Rat dissection labs start Rat dissection labs start next week and continue for next week and continue for three weeks total (Labs 10-three weeks total (Labs 10-12)12)

Dissection kits are provided Dissection kits are provided (check your drawers now), (check your drawers now), but you are welcome to bring but you are welcome to bring your own kityour own kit

Lab 9: Lab 9: Animals III: Animals III: DeuterostomesDeuterostomes

TODAY YOU HAVE ATODAY YOU HAVE A

HAND INHAND INFOR YOUR EXIT ACTIVITYFOR YOUR EXIT ACTIVITY

Task C-2 today Task C-2 today does NOT deal with does NOT deal with echinoderms and echinoderms and

chordates…chordates…

Let’s do it first!Let’s do it first!

• 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 Crustacea9. One pair of antennae, cephalothorax absent................(mark out old subphylum here)...10

10. Wings usually present; three pairs of walking legs....subphylum Hexapoda/class Insecta10. 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

Task C-2: Invertebrate keying

• 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….

Phylum Echinodermata

• examine the preserved specimens, note the following:

• for each: compare to Fig. 9-1, note body plan 5-part radial symmetry, endoskeleton, lack of segmentation

Task A-1: Phylum Echinodermata

•Asteroidea (sea stars) – five arms, madreporite, central disc, mouth, tube feet, coelom

•Ophiuroidea (brittle stars) – five arms, central disc

• 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)

Task A-1: Phylum Echinodermata

Radial Radial musclemuscle

CloaCloaca & ca & ventvent

• 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….

Phylum Chordata

• 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

Task B-1: Invertebrate Chordates

• 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

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)

Task B-2: Subphylum Vertebrata