 today does
NOT deal with
echinoderms and
chordates…
Let’s do it first!
Task C-2: Invertebrate keying
•
work as a pair
•
get one of the invertebrate keying boxes
•
use the dichotomous key (Table 9-1)
•
CORRECTIONS to Table 9-1 in your lab manual:
9. Two pairs of antennae; cephalothorax present........subphylum Crustacea/class Crustacea
9. One pair of antennae, cephalothorax absent................(mark out old subphylum here)...10
10. Wings usually present; three pairs of walking legs....subphylum Hexapoda/class Insecta
10. Wings absent; more than three pairs of walking legs..............subphylum Myriapoda...11
Task C-2: Invertebrate keying
•
fill in Table 9-3 for each organism in the box (TAs will
be checking for this as part of your exit activity)
•
if you don’t know common names, ask a TA
•
not all have subphyla
•
you should expect to be able to make such phylum,
subphylum, and class identifications on the lab final
(without help or a key) for these and any other
specimens that have been in lab
Phylum Echinodermata
•
coelomate; unsegmented
•
pentamerous radial symmetry
•
water vascular system
•
dermal endoskeleton with spines
Phylum Echinodermata
•
•
4 selected classes to examine in lab:
•
Asteroidea (sea stars or starfish)
•
Ophiuroidea (brittle stars)
•
Echinoidea (sea urchins and sand dollars)
•
Holothuroidea (sea cucumbers)
watch the video for body plan and feeding….
Task A-1: Phylum Echinodermata
•
examine the preserved specimens, note the following:
•
for each: compare to Fig. 9-1, note body plan 5part radial symmetry, endoskeleton, lack of
segmentation
•Asteroidea (sea stars) –
five arms, madreporite,
central disc, mouth, tube
feet, coelom
•Ophiuroidea (brittle
stars) – five arms, central
disc
Task A-1: Phylum Echinodermata
•
examine the preserved specimens, note the following:
•
Echinoidea (sea urchins and sand dollars) – look
for pentamerous characteristics; jaws
Task A-1: Phylum Echinodermata
•
examine the preserved specimens, note the following:
•
Holothuroidea (sea cucumbers) – not typically
sedentary, just slow (lab manual is wrong)
Radial
muscle
Cloaca
& vent
Phylum Chordata
•
group unified by four traits present at some point
in the life cycle for all members
Phylum Chordata
•
•
three subphyla
•
Urochordata – tunicate or sea squirt
•
Cephalochordata – lancelet or amphioxus
•
Vertebrata – have a backbone; fish, amphibians,
reptiles, birds, and mammals (classes listed
later)
watch the video for some information on the body
plan and development….
Task B-1: Invertebrate Chordates
•
examine the preserved specimens and models, note
the following:
•
Urochordata – tunicate or sea squirt
•
sessile adult; cellulose tunic, holdfast, siphons,
pharynx
•
image on following slide….
Task B-1: Invertebrate Chordates
•
examine the preserved specimens and models, note
the following:
•
Cephalochordata – lancelet or Amphioxus
•
specimen, model, and slide; match to Figs. 9-2
and 9-3
•
note oral hood, fins, myotomes, dorsal nerve
cord, notochord, pharynx, pharyngeal gill slits,
postanal tail; other items from figures
Subphylum Vertebrata
•
Vertebrata – 7 selected classes
•
Agnatha – jawless fish
•
Chondrichthyes – cartilaginous fish (sharks,
skates, and rays)
•
Osteichthyes – bony fish with paired fins
•
Amphibia – two pairs of legs; smooth skin (frogs,
salamanders, etc.)
•
Reptilia – two pairs of legs; scaly skin (lizards,
snakes, alligators, etc.)
•
Aves – feathers; paired wings and legs (birds)
•
Mammalia – hair, mammary glands, two paired
appendages
Task B-2: Subphylum Vertebrata
•
obtain a “vertebrate box” and examine the
preserved specimens, note the following:
•
Agnatha – brook lamprey
•
•
jawless; single median dorsal and caudal fins
(no paired lateral fins); 7 pairs of external gill
slits
Chondrichthyes – shark
•
scales (makes sandpapery skin); various fins
(note especially those in pairs); claspers on
pelvic fins of mature males; cloacal opening
Task B-2: Subphylum Vertebrata
•
Osteichthyes – yellow perch
•
•
scales, operculum over gills, various fins (note
pairs); lateral lines (from operculum to caudal
fin)
Amphibia – leopard frog and salamander
•
smooth skin (no scales); 4 legs – count digits;
tympanum on frog; eyelids (do other box
items have eyelids?)
Task B-2: Subphylum Vertebrata
•
Reptilia – green anole lizard, turtle, and garter
snake
•
•
•
scaly skin, 4 legs (reduced to vestigial in
snake); lizard – claws, eyelids; turtle –
carapace and plastron
Aves and Mammalia – no specimens
demonstration table – identify specimens by class
(you do NOT include them on Table 9-2, but they
ARE eligible to be on the lab final)